a. Photomicrograph of thin (lO^m) section of the Andura meteorite, an olivine bronzite-chondrite (H6) . Note the strong

contrast between the relatively coarse, equigranular, "metamorphic" texture of the matrix surrounding the chondrule, lower

left, and the fine-grained, unrecrystallized texture of the chondrule itself and other parts of the matrix, a contrast that indicates

a nonmetamorphic origin. Silicates, mostly olivine and pyroxene, show light pastel colors, metal (NiFe) brown, troilite (FeS)

dark brown. This section also illustrates the extreme difficulties in performing a modal analysis optically. Length of section

2.3 mm. b. Photomicrograph of thin (10/tm) section of the Pulsora olivine-bronzite chondrite (H3 to H7?) . Upper left

part consists of skeletal and zoned olivine (Fai3 to Faie) in silica-rich glass (H3) . The normal matrix, lower right, containing

numerous chondrules and fragments, is unsorted, mostly fine-grained and has the same (and constant) olivine-pyroxene

composition as the chondrules. Some lithic fragments, also with constant olivine composition, show an "achondritic" (H7?)

texture. Silicate minerals show varying pastel colors, the glass is pinkish, and the opaques (metal and troilite) are dark. Note

the eutectic metal/troilite spherule, top left. This section clearly demonstrates that the Pulsora chondrite never suffered

thermal metamorphism. Length of section 3.6 mm. (Fredriksson et al., "The Pulsora Anomaly.")
SMITHSONIAN CONTRIBUTIONS TO THE EARTH SCIENCES • NUMBER 14

Mineral Sciences Investigations

1972-1973

George S. Switzer

EDITOR

SMITHSONIAN INSTITUTION PRESS

City of Washington

1975
ABSTRACT

Switzer, George S., editor. Mineral Sciences Investigations, 1972-1973. Smithsonian Contributions to the Earth Sciences, number 14, 88 pages, 29 figures,

and frontispiece, 1975.—Thirteen short contributions from the Smithsonian's

Department of Mineral Sciences for 1972 and 1973 are gathered together in this

volume. Scientific contributions include new data on some mercury minerals

from Terlingua, Texas; a description of dashkesanite from St. Paul's Rocks; a

note on high-alumina basalt from the Aleutian Trench; descriptions of samples

from the Apollo 15 and 16 lunar missions; chondrule composition of the Allende

meteorite; the Pulsora meteorite and metamorphic equilibration in chondrites;

the possible survival of very large meteorites that encounter the earth's surface;

data on eight observed-fall chondritic meteorites; chemical analyses of two microprobe standards; and a technological note on the preparation of multiple microprobe samples. A history of mineral sciences in the Smithsonian Institution and

a list of meteorites in the Smithsonian collections complete the volume.

OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. SI PRESS NUMBER 5138. SERIES

COVER DESIGN: Aerial view of Ulawun Volcano, New Britain.

Library of Congress Cataloging in Publication Data

Switzer, George S., comp.

Mineral sciences investigations, 1972-1973.

(Smithsonian contributions to the earth sciences, no. 14)

Supt. of Docs, no.: SI 1.26: 14

"Thirteen short contributions from the Smithsonian's Department of Mineral Sciences."

1. Meteorites. 2. Mineralogy. 3. Lunar petrology. I. National Museum of Natural History.

Dept. of Mineral Sciences. II. Title. III. Series: Smithsonian Institution. Smithsonian

contributions to the earth sciences, no. 14.

QE1.S227 no. 14 [QE395] 55O'.8s [549] 74-10590

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington, D.C. 20402 - Price $2.50 (paper cover)
Contents

HISTORY

Page

MINERAL SCIENCES IN THE SMITHSONIAN INSTITUTION, by Brian Mason .. . 1

MINERALOGY

NEW DATA ON SOME MERCURY MINERALS FROM TERLINGUA, TEXAS, by

Roland C. Rouse 11

DASHKESANITE: HIGH-CHLORINE AMPHIBOLE FROM ST. PAUL'S ROCKS,

EQUATORIAL ATLANTIC, AND TRANSCAUCASIA, U.S.S.R., by Sara S. Jacobson 17

PETROLOGY

NOTE ON HIGH-ALUMINA BASALT DREDGED NEAR THE ALEUTIAN TRENCH,

by William G. Melson 21

LUNAR STUDIES

COMPOSITION OF THREE GLASS PHASES IN AN APOLLO 15 BASALT FRAGMENT, by George S. Switzer 25

PETROGRAPHIC ANALYSIS OF APOLLO 16 SAMPLES 66083,1 AND 67943,1, by

Brian Mason 31

METEORITES

T H E ALLENDE METEORITE: CHONDRULE COMPOSITION AND THE EARLY

HISTORY OF THE SOLAR SYSTEM, by Andrew L. Graham 35

T H E PULSORA ANOMALY: A CASE AGAINST METAMORPHIC EQUILIBRATION IN CHONDRITES, by Kurt Fredriksson, Ananda Dube, Eugene

Jarosewich, Joseph A. Nelen, and Albert F. Noonan 41

IMPACT SURVIVAL CONDITIONS FOR VERY LARGE METEORITES, WITH

SPECIAL REFERENCE TO THE LEGENDARY CHINGUETTI METEORITE,

by Robert F. Fudali and Dean R. Chapman 55

PRELIMINARY DATA ON EIGHT OBSERVED-FALL CHONDRITIC METEORITES,

by Roy S. Clarke, Jr., Eugene Jarosewich, and Albert F. Noonan 63

LIST OF METEORITES IN THE NATIONAL MUSEUM OF NATURAL HISTORY,

SMITHSONIAN INSTITUTION, compiled by Brian Mason 71

STANDARDS FOR CHEMICAL ANALYSIS

CHEMICAL ANALYSES OF TWO MICROPROBE STANDARDS, by Eugene

Jarosewich 85

POLISHED SECTION TECHNIQUES

PREPARATION OF MULTIPLE MICROPROBE SAMPLES, by Grover C. Moreland and Richard Johnson 87

iii
MINERAL SCIENCES INVESTIGATIONS

1972-1973

Dedicated to

EDWARD P. HENDERSON

Curator Emeritus, Department of Mineral Sciences

Smithsonian Institution
Mineral Sciences Investigations

1972-1973

Mineral Sciences in the Smithsonian Institution

Brian Mason

ABSTRACT

The Smithsonian Institution's interest in mineral

sciences extends back to the founding of the Institution, whose founder, James Smithson, published

a number of mineralogical papers. This account

traces the development of the mineral sciences (including all of geology, except paleontology and

stratigraphy) in the Smithsonian from its founding

in 1846 to 1963.

Introduction

This history has been compiled to record the

origin and development of mineral sciences as a

part of the Smithsonian Institution. Mineral sciences are interpreted in a very broad sense as including all of geology, except paleontology and

stratigraphy. This is essentially how the subject has

evolved in the Institution, and the present Department of Mineral Sciences is responsible not only

for mineralogy and petrology (both terrestrial and

extraterrestrial—meteorites and lunar rocks), but

also for most aspects of physical geology, including

the exhibition hall "Our Restless Planet" and the

answering of many queries from the public on

general geology. The sources of this history include

published information from annual reports and

Brian Mason, Department of Mineral Sciences, National

Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560.

research papers, excerpts from manuscripts in the

department's files (including a lengthy historical

account written by Dr. G. P. Merrill near the end

of his long curatorship), and verbal reminiscences

by staff members and others. The account has been

carried up to 1963, when the Department of Geology was divided into two departments, Paleobiology

and Mineral Sciences. This seems to be a convenient

point in time to stop, since subsequent developments are well known both from published reports

and from the personal knowledge of the present

staff.

Although the Department of Mineral Sciences

was established as recently as 1963, the Smithsonian's interest in this field extends back to the

establishment of the Institution—or even before, if

we consider James Smithson's own contributions

to mineralogy. He published a number of mineralogical papers, the most notable being one in the

Philosophical Transactions of the Royal Society

(1803), in which he showed that the material then

known as calamine comprised two distinct minerals, zinc carbonate (now known as smithsonite) and

zinc silicate (hemimorphite). Along with Smithson's

monetary bequest, the Institution received his

cabinet of minerals, described (Goode, 1897:305)

as "a cabinet, which . . . proves to consist of a choice

and beautiful collection of minerals, comprising

probably eight or ten thousand specimens. The

specimens, though generally small, are extremely

perfect, and constitute a very complete geological

and mineralogical series, embracing the finest varities of crystallization, rendered more valuable by
SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

accompanying figures and descriptions by Mr.

Smithson, and in his own writing. The cabinet also

contains a valuable suite of meteoric stones, which

appear to be suites of most of the important meteorites which have fallen in Europe during several

centuries." This collection was unfortunately lost

in the disastrous fire at the Institution in 1865.

The original charter of the Smithsonian Institution provided not only for a museum, but also for

a chemical laboratory. The chemical laboratory

was established by 1853, since in his report for 1854

the then Secretary, Joseph Henry (1854:18), recorded: "The laboratory of the Institution during

the past year has been used by Professor J. Lawrence

Smith in the examination of American minerals.

. . . He also made a series of analyses of meteorites,

among which were fourteen specimens belonging

to the cabinet of James Smithson." This work was

published as "Re-examination of American Minerals" (1853-1854) and "Memoir on Meteorites"

(1855). Unfortunately, the specific meteorites from

the Smithson collection are not identified and

presumably were lost in the 1865 fire. J. Lawrence

Smith moved to Louisville in the fall of 1854, after

giving a series of lectures during the winter of 1853-

1854 (for which he was paid $550, according to the

financial records). Apparently, however, he worked

in the Smithsonian chemical laboratory during

several subsequent summers.

After the brilliant beginning provided by Smith,

the mineral sciences languished for the next quarter

century. Joseph Henry was unwilling to commit the

Institution's limited income for the development

of a museum. Indeed, he appears to have discouraged the accumulation of large collections. In 1861

Professor Thomas Egleston of the School of Mines

at Columbia University, a prominent mineralogist,

was employed in the Smithsonian laboratory examining and classifying the collections representing

the acquisitions of the various land office surveys,

exploring expeditions, and other sources (Henry,

1862:38). It is further recorded (Henry, 1873:51)

that during the interval 1861-72 "a large number

of specimens in mineralogy and geology were also

packed up and transmitted to Professors Egleston

and Newberry of the School of Mines of New York

under the existing arrangements with those gentlemen to select and label a perfect single series for the

U.S. National Museum and to exchange the duplicate specimens in its interest." This may not have

been altogether in the interest of the Smithsonian

Institution; Merrill comments:

It is impossible, however, from the available records

to state the full number in the collections at any one time,

owing to the manner in which sets were made up to send

out under the administration of Messrs. Egleston and Newberry. There is here shown a singular and inexplicable

discrepancy between manifested intentions and actual accomplishment since under the administration of Egleston and

Newberry these collections were largely, and in some cases

almost completely dissipated or depleted.

In this connection the following excerpt (Merrill,

c.l 925) of a letter from W. P. Blake to G. P. Merrill

dated 12 October 1899 is significant:

I was also astonished in looking through the museum

collection at Columbia College, New York to see the series

of very remarkable concretions I collected on the Colorado

desert in the cases. Wondering how they got there I inquired

of Prof. Baird and he told me that an arrangement had been

made with Newberry to look over the mass of material which

had been accumulated with permission to him to take such

duplicate material as he liked. [Merrill (c.1925) comments:]

"Evidently Prof. N. made the most of his opportunity!"

In 1873 F. M. Endlich was appointed chemist and

mineralogist in the Institution and served until

1879 when he resigned. During this period he was

engaged during the summers as a geologist on the

Hayden surveys in Colorado. Endlich reported in

1873 that the geological collections all told constituted 6300 specimens of which 3000 were minerals,

representing 230 species; 2300 rocks and 500 ore

specimens, with about 800 samples on hand awaiting classification. In his final report Endlich (1880:

333-335) listed 343 species and varieties of minerals

in the collection.

The museum operations of the Smithsonian Institution were reorganized and greatly expanded in

1880, following the great accretion of collections

from the Centennial Exhibition of 1876 and the

provision of a large new building to house them

(the present Arts and Industries Building). In a

handwritten manuscript Merrill commented:

It was a square squatty affair of red, blue and yellow

brick, exteriorly an architectural horror, interiorly a barren

waste. It presented but one redeeming feature—space; and

as it was space that Baird was after I presume it may at

first thought have been considered a success. One can here

but be reminded of the reply made by a high official after

being shown thru the then newly finished Pension Office

building. "Well," it was asked, "have you any criticism?"

"Yes," was the reply, "it is fireproof."
NUMBER 14

FIGURE 1.—George P. Merrill (1854-1929).

The expansion and reorganization of 1880 found

expression in the creation of several departments

and the appointment of salaried officials to take

charge of the various collections. Dr. George W.

Hawes was appointed curator of geology and mineralogy. In 1881 he was given three aids: F. P.

Dewey for chemistry and metallurgy, G. P. Merrill

for petrology (Figure 1), and W. S. Yeates for mineralogy. The organization thus formed was shortlived, being terminated by the death of Dr. Hawes

on 22 June 1882. Upon the death of Dr. Hawes,

Mr. Dewey was appointed an assistant curator and

shortly afterwards full curator of a separate Department of Metallurgy and Economic Geology. In

December 1883, Dr. F. W. Clarke of the U.S. Geological Survey was made honorary curator of the

Department of Mineralogy, with Mr. Yeates as

assistant. In the same year Dr. Merrill was made

assistant acting curator in charge of the newly

created Department of Lithology and Physical Geology. In 1889, after the resignation of Mr. Dewey

to become assayer at the Bureau of the Mint, the

two departments of Metallurgy and Economic

Geology, and Lithology and Physical Geology were

united under the title of Department of Geology,

Systematic and Applied, and Dr. Merrill appointed

curator. A complete reorganization in 1897 created

a single Department of Geology, with three divisions: Physical and Chemical Geology, Mineralogy,

and Stratigraphic Paleontology. Merrill was appointed head curator of the department, and was

also curator of physical and chemical geology.

Clarke remained as honorary curator of mineralogy,

with Wirt Tassin assistant curator and Dr. L. T.

Chamberlain as honorary custodian of gems and

precious stones. The Department of Geology so constituted survived with minor modifications for over

sixty years, until the creation of separate departments of Mineral Sciences and Paleobiology in

FIGURE 2.—William F. Foshag (1894-1956).
SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

1963. Throughout this time, however, the divisions

of Physical and Chemical Geology, and of Mineralogy actually functioned essentially as a single

unit, although they appear as separate units on the

table of organization until 1942. Merrill was effectively curator of both divisions until his death in

1929. He was succeeded as head curator of the Department of Geology by Dr. R. S. Bassler, a paleontologist, and Dr. W. F. Foshag (Figure 2) was

appointed curator of both divisions. Dr. Bassler retired in 1948, and Foshag succeeded him as head

curator, a position he held until his death in 1956.

Dr. G. A. Cooper, also a paleontologist, then became head curator, and Dr. G. S. Switzer, curator

of mineralogy, an arrangement that continued until

the eventual formation of separate departments of

Paleobiology and Mineral Sciences.

Functions of the Department

With this introduction, it is convenient to describe the operations of the different segments of

the department under the headings of mineralogy,

petrology, meteorites, and gems and precious stones.

MINERALOGY

William S. Yeates, the first appointee specifically

in mineralogy, graduated M.A. in 1881 from Emory

and Henry College, Virginia, and immediately

thereafter became an assistant to Dr. Hawes. After

Hawes' death in 1882, Yeates remained as the

salaried officer in charge of the mineral collections

until May 1893, when he resigned to become state

geologist of Georgia. He was apparently more an

administrative officer than a scientific investigator,

and his work at the Smithsonian Institution contributed little to the published record. Yeates was

succeeded for a short period by O. C. Farrington,

whose career is essentially linked with the Field

Museum of Natural History in Chicago, where he

was curator of geology from 1894 to 1930. In 1894

Wirt Tassin became assistant curator, with F. W.

Clarke continuing as honorary curator.

Tassin worked in the Division of Mineralogy

from 1894 to May 1909, when he resigned to go into

private business. He left an interesting and informative manuscript account of the history of the

division up to 1906:

FIGURE 3.—Joseph E. Pouge (1887-1971).

In 1883 Mr. F. W. Clarke was appointed honorary curator.

This marks the real beginning of the present Division of

Mineralogy. To Mr. Clarke more than any other is due the

present standing of the collection. His appreciation of good

minerals, his knowledge of their value, his enthusiasm, his

widespread acquaintance and his position on the Geological

Survey and on exposition boards has been of incalculable

value to the collection. In fact it would be almost impossible

to say too much concerning the value of his influence in

securing fine specimens.

Tassin gave an account of the growth of the

mineral collections from 1859 to 1906. The total

number grew slowly from 793 in 1859 to 3551 in

1880, and then increased rapidly, evidently due to

the reorganization, reaching 45,291 in 1895; growth

then leveled off, the total in 1906 being 48,987.

While Tassin evidently devoted much of his work

to his curatorial and exhibition responsibilities, he

also did some research. His name is associated with

Dr. Merrill's in the investigation of several meteorites, the first such research in the Institution since

that of J. Lawrence Smith half a century earlier.

Tassin was succeeded in 1909 by Dr. Joseph E.

Pogue (Figure 3), of whom Merrill (c.1925) remarked: "For the first time in the history of the

Department the collections were administered by a
NUMBER 14

FIGURE 4. Edgar T. Wherry (1885- ) . Photograph taken in his garden in Chevy Chase, D. C, about 1917.

,-?J.-,**

trained mineralogist." Pogue worked as assistant

curator of the Division of Mineralogy until October

1913, when he resigned to join the U.S. Geological

Survey. Much of his time must have been occupied

in moving the collections and exhibits into the present Natural History Building, which was opened

in 1910. During his term in office Dr. Pogue visited

many European museums, studying collections and

displays. He also published several papers involving original research, among them a monograph

on turquoise published by the National Academy of

Sciences in 1915.

Pogue was followed by Dr. Edgar T. Wherry

(Figure 4), who carried on the work of the division

along the lines laid down by his predecessors, but

who was able to devote more time to research. He

published a number of papers, including one in

1917 giving the name "merrillite" to a new calcium

phosphate mineral that Dr. Merrill had recognized

as a meteoritic constituent in 1915. He was one of

the founders of the American Mineralogist and its

first managing editor (1916-1921), and president

of the Mineralogical Society of America in 1923.

He resigned from the Smithsonian Institution in

August 1917 to join the Bureau of Chemistry of the

Department of Agriculture.

When contacted in April 1972, Dr. Wherry was

kind enough to provide the following reminiscences:

In 1913 I was teaching mineralogy at Lehigh University,

Bethlehem, Pennsylvania, and spending summers as field

assistant to Professor Florence Bascom of Bryn Mawr College

in the preparation of geologic folios of quadrangles in

southeastern Pennsylvania, for the U. S. Geological Survey.

I was also collecting the minerals of the state, and writing

articles about them. Finding these activities somewhat overtaxing I was glad to accept an invitation from Dr. George
SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

P. Merrill, head curator of Geology at the Smithsonian, to

join his staff as assistant curator of Mineralogy and Petrology.

Some years before this position had been held by a Mr.

Wirt Tassin, who had arranged the mineral collection as a

sort of textbook, accompanying each specimen with an elaborate descriptive label, the study of which would take far

more time than most visitors could spare. When he retired,

his place was taken by Joseph Pogue, who rearranged the

collection in accordance with standard classifications, replacing the textual labels with simple ones bearing name,

composition, and locality. He resigned to go into business,

and I was taken on to complete his reorganization of the

collection.

My duties included answering correspondence about

minerals, including especially requests for identification of

specimens submitted, usually with reference to their potential

commercial value. Sometimes my reports would be questioned, but to make me feel at ease, the Smithsonian office

showed me a bit of pertinent correspondence: this comprised

a report on a specimen made by Dr. Merrill, a response from

the sender questioning its correctness, and the marginal

annotation addressed by Merrill to the Secretary of the

Smithsonian Institution, "If what this man says is true,

Merrill ought to be fired."

The most worth-while specimen I received was a bit of

clay, and instead of an inquiry as to its value, the question

was: "Is this of igneous or sedimentary origin?" Finding it

to be free from quartz grains, which make up the large bulk

of ordinary sediments, I guessed that it represented altered

volcanic ash. I Was promptly contacted by a patent-lawyer,

who explained that his client held a patent on the use of

igneous material for water-softening, and wished to claim

royalties from the organization marketing this clay for that

purpose, if it was indeed of igneous origin. I was accordingly invited to go to South Dakota where the material

occurred, and study it fully. I was thereby enabled to

establish the nature of "bentonite" as representing altered

volcanic ash, which has had important geological applications.

In the course of that trip I stopped off at several notable

mineral localities, and collected multiple specimens of such

things as geodes, and lead-zinc ore-minerals. These were

packed in barrels, which could then be shipped under

government frank, and sent back for adding to the educational collections which the Smithsonian Institution was

distributing to schools.

In those days the whole field of mineralogy was handled

by one man, and I never had a technical assistant or understudy. Records were kept by a pleasantly efficient secretary,

Miss Margaret W. Moody. She had scratched with a diamond

point a catalog number on the back of every gem-stone; and

when I resigned, it was her duty to check the gems against

the catalog, to see that I had not lost any of them. It was

pleasant to hear that only one ruby appeared to be missing,

but that turned out to have been transferred to a special

exhibit of North Carolina specimens.

Dr. Wherry was succeeded as assistant curator by

William F. Foshag, and at about the same time

Earl V. Shannon was appointed assistant curator

in the Division of Physical and Chemical Geology,

Merrill being curator of that division as well as

head curator of the Department of Geology. Shannon was an accomplished analyst and a keen mineralogist, and an extremely diligent worker. Between

1919 and 1929 he published over 80 papers, many

of them short notes but also some lengthy ones, including a 483-page monograph on the minerals of

Idaho. Tragically he suffered a mental breakdown in

1929 and left the Institution. He was succeeded by

Edward P. Henderson, who served for over 35 years

until his retirement in 1966, and is still active in

the department as a research associate.

In 1926 the mineral collection was enormously

enriched by two remarkable bequests, which raised

it from comparatively undistinguished stature to

one of the world's great mineral collections. These

were the Roebling and Canfield bequests.

Colonel Washington A. Roebling (the Colonel

was a Civil War veteran) was a civil engineer and

the builder of the Brooklyn Bridge. During the

latter work he suffered "cassion disease," with permanent impairment of his health. This caused him

to turn his attention to mineral collecting. He

sought not only beautifully developed specimens

but also those that were rare—indeed his aim was

to secure a representative of every known mineral,

however insignificant and uninteresting in appearance. In this he was eminently successful, the collection on his death lacking only about a dozen of

the accepted mineral species at that time. His impaired health made travel and field collecting impossible for him, but he had ample financial means,

and corresponded vigorously with mineralogists

and mineral dealers throughout the world. He died

on 28 July 1926, leaving his collection of 16,000

carefully selected specimens to the Smithsonian

Institution. His son, John A. Roebling, generously

established an endowment fund of $150,000, the

income to be used for the acquisition of additional

material. This endowment has provided for the

continued growth of the Roebling collection.

The Canfield collection really comprises three

collections. The nucleus was formed by Mahlon

Dickerson of Dover, New Jersey, who began collecting in the early part of the nineteenth century.

This collection passed to his nephew, Frederick

Canfield, and to it were added many fine specimens

collected at Franklin and Sterling Hill between

1840 and 1866. This collection, comprising some
NUMBER 14

1600 specimens, was displayed in the family mansion near Dover, where it remained until it was

transferred to Washington in 1926. Frederick A.

Canfield, son of Frederick Canfield, who inherited

the collection, preferred to leave it intact and begin

a new one of his own. This, at the time of his

death on 3 July 1926, totaled some 7500 specimens.

Frederick A. Canfield was educated as a geologist

and mining engineer at Rutgers and Columbia

Universities. In the practice of his profession he

had the opportunity to travel and acquire many fine

specimens at first hand. He also subsidized workmen

in the railway tunnels and quarries of northern

New Jersey, and in that way obtained many choice

specimens of the trap rock minerals. His professional connection with the Franklin and Sterling

Hill mines enabled him to keep pace with the new

and rare minerals constantly found there. He also

obtained many fine suites of specimens from outstanding mineral localities. With the bequest of

the mineral collections Mr. Canfield also provided

an endowment of $50,000 for future accessions.

Dr. Merrill died on 15 August 1929 and was succeeded as head curator of the Department of Geology by Dr. R. S. Bassler. Dr. Foshag was appointed

curator of both the Division of Mineralogy and

Petrology, and the Division of Physical and Chemical Geology, in effect combining the two divisions,

although on the table of organization the Division

of Physical and Chemical Geology survived until

1942. Dr. Foshag was born on Long Island in 1894,

but his family moved to California and he graduated from the University of California in 1919. In

1917 and 1918 he served as chemist for the Riverside

Portland Cement Company at the famous mineral locality of Crestmore, which probably effectively started his career in mineralogy. During his

service with the Smithsonian Institution he examined many famous mineral localities in the

United States and Mexico. During World War II

he spent most of his time in the latter country in

cooperative work with the Mexican authorities in

the development of mineral deposits. During that

time, in 1944, the new volcano Paricutin erupted,

and he began a long-continued study of its eruptive

processes and products, a study terminated by his

death. His Mexican work also led him to an interest

in Latin American archeology and specifically a

study of jade objects from Central America. He was

successful in pinpointing a source for this jade in

Guatemala. His contributions to mineralogy were

recognized by the ward of the Roebling Medal of

the Mineralogical Society of America in 1953.

Dr. Foshag died on 21 May 1956 and was succeeded as curator of the Division of Mineralogy

and Petrology by Dr. George S. Switzer, who had

joined the museum as associate curator in the division in April 1948. In August 1957 Paul E. Desautels was appointed associate curator in the

division, and later in the same year Roy S. Clarke,

Jr., was appointed chemist. These men, together

with Dr. Henderson and Dr. Switzer, comprised

the professional staff when the division was reformed as the Department of Mineral Sciences in

1963.

PETROLOGY

Systematic petrology in the Smithsonian Institution can be fairly dated from the appointment of

G. W. Hawes as curator of the Department of Geology on 1 January 1881. Hawes was one of the

pioneers in the use of the petrographic microscope

in the United States, having learned its use during

graduate work at Yale University with Professor

E. S. Dana, and at the University of Heidelberg

with Professor Harry Rosenbusch; he received the

Ph.D. degree from the latter university in 1880. At

the same time as his appointment to the Smithsonian Institution, Hawes began an investigation of

the building-stones of the United States as part of

the Tenth Census; the Annual Report for 1881

(Baird, 1882:110) states:

Dr. Hawes . . . has gathered specimens of stone from every

quarry in the United States; and a force of fifteen men, in

part detailed from the Census Office, has been occupied all

the year in preparing them for study and exhibition. . . .

Numerous analyses of building-stones by the chemical and

specific gravity methods have been made by Messrs. F. P.

Dewey and F. W. Taylor. Since the 1st of June (1881), Mr.

Geo. P. Merrill has prepared 1550 microscopic slides of

building-stones, to be used in connection with the investigation.

Unfortunately Hawes developed tuberculosis during

1881, and the disease advanced rapidly. In 1882 he

went to Colorado in the hope of checking it, but

he died in Manitou Springs on 22 June 1882. On

his death the petrographic work on the buildingstones fell to G. P. Merrill, who noted in his manuscript (c.1925) that he was wholly inexperienced in
SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

this field. He evidently learned quickly and well,

however, since he was one o£ the co-authors of

"Reports on the Building-Stones of the United

States and Statistics of the Quarry Industry for

1880" (1884), in which he contributed an article

on the microscopic structure of the building-stones

and eighteen reproductions of photomicrographs.

Merrill continued his petrographic work on

building-stones and became an authority on the

subject, writing several monographs and books

thereon. He served as a special agent in this field

for the Twelfth Census (1912). He was consulted

frequently by both private and public officials regarding the stone to be used for various structures.

He thus served in an advisory capacity in the selection of stone for the Natural History Building, the

Old Post Office Building, Constitution Hall, the

columns on the west face of the Treasury Building,

and numerous others. Perhaps the most momentous

question left for his decision was the choice of stone

for the Lincoln Memorial (Yule marble from Colorado). Probably through his work on buildingstones, Merrill became very interested in rock

weathering, and wrote extensively on this subject,

culminating in his book, A Treatise on Rocks,

Rock Weathering, and Soils. He also authored The

Nonmetallic Minerals: Their Occurrence and Uses.

After the turn of the century, Merrill's interest

turned to meteorites, and for the remainder of his

life his research work was concentrated in this field.

The petrological collections continued to grow,

largely through accessions of material from the

U. S. Geological Survey illustrating regional monographs and bulletins. In 1916, however, Joseph P.

Iddings was appointed honorary curator of petrology, and after his death in 1920 Whitman Cross

succeeded to this honorary position and held it until

his death in 1949. These appointments brought two

of the authors of the CIPW system of igneous rock

classification into the Smithsonian Institution; a

third, Henry S. Washington, was at the Geophysical

Laboratory of the Carnegie Institution of Washington and many of his collections were eventually

given to the Smithsonian Institution. During his

period as honorary curator, Cross developed a collection of some 2000 igneous rocks comprising most

of the types established by the CIPW system. Each

rock has a thin section accompanying it, with a

meticulous description on a file card; many are

chemically analyzed. This is probably the most comprehensive systematic collection of igneous rocks in

existence.

After the death of Cross active curatorial and research work in petrology was largely discontinued,

because of inadequate staffing. This situation was

remedied by the establishment of a Division of

Petrology within the newly organized Department

of Mineral Sciences in 1963, and the appointment

of Dr. William G. Melson in 1964 to direct it.

METEORITES

As mentioned earlier, the original Smithson bequest included his cabinet of minerals, which contained "a valuable suite of meteoric stones, which

appear to be suites of most of the important meteorites which have fallen in Europe during several

centuries" (Goode, 1897:305). Some of these were

analyzed by J. Lawrence Smith in the chemical

laboratory of the Institution in 1853-54. Unfortunately, these meteorites were evidently lost along

with the rest of Smithson's cabinet in the fire of

1865.

The number of falls actually represented in the collection

at the first date mentioned (1880) cannot with absolute

certainty be given owing to the imperfection of the record,

but it was small; seven localities were represented: Imilac and

Vaca Muerta, Chile; Marietta (New Concord), Ohio; Parnallee, India; Searsmont, Maine; and Cold Bokkeveld, South

Africa. The Tucson iron which should have formed the chief

attraction was not catalogued, though brought, through the

influence of Dr. B. J. D. Irwin, to Washington in 1863. The

Casas Grandes iron which came to Washington from the

Philadelphia Centennial should also have received attention

(Merrill, c.1925).

The collection grew rapidly, evidently largely

through the work of Dr. F. W. Clarke, who was appointed honorary curator in the Department of

Mineralogy in December 1883. In 1889 he published

a catalog of the meteorite collection as of October

1888, in which he lists 128 distinct falls and finds;

in addition, there were 217 meteorites in the Shepard collection, which was deposited in the museum

by Shepard's son in 1886 (and ultimately bequeathed to the Smithsonian Institution in 1915).

There was considerable duplication between the

two collections and many of the specimens in both

collections were fragments. Nevertheless, the building-up of the meteorite collection by Clarke, almost

entirely by exchanges, was a notable contribution at

this early time.
NUMBER 14

In 1888 Merrill published his first paper on

meteorites, and was an active researcher in the field

until his death in 1929, publishing over eighty

papers on meteorites. The collection continued to

grow. In 1902, Tassin brought the Clarke catalog

up to date. For the purposes of this catalog the

Shepard meteorites were listed along with the museum's collection. The combined collections contained 348 distinct falls and finds. In 1916 Merrill

published a "Handbook and Descriptive Catalogue

of Meteorite Collections in the United States National Museum". The combined collections at that

time contained 412 independent falls and finds. The

meteorite collection has continued to grow steadily

and may now be the world's largest and most comprehensive from the standpoint of the number of

meteorites represented.

The tradition of meteorite research begun by

Merrill has continued. Dr. Foshag wrote a number

of papers on meteorites during his curatorship, and

his presidential address (1940) to the Mineralogical

Society of America was entitled "Problems in the

Study of Meteorites." Meteorite research within the

Institution, however, became the major interest of

Dr. Edward P. Henderson. Beginning in 1934 and

continuing throughout his curatorship and after

his retirement, he had published over thirty papers

on meteorites. Many of these were written in collaboration with Stuart H. Perry (1874-1957), a Michigan newspaper publisher. Perry graduated in 1894

from the University of Michigan, where he studied

chemistry, geology, and zoology. Fossils were his

first love, but around 1930 his scientific interests became directed towards the study of meteorites. He

was a vigorous collector, being aided in this respect

by adequate private means. In 1944, the Smithsonian published Perry's "Metallography of Meteoritic Iron," which for many years has been the

standard reference in this field. He also compiled

and privately published nine albums of photomicrographs of iron meteorites (166 in all), of which

six sets were produced. Through the years that

Perry was studying and collecting meteorites he

generously shared his knowledge and specimens

with others. Although he presented specimens to

many institutions, and privately assisted others in

their studies of meteorites, he was sincerely interested in the growth of the national collection and

presented what he considered to be his most important specimens to the Smithsonian Institution. During his life Perry donated 192 meteorites in this

way.

After J. Lawrence Smith's death in 1883, his

widow endowed the Lawrence Smith Medal, to be

awarded by the National Academy of Sciences for

"original investigation of meteoric bodies." This

medal was awarded to George P. Merrill in 1922,

Stuart H. Perry in 1945, and Edward P. Henderson

in 1970.

GEMS AND PRECIOUS STONES

This collection owes its beginning to an exhibit

made by F. W. Clarke and paid for ($2500) by

funds appropriated for the New Orleans Exposition of 1884. The same collection was displayed at

the Cincinnati Exposition the following year, after

which it was returned to Washington and placed

on exhibition in the museum. A detailed description of this collection was published by G. F. Kunz

in 1889. In 1891 the collection was greatly augmented by purchases from the estate of Dr. Joseph

Leidy of Philadelphia, and was exhibited at the

Columbian Exposition in Chicago in 1893. In 1894,

Mrs. Frances Lea Chamberlain gave the museum a

collection of precious stones that had been made by

her father, Dr. Isaac Lea. Later, in 1897, her husband, Dr. L. T. Chamberlain, was appointed honorary curator of the collection and added a large

number of desirable specimens. On his death in

1913 he bequeathed a sum of money, the income

from which is used for its further increase.

The growth of the gem collection is documented

by the 1900 "Descriptive Catalogue" by Wirt Tassin

and in the 1922 "Handbook and Descriptive Catalogue" by G. P. Merrill. A recent popular account is

Gems in the Smithsonian by Paul E. Desautels.

Literature Cited

Baird, S. F.

1882. Report of the Secretary. Annual Report of the

Board of Regents of the Smithsonian Institution

for the Year 1881, 839 pages.

Clarke, F. W.

1889. The Meteorite Collection in the U.S. National

Museum: A Catalogue of Meteorites Represented

November 1, 1886. Annual Report of the Smithsonian Institution for 1886, 2:255-265.

Desautels, P. E.

1972. Gems in the Smithsonian. Washington, D.C.: Smithsonian Institution Press.
10 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

Endlich, F. M.

1874. Mineralogical Collection. Annual Report of the

Board of Regents of the Smithsonian Institution

for the Year 1873, pages 51-53.

1880. List of Species and Varieties of Minerals in the

National Museum of the United States in 1879.

Proceedings of the United States National Museum,

3:333-335.

Goode, G. B.

1897. The Smithsonian Institution, 1846-1896. Washington, D.C.

Henry, J.

1854. Report of the Secretary. Ninth Annual Report of

the Board of Regents of the Smithsonian Institution, 463 pages.

1862. Report of the Secretary. Annual Report of the

Board of Regents of the Smithsonian Institution

for the Year 1861, 463 pages.

1873. Report of the Secretary. Annual Report of the

Board of Regents of the Smithsonian Institution

for the Year 1872, 456 pages.

Kunz, G. F.

1889. Gem Collection of the U.S. National Museum.

Annual Report of the Smithsonian Institution for

1886, 2:267-275.

Merrill, George P.

1879. A Treatise on Rocks, Rock Weathering, and Soils.

1st edition, 411 pages. New York: MacMillian and

Co. [2nd edition, 400 pages, published in 1906.]

1884. Reports on the Building-Stones of the United States

and Statistics of the Quarry Industry for 1880. U.S.

Tenth Census, 10:1-410.

1888. On the San Emigdio Meteorite. Proceedings of the

United States National Museum, 11:161-167.

1904. The Nonmetallic Minerals: Their Occurrence and

Uses. 414 pages. New York: John Wiley and Sons.

1916. Handbook and Descriptive Catalogue of Meteorite

Collections in the United States National Museum.

United States National Museum Bulletin, 94:1-206.

1922. Handbook and Descriptive Catalogue of the Collections of Gems and Precious Stones in the United

States National Museum. United States National

Museum Bulletin, 118:1-225.

[c. 1925.] [History of the Department of Geology.] Manuscript, files of the Department of Mineral Sciences,

National Museum of Natural History, Smithsonian

Institution.

Perry, S. H.

1944. Metallography of Meteoritic Iron. United States

National Museum Bulletin, 184:1-206.

Pogue, J. E.

1915. The Turquoise: A Study of Its History, Mineralogy,

Geology, Ethnology, Archaeology, Mythology, Folklore, and Technology. Memoirs of the National

Academy of Sciences, 12 (2, 3d memoir), 162 pages,

22 plates.

Shannon, E. V.

1926. The Minerals of Idaho, United States National Museum Bulletin, 131:1-483.

Smith, J. L.

1853.—1854. Re-examination of American Minerals. American Journal of Science, 15:207-215; 16:41-53, 365-

373; 18:372-381.

1855. Memoir on Meteorites. American Journal of Science,

19:153-163, 322-343.

Smithson, J.

1803. A Chemical Analysis of Some Calamines. Philosophical Transactions of the Royal Society (London),

93:12-28.

Tassin, W.

1900. Descriptive Catalogue of the Collection of Gems in

the United States National Museum. Annual Report of the Smithsonian Institution for 1900, pages

473-670.

Tassin, W.

1906. [The Mineral Collections, 1859-1906.] Manuscript,

files of the Department of Mineral Sciences, National Museum of Natural History, Smithsonian

Institution.

Wherry, E. T.

1917. Merrillitc, Meteoritic Calcium Phosphate. American

Mineralogist, 2:119.
New Data on Some Mercury Minerals from Terlingua, Texas

Roland C. Rouse

ABSTRACT

An X-ray study has been performed on the three

mercury minerals eglestonite, mosesite, and kleinite.

Previous work is reviewed and, where necessary, corrected in the light of new data. Eglestonite is cubic,

Ia3d, with a =16.04 A and has the formula Hg4

C12O. Mosesite and kleinite are mercury nitrogen

chloride sulfates. Mosesite is cubic with a = 28.62

A and kleinite, hexagonal with a = 40.60 and c =

11.16 A. Although the chemical formulas of their

supercells are still uncertain, their subcell formulas

correspond essentially to the chloride salts of MilIon's base (Hg2NOH»H2O).

Introduction

The mercury deposit at Terlingua, Brewster

County, Texas, is known mineralogically for its

suite of secondary mercury minerals. It is, in fact,

the type locality for six of them including terlinguaite (Hg4O2Cl2), eglestonite (Hg4Cl2O), and the

mercury nitrogen chloride sulfates mosesite and

kleinite. These minerals are known from but a few

localities and one investigator (Lipscomb, 1957) in

a review of the crystal chemistry of mercury found

it quite remarkable that kleinite and mosesite

should occur at all in nature. The latter two are of

particular interest as they are thought to be stuffed

derivatives of the high tridymite and high cristobalite structures, respectively. They contain NHg4

tetrahedra, which play the same structural role as

SiO4 tetrahedra do in silicates.

There exists one definitive study of the whole

group, that of Hillebrand and Schaller (1909). Subsequent investigators have compiled a large body

Roland C. Rouse, Department of Geology and Mineralogy,

The University of Michigan, Ann Arbor, Michigan 48104.

of chemical, optical, and crystallographic data, but

their results have often been ambiguous or contradictory. An accurate determination of the crystal

structure has been made only for terlinguaite and

since this has resolved most of the problems associated with this mineral, it was not included in the

present study. The terlinguaite structure (Aurivillius and Folkmarson, 1968) is interesting from a

crystal chemical viewpoint as it contains mercury

in two valence states. Some of the mercury atoms

are divalent and form the characteristic linear

O-Hg-O groups (Grdenic, 1965). Others are arranged in equilateral triangular clusters in which

each mercury has a formal oxidation number of

+ 4/3. The Hg-Hg distances in the cluster are

shorter than those in solid mercury indicating intermetallic bonding, and terlinguaite is therefore a

metal cluster compound.

Experimental Methods

The study of eglestonite, mosesite, and kleinite

is rendered difficult by their tendency to occur as

multiple crystals, whether as twins, parallel growths

or random intergrowths. In the case of kleinite this

seems to be invariably the case. The specimens

used in this study were from Terlingua and Huahuaxtla, Mexico, and were obtained from the U. S.

National Museum collections. As reported by previous workers, eglestonite is photosensitive, its color

changing rapidly from yellow to brown to black.

The color change produced no obvious changes in

the x-ray diffraction patterns, but this matter was

not investigated systematically.

Unit cell parameters were determined from precession photographs and verified by the cone-axis

or rotating crystal methods. Space groups were

determined from precession and Weissenberg photographs taken with MoKa and CuKa radiations,

11
12 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

respectively. The cell parameters were refined from

powder data by the method of least-squares using

the program of Appleman and Evans. In the case

of mosesite and kleinite the data were obtained

from a powder diffractometer utilizing monochromatized CuK« radiation and quartz as an internal

standard. Since there was not enough eglestonite

available for this procedure, it was necessary to use

16 reflections between 102° and 165° 2e measured

from a Debye-Scherrer photograph. The powder

patterns in Tables 1, 2, and 3 were likewise measured from shrinkage-corrected Debye-Scherrer photographs taken with a 114.6 mm diameter camera

and filtered CuK« radiation. Intensities were estimated visually.

Minerals Studied

EGLESTONITE

Eglestonite was first described by Moses (1903)

as a cubic mineral having the formula Hg6Cl3O2.

Hillebrand and Schaller (1909:145, 147) confirmed

the cubic symmetry but found the formula to be

Hg4Cl2O on the basis of three chemical analyses.

The crystal class was determined to be m3m from

the presence of the hexoctahedron as a common

form.

The crystal structure of eglestonite is of some

interest due to the presence of the binary ion

Hg2

+2

. Two structures have been proposed, both

by the same investigator. Hedlik (1948) found

eglestonite to be cubic, Pm3n, with a =16.07 A.

She went on to propose a structure containing the

mercurous ion and having Hillebrand and Schaller's chemical formula. However, in Hedlik (1950)

there appeared a revised structure based on a cell

having a = 8.03 A and symmetry Im3m. The formula was also changed to Hg6Cl4O, which is not

in accord with the existing chemical analyses. No

explanation was offered for the revisions and since

both structures were derived with powder and

rotating crystal data, neither can be considered reliable. To compound the confusion, Wolfe (cited

in Palache, et al., 1951:51) reported the cell parameter a =16.03 A and a probable space group

Ia3d for eglestonite.

The present study has confirmed Wolfe's results.

Eglestonite is cubic, Ia3d, with a refined parameter

a = 16.0398 ± 0.0003 A. There is also a very promiTABLE 1

/

10

40

100

< 1

7

7

10

50

5

10

5

< 1

< 1

1

1

80

1

< 1

3

20

1

10

< 1

1

1

5

5

< 1

5

1

5

10

< 1

< 1

5

3

< 1

5

Plus ca. 65 more

.—Powder

dohs

6.549

4.006

3.271

3.142

2.925

2.832

2.599

2.529

2.471

2.313

2.265

2.179

2.135

2.034

2.003

1.887

1.858

1.811

1.788

1.707

1.687

1.633

1.617

1.586

1.554

1.526

1.499

1.475

1.461

1.384

1.373

1.334

1.308

1.290

1.266

1.237

1.215

1.182

lines to 0.777

pattern of

dcalc

6.548

4.010

3.274

3.146

2.928

2.835

2.602

2.536

2.475

2.315

2.268

2.183

2.143

2.037

2.005

1.890

1.865

1.816

1.793

1.710

1.691

1.637

1.620

1.588

1.558

1.529

1.502

1.477

1.464

1.386

1.375

1.337

1.310

1.293

1.268

1.237

1.216

1.182

A

eglestonite

hkl

211

400

422

510, 431

521

440

611, 532

620

541

444

543, 710,

550

721, 633,

552

642

651, 732

800

660, 822

831, 750,

743

752

840

664

851, 930,

754

844

941, 853,

770

10 • 1 • 1, 772

943

10.3« 1, 952

871

961, 10.3*3

10*4.2

11 .3«2, 10.5.3,

972

10.6.0, 866

12.C0 , 884

10.7.1 , 11 .5. 2

12«3. 1, 983

12.4.0

10.8*2

13.2.1 , H'7. 2

12.6-2

nent subcell having ^4= a/2 = 8.02 A and symmetry

Im3m. That the 16.04 A cell is the correct one is

confirmed by powder data (Table 1), which can only

be indexed fully on the larger cell. The unit cell

contents calculated from the average of Hillebrande's analyses are Hg9411 C149J6 O23.76. From

a consideration of the available equipoints in
NUMBER 14 13

Ia3d, the correct formula must be Hg4Cl2O with

Z = 24. These results indicate that Hedlik's revised

structure is necessarily wrong since it is based on

the subcell rather than the true cell and gives a

formula inconsistent with the chemical analyses.

Preliminary work on a redetermination of the

eglestonite structure is underway and a complete

study is planned.

MOSESITE

Mosesite was described by Canfield, et al. (1910)

as a new mercury-ammonium compound containing

chloride, sulfate, and water. Although cubic in

morphology, it was weakly birefringent but became

isotropic when heated to ^186°C. From this they

concluded that mosesite exists in high and low

temperature polymorphic forms with the inversion

temperature being 186°C. This, of course, is not

necessarily the case as many cubic materials show a

weak, anomalous birefringence. In a study of mosesite from the Fitting district of Nevada, Bird (1932)

found on the basis of powder data that mosesite

is cubic with a face-centered lattice and a = 9.57 A.

A restudy of mosesite was performed by Switzer,

et al. (1953), who obtained the first complete chemical analysis of the mineral. Noting the strong

similarity of its powder pattern and chemistry to

those of Millon's base (Hg2NOH-2H2O), they derived a formula Hg2N(Cl,SO4,MoO4,CO3)»H2O

(Z=8) for material from Huahuaxtla Mexico. Mosesite is, therefore, the chloride salt of Millon's

base with lesser amounts of other large anions. The

structure of Hg2NOH»H2O was determined by

Lipscomb (1951) to be cubic, F43m, with « = 9.58 A.

It is a stuffed derivative of the high cristobalite

structure with a 3-dimensional framework of linked

NHg4 tetrahedra. The OH" and H2O occupy the

large open channels in the framework. This explains the presence of large complex anions in the

mosesite formula. Switzer, et al. (1953) also proposed a structure for mosesite analogous to that of

Millon's base. The structure is cubic, F43m, with

a = 9.524 A, which is consistent with the powder

pattern.

The author has reexamined the mosesite crystals

from Huahuaxtla, Mexico, analyzed by Fahey (in

Switzer, et al., 1953). Although the X-ray study of

this material is not yet complete, several important

results can be reported. Weissenberg photographs

TABLE 2.—Powder pattern of mosesite

1

75

10

90

100

40

40

25

35

25

20

30

20

20

20

10

10

15

20

15

15

Plus ca.

dobs

5.512

3.375

2.877

2.756

2.382

2.186

1.834

1.685

1.610

1.454

1.436

1.375

1.334

1.241

1.192

1.165

1.102

1.093

1.066

1.047

16 more lines

dcalc

5.508

3.373

2.876

2.754

2.385

2.188

1.836

1.832

1.686

1.683

1.612

1.607

1.455

1.453

(mostly broad bands)

hkl

333, 511

660, 822

933, 771,

755

666, 10.2. 2

12-0. 0

993, 13 • 1 • 1

999, 15.3. 3

12.10. 0

12-12 • 0

17*0.0

17.5. 1

14.1L0

19.5.1

18.8.0

to 0.787 A

confirm the cubic symmetry, but the space group

has not yet been determined with certainty. A

rotating crystal photograph shows that mosesite

has a supercell with a = 28.8 A, three times the value

previously reported. The refined value is a = 28.618

± 0.002 A. The subcell has A =a/3 = 9.54 A. There

is also a second subcell, defined by the strong reflections, which has ,4' = a/12 = 2.38A.

Powder data for mosesite are presented in Table

2. The pattern is similar to that of Switzer, et al.

(1953), except that the d-values and. intensities of

the reflections are in better agreement with those

of Hg2NOH>2H2O than are the data of Switzer,

et al. This is especially true of the line at 5.512 A,

whose intensity is much greater than reported by

those authors. The indexed reflections in Table 2

do obey the presence rule for a face-centered 9.54

A cell. Powder diffractometer scans, however, show

a small peak at 12.87 A, which can only be indexed

as 210 (dcalc= 12.80 A) of the 28.62 A supercell.

This is in accord with the single crystal results and

also seems to require a primitive lattice for mosesite.

It is possible that the 9.54 A subcell is face-centered,
14 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

while the supercell is primitive. The substructure

corresponds to the structure of Millon's base and

the superstructure is perhaps connected with ordering of the several kinds of large interstitial anions

in mosesite. The symmetry and lattice type of the

supercell is the subject of continuing single crystal

studies.

KLEINITE

A fourth yellow mercury mineral occurring at

Terlingua was mentioned by Moses (1903), but it

remained for Sachs (1905) to name it kleinite. Hillebrand and Schaller (1909) found it to be another

mercury ammonium compound with chloride and

sulfate, but despite many chemical analyses they

could not derive a satisfactory formula. They also

described in detail the highly anomalous optical

properties of kleinite. Although the mineral is morphologically hexagonal, basal sections are strongly

birefringent. Above about 130°C, however, kleinite

becomes uniaxial and, as in the case of mosesite,

this was ascribed to polymorphism. They also noted

that birefringent basal sections would not extinguish under crossed polars. This was explained by

assuming each crystal to be composed of a group of

parallel biaxial plates stacked along c. During further heating experiments, Canfield, et al. (1910)

made the interesting observation that kleinite becomes isotropic above 186°C.

In an x-ray investigation Heritsch (1949) found

that all kleinite crystals are composed of several

individuals and that heating above the supposed

inversion temperature does not change this. His

crystals were all hexagonal, probably P63/mmc,

with a= 13.56 and c— 11.13 A. There is also a subperiodicity of a/2 = 6.78 A. A crystal structure was

deduced using rotating crystal data. In a later paper

Heritsch (1954) noted that mosesite had been

shown to be isostructural with Millon's base, which

is in turn a high cristobalite derivative. By analogy,

he proposed that kleinite is a high tridymite derivative with the formula (Hg2N) (Cl,SO4)»xH2O

where x^\/4. As with mosesite the structural channels contain the large anions and water molecules.

Nijssen and Lipscomb (1954) came to the same

conclusion on the basis of the close relationship

between kleinite and Hg2NBr. They determined

the structure of the latter to be a derivative of high

tridymite. Hg2NBr is hexagonal, P63/mmc, with

0 = 6.65 and c= 11.26 A, which corresponds to the

kleinite subcell. In a later paper, however, Lipscomb (1957) reported evidence that the a parameter

of kleinite given by Heritsch should be tripled. He

further suggested on the basis of some intensity

calculations that the channels in the kleinite structure contain mercury atoms as well as anions.

In the present study, the interpretation of the

diffraction photographs was greatly hindered by the

fact that every crystal examined was multiple. In

some cases, however, the volume of one individual

was considerably greater than those of the others.

It was therefore possible to separate its reciprocal

lattice pattern from those of the others and study

its symmetry and cell parameters. This approach

is not infallible, but its results are supported by the

powder data, which are not subject to the uncertainties introduced by the multiplicity of the single

crystals.

Rotation photographs around the c-axis are consistent with Hillebrand and Schaller's model of a

stacking of parallel plates along c. Adjacent individuals, however, seem to be slightly tilted with

respect to one another by ^—1.5° in those crystals

examined.

As suggested by Lipscomb (1957), kleinite is

hexagonal with a three times the value given by

Heritsch. The refined cell parameters are a = 40.599

±0.005 and c=11.155±0.003 A. There are two

subcells. One, denned by the total pattern of medium plus strong reflections, has A= a/6 = 6.77 and

C = c= 11.16 A. The other, denned by the strong

reflections alone, has /4' = a/12 = 3.39 and C' = c/2 =

5.58 A. An independent check on these parameters

is provided by the powder pattern (Table 3). It

contains four low-angle reflections (220, 222, 811,

and 702), which cannot be indexed on Heritsch's

cell but which can be indexed quite satisfactorily

on the 40.60 A cell.

The space group of the supercell could not be

determined since the superstructure reflections on

the Weissenberg photographs are too few and

scattered. However, the 6.77 A subcell does have

symmetry P63mc, P62c, or P63/mmc. This subcell

is the analog of the Hg2NBr cell.

Using the average chemical analysis of Hillebrand and Schaller (1909), the supercell contents

are

Hg330.47^141.41*->1158.95C)24.96

 W143.91H,
NUMBER 14

/

10

15

15

25

5

20

<1

1

10

5

100

70b

15

90

3

TABLE 3.—-

dth,

10.19

5.871

5.577

5.188

4.890

4.040

3.850

3.731

3.382

3.132

2.931

2.888

2.831

2.788

2.688

100

5

5

V

10

10

1

10

20v

3

15

3

3

30

dcalc hkl

2.592

2.518

2.446

2.306

2.215

2.171

2.084

2.057

2.019

1.900

1.843

1.772

1.736

1.690

10.15

5.860

5.577

5.188

4.888

4.040

3.861

3.836

3.732

3.383

3.140

3.127

2.930

2.893

2.890

2.883

2.834

2.789

2.693

2,689

2.594

2.592

2.518

2.513

220

600

002

601

222

602

811

820

702

660

603

433

12»0« 0

662

860

752

12 • 0 • 1

004

903

224, 960

12*0. 2

504

604

10 .4* 2

Plus ca. 40 more lines (mostly broad bands) to 0.781 A

b

 broad,

 vb

 very broad

On the basis of the available data it is difficult to

derive a satisfactory formula from this. A formula

for the 6.77 A subcell, however, may be derived by

analogy to that of Hg2NBr. The subcell contents

are

9 3C 1 4 42 O4

or very nearly Hg9N4(Cl,SO4)5'H2O. This can be

rewritten as 4H^NCl»Hg(Cl,SO4)-H2O. Presumably, the 4Hg2NCl represents that part of the substructure analogous to Hg2NBr (for which Z = 4),

while the remainder represents the contents of the

structural channels.

15

The true symmetry and formula of the superstructure can only be settled by a complete structure determination combined with a new chemical

analysis. The former objective, however, may not

be attainable due both to the lack of single crystals

and the experimental difficulties inherent in treating highly absorbing compounds with very large

supercells. The outlook for mosesite is more hopeful, however, and further work is anticipated on

this mineral.

Literature Cited

Aurivillius, K., and L. Folkmarson

1968. The Crystal Structure of Terlinguaite Hg4O2Cl;,.

Ada Chemica Scandinavica, 22:2529-2540.

Bird, P. H.

1932. A New Occurrence and X-Ray Study of Mosesite.

American Mineralogist, 17:541-550.

Canfield, F. A., W. F. Hillebrand, and W. T. Schaller

1910. Mosesite, a New Mercury Mineral from Terlingua,

Texas. American Journal of Science, 4th series,

30:202-208.

Grdenic, D.

1965. The Structural Chemistry of Mercury. Quarterly

Reviews (London), 19:303-328.

Hedlik, A.

1948. Uber die Formel und Struktur von Eglestonit.

Experientia, 4:66.

1950. Uber Formel und Struktur des Mercurooxychlorides

Eglestonit. Tschermaks Mineralogische und Petrographische Mitteilungen, Dritte Folge, 1:378-389.

Heritsch, H.

1949. Rontgenuntersuchungen an Kleinit. Tschermaks

Mineralogische und Petrographische Mitteilungen,

Dritte Folge, 1:300-312.

1954. Bemerkungen zur Kristallchemischen Konstitution

des Kleinites. Anzeiger der Osterreichischen Akademie der Wissenschaften, Mathematisch-Wissenschaftliche Klasse, 1:1-4.

Hillebrand, W. F., and W. T. Schaller

1909. The Mercury Minerals from Terlingua, Texas.

United States Geological Survey Bulletin, 405.

Lipscomb, W. N.

1951. Th e Structure of Millon's Base and Its Salts. Acta

Crystallographica, 4:156-158.

1957. Recent Studies in the Structural Inorganic Chemistry of Mercury. Annals of the Neiv York Academy

of Sciences, 65:427-435.

Moses, A. J.

1903. Eglestonite, Terlinguaite and Montroydite, New

Mercury Minerals from Terlingua, Texas. American Journal of Science, 4th series, 16:253-263.
16 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

Nijssen, L., and W. N. Lipscomb 1905. Der Kleinit, ein Hexagonales Quecksilberoxydchlorid

1954. A Hexagonal Modification of a Salt of Millon's von Terlingua in Texas. Sitzungberichte der KonBase. Ada Crystallographica, 7:103-106. iglichen Preussischen Akademie der Wissenschaften

Palache, C, H. Berman, and C. Frondel (Berlin), 1091-1094.

1951. Dana's System of Mineralogy. Volume 2, 7th edition. Switzer, G., W. F. Foshag, K. J. Murata, and J. J. Fahey

New York: John Wiley and Sons. 1953. Re-examination of Mosesite. American Mineralogist,

Sachs, A. 38:1225-1234.
Dashkesanite: High-Chlorine Amphibole

from St. Paul's Rocks, Equatorial

Atlantic, and Transcaucasia, U.S.S.R.

Sara S. Jacobson

ABSTRACT

New data are given for dashkesanite, a high-chlorine

amphibole, from two localities, Transcaucasia,

U.S.S.R., and St. Paul's Rocks, Equatorial Atlantic.

Four new analyses (by electron microprobe) of the

mineral from Transcaucasia gave a chlorine content ranging from 4.15 to 5.34 percent. The original

analysis by Krutov (1936) by wet chemical methods

reported Cl = 7.24 percent. Five analyses (by microprobe) of dashkesanite from St. Paul's Rocks gave

Cl ranging from 6.03 to 6.51 percent. The mineral

from both localities is low in SiO2 and MgO and

high in FeO, Cl, and K2O compared to other hornblende compositions. It is hastingsitic using the

classification of Ernst (1968).

Introduction

High-chlorine amphibole was first described by

Krutov (1936). He found the mineral in skarn rocks

surrounding sheetlike magnetite ore bodies at Dashkesan, Transcaucasia, U.S.S.R. These skarn rocks

occur about 1200 meters from the ore body and

extend for over 200 meters with an average thickness of 0.60-0.75 meters. The surrounding country

rock is described as porphyrites and tuffs with dikes

of gabbro porphyrite occuring near the skarn. Krutov (1936) named the mineral "dashkesanite" for

the locality.

The mineral was also found by Melson, et al.

(1972) in brown hornblende mylonites from St.

Sara S. Jacobson, Department of Geology, University of

California, Los Angeles, Los Angeles, California 90024.

Paul's Rocks, an ultrabasic intrusion exposed in a

series of islets in the equatorial Atlantic. Brown

hornblende mylonites are the second most abundant of three rock types found on the islets; peridotite mylonites are the most abundant rock type

and clinopyroxene mylonites are the least abundant. All samples examined were collected in 1966

during Cruise 20 of the R. V. Atlantis II. Samples

from both of these areas were investigated in the

present study.

ACKNOWLEDGMENTS.—I wish to thank W. G. Melson for suggesting the project and his help throughout.

Petrography

The specimen from Transcaucasia available for

study (USNM 120180) consists of fine- to mediumgrained, subhedral to anhedral crystals of dashkesanite; minor chlorite and epidote and a finegrained material that may be scapolite are also

found in the specimen. This specimen of dashkesanite is dark green. In thin section, it shows a

strong yellow to blue-green pleochroism. Cleavage

is not well developed; rather a basal parting appears

to dominate. The mineral has inclined extinction

and positive elongation.

Dashkesanite from St. Paul's Rocks was studied

in two sections of brown hornblende mylonite,

(USNM 110393-13 and 110393-31). Both are from

the Southeast Islet. (See Melson, et al., 1972, for

map of localities.) The primary assemblage is

kaersutitic hornblende, plagioclase, and Fe-Ti oxides. These occur with accessory amounts of dashkesanite, allanite, zircon, scapolite and titanbiotite.

17
18 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

FIGURE 1.—Portion of a hornblende augen in section USNM

110393-13. The diagonal grayish area in the central part

of the photo is dashkesanite. Width of field is 1.6 mm x 1.3

The hornblende forms large rounded augen. Dashkesanite occurs in veins in the augen and as overgrowths on the hornblende augen. It is also found

in veins in the fine-grained matrix. It does not occur disseminated in the matrix (Figure 1).

The optical properties of the St. Paul's Rocks

dashkesanite are similar to those described for the

mineral from the type locality. The dashkesanite

forms fine to coarse, anhedral to subhedral masses;

good crystal forms are rare. The mineral again

shows the distinctive, strong yellow-green to bluegreen pleochroism. The dashkesanite is not sheared

nor mylonitized.

Analytical Procedure

Analyses of the above samples were done on an

ARL EMX electron microprobe using a 15kV acceleration potential, 0.15 juA sample current and a

TABLE 1.—Amphibole analyses

Constituent

SiO2

TiO 2

A12O3

Fe 2O3

FeO

MgO

CaO

N a 2O

K.,O

Cl

H2O

O = C1

Total

Si

Al

Al

Ti

Fe**

Mg

Fe+2

Na

Ca

K

OH

Cl

1

36.13

0.30

10.22

7.60

19.99

3.63

10.83

1.24

2.84

7.24

1.05

101.93

1.63

100.30

5.934 |

1.978 \

0.035 /

o.94o y

0.888 I

2.747 *

0.394 1

1.906 >

0.596 \

1.154 I

2.016 S

2

33.90

1.01

11.57

-

31.91*

1.81

11.16

0.74

3.34

4.95

-

100.44

1.12

99.32

7-91

 5

2fx | 8.00

0.26 \

0.13 1

4.67h - \ 5.50

0.47 i

4.64 )

0.25 )

2.90 2.08 I 3.07

0.74 \

3 1 7

 IM

3

35.31

0.75

11.81

-

30.21 •

2.27

11.34

0.89

2.92

4.15

-

99.75

0.94

98.81

6.06 /

1.94 \

0.40 \

0.10 1

0.58 i

4.34 *

0.33 1

2.09 >

C

0.64 )

1.21

4

33.24

1.14

12.21

-

31.761

1.70

11.13

0.75

3.46

5.34

-

100.73

1.20

99.53

NUMBER

8

°° S

0.27

0.15

5.42 -

0.44

4.61

0.25

3 06 2 07

0.77

1.57

5

34.92

0.54

11.99

-

30.57 *

2.27

11.34

0.80

3.47

5.06

-

100.95

1.14

99.81

OF IONS ON

!

\

S)(

\

0.40 \

0.07 1

5.47 - y

0.58 4

4.38 *

0.27 1

3 09 2 08 I

0.76 )

1.47

6

36.66

0.41

11.43

-

26.99*

4.85

11.69

1.82

1.76

6.10

-

101.71

1.38

100.33

THE BASIS OF

8.00 J-JJJ8.0 0

0.33 \

0.05 1

5.43 - y 5.33

1.20 (

3.75 *

0.59 1

3 11 2 08 > 3 04

0.37 )

1.72

7

35.06

0.80

12.27

-

26.71

4.05

11.78

1.75

1.96

6.51

-

101.39

1.47

99.92

24 (O

5.91

2.09

0.35

0.10

-

1.02

3.76

0.57

2 13

0.42

1.86

8

35.76

0.70

12.55

-

26.32*

4.87

11.35

1.77

1.76

6.03

-

101.11

1.36

99.75

, Cl, OH)

1

8

- ;s i

\ 0.41 X

/ 0.09 /

)5.23 - )

( 1,1 (

; 3.66;

j 0.57 1

> 3 12 2 02 i

\ 0.37 \

1.70

9

36.44

0.44

11.60

-

27.03*

4.42

11.35

1.86

1.66

6.20

-

101.00

1.40

99.60

8.00 ^[8.0 0

0.55 \

0.06 f

5.37 - y 5.25

0.87 (

3.77 ;

0.60 )

2 96 2 03 > 2 98

0.35 \

1.75

10

36.00

0.59

11.85

-

27.99*

3.51

11.42

1.79

1.71

6.10

-

100.96

1.38

99.58

6.05 /

1.95 \ '

0.40 \

0.07 1

- ) 5.29

0.88 I

3.94 ;

0.58 )

2 06 > 3 01

0.37 \

1.74

a

 All Fe calculated as FeO.

"Includes Mn 0.06.

Column 1: Krutov's (1936) analysis (includes P2O5 0.10, SO3 0.11, MnO 0.43)

Columns 2-5: Dashkesanite from Transcaucasia. Analyzed on electron microprobe.

Columns 6-10: Dashkesanite from the St. Paul's Rocks. All analyses done on section USNM-110393-31. Analyzed on electron

microprobe.
NUMBER 14 19

SjU.m beam size. The analyses were corrected

using the Bence and Albee (1968) correction procedures, and the summations corrected for chlorine

equivalents of oxygen. The results are given in

Table 1. The ionic proportions were calculated on

the basis of 24 anions with H2O not determined

and all Fe assumed to be ferrous. The choice of 24

anions rather than 23 was made because Cl~ rather

than OH" appears to nearly completely fill the

A site. Since the occupancy of this site is known

and need not be assumed, a normalization on the

basis of 24 anions is a justified approximation. The

actual number of anions is probably between 23

and 24.

Chemistry

Dashkesanite from the two localities has similar

chemistry in some respects. Both are low in SiO2

and MgO and high in FeO, Cl, and K2O compared

to other hornblende compositions (Leake, 1968;

Deer, et al., 1963a:290), while CaO, TiO2, and

A12O3 are consistent with other hornblendes. These

hornblendes are hastingsitic, using the classification of Ernst (1968).

There are also chemical differences between the

two occurrences. The dashkesanite from the St.

Paul's Rocks is higher in SiO2, Cl, Na2O, MgO

and lower in total Fe and K2O than the dashkesanite from Transcaucasia. There are also differences

between Krutov's original analyses and those done

for the present paper. The new analyses show less

Cl, SiO2, and Na2O, and higher A12O3. These

differences may be due to the differences in analytical technique.

The cation sums (Table 1) are high, generally

summing over 16. This is probably because for the

microprobe analyses all iron is assumed to be ferrous. Krutov's analysis shows a considerable amount

of ferric iron, and indicates that from 13 to 14

percent of the ferrous iron reported in the probe

analyses may be ferric.

Particularly, the totals for the Y site (Fe + Ti

+ Mg + octahedral Al) are high, being between

5.23 and 5.50. Leake (1968:249) postulates that

good analyses would have sums between 4.75 and

5.25 for this site. Recalculating the ionic proportions assuming all iron as ferric iron reduces the

sum for this site by approximately 0.70 and reduces

the cation total by approximately 1. Depending on

the amount of ferric iron present, all the cation

proportions are probably less than those reported

for the present analyses in which all iron is assumed as ferrous iron.

Discussion

Dashkesanite from the two localities is close in

optical characteristics and chemical composition in

spite of the differences in the environments in which

they are found. In St. Paul's Rocks dashkesanite is a

late stage mineral, as shown by the absence of shearing or mylonitization. Melson, et al. (1972:241) include dashkesanite in the neomineral group. These

minerals occur as undeformed grains indicating

formation by recrystallization and precipitation

continuously during or after mylonitization. Melson,

et al. (1972:241) speculate the high-chlorine minerals found (dashkesanite, scapolite and chlorapatite)

formed either by reaction of primary minerals with

a chlorine-rich pore fluid or by direct crystallization

from such a pore fluid.

It is possible that the chlorine was derived from

sea water during weathering of the brown hornblende mylonites. The dashkesanite does occur with

scapolite, however, which is most characteristically

formed in upper amphibolite facies rocks (Deer,

et al., 1963b:330); this would indicate moderate to

high temperatures.

The formation of the dashkesanite may be related to the formation of the brown hornblende

mylonites. Of the three rock types present, the

brown hornblende mylonites have the largest

amount of chlorine in their bulk composition

(1.22-1.86% compared with 0.67% in the clinopyroxene-plagioclase mylonite and 0.05-0.20% in the

peridotite mylonites [Melson, et al., 1972]). The

higher amount of chlorine may account for the

observable presence of the dashkesanite and other

high chlorine phases in the brown hornblende

mylonites. High chlorine content appears to be

a characteristic of the strongly undersaturated

alkalic rock clan to which the brown hornblende

mylonites are chemically related (Melson, pers.

comm.).

The dashkesanite in the Trancaucasian rocks

formed by contact metamorphism. Krutov (1936)

feels that the dashkesanite was formed by reaction

of the fluids from the magma, containing large

amounts of FeO and Cl, with the surrounding
20 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

country rocks described as porphyrites and tuffs.

He projects conditions of low temperature and high

fluid pressure. Krutov (1936) thinks the source of

the fluids are the basic differentiates of the intrusion, which have a high chlorine content. These

basic differentiates occur as dikes of gabbro porphyrite near the amphibole skarn.

The differences in chemistry between the two

localities of dashkesanite as noted in the preceding

section can be accounted for by the differences in

environments. There are, however, strong similarities between the two environments. Both occurrences are in silica-undersaturated environments

and this would account for the low SiO2 content of

dashkesanite. Although the specific conditions of

formation are not known, both occurrences of the

mineral appear to be related to the late stage

fluids derived from basic and ultrabasic intrusions.

Dashkesanite may be present but may not have

been recognized in other rocks of similar composition as the Transcaucaian rocks and St. Paul's

Rocks. Further observance of this mineral in other

silica-undersaturated rocks could add to our knowledge of the geochemistry of chlorine, the concentration of chlorine in such rocks, and the late stage

fluids associated with these rocks.

Dashkesanite may also prove interesting crystallographically because the chlorine ion is the largest

(1.81 A) of the ions commonly reported in the A

site in amphiboles (OH~, 0.91-0.105 A and F~,

1.33 A [Bloss, 1971]).

Literature Cited

Bence, A. E., and A. L. Albee

1968. Empirical Correction Factors for the Electron

Microanalysis of Silicates and Oxides. Journal of

Geology, 76:382-403.

Bloss, F. Donald

1971. Crystallography and Crystal Chemistry. 545 pages.

New York: Holt, Rinehart and Winston, Inc.

Deer, W. A., R. A. Howie, and J. Zussman

1963a. Chain Silicates. Volume 2 of Rock-Forming Minerals. 379 pages. New York: John Wiley and Sons.

1963b. Framework Silicates. Volume 4 of Rock-Forming

Minerals. 435 pages. New York: John Wiley and

Sons.

Ernst, W. G.

1968. Amphiboles. 125 pages. New York: Springer-Verlag

New York, Inc.

Krutov, G. A.

1936. Dashkessanite: A New Chlorine Amphibole of the

Hastingsite Group. Bulletin de VAcademie des Sciences de I'URSS, Classe des Sciences Mathematiques

et Naturelles, Serie Geologique, 341-373. [See also

Mineralogical Abstracts, 6(1937): 438.]

Leake, B. E.

1968. A Catalog of Analyzed Calciferous and Subcalciferous Amphiboles Together with their Nomenclature and Associated Minerals. Geological Society

of America Special Paper, 98.

Melson, W. G., S. R. Hart, and G. Thompson

1972. St. Paul's Rocks, Equatorial Atlantic: Petrogenesis,

Radiometric Ages and Implications on Sea Floor

Spreading. Geological Society of America Memoir,

132:241-272.
Note on High-Alumina Basalt

Dredged near the Aleutian Trench

William G. Melson

ABSTRACT

High-alumina basalt was dredged from a small

seamount in the Adak Fracture Zone near and

south of the Aleutian Trench. The basalt, dredged

from magnetic anomaly 25 (about 63 million years

old) has a composition transitional between basalt

from spreading centers and basalt from seamounts.

It thus may have been derived from the ancestral

East Pacific Rise or from younger off-ridge volcanism. Extensive weathering effects have changed

the concentrations of some elements, and obscured

the primary igneous composition.

Introduction

Very little is known about the igneous rocks on

the floor of the north Pacific Ocean. Samples

dredged from this region were transferred to the

National Museum of Natural History, Smithsonian Institution, by Dr. Barrett H. Erickson of the

U.S. National Oceanographic and Atmospheric Administration. These are the only samples in the

Museum's collections from this area, and their description is the subject of this report.

ACKNOWLEDGMENTS.—I am indebted to Dr. Erickson for providing the samples for study; to Mr.

Paul Grim, also of the U.S. National Oceanographic

and Atmospheric Administration, for helpful discussions and information on the Adak Fracture

Zone; to Mr. E. Jarosewich, National Museum of

Natural History, Smithsonian Institution, for perWilliam G. Melson, Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution,

Washington, D. C. 20560.

forming the chemical analyses; and to Dr. S. R.

Cann and his associates, University of East Anglia,

England, for performing trace element analyses on

the samples.

Specimen Features

Two basalt samples were received, both identical

in hand specimen features and weighing 195 gm

(USNM 112471) and 400 gm (USNM 112472). Both

are angular, and have very thin, black, hydrous

iron-manganese oxide coatings on at least one surface. Other surfaces are free of the coatings, indicating that the fragments were broken off larger

boulders or outcrops by the dredge. A thin, 5 to 10

mm, reddish altered zone extends inward into the

rock from the oxide-encrusted surfaces. The unencrusted surfaces are mottled by small black circular

encrustations, probably composed of hydrous ironmanganese oxides, about 1 to 2 mm across, on a

yellowish background of altered basalt. The lessaltered appearing interior is dark brown, contains

scattered large (up to 1 cm across) rounded, multicrystal aggregates of plagioclase (An80), which compose about 3 volume percent of each sample. The

groundmass contains abundant plagioclase microlites (average An60-An70), and small granules and

sheaflike quench crystals of clinopyroxene. The

large plagioclase crystals are altered to white clay

minerals on the outer, oxide-encrusted surface. The

very fine grain-size of the samples shows that they

cooled near quenched surfaces, although neither

fresh glass nor palagonitized glass surfaces occur.

There are no obvious grain-size gradients across

the samples. These features indicate that the

samples are from the interior, but probably less

than 20 centimeters from a cooling surface, of a

21
22 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

pillow lava or from the contact of a shallow intrusion.

Bottom Exposure Age

The thickness of the hydrous iron-manganese

oxide coating on deep-sea rocks is proportional to

the length of time of exposure on the sea-floor.

The rate of deposition ranges between 1 and 10

mm per million years (Bender et al., 1966; Ku and

Broecker, 1967; Somayujulu, 1967). The maximum

thickness of 1 mm on these samples thus indicates

a bottom exposure age of from 0.1 to 1 million

years.

Sample Locality and Oceanic Basement Age

The sample was dredged from a depth of 4714

m on the south side of a small seamount which rises

to 3790 m. The locality (49°30.43' N, 177°32.88'

W) is on magnetic anomaly 25 (Grim and Erickson, 1969; Erickson and Grim, 1969), which has an

age estimated at 63 million years according to the

magnetic reversals time scale of Heirtzler, et al.

(1968). The thin hydrous iron-manganese encrustation shows that the sample has been exposed at the

sea floor for a much shorter period of time than

this. The inference, then, is that it has only recently been exposed at the sea-floor by faulting or

slumping off of overburden, and/or it is a geologically recent eruptive rock.

The unnamed seamount from which the samples

were dredged is elongated in an east-northeast direction, and rises 1210 m over a distance of 15 km in

this direction. Steepest slopes are perpendicular to

this direction, and average about 10°. The bathymetry itself would indicate formation of the feature

as an off-ridge submarine volcano. However, the

direction of elongation is nearly paralled to the

trend of the regional magnetic anomalies. This

feature raises the possibility that the seamount was

a bathymetrically high ridge formed originally at

a spreading center. The composition of the basalt

from the seamount, as will be discussed, does not

indicate unambiguously which of these possibilities

is true.

Composition

The Adak Fracture Zone basalt samples are highalumina basalt with evidence of significant weatherTABLE 1.—Chemical composition of high-alumina

basalt from the Adak Fracture Zone

Constituent

SiO2

A1,O3

FesO,

FeO

MgO

CaO

Na2O

K2O

H2O+

H 2 O -

TiO2

MnO

Total

Total FeO*

Rb

Sr .

Y

Zr

Nb

46.80

17.99

7.52

3.52

4.48

12.14

2.84

0.37

1.66

0.77

1.67

0.17

0.19

100.12

10.05

49.61

16.01

2.21

7.19

7.84

11.32

2.76

0.22

0.63

0.45

1.43

0.14

0.18

0.72

0.85

0.74

1.25

0.90

0.64

0.25

0.12

0.22

0.30

0.29

0.07

0.04

49.84 48.16

14.09 18.31

3.06

8.61

8.52

10.41

2.15

0.38

4.24

5.89

4.87

8.79

4.05

1.69

2.52 2.91

0.26 0.93

0.16 0.16

11.49 1.27 11.36 9.71

TRACE ELEMENTS

7.2

148

57

111

0.8

123

43

100

46

12

42

* All Fe recalculated as FeO.

Column 1: Using classical methods, E. Jarosewich, analyst;

trace elements by X-ray fluorescence by J. R. Cann and coworkers.

Column 2: Average ocean-floor basalt (Cann, 1971), 94 analyses; Fe2O3, FeO, H2O + , H2O —, and trace element averages

(Melson and Thompson, 1971).

Column 3: Standard deviations for column 2.

Column 4: Average of 181 olivine tholeiites and tholeiites from

the Hawaiian Islands (MacDonald and Katsura, 1964).

Recalculated on an anhydrous basis.

Column 5: Average of 10 samples of alkali basalt from submarine volcanoes and islands of the eastern Pacific Ocean

(Engel, et al., 1965). Recalculated on an anhydrous basis.

ing (Table 1). The ferric to ferrous iron ratio is

considerably greater than fresh oceanic basalts, and

reflects submarine oxidation. The water content, on

the other hand, is higher (2.43 versus 1.08) than

most midocean ridge basalts (Table 1). Weathering

of deep-sea basalts commonly produces potassiumrich smectite (Melson and Thompson, 1973) which

significantly increases the bulk K2O content of even

slightly weathered submarine basalts. Although

clay minerals are abundant in the mesostasis, the

K2O content of the sample, 0.37 percent, is barely

higher than the average for fresh ocean-floor basalt

(0.22, Table 1).
NUMBER 14 23

TABLE 2.—Trace element composition (ppm) of the

Adak Fracture Zone high-alumina basalt compared

to other regions (all data and averages by Dr. J. R.

Cann and colleagues; averages from Pearce and

Cann, 1971)

Sample

Adak Basalt

USXM 112471 . . .

USNM 112472 . . .

Average Ocean

floor basalt

Average Island

arc andesitc

Average Hawaii

basalt

Ti

10012

-

7760

4050

15360

Rb

7.2

9.7

-

-

-

Sr

148

144

-

-

-

Y

57

49

27

21

24

Zr

111

108

80

106

162

Nb

0.8

4.2

-

-

—

Origin of High-Alumina Content

High-alumina content can be a feature of erupted

liquid, or a reflection of an abundance of already

present calcic plagioclase phenocrysts. In the Adak

high-alumina basalt, the high-alumina content is a

reflection of a high-alumina liquid composition.

Although large rounded plagioclase crystals occur,

they compose on the order of 3 volume percent of

the samples, an amount much too small to account

for the high-alumina content of the sample. The

large, rounded calcic plagioclase crystals are probably cognate, and may reflect convective movements

or settling of early forming plagioclase crystals

from cooler to hotter portions of the pre-eruption

magma chamber.

In this region of the Adak Fracture Zone old

oceanic crust formed by sea-floor spreading at the

northern extension of the east Pacific rise about

63 million years ago? Or, is the seamount from

which it was dredged the product of much younger,

off-ridge volcanism? These two modes of origin

correlate with distinct differences in chemical composition. A number of elements whose concentrations commonly differ in these two settings were

determined in the Adak sample. These include Ti,

K, and Zr, which are characteristically higher in

volcanic islands and seamounts compared to deepsea basalts from spreading ridges.

The most striking compositional differences between the Adak Fracture Zone basalt and most

ocean-floor basalts, are its high alumina content,

low magnesia content, and high total iron to magnesia ratio. These features are probably not a

result of weathering. The Zr and Ti contents are

transitional between seamount basalt and basalt

derived from spreading centers (Table 2). Chemically, it is thus not clear to which category the

Adak Fracture Zone basalt belongs.

If actually derived from a spreading center about

63 million years old, its chemically and perhaps

even bathymetric corresponding half would be

identifiable on the opposite side of the spreading

center at magnetic anomaly 25. This test of a seafloor spreading origin for the basalt cannot be

made because the eastern counterpart of the region from which the Adak basalt may have come

has long since been subducted beneath North

America.

Literature Cited

Bender, M. L., T. Ku, and W. Broecker

1966. Manganese Nodules: Their Evolution. Science, 151:

325-328.

Cann, J. R.

1971. Major Element Variations in Ocean-Floor basalts.

Philosophical Transactions of the Royal Society of

London, A.268:495-505.

Engel, A. E. J., C. G. Engel, and R. G. Havens

1965. Chemical Characteristics of Oceanic Basalts and the

Upper Mantle. Geological Society of America

Bulletin, 76:719-734.

Ericksson, B. H., and P. J. Grim

1969. Profiles of Magnetic Anomalies South of the Aleutian Island Arc. Geological Society of America

Bulletin, 80:1387-1389.

Grim, P. J., and B. H. Ericksson.

1969. Fracture Zones and Magnetic Anomalies South of

the Aleutian Trench. Journal of Geophysical Research, 74:1488-1494.

Heirtzler, J. R., G. O. Dickson, E. M. Herron, W. C. Pitman

III, and X. Le Pichon

1968. Marine Magnetic Anomalies, Geomagnetic Field

Reversals, and Motions of the Ocean Floor and

Continents. Journal of Geophysical Research, 73:

2119-2136.

Ku, T., and W. S. Broecker

1967. Uranium, Thorium and Protactinium in a Manganese Nodule. Earth and Planetary Science Letters,

2:217-320.

MacDonald, G. A., and T. Katsura

1964. Chemical Composition of Hawaiian Lavas. Journal

of Petrology, 5:82-133.

Melson, W. G., and G. Thompson

1971. Petrology of a Transform Fault Zone and Adjacent

Ridge Segments. Philosophical Transactions of the

Royal Society of London, A.268:423-441.

1973. Glassy Abyssal Basalts, Atlantic Sea Floor near St.
24 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

Paul's Rocks: Petrography and Composition of Analysis Using Ti, Zr, and Y. Earth and Planetary

Secondary Clay Minerals. Geological Society of Science Letters, 12:339-349.

America Bulletin, 84:703-716. Somayujulu, B. L. K.

Pearce, J. A., and J. R. Cann 1967. Beryllium-10 in a Manganese Nodule. Science, 156:

1971. Ophiolite Origin Investigated by Discriminant 1219-1220.
Composition of Three Glass Phases

in an Apollo 15 Basalt Fragment

George S. Switzer

ABSTRACT

The fragment studied contains glass of three distinct types: A: colorless, high silica glass; B: brown,

high-iron interstitial glass. Microprobe analyses show

high-iron interstitial glass. Microprobe analyses show

there has been strong partitioning of certain elements, especially of K into the high-silica glass,

and P and Ti into the high-iron glasses. The highiron glasses are thought to have been formed as immiscible liquids.

Introduction

Some silicate liquids on cooling separate into two

or more liquids of markedly different compositions.

This process, generation of immiscible liquids, may

be an important process in the generation of certain classes of igneous rocks, such as those in the

syenitic and granitic families (Roedder, 1951; Philpotts and Philpotts, 1969; Roedder and Weiblen,

1970). Immiscibility has long been known in certain experimentally studied systems (Greig, 1927;

Roedder, 1951), but was first documented in natural

materials in Apollo 11 basaltic rocks (Roedder and

Weiblen, 1970). Here I describe one of the best

examples of liquid immiscibility yet reported in

lunar samples.

During a study of Apollo 15 soil sample 15272,11

an unusual basalt fragment was encountered that

contains glass of three distinct types, which for

convenience are designated types A, B, and C: A

George S. Switzer, Department of Mineral Sciences, National

Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560.

is a colorless, high-silica glass; B is brown, highiron blebs immiscible in A; and C is a brown, highiron interstitial glass.

The sample is an angular, 2.0 mm fragment composed primarily of plagioclase, orthopyroxene, glass,

cristobalite, ilmenite, and clinopyroxene, in that

order of abundance. The density of the fragment is

> 2.90 < 3.00. A photomicrograph is shown in

Figure 1.

Microprobe analyses and microscopic examination yielded the following data on the principal

minerals. Plagioclase crystals up to 0.2 X 0.8 mm in

size have a composition near An86, with slightly

more sodic (An83) rims. The orthopyroxene, in

crystals up to 0.5 mm, has composition En75Fs25Wo2.

A single crystal of clinopyroxene is En34Fs26Wo40.

FIGURE 1.—Thin section of basalt fragment from Apollo 15

soil sample 15272,11. Maximum dimension of fragment 2.0

mm. Transmitted light.

25
26 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

Vo

•?••« A

FIGURE 2.—Umenite crystal surrounded by interstitial Type C glass except where in contact

with plagioclase. Area on left with mosaic structure is cristobalite. Note darkening of glass

due to reaction with ilmenite. a, Transmitted light, b, Reflected light. Length of bar = 0.1

mm.

The cristobalite shows typical mosaic structure.

Droplets of iron and possibly some sulfide are

scattered throughout the specimen. The ilmenite

contains 2.8 percent MgO.

Ilmenite-Glass Reaction

Ilmenite is a prominent phase (about 5 volume

percent). Where ilmenite is in contact with Type

C glass, the glass is frequently dark brown to

opaque, with the depth of color decreasing away

from the contact, as though ilmenite has reacted

with the glass (Figure 2a, b). A microprobe step

scan for Fe and Ti at 2/j.m intervals across an

ilmenite-glass contact (along A-Ar of Figure 3a)

yielded the data plotted in Figure 4. There has

been some reaction between the two phases, but an

apparent more extensive reaction seen in the thin

FIGURE 3.—Ilmenite crystal in contact with (to left) Type C interstitial glass, and (to right) with

high-silica glass (Type A) with high-iron (Type B) immiscible blebs. A-A' is line along which

step scan analysis was made (see Figure 4). a, Transmitted light, b, Reflected light. Length

of bar = 0.1 mm.
NUMBER 14

27

u

UI

CL

z

Ul

u

ac

ui

a.

30 -

20 -

10 -

10 -

-

-

HIGH IRON

GLASS /

j

TYPE C

1 1 1 1

Tl ^ — '

r

1

i n

i—

z

S

_•

i ___-— — •

1

\ " <

11 -J **i

r

1

1

\

\ ^

i

HIGH SILICA

GLASS

TYPE A

HIGH IRON

GLASS

TYPE B

r

1

1 i i

HIGH SILICA

GLASS

TYPE A

Tl

2 0 4 0 60

MICRONS

8 0

FIGURE 4.—Microprobe step scan for Fe and Ti along A-A' of Figure 3.

100

T '

FIGURE 5.—Large area of immiscible glass (left) consisting of high-silica colorless glass (Type

A) with blebs of high-iron (Type B) glass. Right half of each photograph is same area as

shown in Figure 3. a, Transmitted light, b, Reflected light. Length of bar = 0.1 mm. Circular,

highly-reflective area in upper left is iron.
28 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

TABLE 1.—Composition of glass phases

Constituent

SiO,

A12O,

FeO

CaO

MgO

K2O

Na2O

TiO2

P,O5

MnO

BaO

Total

Qtz

Or

Ab

An

Di

Hy

11

Ap

C

Apollo 15 Apollo 11 and 12

Type A Type B Type C

1 2 3 4 5 6 7

ANALYSES

75.7 53.1 43.4 76.3 75.8 42.2 44.1

11.9 8.3 8.0 11.5 11.4 5.4 3.0

2.7 24.8 24.6 3.0 2.5 32.9 31.2

1.5 7.1 10.3 1.6 1.8 10.7 10.9

0.3 0.5 4.7 0.07 0.25 0.79 1.9

6.6 1.9 0.8 6.7 6.4 0.41 0.25

1.1 0.4 0.4 0.14 0.35 0.16 0.11

0.5 2.7 6.3 0.68 0.53 4.2 3.8

0.0 1.1 0.8 0.15 - 0.57 1.2

0.0 0.2 0.2 0:05 - 0.32

0.3 0.6 0.2 0.62 - 0.0

100.6 100.7 99.7 100.81 99.03 97.65 96.46

NORMS

38.5 14.5 1.3 44.7 43.4 0.5 5.0

39.0 11.2 4.7 39.6 37.8 2.4 1.5

9.3 3.4 3.4 1.1 3.0 1.4 0.9

7.4 15.2 17.7 7.0 8.9 12.8 7.0

11.4 24.2 - - 32.4 34.6

4.9 36.7 34.4 4.7 4.3 38.9 37.6

1.0 5.1 12.0 1.3 1.0 8.0 7.2

2.6 1.9 0.4 - 1.3 2.8

0.2 - - 1.5 0.6

Column 1: High-silica immiscible colorless glass.

Column 2: High-iron immiscible brown glass bleb.

Column 3: High-iron brown interstitial glass (average of 2 analyses).

Column 4: High-silica colorless glass from Apollo 12.

Average of 15 analyses (Roedder and Weiblen, 1971).

Column 5: High-silica colorless glass from Apollo 11.

Average of 35 analyses (Roedder and Weiblen, 1971) .

Column 6: High-iron brown glass from Apollo 12.

Average of 5 analyses (Roedder and Weiblen, 1971) .

Column 7: High-iron brown glass from Apollo 11.

Average of 7 analyses (Roedder and Weiblen, 1971).

section is due to inclined grain boundaries in a

section that is approximately 40 ^m thick.

The Glass Phases

Microprobe analyses of the three glasses are given

in Table 1. The analyses were made using close

standards and corrected by use of the ABFAN program of the Geophysical Laboratory (Boyd, et al.,

1969). For comparison are given compositions of

immiscible glass in Apollo 11 and 12 rocks described by Roedder and Weiblen (1971).

The areas of high-silica glass with immiscible

blebs of high-iron glass (Figure 5a, b) are similar

to those described in Apollo 11 and 12 rocks by

Roedder and Weiblen (1970, 1971). Comparison of

the high-silica glasses (Table 1, columns 1, 4, and

5) shows them to be similar, and characterized (in

addition to high-silica), by low iron, calcium, and

magnesium, and high potassium.

The correspondence between analyses of the

brown immiscible blebs (columns 2, 6, and 7) is not
NUMBER 14 29

\ 1

..<

FIGURE 6.—Area of Type C high-iron glass interstitial to plagioclase and surrounding crystal

of ilmenite. Triangular area above is high-silica glass (Type A) with high-iron glass blebs

(Type B). a, Transmitted light, b, Reflected light.

as close. However, it should be pointed out that

Roedder and Weiblen's analyses of high-iron glasses

in Apollo 11 and 12 rocks are averages of seven and

five analyses, repectively, with a range in SiO2 of

36.5-50.2 percent (for Apollo 11), and 40.0-45.0 (for

Apollo 12). These authors point out that the highiron glass in their samples varied somewhat in composition between samples, between blebs, and even

within blebs. The new analysis presented here for

Apollo 15 is of a single 20jU,m diameter bleb.

An analysis of the high-iron Type C glass is

given in Table 1, column 3. This glass is clear and

vitreous and typically interstitial (Figure 6), and

quite distinct in this latter feature from the Type

B immiscible blebs. It also differs chemically from

Type B, as can be seen by comparison of columns

2 and 3 of Table 1.

Discussion

Apollo 15 glass analyses in Table 1 show that

there has been strong partitioning of certain elements into one or the other liquid, the same as

found by Roedder and Weiblen (1970, 1971) in

their studies of immiscible glasses in Apollo 11 and

12 rocks. Of particular interest is the high concentration of K in the high-silica glass and the high

concentration of P in the high-iron glasses. The

depletion of phosphorus in the high-silica (granitic) fraction is a reverse trend to that in normal

fractional crystallization and is thought to be the

result of the separation of the liquids by immiscibility (Anderson and Greenland, 1969, and Roedder and Weiblen, 1970, 1971).

Because phosphorus is enriched in both types (B

and C) of high-iron glasses described here, one can

conclude that both were formed as immiscible

liquids. The question then is why one of the two

high-iron glasses occurs as blebs in high-silica glass,

and the other interstitial to the plagioclase and

pyroxene. One possible explanation is that, due to

a complex cooling history, initially two immiscible

liquids formed, of compositions (A + B) and C.

Then on further cooling (A + B) further separated

into Type B blebs immiscible in Type A.

Literature Cited

Anderson, A. T., and L. P. Greenland

1969. Phosphorus Fractionation Diagram as a Quantitative Indicator of Crystallization Differentiation of

Basaltic Liquids. Geochimica and Cosmochimica

Ada, 33:493-505.

Boyd, F. R., L. W. Finger, and F. Chayes

1969. Computer Reduction of Electron-probe Data. Carnegie Institution Year Book 67, Annual Report of

the Director, Geophysical Laboratory, pages 210-215.

Greig, J. W.

1927. Immiscibility in Silicate Melts. American Journal of

Science, series 5, 13:1-44.
30 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

Philpotts, A. R., and J. A. Philpotts

1969. Liquid Immiscibility Between Syenitic and Gabbroic

Magmas (Abstract). Geological Society of America

Abstracts 1969, pages 176-177.

Roedder, E.

1951. Low Temperature Liquid Immiscibility in the

System K2O-FeO-Al2O3-SiO2. American Mineralogist, 36:282-286.

Roedder, E., and P. W. Weiblen

1970. Lunar Petrology of Silicate Melt Inclusions, Apollo

11 Rocks. Pages 801-837 of volume 1 in A. A. Levinson, editor, Proceedings of the Apollo 11 Lunar

Science Conference, Houston, Texas, January 5-8,

1970. Geochimica and Cosmochimica Ada, supplement 1, volume 34.

1971. Petrology of Silicate Melt Inclusions, Apollo 11

and Apollo 12 and Terrestrial Equivalents. Pages

507-528 of volume 1 in A. A. Levinson, editor,

Proceedings of the Second Lunar Science Conference, Houston, Texas, January 11-14, 1971.

Geochimica and Cosmochimica Acta, supplement

2.
Petrographic Analysis of Apollo 16 Samples

66083,1 and 67943,1

Brian Mason

ABSTRACT

Two samples of 2-4 mm fines collected on the

Apollo 16 mission consist largely of fragments of

anorthositic rock and breccias derived therefrom.

Sample 66083,1 was a 0.5 g sample of 2-4 mm

fines from a clod of white impact ejecta collected at

Station 6 on the southwest wall of a subdued 10

m crater on the lowest "bench" of Stone Mountain,

near its base; the astrogeology report (Apollo 16,

1973) says "possibly from South Ray crater, but

location generally shadowed from South Ray crater

ejecta."

The sample as received contained 12 fragments

> 2 mm, with a total weight of 0.433 g, and an

average weight of 0.036 g; there was 0.066 g of

material < 2 mm. The > 2 mm fragments were

density-fractionated in methylene iodide-acetone

liquids, with the results as shown in Table 1.

Polished thin sections were made of fragments

B, C, D, E, F, and of one from 60083,1 A (designated

as 66083,1AA). Half of fragments AA and F were

ground and fused with lithium tetraborate flux,

and the resulting glasses analyzed with the microprobe, with the results given in Table 2. A polished

thin section (66083,1H) was also prepared from the

0.2-0.4 mm material obtained by sieving from the

coarser fragments; this material contained 334 individual particles, which were classified as shown

in Table 3.

Brian Mason, Department of Mineral Sciences, National

Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560.

There appears to be a continuous sequence between breccia and crystalline rock fragments, and

for some fragments the assignment to one class or

the other is to some degree arbitrary.

Microprobe analyses of mineral grains gave the

following results (number of grains analyzed in

parentheses): plagioclase (10): An88_97, mean An93;

olivine (4): Fa2o-25> mean Fa23; orthopyroxene (6):

Wo2-4, Fs21_26, mean Wo3Fs25; augite (1): Wo41Fsn

En48. Six glass fragments were also analyzed, with

the results as shown in Table 4. Glasses 1, 2, and

3 could be melted regolith from this site; 2 and 3

are very similar to AA in Table 2, while 1 is somewhat more feldspathic. Glass 6 corresponds to a

completely melted mare basalt. The interpretation

of the compositions of glasses 4 and 5 is not so

clear-cut, and they probably represent mixtures of

different components.

The petrography of the fragments larger than 2

mm is as follows:

AA. A breccia with a glassy matrix containing

about 20-30 percent of crystal fragments. The fragments are predominantly plagioclase (maximum

TABLE 1.—Density-fractionation results

for 66083,1

Fragment

A

B

C

D

E

F

Total

Density

<2.70

2.72

2.85

2.90

3.03

3.07

Number of

fragments

7

1

1

1

1

1

12

Grams

0.208

0.030

0.042

0.029

0.025

0.099

0.433

31
32 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

TABLE 2.—Analyses and norms of two fragments

from 66083,1 (analyst: J. Nelen)

TABLE 4.—Analysis of six glass fragments from

66083,1 H

Constituent

SiO2 ... .

TiO2

A12O3 . .

Cr2O3 . .

FeO .. .

MnO

MgO .

CaO .

Na2O . .

K2O . .

P2O5 ...

Total

An

Ab

Or

Di

Hy

01

II

Ap

Cr

AA

ANALYSES

44.8

0.62

25.5

0.14

5.76

0.12

6.11

14.7

0.52

0.18

0.1

47.3

0.92

19.2

0.18

9.20

0.16

9.86

11.4

0.59

0.32

0.3

98.6 99.4

NORMS

66.4

4.4

1.1

4.7

13.5

6.6

1.2

0.2

0.2

48.8

5.0

1.9

4.9

31.6

3.9

1.8

0.7

0.3

AA = fragment with D<2.70; F = fragment with D = 3.O7.

size 0.3 mm), with minor olivine and orthopyroxene, and some lithic fragments, also mainly

plagioclase. Some of the plagioclase fragments show

bending of the twin lamellae. This fragment appears to be typical for the material with D <2.70;

its analysis (Table 2) is very similar to that of fines

TABLE 3.—Classification of 334 particles from

66083 JH

Particles

Crystalline rock fragments . .

Breccia fragments

Glass (clear and devitrified)

Plagioclase fragments

Plagioclase, partly melted . . .

Spherules, glass or devitrified

Metal fragment

Total

Number Percent

126

125

36

31

8

7

1

334

37.7

37.4

10.8

9.3

2.4

2.1

0.3

100.0

Constituent

SiO2

TiO2

A12O3

FeO

MnO

MgO

CaO

Na2O

K2O

Total

1

44.0

0.54

31.2

3.58

0.03

3 39

180

0.26

0.03

101.0

2

46.6

0.60

27.8

5.32

0.03

5.87

15.8

0.94

0.06

103.0

3

44.5

0.88

26.8

5.99

0.03

6.49

14.3

0.69

0.11

99.8

4

47.7

0.53

20.9

7.08

0.03

12.0

12 0

0.62

0.08

100.9

5

50.9

0.69

17.5

10.9

0.10

9.45

10.2

0.75

0.11

100.6

6

45.7

3.88

9.89

20.4

0.15

10.0

7.94

0.86

0.24

99.1

from the same location (66081, H. Rose pers.

comm.), indicating that it represents partially

melted soil.

B. A fragment of partly devitrified glass, with

some plagioclase fragments (maximum size 0.1 mm)

in one area; one spherule of metal, 0.1 mm diameter, was noted.

C. A fine-grained feldspar-rich rock, made up

of a felted aggregate of small plagioclase laths

(up to 0.01 mm long) with about 10 percent of

interstitial pyroxene and olivine; and minor

amounts of opaques (probably ilmenite); occasional

larger equidimensional grains of plagioclase (up to

0.1 mm) are also present. The texture suggests a

recrystallized breccia, with the larger plagioclase

grains being relict fragments from a coarse-grained

rock.

D. A breccia consisting of clasts of plagioclase

(up to 0.25 mm) and plagioclase-rich rock (up to

2 mm) in a fine-grained microcrystalline feldspathic

groundmass; four metal spherules, the largest 0.35

mm in diameter, are present. Microprobe analyses

give an average plagioclase composition of An90

(range An88-An94); four pyroxene grains show a

range of Wo43.116, Fs17.6_22.o;

 on e

 grain of olivine

gave Fa29.

E. A fragment consisting of plagioclase clasts

(up to 0.3 mm) in a fine-grained groundmass of

plagioclase and ferromagnesians (olivine and pigeonite) in subequal amounts, with some opaques

(ilmenite and a few metal grains); the texture of

the groundmass suggests that it may represent a

recrystallized glass. Microprobe analyses of the

individual minerals (number of grains analyzed in

parentheses) gave plagioclase (9), An84_An95, mean
NUMBER 14

TABLE 5.—Density-fractionation results for 67943,1

Density

Number of

fragments

TABLE 6.—Analyses and norms of three fragments

from 67943 (analyst: J. Nelen)

Grams

<2.70

2.70-2.80

2.80-2.90

2.90-3.00

2

6

5

3

0.061

0.051

0.199

0.049

An90; pigeonite (7), Wo8_12, Fs22_24, mean Wo9,Fs23;

olivine (14), Fa25_27, mean Fa26.

F. A crystalline rock made largely of subequal

amounts of plagioclase and ferromagnesians (pyroxenes and olivine), with a minor amount of

opaque material (mainly ilmenite, but with some

prominent metallic spherules up to 0.4 mm in

diameter). There are distinct areas of different

grain size, suggesting the rock is a recrystallized

breccia of lithic and mineral fragments; this is

supported by the presence of occasional large

(up to 0.4 mm) plagioclase grains, probably porphyroclasts.

Microprobe analyses of the individual minerals

gave the following results (number of grains analysed in parentheses): plagioclase (12): An90_98,

mean An95; olivine (18): Fa38_43, mean Fa41; orthopyroxene (17): Wo3_7, Fs25_32, mean Wo4Fs28; pigeonite (6): Wo]0_12, Fs30_31, mean WonFs31; augite

(18): Wo34_40, Fs16_20, mean Wo37Fs17; metal (7):

Ni 4.7-6.5 percent, mean 5.1 percent, and Co

0.58-0.77 percent, mean 0.67 percent.

The analysis (Table 2) shows that the fragment

is of noritic composition, but the texture is hornfelsic rather than igneous, suggesting recrystallization of a norite breccia at high temperatures

(perhaps high enough to produce a metal-sulfide

melt, represented by the metallic spherules, but not

high enough to melt the silicates). The fragment is

very similar in composition and texture to 65015, a

1.8 kg rock collected at the adjacent Station 5 and

ascribed by the Geology Investigation Team to

South Ray crater ejecta.

Sample 67943,1 was a 0.5 g sample of 2-4 mm

fines, one of the sieve fractions from 67940, a soil

sample collected from the House Rock area on the

southeast of North Ray crater (Station 11 of the

Apollo 16 traverses).

The sample as received contained 16 fragments

>2 mm, with a total weight of 0.453 g, and an

Constituent

SiO2 ... .

TiO2

A12O3 . . .

FeO

MnO . . .

MgO

CaO . .

Na2O . .

K2O .. .

Total

An

Ab

Or

Di

Hy

Ol

II

An

Fa

Pyx

D = 2.70-2.80 D = 2.70-2.80 D=2.80-2.90

44.9

0.42

29.6

3.52

0.05

3.22

16.8

0.68

0.10

99.3

77.6

5.8

0.6

4.9

4.8

4.9

0.8

93

35.8

ANALYSES

43.4

0.35

29.2

3.58

0.08

3.24

16.4

0.60

0.09

96.9

NORMS

76.6

5.1

0.6

3.9

3.5

6.4

0.7

93

36.8

44.6

0.44

27.9

4.29

0.07

5.43

15.4

0.67

0.15

99.0

72.4

5.7

0.9

3.2

6.1

9.5

0.8

91

29.8

Ca25Mg48Fe27 Ca2eMg47Fe27

average weight of 0.029 g; there was 0.047 g of

material <2 mm. The >2 mm fragments were

density-fractionated in methylene iodide-acetone

liquids, with the results as shown in Table 5. Compared to 66083, another sample of 2-4 mm fines

analyzed, this sample shows a smaller density range,

and a concentration of material where D = 2.70-

2.90.

Polished thin sections were made of 11 fragments

covering the full density range; for three of them

sufficient material remained after sectioning for

microprobe analysis after fusion with lithium tetraborate flux, and the results are given in Table 6.

Except for two fragments in the D = 2.90-3.00

fraction, the individual fragments could all be

classed as brecciated anorthosites; they differed one

from another mainly in the amount of glass in the

matrix, the lower density fragments having larger

amounts of glass. This glass was usually pale brown

and isotropic, sometimes showing incipient devitrification. The analyses in Table 6 confirm the

anorthositic composition of these fragments; they

all show over 80 percent normative plagioclase of
34 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

anorthite composition, with minor amounts of

olivine and pyroxene.

Of the two non-anorthositic fragments, both

with density between 2.90 and 3.00, one was an

equigranular plagioclase-rich microgabbro, with individual grains averaging 0.1 mm across. The estimated mineral composition is 65 percent plagioclase

(An94), 15 percent olivine (Fa19), 15 percent pigeonite (Wo12Fs23En65), and 5 percent opaques (mostly

ilmenite). The compositions given for the minerals

are averages of microprobe analyses; plagioclase and

olivine are very uniform in composition, whereas

pigeonite shows minor variability from grain to

grain.

The other non-anorthositic fragment appeared to

be a composite particle, consisting of a relatively

coarse (plagioclase grains up to 0.6 mm) troctolite

welded to a fine-grained (maximum grain size 0.1

mm) gabbroic anorthosite. However, the mineralogy of the two parts of the fragment are identical

—plagioclase (An94), olivine (Fa21), minor hyperpersthene (Fa19), and a little opaques—and the

fine-grained material may be comminuted and recrystallized troctolite. The boundary between the

two parts is quite sharp.

These two non-anorthositic fragments may represent primary igneous rocks from the Apollo 16 site

that have escaped the ubiquitous brecciation and

recrystallization so characteristic of most of the

rocks collected on this mission. Alternatively, they

may be exotic fragments transported to the Apollo

16 site from some other region on the Moon.

ACKNOWLEDGMENT.—This research was supported

by a grant from the National Aeronautics and

Space Administration (NGR 09-015-146).

Literature Cited

Apollo 16 Preliminary Examination Team

1973. The Apollo 16 Lunar Samples. Science, 179:23-34.
The Allende Meteorite: Chondrule Composition

and the Early Histroy of the Solar System

Andrew L. Graham

ABSTRACT

Fifty chondrules and aggregates from the Allende

meteorite (Type III carbonaceous chondrite), have

been analyzed for the major elements using a fusion technique and subsequent microprobe analysis

of the resulting glass bead. A portion of each

sample was retained and made into a polished thin

section for mineralogical studies. The major

element chemistry suggests that the Ca/Al-rich

chondrules and aggregates exhibit compositional

changes, whereas the Mg/Fe-rich chondrules do

not. There appears to be no simple relationship

between these two chondrule groups. Concomitant

with a decrease in the (CaO + Al2O3) content is a

decrease in TiO2 and an increase in Na2O. This

is paralleled by changes in the mineralogy of the

chondrules. Although the (CaO-f A12O3) to TiO2

relationship is that which has been predicted in

terms of a condensing solar nebular model, that of

(CaO + Al2O3) with Na2O does not conform to this

model. Other evidence against the primary nature

of the Ca/Al-rich Allende chondrules is cited.

Introduction

The Allende meteorite is a Type III carbonaceous chondrite of the Vigarano subgroup (Clarke,

et al., 1970). It is composed of chondrules and

microcrystalline aggregates distributed heterogeneously throughout a black, olivine-rich matrix.

Some of the chondrules and aggregates contain minerals rarely found in meteorites. These include

melilite, magnesian spinel, fassaite, wollastonite,

cordierite, hibonite, and grossular (Clarke, et al.,

Andrew L. Graham, Department of Mineralogy, British

Museum (Natural History), London S.W. 7, England.

1970; Fuchs, 1969, 1971; Marvin, et al., 1970). From

a possible composition of the primitive (that is, undifferentiated), solar nebular gas (e.g., table in

Cameron, 1968:127), and making assumptions as to

the initial temperature of this gas, the condensation

sequence with falling temperature of stable molecules can be calculated. Such calculations (Lord,

1965; Grossman, 1972) indicate that corundum,

spinel, and melilite form early in this sequence. It

is, therefore, tempting to suggest that the occurrence

of these minerals in Type III carbonaceous chondrites is evidence supporting the thermodynamically

derived condensation sequence. It is not at present

known whether the Ca/Al-rich aggregates and the

melilite-bearing chondrules of the Allende and similar meteorites are "bulk primary" condensates or

not. Does their bulk composition represent a quasiequilibrium state, similar to that shown by terrestrial igneous processes, in which the crystalline

solids represent one side of an equilibrium solidification sequence, or are these chondrules and aggregates the result of the association of material after

the condensation sequence had finished?

The structure and chemistry of the carbonaceous

chondrites provide the basis for a strong argument

against the metamorphism of these meteorites subsequent to their accretion. This is particularly

shown by the wide variation in the Fe/Fe + Mg of

the olivines they contain, and by the presence of

glass within the chondrules. The bulk chemistry

of the chondrules has not, therefore, been changed

by metamorphism since the formation of the meteorite. In this work chondrules and aggregates

separated from the Allende meteorite have been

analyzed for their major elements to see whether

there is a sequential relationship in their chemistry.

Do they represent particular stages in the condensa35
36 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

TABLE 1.—The composition of some chondrules and aggregates from the

Allende meteorite

Constituent

SiO2

TiOa

A12O3 . .

FeO

MgO

CaO

Na2O

ICO

Cr2O3

Total

1

43.1

0.2

5.7

8.9

38.6

3.8

0.7

0.03

0.5

101.53

2

50.9

0.4

1.2

7.6

37.9

0.9

0.2

0.03

0.8

99.93

3

40.6

0.2

7.0

6.6

38.7

4.5

0.5

0.03

0.7

98.83

4

32.0

1.4

27.3

4.8

12.4

21.5

0.8

0.03

0.2

100.43

5

41.5

1.1

25.8

2.2

14.8

12.7

1.3

0.03

0.4

99.83

6

26.9

1.3

30.0

1.0

9.8

30.9

0.2

0.03

0.05

100.18

7

35.7

1.2

24.8

0.9

7.1

29.8

0.4

0.03

0.02

99.95

8

30.9

1.0

28.1

0.3

9.8

30.3

0.2

0.03

0.01

100.64

Columns 1-3: Mg/Fe-rich chondrules

Columns 4-5: Fine-grained aggregates

Columns 6-8: Coarse-grained Ca/Al-rich chondrules

tion of the nebular gas or are they random associations which have been formed for material produced

by this primitive condensation? If the latter is the

case then no chemical trends would be expected,

while if the former is the case then a sequential

chemistry may be shown.

ACKNOWLEDGMENTS.—This work was performed

during the tenure of a Smithsonian Research Fellowship. Dr. B. Mason and Dr. R. F. Fudali are

thanked for their assistance and also Dr. L. Walter

who gave advice on the analytical procedure used.

The constructive criticism and suggestions of Dr.

A. A. Moss and Dr. R. F. Fudali much improved

the manuscript.

Method

Chondrules and aggregates were picked from

fractured faces of specimens of the Allende meteorite. The aggregates, which are friable, were removed from the bulk material with a stainless steel

needle. Each sample was then crushed in an agate

mortar. An aliquot of between 1 and 2 mg was

mixed with 2.5 times its weight of a lithium tetraborate/lithium carbonate flux prepared according

to the method of Norrish and Hutton (1969). The

mixture was fused to a glass bead in a small gold

crucible by maintaining it at 960° C for five

minutes in a vertical quench furnace. After quenching, the bead was mounted in a lucite disc, polished

and analyzed for nine elements in an A.R.L. EMX

electron microprobe. United States Geological

Survey standards Wl, AGV1, DTS1 and the Allende

bulk standard were prepared in the same way and

used as standards. The homogeneity of the standards and unknowns was checked by performing

multiple analyses of the standards and three separate analyses of each unknown. Reproducibility

of the whole procedure was checked by making six

separate beads of a standard and analyzing each as

an unknown. The relative mean deviation of the

analyses in this case was ±3 percent for elements

present in the undiluted material at concentrations

greater than 0.5 percent by weight. Summation to

100 percent was also used as a test; any analysis that

did not total 100 ± 2 percent was rejected. The

values used for the composition of the USGS standards were those given by Flanagan (1969), and

those of the Allende bulk standard were given in

Clarke, et al. (1970).

Results

The analyses of 50 chondrules and aggregates

have been used to plot Figures 1-3 and in Table

1 representative analyses are quoted for eight individual samples. The mineralogy of most of the

samples was examined by preparing a thin section

from a fragment of each. Analyses 1-3 of Table

1 are of Mg/Fe-rich chondrules. Analyses 4 and 5

are of fine-grained aggregates; these are too fine

for microscopic identification of their constituent

minerals, but x-ray powder diffractrograms show

the presence of clinopyroxene, melilite, and spinel.
NUMBER 14 37

gehlenite)

spinel \ —>

minor clinopyroxene \

melilite)

clinopyroxene I —

anorthite \

enstatite

> anorthite

olivine

FIGURE 1.—Ternary plot of SiO2 against (CaO + ALO3) and

(FeO+MgO), all in weight percent, for the chondrules and

aggregates from the Allende meteorite. The line shown is a

possible fractionation trend.

• well crystallized Ca/Al-rich chondrules

• finely crystalline aggregates

^ olivine-rich chondrules

Analyses 6-8 are of coarse-grained chondrules composed of melilite and clinopyroxene with minor

spinel. The composition of a melilite and some

clinopyroxenes from similar chondrules are given

in Clarke, et al. (1970) and in Marvin, et al. (1970).

Figure 1 is a ternary plot of (CaO + AI2O3)

against SiO2 and (MgO + FeO) for the data obtained in this work. FeO was combined with MgO

as most of the analyses showed less than 5 percent

FeO, except for the olivine chondrules in some of

which the FeO content rises to 14 percent. From

the distribution of points it can be seen that there

are two chondrule/aggregate groups. One shows

evidence for a development trend, that is to say

its composition could be regarded as changing

regularly in some manner, but the second shows

no such vector properties in the diagram. The

former group is made up of the Ca/Al-rich bodies

and the latter of chondrules containing olivine

and orthopyroxene and, occasionally, glass. The

group with a trend in bulk chemistry also shows

a corresponding mineralogical development. At

the Ca/Al-rich end, the chondrules are composed

predominantly of gehlenite with a little spinel and

clinopyroxene. Progressing from this extreme towards the (MgO + FeO)-SiO2 join the following

trends are observed:

This is accompanied by a decrease in the TiO2

content and an increase in the Na2O content of

the chondrules. The concentration of K2O is too

low to be meaningful with the analytical method

used. Figure 2 shows the distribution of TiO2 contents. The average concentration of TiO2 in the

melilite plus clinopyroxene chondrules is 1.2 percent, and this decreases on moving from the most

Ca/Al-rich compositions plotted in Figure 1 towards the SiO2-(FeO + MgO) join. The olivine

chondrules show a uniform TiO2 content of around

0.2 percent by weight. The changes in the concentration of Na2O in the same sequence is more complex, as shown in Figure 3. The maximum Na2O

content is observed in those chondrules whose compositions plot in the middle of Figure 1; the MgO +

FeO-rich chondrules are almost as low in Na2O as

are the gehlenite-rich bodies. Petrographic examination of the thin sections confirms the distinction

between the two groups shown in Figure 1. The

group richest in CaO and A12O3 contains soda-free

melilite and clinopyroxene with spinel and occa10 15 2 0

TiO

FIGURE 2.—A histogram of TiO2 concentrations in Allende

chondrules and aggregates. The peak at 1.2 percent TiO2

occurs at the Ca/Al-rich end of the line drawn on Figure 1.
38

FIGURE 3.—A histogram of Na2O concentrations in Allende

chondrules and aggregates. The peak at about 0.2 percent

Na2O is due to the melilite chondrules and that at 0.6 percent Na^O to the olivine chondrules.

sionally anorthite while the other group contains

olivine and orthopyroxene with occasional glass.

The coexistence of olivine and melilite was not

seen nor was that of olivine and clinopyroxene. A

further interesting observation, not expected from

experience with terrestrial samples, is the coexistence of anorthite and melilite. Schairer and Yoder

(1969) reported the coexistence of these minerals

in experimental runs and commented that this had

not, so far, been observed in nature.

Discussion

The distinctive petrographic and chemical differences between the Ca/Al-rich chondrules and aggregates and the Mg/Si-rich chondrules strongly

suggest that there was very little brecciation and

mixing of chondrule fragments prior to their incorporation in this meteorite. It is, therefore, possible to regard the bulk composition of the Ca/Alrich chondrules and aggregates as being that of the

solid phases of a fractionation sequence and so any

trends in their major element chemistry can be

interpreted as reflecting changes in the composition of their parent material. Changes in the pressure and temperature of the parent material, the

nebular gas of the condensation hypothesis, will

have very little effect upon this relationship, since

dP/dT for the vapor to solid transition for melilite,

enstatite, forsterite, and spinel is almost constant

over a pressure range of 10~7 to 10~2 atmospheres,

and has very nearly the same value for all these

SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

phases (Grossman, 1972). A further point is that

fine-grained aggregates are similar in composition

to the more coarsely crystalline Ca/Al-rich chondrules. It is not possible to distinguish between

them in terms of those elements used to construct

Figure 1. This may, in part, be due to the small

number of analyses, data for only six fine-grained

aggregates being currently available, but these all

plot within the field defined by the analyses of the

coarse-grained Ca/Al-rich chondrules. The implication is that either the conditions favoring the crystallization of material from a similar parent were

not uniform during the formation of the Ca/Alrich bodies, or that subsequent recrystallization of

the first-formed microcrystalline aggregates produced the coarsely crystalline chondrules. Evidence

suggesting that some recrystallization has occurred

comes from the Rb/Sr systematics of the Ca/Al-rich

bodies. They do not define a single isochron (Gray,

et al., 1973), implying that there has been some

movement of Rb and/or Sr since their formation.

It has been shown, however, that the chondrule

olivines show radiation damage whereas the matrix

olivines do not (Green, et al., 1971). Since this

damage is removed by heating to about 500° K

(Green, et al., 1971), the chondrule olivines must

have remained below this temperature during and

after the accretion of the meteorite. Further, the

presence of grossular in some of these aggregates

(Clarke, et al., 1970) and of andradite (Fuchs, 1971)

implies temperatures of the order of 700° K. Grossular has been synthesized at 800° C from a glass

(Yoder, 1954) and at 400° C from a mixture

of 3SiO2-Al2O3-3CaCO3 (Christophe-Michel-Levy,

1956). Thus an upper temperature limit of about

700° K can be given for the postformation history

of the Ca/Al-rich bodies of this meteorite, and of

about 500° K for the Mg/Fe-rich chondrules. These

temperatures are too low to cause the formation

of the coarse-grained chondrules from the finegrained aggregates by recrystallization during or

after the accretion of the meteorite.

The changes in the bulk chemistry of the two

chondrule types, Ca/Al-rich and Mg/Fe-rich, are

such that it is not possible at present to connect

them unequivocally into a single fractionation sequence with a common parent. It may be that any

sequential change in the Mg/Si ratio of the olivinerich chondrules that developed as a result of early

condensation processes has been modified by sub-
NUMBER 14 39

sequent exchange between these chondrules and

the residual material prior to the accretion of the

Allende meteorite. In particular, the magnesium

silicates, enstatite, and forsterite will become more

iron-rich by this process, which moves their composition toward the MgO + FeO apex of Figure

1. Plotting this figure on an iron-free basis does

not, however, cause the magnesium-rich chondrules

to plot on an extension of the line drawn; the

distinction between the two groups of chondrules

remains.

The alignment of chondrule compositions in the

Ca/Al-rich portion of Figure 1 suggests that their

bulk compositions were fixed by a fractionation

sequence similar to that derived by Grossman

(1972) from theoretical considerations of the primitive nebular gas. Fuchs and Blander (1973), however, give a summary of the phenomena that they

have observed in Ca/Al-rich chondrules from the

Allende meteorite that suggests a liquid precursor

for these chondrules, rather than their formation

from a vapor by direct condensation. In particular

they note the spherical nature of the chondrules

and the occurrence of eutectic intergrowths of pyroxene and anorthite and also gehlenite and anorthite. Grossman and Clark (1973) maintain that the

formation of any liquid took place after the main

condensation sequence, from solids produced in this

sequence. This is required by their theory because

the calculated condensation sequence predicts the

formation of some phases, for example clinopyroxene and anorthite, at temperatures that are

below their solidi. The direct condensation hypothesis has difficulty in explaining the observed

Mg/Si ratios of the Ca/Al-rich chondrules, which

are almost constant during the decrease in (CaO +

A12O3) content (Figure 1). The direct condensation

hypothesis predicts spinel as an early solid phase,

subsequent condensates being more siliceous. There

should then be a decrease in the Mg/Si ratio of

the succeeding chondrules as condensation proceeds.

This trend is not observed for the chondrule compositions plotted in Figure 1; actually there is a

slight increase in this ratio.

The evidence from the Allende Ca/Al-rich chondrules suggests that, if they are "primary condensates,'.' they have had a more complicated history

than simply that of condensation and incorporation into Type III carbonaceous chondrite matrix.

How far this has erased evidence of the primitive

state of these condensates is not clear. The great

heterogeneity of the meteorite is remarkable and it

may be that further samples will provide a better

means for distinguishing between phenomena that

could be produced by the early condensation sequence in the solar nebula, and those that are the

result of processes subsequent to this event.

Literature Cited

Cameron, A. G. W.

1968. A New Table of Abundances of the Elements in the

Solar System. Pages 125-143 in L. H. Ahrens, editor,

Origin and Distribution of the Elements. New York:

Pergamon.

Christophe-Michel-Levy, M.

1956. Reproduction artificielle des granats caliques: grossulaire et andradite. Socie'te Francaise de Mineralogie

et de Cristallographie Bulletin, 79:124-128.

Clarke, R. S., Jr., E. Jarosewich, B. Mason, J. Nelen, M.

Gomez, and J. R. Hyde

1970. The Allende, Mexico, Meteorite Shower. Smithsonian Contributions to the Earth Sciences, 5:1-52.

Flanagan, F. J.

1969. U. S. Geological Survey Standards-II: First Compilation of Data for the New USGS Rocks. Geochimica

et Cosmochimica Ada, 33:81—120.

Fuchs, L. H.

1969. Occurrence of Cordierite and Aluminous Orthoenstatite in the Allende Meteorite. American Mineralogist, 54:1645-1653.

1971. Occurrence of Wollastonite, Rhonite and Andradite

in the Allende Meteorite. American Mineralogist,

526:2053-2067.

Fuchs, L. H., and Blander, M.

1973. Calcium-Aluminium Rich Inclusions in the Allende

Meteorite: Textural and Mineralogical Evidence for

a Liquid Origin (abstract) . Transactions of the

American Geophysical Union, 54:345.

Gray, C. A., D. A. Papanastassiou, and G. J. Wasserburg

1973. The Identification of Early Condensates from the

Solar Nebula. Icarus, 20:213-239.

Green, H. W. II, S. V. Radcliffe, and A. H. Heuer

1971. Allende Meteorite: A High Voltage Electron Petrographic Study. Science, 172:936-939.

Grossman, L.

1972. Condensation in the Primitive Solar Nebula. Geochimica et Cosmochimica Ada, 36:597-619.

Grossman, L., and S. P. Clark, Jr.,

1973. High Temperature Condensates in Chondrites and

the Environment in Which They Formed. Geochimica et Cosmochimica Ada, 37:635-650.

Lord, H. C, III

1965. Molecular Equilibria and Condensation in a Solar

Nebula and Cool Stellar Atmospheres. Icarus, 4:

279-288.
40 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

Marvin, U. B., J. A. Wood, and J. S. Dickey, Jr.

1970. Ca-Al-rich Phases in the Allende Meteorite. Earth

and Planetary Science Letters, 7:346-350.

Norrish, K., and J. T. Hutton

1969. An Accurate X-ray Spectrographic Method for the

Analysis of a Wide Range of Geological Samples.

Geochimica et Cosmochimica Ada, 33:431-454.

Schairer, J. F., and H. S. Yoder, Jr.

1969. Critical Planes and Flow Sheet for a Portion of

the System CaO-MgO-ALO3-SiO2 Having Petrological

Significance. Carnegie Institution Year Book, 68:

202-214.

Yoder, H. S., Jr.

1954. Garnets and Staurolite. Carnegie Institution Year

Book, 53:120-121.
The Pulsora Anomaly: A Case against

Metamorphic Equilibration in Chondrites

Kurt Fredriksson, Ananda Dube, Eugene Jarosewich, Joseph A. Nelen,

and Albert F. Noonan

ABSTRACT

Four Indian H-group chondrites, Andura, Butsura,

Pulsora, and Sitathali, with almost identical chemical composition but differing in texture and structure, are described. All have essentially the same

and constant ("equilibrated") olivine and pyroxene

composition. Pulsora, however, contains lithic fragments, some of which are coarsely crystalline with

almost no metal, while others contain skeletal olivine in silica-rich glass. Thus Pulsora could not have

been "equilibrated" after the final agglomeration,

nor is it necessary to postulate any such "metamorphic" equilibration to explain the texture and mineralogy of other chondrites.

Introduction

Circumstances of fall, morphology, and general

classification of the four Indian H-group chondrites, Andura, Butsura, Pulsora, and Sitathali,

have been reported by Murthy, et al. (1969), who

also referred to some previous work by Coulson

(1940). A more detailed description of Sitathali was

published by Viswanathan, et al. (1971). Andura

and Butsura were grouped together by Murthy, et

al., while according to Coulson (using the Rose,

Tschermak, Brezina classification) they were respectively Cck, crystalline spherical, and Ci, intermediate chondrites. Pulsora and Sitathali were described

Kurt Fredriksson, Eugene Jarosewich, Joseph A. Nelen, and

Albert F. Noonan, Department of Mineral Sciences, National

Museum of Natural History, Smithsonian Institution, Washington, D. C. 20560. Ananda Dube, Geological Survey of

India, Calcutta 13, India.

by Murthy, et al (1969) as brecciated chondrites

with "fine" and "coarse" matrix respectively and as

Cib, brecciated intermediate, and Chob, brecciated

howarditic chondrites by Coulson (1940). All four

belong to the H-group (high iron) as defined by

Urey and Craig (1953) and Keil and Fredriksson

(1964). According to the subdivision, mainly on degree of "crystallinity," proposed by Van Schmus

and Wood (1967), Butsura is H6 and Sitathali H5.

Andura and Pulsora have not been classified previously according to this system. However, by

applying the criteria of Van Schmus and Wood,

Andura is definitely within the H5-H6 range. Pulsora on the other hand shows a variety of features

allowing it to be placed in any group from H3 to

H6 similarly as the Hedjaz L-group chondrite

(Kraut and Fredriksson, 1971).

These four meteorites were selected for detailed

comparative studies from a number of meteorites

currently being investigated under a joint program

of the Geological Survey of India and the Smithsonian Institution, because of their essentially

identical chemical composition in spite of gross

morphological and textural differences as indicated by the studies referred to above as well as our

data.

ACKNOWLEDGMENTS.—We are grateful to the Director General of the Geological Survey of India,

Dr. M. K. Roy Chowdhury, as well as his predecessors for encouraging this cooperative work over

many years. Mr. R. K. Sundaram and Drs. S. V. P.

Iyengar and M. V. N. Murthy, all of the Geological

Survey of India, also gave much assistance. For

various data reductions we are indebted to the

Smithsonian Information Systems Division and B.

41
42 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

FIGURE 1.—Photomicrograph of thin section of the Andura bronzite-chrondrite (H6). Only

one chondrule, right center, is discernible; its boundaries are indistinct. Part of the matrix

is relatively coarse and equigranular; other parts, however, are still fine-grained. White to gray

are silicates; black, metal and troilite. Length of section 5 mm. Compare with frontispiece (a).

J. Fredriksson. This work has been supported in

part by grants from the Smithsonian Research

Foundation and NASA (NGR 09-015-207).

Mineralogy and Textures

Figures 1-4 and the frontispiece show low magnification photomicrographs of thin sections of the

four chondrites. The distinction between Sitathali

(H5), Andura (H5-6), and Butsura (H6) with regard to grain size, degree of crystallinity and "integration" between chondrules and matrix (Van

Schmus and Wood, 1967) is clearly open to rather

subjective judgment. Pulsora has parts similar in

texture to the other three, but Figure 5 shows a

relatively coarsely crystalline fragment within Pulsora with clear crystals of plagioclase (typical of

Type 6), diopside and minor whitlockite. This

fragment is also nearly devoid of metal and troilite,

like so-called amphoterites, or LL-group chondrites,

but its olivine is typical of the H-group (also nearly

the same as in the main mass of Pulsora, see Tables

1, 5, and 6) and its texture is achondritic (perhaps

a "Grade 7" in the Van Schmus and Wood (1967) 1
NUMBER 14

43

FIGURE 2.—Photomicrograph of thin section of the Butsura bronzite chondrite, classification

H5 (towards H6). Chondrules are somewhat more discernible than in Figure 1, while the

matrix shows some relatively fine-grained areas. Length of section 5 mm.

to 6 petrographic scale). The Pulsora section shown

in Figures 6 and 7, on the other hand, includes

a fragment (chondrule?) with skeletal to euhedral

olivine in clear glass of the kind usually found only

in Type 3 chondrites. The detailed composition

and significance of these fragments are discussed

further below.

Table 1 summarizes electron probe analyses of

the major silicate phases, olivine, low and high

calcium pyroxenes and plagioclase in the four

meteorites. In addition, the modal composition was

determined by point counting by probe analysis of

(Fe, Ca, Mg) on a grid 0.3 X 0.3 mm. The calculated weight percentages of these four silicates are

also indicated in Table 1. The complete modal

analysis is reported in Table 3 and compared to

the norm. The technique and the computer program used is described in the Appendix.

The phase compositions in Table 1 are averages

from analyses performed at various times with

different instruments and we estimate the accuracy

to be at the best ±2 percent relative but usually

better than ±6 percent.

Olivine: The iron value, which is the most reliable, is no more accurate than ±2 percent of the

values given (this is about the best which can be
44 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

FIGURE 3.—Photomicrograph of thin section of the Sitathali bronzite chondrite (H5). The

structure is similar to that shown in Figure 2. Chondrules, e.g., center and top left, are

somewhat more abundant and distinct. Length of section 5 mm.

achieved by using a close standard and the Bence

and Albee (1968) correction factors); this makes the

olivines in all four chondrites essentially identical.

The precision, however, while measuring olivine

in a single sample is higher (±0.1% FeO), and

relative differences in olivine composition in Pulsora are discussed below. Manganese, magnesium,

and silicon were also measured but with less accuracy.

Pyroxenes: A calcium-poor orthopyroxene is the

most abundant in all four meteorites and has essentially constant composition within each stone

but small and probably real differences between

the meteorites. Like the olivines they are relatively

coarse, well defined and distinguishable in the

modal analysis. The less abundant calcium-rich

pyroxenes show greater chemical variations (especially in Pulsora), are fine-grained, and occur as

inclusions in the other minerals (lamellae in Capoor pyroxenes) or intergrown with plagioclase in

devitrified areas. Like the plagioclase they are,

therefore, hard to distinguish during modal analysis (Appendix) and the average composition given

in Table 1 is rather uncertain.

Plagioclase: This phase is almost impossible to

identify microscopically (except in a fragment in
NUMBER 14 45

FIGURE 4.—Photomicrograph of thin section of the Pulsora bronzite chondrite. The classification

for this section is H4 to H5, but compare also Figures 5 to 8, and frontispiece (b). Chondrules

and lithic fragments, e.g., right center, are clearly visible in the mostly fine-grained, gray to

opaque matrix. Large, coherent black areas are metal, troilite, and other opaque minerals.

Length of section 5 mm.

Pulsora) and almost invariably contains pyroxene

crystallites. The reported composition is based on

the calcium content obtained in areas where iron

and magnesium values approach minimum ( ^

background). In the modal analyses allowance was

made for substantial apparent contents of magnesium and, especially, iron.

Metal, both taenite and kamacite, troilite and

whitlockite were identified in our modal analyses

and although numerous grains were analysed and

counted detailed descriptions are not warranted because they are of average composition and abundance. Also, the absolute abundance of these phases

can be estimated more accurately from the bulk

chemical analyses. A number of common accessory

minerals, e.g., chromite and ilmenite, as well as

more exotic ones, like copper and spinels, were also

identified (cf. Ramdohr, 1973) but these phases

seem to contribute little to the understanding of

current models for the origin of chondrites, especially ours involving impact-melting and brecciation.
46 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

TABLE I.—Abundance and average composition of major silicate phases

Constituent

AN DURA

Olivine

Pyroxene 1

Pyroxene 2

Plagioclase

BUTSURA

Olivine

Pyroxene 1

Pyroxene 2

Plagioclase

PULSORA

Olivine

Pyroxene 1

Pyroxene 2

Plagioclase

SlTATHALI

Olivine

Pyroxene 1

Pyroxene 2

Plagioclase

Mode

wt.% FeO CaO MgO SiOt

 AltO3 NatO K2O MnO

29.0 18.4 42.4 39.6 -

27.2 11.3 0.8 31.4 56 M).l 0.2

6.0 5 21 18.0 55 0.8 0.5

6.1 - 2.4 - 65.6 21.5 10.4 (0.7)

25.5 18.3 - 42.4 39.4 -

27.8 11.4 0.8 31.1 56.5 -

7.8 5 21 17 56 -

4.9 - 2.6 - 66 21.7 10.3 (0.7)

22.6 18.3 - 42 39.7 -

26.5 11.0 1.3 30 55 0.3 0.1

11.3 5 19.6 17.5 54.5 0.7 0.6

3.0 - 2.5 - 65.4 21.8 10.4 1.0

28.7 18.0 - 42.3 39.6 -

24.6 11.2 0.6 31.2 56.5 -

6.7 4.1 21.4 17.6 56

5.3 - 2.5 - 65.8 21.6 10.3 (0.7)

^0. 2

^0. 2

Chemical Composition

The analyses reported in Table 2 are almost

identical. Only Andura shows less metallic Fe and

more FeO. Apparently some of its metal (and/or

troilite) has been more susceptible to atmospheric

oxidation. This assumption is strongly supported by

the fact that the calculated normative fayalite content of the olivine, Fa23 (Table 3), is considerably

higher than the measured value, Fa19 (Table 1),

which is the same as in the three other stones.

Andura also has a more "rusty" appearance both

macroscopically and in thin section. Pulsora and

Butsura seem to have higher carbon contents than

the other two but the possibility of contamination

cannot be entirely disregarded. (The analysis of

Sitathali reported by Viswanathan, et al. (1971) is

apparently erroneous, especially with regard to the

iron content as the authors suspected.)

In Table 3 the normative and modal compositions are compared. The mode was obtained by

electron probe analysis as described above and in

the Appendix. The composition of the normative

minerals agrees closely with the values obtained

TABLE 2.—Chemical composition (analysts: J. Nelen,

Andura; and E. Jarosewich, Butsura, Pulsora,

Sitathali)

Constituent

Fe

Ni

Co .

FeS

SiO2

TiO2 ... .

A12O3

Cr2O3

FeO

MnO

MgO

CaO

Na2O

K2O

P2O3

H2O +

H 2 O -

C . .

Tota l

Tota l Fe . .. .

Andura

13.72

1.62

0.08

5.57

36.85

0.16

1.85

0.53

12.23

0.39

23.42

1.97

0.91

0.12

0.29

0.19

0.10

0.05

100.05

26.74

Butsura

16.61

1.75

0.07

5.89

36.27

0.12

1.98

0.56

9.65

0.31

23.21

2.00

0.85

0.08

0.31

0.53

0.13

0.15

100.47

27.85

Pulsora

17.23

1.78

0.10

4.99

35.97

0.12

2.26

0.52

10.58

0.29

22.77

1.59

0.84

0.10

0.26

0.00

0.10

0.14

99.64

28.62

Sitathali

16.08

1.79

0.09

5.76

36.65

0.14

2.37

0.43

9.96

0.31

23.45

1.71

0.87

0.10

0.30

0.10

0.06

0.05

100.22

27.48
NUMBER 14 47

TABLE 3.—Normative and modal (weight percent) compositions

Phase

Ni/Fe

FeS . .

Ap

Cr . .

11

Or

Ab

An

Wo

En

Fs

Fo

Fa

C

Residue . . .

Total

Andura

Norm

15.42

5.57

0.97

0.85

0.30

0.72 )

7.70 I 9.0

0.58 \J

2.70 )

17.34 I 26.7

6.71 \

}

12.18 \ 40"

7

0.05

Mode

17.1

5.8

0.5

_

*

6.1

6.0*

27.2 f

]

29.0

8.4

100.1

Norm

18.43

5.89

0.74

0.90

0.23

0.44 -

7.18

1.36 '

2.73 j

k 33.2 20.56 I

6.30 \

25.90

8.75

0.15

But sura

Mode

16.3

3.6

_

> 9.0 4.9

27.8 t

J

• 34.7 25.5

14.1

100.0

Pulsora

Norm

19.11

4.99

0.60

0.83

0.24

0.56 )

7.07 I 9.7

2.11 \

1.71 )

35.6 20.09 I 28.7

6.86 \

25.47 )

9.62 }

0.14

Mode

17.1

4.0

0.2

_

3.0

26.5 f f

22.6

15.4

100.1

Norn

17.96

5.76

0.71

0.68

0.26

0.25

7.34

2.25

1.79

20.28

6.38

26.52

9.20

0.05

Sitathali

i Mode

16.1

3.9

0.2

_

• 9.8 5.3

28.5

 6

A'

7

*, { 31.3

24.6 f (

J

• 35.7 28.7

14.4

99.9

•Pyroxene 2, see Table 1.

f Pyroxene 1, see Table 1.

by probe analysis (except for the high Fa value in

Andura, explained above). Although in the modal

analysis only two pyroxenes were distinguished, i.e.,

those with <1 % CaO (Pyroxene 1) and >1 % CaO

(Pyroxene 2), the average composition calculated

according to Table 1 is Wo10En75Fs15 while the

normative pyroxenes (Table 3) are in the range

Wo6_9En72_76Fs18_19. The amount of pyroxene in

the norm, however, is consistently lower than in

the mode while the reverse is true for olivine and

plagioclase. Because the "Residue" in the modal

analyses is substantial, we have attempted to establish its chemical composition by deducting the elements in the modal minerals as well as normative

metal, troilite, chromite, ilmenite, and apatite. In

Table 4 these residues are compared with the chemical composition of the bulk silicates obtained by

deducting FeO for ilmenite and chromite and CaO

for apatite from the chemical analyses in Table 2.

It seems clear that the residue is severely deficient

in silica but enriched in alumina and alkalies.

Since a large part of the residue in these finegrained rocks must be due to "overlap" between

two or more phases, we attempted to remove first

olivine, requiring least silica, and secondly pyroxene, having the same composition as in the

"bulk" (but different proportions), from the residue. In all the four cases the end result is substantial excess of alumina and FeO, ^-'l percent and

0.5 to 1.5 percent, respectively, of the total weight.

Alkalies show a similar excess in all cases while

calcium appears to be deficient in all but Andura.

This calcium deficiency is probably not real but is

due to uncertainty in the analysis of the Ca-rich

pyroxenes.

Iron and magnesium, as might be expected, are

about the same in bulk silicates and residue, again

excepting Andura for which the results are distorted because of the oxidation discussed previously.

This supports the probability that most of the finegrained "matrix" is indeed "rock flour" similar in

composition to the bulk meteorites. The excess

iron may possibly be explained as admixed ultrafine metal and/or troilite. The excess of alumina

and alkalies, however, is more puzzling. Three

possible interpretations are offered: (1) Our modal

and phase analyses are too inaccurate to allow these

kinds of calculations. The consistency of the results,

however, speaks against this, as well as the fact that

if olivine is underestimated and pyroxene overestimated in the mode, which seems most likely, the

discrepancies become worse. (2) A small amount of

an undiscovered discreet phase(s) is present, e.g.,

corundum or spinel for alumina, or some silicate
48 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

TABLE 4.—Chemical composition of bulk silicates from chemical analyses and of unidentified fractions

residue in the modal analyses

Constituent

SiOo .

A12O3

FeO

MgO

CaO .

Na2O

K2O

Andura

Silicate

fraction

(76% of

total)

47.8

2.4

15.4

30.4

2.6

1.2

0.2

Residue

(8.4% of

total)

33 7

5.7

38.1

18.0

0.2

3.3

1.0

Butsura

Silicate

fraction

(73% of

total)

49.2

2.7

12.7

31.5

2.7

1.2

0.1

Residue

(14.1% of

total)

38.0

11.3

14.0

32.0

0.0

4.5

0.7

Pulsora

Silicate

fraction

(73% of

total)

48.7

3.1

13.9

30.9

2.2

1.1

0.1

Residue

(15.4% of

total)

38.0

11.9

21.8

27.0

0.0

3.5

0.6

Sitathali

Silicate

fraction

(74% of

total)

49.0

3.2

12.9

31.3

2.3

1.2

0.1

Residue

(14.4% of

total)

42.0

13.2

15.5

25.4

0.0

3.3

0.6

strongly enriched in alumina and alkalies and possibly iron. Our studies have not so far revealed

any such exotic minerals though we have searched

for all the ones recently described by Ramdohr

(1973) and Mason (1972). (3) The fine-grained

ground mass does contain a "real matrix" entirely

different from the bulk meteorite. This is in accordance with suggestions by Fredriksson and Keil

(1964) that some carbonaceous chondrites are mixtures of low and high temperature fractions. Similar

mixture models have been pursued in great detail

by the Chicago group led by E. Anders in a number

of papers, e.g., Anders (1964) and Laul, et al. (1973);

(this paper has numerous references), for especially

gas-rich and/or unequilibrated chondrites. A study

of carbon distribution in some chondrites (Fredriksson and Nelen, 1969) led to the conclusion that

also ordinary equilibrated chondrites may have

small amounts of a low temperature real matrix

and current work (Fredriksson, et al., in prep.) indicates that this matrix is also enriched in some heavy

volatiles, e.g., Pb, Zn, and possibly also N and F

(Kerridge, pers. comm.). From our present study,

however, we can only conclude that if such a matrix

is present, its bulk chemistry is still uncertain although Al/Si, Na/Si, and probably Fe/Si are higher

than in the bulk silicates of H-group chondrites (as

in some carbonaceous chondrites).

The Pulsora Anomaly

It has been demonstrated that Pulsora is chemically and mineralogically almost identical to three

other ordinary equilibrated chondrites although

its petrographic grade (Van Schmus and Wood,

1967), even on cursory inspection, seems somewhat

lower, i.e., 4-5, than the others of 5-6. Detailed

studies of a number of thin sections, however, have

revealed several unusual lithic fragments that are

not conspicuous in hand specimens. Two of these,

extremely different from each other and from the

bulk, are described in some detail because they have

profound implications as to the thermal history of

Pulsora and by analogy of other H-group chondrites. The achondritic fragment (Figure 5) referred

to previously consists of relatively coarse, equiFIGURE 5.—Crystalline "achondritic" (H7?) fragment, lower

right quarter, in Pulsora. Diopside (D), plagioclase (P) and

whitlockite occur as large clear crystals together with normal

olivine and orthopyroxene. Note the scarcity of metal and

troilite (black) as compared to the main mass. Length of

section 4 mm.
NUMBER 14 49

TABLE 5.—Phase compositions in Pulsora

achondritic fragments

Constituent

SiO2

TiO2

A12O3

FeO

MgO

CaO

Na 2O . .. .

K2O

Olivine Pyroxene 1

-

18.0 10.8

40.5 28.8

2.2

Pyroxene

-

1.6

5.2

17.9

19.0

2 Plagioclase

1.6

granular (in strong contrast with the bulk) olivine,

ortho-pyroxene, diopside, plagioclase and apatite,

in order of decreasing abundance. The composition

of the major silicate phases are given in Tables 5

and 6. Although the accuracy of our iron determinations is no better than ±2 percent relative, we

believe that we obtained a precision better than ±

0.1 percent FeO in alternate measurements between

fragment and matrix and thus established a small

difference in olivine composition, i.e., 18.0 (Table

5) in the fragment and 18.3 (Table 1) in the bulk.

The ortho-pyroxene in the fragment (Pyroxene 1)

has decidedly higher (2.2%, Table 5) CaO content

than in the bulk (1.3%, Table 1) indicating a higher

temperature of "equilibration," whereas the plagioclase is somewhat less calcic, An5_7 versus An10, in

the bulk. In the fragment, troilite and metal are

scarce (^0.5%), the latter consisting of about equal

amounts of taenite (r~45% Ni) and kamacite (^

5% Ni). In contrast the main mass contains 17

percent metal with only minor amounts of taenite

with ^45 percent Ni; its kamacite has ^ 7 percent

Ni. The overall Ni content of the Pulsora metal

(Table 2) is 9 percent corresponding to ^95%

kamacite and ^5 % taenite.

The glassy fragment (Figures 6, 7) consists of

euhedral and skeletal crystals of olivine (^65%)

displaying normal zoning, in clear glass ('—'35%)

enriched in silica; the composition is given in Table

6. The olivine has somewhat lower average iron

content than olivine in the bulk and in other lithic

fragments. The variation indicated in Table 6 is

mostly due to zoning in the individual crystals, i.e.,

the cores have almost constant composition with

10-12 percent FeO. The glass is enriched in Si, Al,

Ca, and Na and depleted in Mg and Fe. In its overall composition this fragment resembles some

glassy chrondrules described from unequilibrated

chondrites (e.g., Fredriksson and Reid, 1965) although the iron content of the olivine is unusually

high and the glass has > 5 percent normative

quartz, also unusual in glassy chondrules. In addition it contains a small, 0.5 mm, metal-sulfide

spherule (Figure 8) with ^65 percent kamacite

(7.3% Ni), ^35 percent troilite and a eutectic texture. The troilite contains 0.9 percent Ni in sharp

contrast to troilite in the main mass of Pulsora, as

well as in other ordinary chondrules, which have

< 0.05 percent Ni. The texture indicates rapid

crystallization and the 0.9 percent Ni content of

the troilite would indicate quenching from ^1000°

C (Kullerud, 1963) without any appreciable reheating.

This fragment might be a deformed chondrule

even if applying the restricted definition proposed

by Fredriksson, et al. (1973), but the irregular shape

and the fact that other similar but angular fragments were found lead us to believe that it is a

TABLE 6.—Phase compositions in Pulsora glassy

fragments

Constituent

SiO2

TiO2

A12O3

FeO

MgO

CaO

Na2O

K2O

Qtz .

C ..

Or. .

Ab. .

An. .

Wo. .

En. .

Fs. . .

Fo.. .

Fa ..

II. ...

Olivine Glass Calculated bulk*

41-39

-

-

10-15

49-44

-

-

-

ANALYSES

65

0.4

7.8

11.0

6.5

5.7

2.5

0.3

NORMS

5.5

0.3

2.3

30.6

40.8

-

8.7

11.2

48.5

0.1

2.6

12.2

33.7

1.9

0.8

0.1

_

-

0.8

11.7

6.3

1.9

21.2

5.6

0.5

40.5

11.8

0.2

* Modal analysis gave ^V% olivine and ^14 glass of the

composition indicated in the two preceding columns. Compare bulk silicates in Table 4.
50 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

FIGURE 6.—Thin section of Pulsora including a lithic fragment consisting of olivine in a

silica-rich glass (outlined by black, dotted line). Compare Figure 7. The black sphere consists

of metal and troilite; see Figure 8. Length of section 11 mm.

fragment of a pre-existing rock. In Table 6 we also

present the calculated bulk composition of the silicate in this glassy fragment. It is remarkably similar

to the composition of the Pulsora bulk silicates as

given in Table 4, again indicating a common parent

material.

Clearly, the glassy fragments have not been equilibrated within themselves or with the rest of Pulsora

either before or after incorporation in the meteorite. The achondritic fragment might have been

equilibrated or recrystallized and drained of metal

before incorporation in the bulk which then, if

metamorphic equilibration is invoked, must have

been metamorphosed somewhere else, then broken

up and reassembled together with its fragments,

most of which have identical olivine and pyroxene

composition. Pulsora, or at least its main mass,

must have been "metamorphosed" to exactly the

same degree as the higher grade Andura, Butsura,

and Sitathali, since their chemistry and mineralogy

are essentially identical, implying recrystallization

at various temperatures and/or length of time without any differentiation. This seems incomprehensible and to explain the chemical similarities between

our four chondrites as well as their textural differences it seems necessary to have (1) a common

parent material, (2) heating and cooling rapid

enough to retain olivine in silica-rich glass and to
NUMBER 14 51

FIGURE 7.—Detail of Figure 6. Skeletal to euhedral zoned

olivine (Fai3, center to Fa10, margin) in clear, quartz-normative

glass. The bulk composition equals that of the silicates in

Pulsora. Length of section 0.9 mm.

prevent chemical differentiation (except for draining of metal), and (3) repetitious brecciation and/

or recrystallization processes which again do not

cause gross chemical changes and consequently no

equilibration.

FIGURE 8.—Metal (kamacite, 7% Ni) and troilite spherule in

the glassy fragment shown in Figures 6 and 7. The eutectic

texture and high (0.9%) Ni content in the troilite indicate

quenching from about 1000° C. Diameter 0.5 mm.

Conclusion

We have demonstrated that the Pulsora chondrite, in spite of its constant olivine-pyroxene composition, has never been exposed to thermal

metamorphism after agglomeration as has been suggested for most chondrites (e.g., Merrill, 1921; Van

Schmus and Wood, 1967; Dodd, 1969). Still, Pulsora, including its greatly variable (H3 to H7) lithic

fragments, is practically identical, both chemically

and with regard to major phase (and possible matrix) composition, to Andura, Butsura, and Sitathali. These latter three stones may seem to be of a

higher average petrographic grade but they do

contain, as might be perceived from Figures 1-4,

more fine-grained parts similar to the main mass of

Pulsora (while Pulsora has high grade fragments).

Thus, by analogy, we contend that there is no compelling evidence for the assumption that the three

other chondrites here described, or any other ordinary chondrite, ever suffered severe, long term thermal metamorphism, or that the constant olivinepyroxene compositions were established by such

processes. Rather, it seems that rapid, multiple

processes acting on a common (at least chemically)

parent material may create conditions under which

olivine-pyroxene may retain their constant initial

composition once established by subliquidus, or

even subsolidus, crystallization (Fredriksson, 1963;

Kurat, 1967; Blander, et al., 1970). Impacts on moderate sized bodies, > 102

 to ^ 103 km, seem to be

the most plausible and currently most accepted explanation for the contradictions presented by ordinary chondrites. Recent investigations of lunar

impact breccias, glasses, and chondrules and the

interpretation thereof also seem to corroborate the

impact origin of chondrites (Fredriksson, et al.,

1973).

Appendix

MODAL ANALYSIS WITH THE ELECTRON PROBE

Like most chondrites the four stones investigated

in this study are fine grained and the minerals are

intricately intergrown. Thus modal analysis by

point counting under the microscope is practically

impossible as illustrated in Figures 1-4 and especiallly in the frontispiece. The proportions of metal,

troilite (some oxides) and silicates can be readily

estimated (e.g., Keil, 1962) but even estimates of
52

TABLE 7.—Identification of phases by number of

total counts

Phase

1 Kamacite . . .

2 Taenite ... .

3 Troilite ... .

4 Olivine ... .

5 Pyroxene-1 .

6 Pyroxene-2 .

7 Plagioclase .

8 Apatite ... .

9 "Others"

or no fit

FeKa

>

21000

15000

15800

2500

1500

500

20

20

-

<

99000

21000

17500

5000

3000

3000

500

400

-

CaKa

>

50

200

100

50

150

600

500

10000

-

<

500

500

200

150

600

10000

1500

25000

-

MgKa

>

20

20

20

4500

1500

1300

20

20

-

<

500

500

500

10000

5000

5000

300

1000

-

Note: Taenite is distinguished from troilite by the

count, i.e., the background, the difference (somewhat uncertain) being caused by the different average atomic number

(this adds another variable) . In some cases "Taenite 2" was

substituted for apatite by changing the criteria for Phase 8

to Fe, >10000and <15000; Ca. (i.e., background) >200 and

<500; and Mg >20 and <500.

the ratio of olivine to pyroxene in Andura (relatively coarse) differed by more than 50 percent

between two of us and the amount of residue (unidentified) varied from 18 to 30 percent. In a study

of Forest Vale (Noonan, et al., 1972) more rigorous

optical criteria were applied which resulted in better olivine/pyroxene ratios but left /—' 45 percent

of the points (i.e., > 50% of the silicates) unidentified. We, therefore, decided to resort to point counting by electron probe, simultaneously registering

the relative abundance of three elements. Similar

techniques have been used before (e.g., Keil, 1962,

1967), but we believe that the procedure used for

this study warrants a brief description for three

reasons: (1) to illustrate the accuracy (or lack) of

some of our calculations, (2) some of the modifications appear to be new and easily adapted to other

systems that include computerized data reduction,

and (3) the inherent possibility to identify ultrafine

interstitial or intergrown minerals, especially if

relative abundances of six or more elements are

determined simultaneously, as is possible with various modern instruments.

In our study we used an ARL EMX instrument

run at 20 kV, and ,- 0.25/xA beam (-— 0.025^A

sample) current. The three spectrometers were

SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

tuned to Fek«, Caka and Mgk« and intensities recorded in silicate standards were approximately 125

cps (counts per second) per 1 percent Fe, 220 cps/1

percent Ca and 115 cps/1 percent Mg. Counting

time was 2 seconds per point and the sample

was moved mechanically (manually) under the

beam on a 0.3 X 0.3 mm grid during the print out

(typewriter and punch cards) time of <~• 3 seconds;

thus each point required an average of r~> 6 seconds and a typical thin section ^ 1 cm2

 was

analyzed within I1/2 hours. No real concentrations

were estimated. Rather, phases were identified

by number of total counts as established for each

run as illustrated in Table 7. Similarly any

other phases can be introduced and of course any

suitable elements can be substituted for Fe, Ca,

Mg to characterize these phases. The developed

computer program readily accommodates such

changes, i.e., it accommodates eight "fixed" phases,

one "unknown" (frequently caused by overlap of

different phases) and one "reject," i.e., if all three

channels register background or less, the point is

not counted but the number of such points is registered and might in special cases be used to identify a special "phase," e.g., holes or pores in a sample,

etc. If the counts for each of the three channels are

registered on punch card only, the limits as exemplified in the table have to be added, i.e., 48 digit

(up to 107 counts per channel!) numbers which can

be accommodated on 5 IBM cards. (A print out of

the current program in Fortran IV is available on

request.) The program at present is designed to

accomodate up to 750 points, which we consider

more than adequate for most thin sections. An

average run on a Honeywell 1250 takes a maximum

of 2 minutes.

In the near future an electron probe capable of

registering simultaneously nine elements will be

available. This will make it possible to define more

sharply a greater number of phases, but this may

not lead to a much greater resolution of phases in

fine-grained rocks, especially those with a glassy or

crypto-crystalline matrix. It should, however, be

possible to obtain the average composition of such

a fine-grained matrix and/or apportion (i.e., calculate the norm) unidentified points among the major

phases, leaving only small amounts of excess elements or compounds.
NUMBER 14

Literature Cited

Anders, E.

1964. Origin, Age and Composition of Meteorites. Space

Science Reviews, 3:583-714.

Bence, A. E., and A. L. Albee

1968. Emperical Correction Factors for the Electron Microanalysis of Silicates and Oxides. Journal of

Geology, 76:382-403.

Blander, M., K. Keil, L. S. Nelson, and S. R. Skaggs

1970. Heating of Basalts with Carbon Dioxide Laser.

Science, 170:435-438.

Coulson, A. L.

1940. Catalogue of Indian Meteorites. Memoirs of the

Geological Survey of India, 75:1-346.

Dodd, R. T.

1969. Metamorphism of the Ordinary Chondrites: A Review. Geochimica et Cosmochimica Ada, 33:161-203.

Fredriksson, K.

1963. Chondrules and the Meteorite Parent Bodies. Transactions of the New York Academy of Sciences, series

2, 25:756-769.

Fredriksson, K., and K. Keil

1964. The Iron, Magnesium, Calcium and Nickel Distribution in the Murray Carbonaceous Chondrite.

Meteoritics, 2:201-217.

Fredriksson, K., and J. Nelen

1969. Carbon Distribution in Chondrites. Meteoritics,

4:271-272.

Fredriksson, K., A. Noonan, and J. Nelen

1973. Meteoritic, Lunar and Lonar Impact Chondrules.

The Moon, 7:475-482.

Fredriksson, K., and A. M. Reid

1965. A Chondrule in the Chainpur Meteorite. Science,

149:856-860.

Keil, K.

1962. Quantitative-erzmikroskopische Integrationsanalyse

der Chondrite. Chemie der Erde, 22:281-348.

1967. The Electron Microprobe X-ray Analyzer and Its

Application in Mineralogy. Fortschrittee der Mineralogie, 44:4-66.

Keil, K., and K. Fredrikkson

1964. The Iron, Magnesium and Calcium Distribution in

Coexisting Olivines and Rhombic Pyroxenes in

Chondrites. Journal of Geophysical Research, 69:

3487-3515.

Kraut, F., and K. Fredriksson

1971. Hedjaz an L-3, L-4, L-5 and L-6 Chondrite. Meteoritics, 6:284.

Kullerud, G.

1963. The Fe-Ni-S System. Pages 175-189 in Annual

Report of the Director of the Geophysical Laboratory, 1962-1963. Carnegie Institution of Washington.

[Also as number 1412 in Papers from the Geophysical Laboratory.]

Kurat, Gero

1967. Einige Chondren aus dem Meteoriten von MezoMadaras. Geochimica et Cosmochimica Ada, 31:

1843-1857.

Laul J., C. R. Ganapathy, Edward Anders, and John W.

Morgan

1973. Chemical Fractionation in Meteorites-VI: Accretion

Temperature of H-, LL-, and E-Chondrites, from

Abundance of Volatile Trace Elements, Geochimica

et Cosmochimica Ada, 37:329-357.

Mason, B.

1972. The Mineralogy of Meteorites. Meteoritics, 7:309-

326.

Merrill, G. P.

1921. On Metamorphism in Meteorites. Bulletin of the

Geological Society of America, 32:395-414.

Murthy, M. V. N., S. N. P. Srivastara, and A. Dube

1969. Indian Meteorites. Memoirs of the Geological Survey

of India, 99:1-192.

Noonan, A. F., K. Fredriksson, and J. Nelen

1972. Forest Vale Meteorite. Smithsonian Contributions to

the Earth Sciences, 9:57-64.

Ramdohr, P.

1973. The Opaque Minerals in Stony Meteorites. 245

pages. Amsterdam: Elsevier Publishing Company.

Urey, H. C, and H. Craig

1953. The Classification of the Stone Meteorites and the

Origin of the Meteorites. Geochimica et Cosmochimica Ada, 4:36-82.

Van Schmus, W. R., and J. A. Wood

1967. A Chemical and Petrologic Classification for the

Chondritic Meteorites. Geochimica et Cosmochimica

Ada, 31:747-765.

Viswanathan, T. V., N. R. Sen Gupta, D. R. Das Gupta, and

S. Banerjee

1971. The Sitathali Meteorite. Mineralogical Magazine,

38 (September):335-343.
Impact Survival Conditions for Very Large Meteorites,

with Special Reference to the

Legendary Chinguetti Meteorite

Robert F. Fudali and Dean R. Chapman

ABSTRACT

Contrary to popular belief, very large meteorites

( > > 1000 tons) can be sufficiently slowed by aerodynamic drag to survive impact with the earth's

surface provided that they enter the atmosphere

at very low angles. This is a stringent requirement

and survival probabilities for large, unguided objects are low; but they are not zero. Based on highvelocity impact experiments and published tabulations of the parameters of shallow angle entry

trajectories, we estimate the probability of survival

for an iron meteorite approximately the size and

shape of the legendary Chinguetti meteorite (100

meters x 40 meters x 20-40 meters) to be between

0.1 and 1 percent. Together with a limiting estimate of the flux of such bodies encountering the

earth, this leads to an expected survival rate of one

per 108—10° years on the earth's land surface.

Introduction

In 1916, a small (4.5 kg) meteorite was found in

the Adrar region of Mauritania (then French West

Africa) by a captain in the French army, Gaston

Ripert. It was designated the Chinguetti Meteorite,

after the nearby oasis of Chinguetti (20° 28'N, 12°

20'W). The meteorite presently resides in the

Museum National d'Histoire Naturelle (Paris).

The fascinating part of the story is that Ripert

Robert F. Fudali, Department of Mineral Sciences, National

Museum of Natural History, Smithsonian Institution, Washington, D. C. 20560. Dean R. Chapman, Thermo- and GasDynamics Division, NASA Ames Research Center, Moffett

Field, California 94035.

claimed the meteorite was but the tiniest part of a

gigantic mass that he was led to, with the greatest

reluctance, by the then chieftain of Chinguetti, Sidi

Ahmed Ould Zein. Following is Ripert's description

of the find (as originally transcribed by Lacroix,

1924, and cited in Monrod, 1952):

This specimen was collected about 45 km. to the southwest

of Chinguetti and to the west of Aouinet N'Cher. It was

lying on top of an enormous metallic mass measuring about

100 m. on one side and about 40 m. in height, which stands

up in the middle of dunes covered by a desert plant called

'sba' [sic]. (The mass) is in the form of a compact, unfractured parallelepiped. The visible surface is vertical, standing

like a cliff above the sand, which, driven by the wind, has

grooved its base to such an extent that its upper edge overhangs; the part worn by eolian erosion is polished like a

mirror. The sand has piled up against the opposite face and

hides it entirely, a fact that made it impossible to estimate

its third dimension. The upper surface of the mass bristles

with little needles, which the Arabs have tried to remove;

but, because of the malleability of the metal, these were only

bent. Some less important blocks (of the same material) are

scattered about the neighborhood.

Understandably, this report caused considerable excitement in 1924. If the meteorite existed it would

be of enormous mass. Based on dynamical considerations to fix the unreported third dimension we

estimate a minimum mass of 500,000 tons and a

more likely mass in excess of 1,000,000 tons. Since

it would have had to tumble and skid to rest from

a high velocity, the most stable attitude was probably achieved during the final stages of deceleration

and this would be with the smallest dimension

vertical. In the event that the vertical dimension is

instead the intermediate dimension it is highly unlikely that the unknown horizontal dimension could

55
56 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

be significantly smaller than the vertical dimension.

We therefore assume that the unknown dimension

would be at least 20 meters and more likely in excess of 40 meters.

In addition to the scientific interest, the meteorite

would be large enough to generate thoughts of

commercial gain. Over the next 14 years there were

several, more or less random, attempts made to relocate the original site, without success. Curiously,

it was not until 1932 that Ripert was contacted for

help in these endeavors and, by then, he apparently

retained only a vague notion of the general area of

the site. Further, his guide had long since died. In

reviewing the problem, Monod (1952) reproduced

parts of two letters written by Ripert at about this

time. In 1932 Ripert (translated by Brady) wrote,

in part, to Dr. Jean Bosler, Director of Le Verrier

Observatory in Marseille:

Unfortunately, 16 years have passed since I had occasion

to describe the existence of this meteorite. The times were

such that everything else was blotted out by the dramatic

events that were occurring in France, and I could not realize

at the time all the interest that this meteorite might arouse.

I spoke of it incidentally, when I was leaving Mauritania, to

one of my friends, M. H. Hubert, a Doctor of Science at

Dakar, who did not seem to attach any great importance to

its existence.

Moreover, in order to satisfy the urgent demands of my

guide I had taken with me neither compass nor any material

that would permit me to make notes or any measurements

whatsoever; also, I could remain only a very short time, because of the guide's haste to leave the spot; so my observations were extremely cursory. I was able to state that the

meteorite formed a sort of cliff, with numerous projecting

ridges of sand, lying in an approximately southwest direction,

while the northeast side was completely covered by sand. I

found there a small fragment, well rounded at the edges,

which I turned over to M. Hubert. On one corner (of the

large mass), toward the west, I think, sand had carved out

fairly thick metallic needles, which I could not loosen or remove. Of the metallic nature of the large mass there could

be no doubt at all. Examination of the small specimen given

to M. Hubert proves this fact. I tried to detach one of the

aforesaid needles by pounding it with the small heavy lump

(= the small meteorite). The specimen showed at every

point of contact traces of hammer marks, the same condition

being true of the needles; and, finally, the surface appearance

of the large mass was in no way comparable to that of the

blackish polished surface of the rocks that are found on the

'reg' and on the sandstone plateaus of the Adrar. On my

return, I wrote down my observations (based on my memory,

which was very good at the time), but, since then, I have

moved so much from place to place that I do not know

where I put those notes. In any case, I told M. Hubert everything that I had seen which was then quite clear in my mind.

As you may imagine, this meteorite, half-covered by sand in

1916, is very likely completely covered now, but, even so, I

am astonished that it has not been found by the civilian and

military expeditions that have been sent out since 1929 to

look for it. It seems likely that they have been blocked by a

conspiracy on the part of the natives, who seem anything but

anxious that its existence should be known to Europeans. I

realized this (fact) when I overheard a conversation among

the camel drivers when I was with the Adrar camel corps. I

had spoken of (the meteorite) to the head man of Chinguetti, Sidi Ahmed Zein, who at first vigorously denied its

existence, and it was only after long conversations (negotiations?) that he consented, in spite of his fears, to lead me

secretly to the spot, on condition that I would take nothing

with me that might permit me to describe the exact position

of the meteorite, or to make notes. Sidi Ahmed died, apparently of poison; and, without wishing to establish any

connection between the facts, I cannot now point out anyone

who could serve as a guide.

And in 1934 he wrote, in part, to Monod (1952;

translated by Brady):

I know that the general opinion is that the stone (rock)

does not exist: that, to some, I am purely and simply an imposter who picked up a metallic specimen on the 'reg' of

Mauritania; that, to others, I am a simpleton who mistook

an exposure of sandstone, blackened and polished as is so

often the case in that country, for an enormous meteorite. I

shall do nothing to undeceive them. I care very little for

what any of them may think. I know only what I saw, because I saw it, and I could probably have found (the mass)

again if I had been directed to do so, when my visual memory and my age still permitted.

Monod in 1934, and one A. Pourquie, in 1938,

conducted search expeditions into the Chinguetti

region—both with negative results (Monod, 1952).

At that point World War II intervened and the

matter was not seriously broached again until the

early 1950s. In his 1952 paper Monod was still convinced the huge meteorite could very well exist.

However, based on his extensive experience in the

region, he cautioned:

Let me add that if the meteorite is actually located among

the dunes of Ouarane, 10 hours to the southeast' of Chinguetti, the very nature of this terrain is unsuited to easy

exploration. It is foolish, of course, to pursue a search (for

the meteorite) in a random fashion merely in the hope of

making a lucky discovery.

Thus far, this point has been academic as there

have been no further efforts to relocate the site.

The reason for this neglect is that it is widely believed to be physically impossible for such an enor1

 The original report of Lacroix describing the find site as

southwest of Chinguetti was subsequently corrected by Ripert

to southeast of Chinguetti (Monod, 1952).
NUMBER 14 57

mous mass to survive an impact with the earth's

surface. This belief is based on simple aerodynamic

calculations, which have been generally interpreted

as precluding any significant atmospheric braking

if the incoming meteoritic mass exceeds a maximum

of 100 to 1000 tons. This has been uniformly asserted in several meteoritic texts that have enjoyed

wide circulation (e.g., Mason 1962; Hawkins, 1964;

Heidi, 1964; Wood, 1968).

With little or no atmospheric braking a meteorite

impacts the earth's surface with enough kinetic

energy to destroy both itself and a significant portion of the target rock. And there surely is ample

evidence—in the form of a number of meteorite

impact craters of modest dimensions—that meteorites of mass far less than that estimated for Chinguetti do normally explode upon encountering the

earth's surface. But what is not generally appreciated is that this is a normal, rather than an inevitable, result. In this paper we demonstrate that,

under special conditions, a Chinguetti-size meteorite could survive a terrestrial impact essentially

intact. In the following sections we delineate the

conditions necessary for the survival of such a

meteorite, and we compute the approximate probability of encountering such conditions. As one

might suspect, the conditions are stringent and the

concomittant probabilities are small—but they are

certainly not zero.

TABLE 1.—Fate of aluminum projectiles impacting

sand targets at high velocities and low incident

angles (NASA Ames Light-Gas Gun Range experiments)

Round

DLG

209

211

221

215

233

VGP

788

791

792

796

(km/sec)

6.1

6.5

5.7

6.3

5.9

1.9

1.8

1.9

1.8

Ti Yr Fate of projectile

(degrees)

2.1 0.9 Essentially intact

4.75 1.1 Two main fragments

7.33 1.15 Three main fragments

15 — Fragmented into small pieces

30 - Fragmented into small pieces

2.1 1.5 Intact

4.75 3.6 Intact

7.33 2.85 Intact

15 1.32 Essentially intact

1/16

1/4

1/2

0.8

1.1

1.2

TABLE 2.—Variation of the effective strength of

aluminum projectiles as a function of their diameter

(NASA Ames Light-Gas Gun Range experiments)

Projectile Impact velocity for Corresponding energy

diameter same degree of deformation for same degree of

(inch) (km jsec) deformation (ergs)

2xlO7

2xlO»

2xlO10

The foregoing should in no sense be considered

an endorsement for the existence of the legendary

Chinguetti meteorite. The primary purposes of this

paper is not to demonstrate that it does exist, but

that such a large meteorite can exist. Clearly this is

the absolute minimal requirement necessary if a

systematic search for the meteorite is ever seriously

contemplated.

ACKNOWLEDGMENTS.—Donald Gault and John

Wedekind of the NASA Ames Research Center

generously furnished us with the unpublished, experimental high-velocity impact data vital to our

study. For this, and for a number of stimulating

discussions on all aspects of the study, we express

our deep appreciation. We also thank Lionel Levy

of the NASA Ames Research Center for the computer-generated trajectories of a large iron meteorite subsequent to ricochet at the earth's surface.

Experimental Data on Impact Survival

There is, of course, no possibility of slowing a

Chinguetti-size meteorite to terminal velocity by

atmospheric braking alone. In the following section

we show that the minimum possible velocity such a

body could have upon impact would be 3-4 km/sec,

and higher velocities are much more probable. We

must therefore consider the possibility of survival

only for impact velocities of 3 km/sec and higher.

Some of the hypervelocity impact experiments

done at the light-gas gun range of NASA Ames Research Center have a direct bearing on this problem. Most of these impact experiments have been

characterized by high angles of impact (> 30°).

But the few experiments carried out at low incident

angles show that, for aluminum projectiles impacting sand targets at velocities between approximately

2 and 6 km/sec, the fate of the projectile is a func-
58 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

0 2 4 6

Impact Angle I? degrees

FIGURE 1.—Relationship between impact angle r\, impact

velocity Vlmp, and rebound angle IY Aluminum projectiles

into sand targets.

tion of both velocity and incident angle. For a

given velocity, as the incident angle is lowered, a

value is reached below which the projectile will

ricochet intact. The pertinent experimental data

are shown in Table 1. Figure 1 plots the angle of

ricochet against the angle of incidence for three

impact velocities. Note that in all cases the ricochet

angle is significantly less than the incident angle.

We have used the data in Table 1 to approximately fix the boundary separating the fragmentation domain from the domain of intact ricochet on

plots of impact velocities versus incident angles in

Figures 2 and 3. Admittedly the data are scanty and

14

12 -

10

6 -

- 4

2 -

Intact

- Ricochet

Domain

Atm. Brakinc

Point

.003 \

Fragmentation

Domain (Al into

\

\

~ .006 <y—-^

.006

, 1.1.1, 1

sand)

11.2 13

i

/ /'°5

/.03

/.02 /

;

L

/

i

16

/.05

/ i

/.04 /

03 /

, 1 ,

20 Km/Sec.

/

/

1,1 ,

2 4 6 8 10 12 14 16

Earth Impact Velocity Km/sec

18 20

there is a rather large uncertainty associated with

this boundary placement, especially at higher velocities. However, it seems likely that the boundary, as

drawn, is conservative. For a Chinguetti-size,

nickel-iron meteorite the true boundary should lie

somewhere to the right of the boundary shown in

Figures 2 and 3. There are two reasons for this:

(1) Nickel-iron has a much greater strength than

aluminum, and (2) scaling up from the tiny experimental projectiles to a large meteorite should be

favorable for impact survival. Although the shock

wave strengths are independent of scale, the deceleration or body forces acting on each element of the

projectile vary inversely with the scale of the projectile. We therefore expect a large projectile to

£ 10

£— 4

20 Km/Sec

FIGURE 2.—Possible earth impact conditions for shallow

angle entry trajectories of an iron meteorite with 7T=2Om.

0 2 4 6 8 10 12 14 16 18

Earth Impact Velocity Km/sec

FIGURE 3.—Possible earth impact conditions for shallow

angle entry trajectories of an iron meteorite with h = 40m.

effectively behave as if it were stronger than a small

projectile. Some experimental confirmation of this

expectation is shown in Table 2.

The conditions a projectile experiences subsequent to ricochet are specifically discussed in the

following section. Here we merely point out that

nothing subsequent to the initial impact can begin

to approach this initial event in potential destructiveness. This is because the projectile loses energy

during ricochet, and is subject to further atmospheric braking after ricochet.

Possible Impact Conditions

Some years ago, Chapman (1959, 1960) published

an analytical method for studying the motion of
NUMBER 14 59

extraterrestrial bodies on shallow entry trajectories

into the earth's atmosphere. So that these trajectory

calculations could be generally applied to any planetary atmosphere and to incoming bodies with any

physical properties, the trajectories were described

in terms of two dimensionless functions. The conic

perigee parameter F p delineates the conditions at

the perigee point of the hypothetical conic trajectory that the incoming body would have had if

there were no planetary atmosphere. It characterizes

the trajectory prior to atmospheric encounter and is

defined as

F = 2(MjCDA) •

 (1)

The trajectory through the atmosphere is characterized by a dependent variable termed the Z function:

pU

)

X

2(M/CDA)

where, for both equations p = air density, r=radius

from the planet's center, /3 = the atmospheric density

decay parameter, M = mass (grams) of the incoming

body, A— cross-sectional area normal to the flight

path (cm2), CD = the atmospheric drag coefficient,

w = the ratio of the horizontal velocity component

at any point along the flight path to the circular

orbital velocity (8 km/sec), and subscript v refers to

conditions at the conic perigee.

For an incoming body of given Fp, initial velocity,

and lift force to drag force ratio (LjD), Z can be

determined at all points on its atmospheric trajectory. If Z is known, a number of other pertinent

entry motion parameters can be calculated, including the horizontal velocity component and the

trajectory angle with respect to the local horizontal.

This has been done for a large number of trajectories and the results are assembled in computergenerated tables (Chapman and Kapphahn, 1961).

One such table is reproduced herein for illustrative

purposes (Table 3).

In order to use these tables for the problem under

consideration, we begin by determining Zju at sea

level (i.e., at impact) for Chinguetti-size meteorites,

using equation 2. This quantity is conveniently

given if we use the density of air at set level, p0, for

the calculation. For purposes of these calculations

the following assumptions and approximations are

made: (1) The meteorite is oriented by aerodynamic forces such that the minimum dimension is

TABLE 3.—Atmospheric behavior of an object entering the earth's atmosphere under the following

initial conditions: Initial velocity—IS km/sec, Lift/

drag — 0, Conic perigee parameter 7^ = 0.466, and

Initial atm. encounter angle— —5.00° (modified

from Chapman and Kapphahn, 1961:155)

Z/fi

0.54

0.59

1.12

il

1.593

1.590

1.585

1.580

1.575

1.570

1.560

1.550

1.500

1.450

1.400

1.350

1.300

1.250

1.200

1.150

1.100

1.050

1.000

.950

.900

.850

.800

.750

.700

.650

.600

.550

.500

.450

.400

.350

.300

.250

.200

.150

.100

.050

Z

.00261

.00986

.02070

.03074

.04026

.04938

.06667

.08297

.15425

.21384

.26505

.30958

.34848

.38253

.41234

.43842

.46123

.48116

.49864

.51405

.52781

.54031

.55202

.56340

.57496

.58727

.60091

.61654

.63485

.65657

.68242

.71309

.74914

.79078

.83749

.88673

.92946

.92114

G

.13

.47

.99

1.46

1.91

2.33

3.13

3.87

6.96

9.32

11.15

12.55

13.61

14.36

14.86

15.14

15.23

15.17

14.97

14.66

14.26

13.79

13.26

12.69

12.09

11.47

10.84

10.20

9.55

8.90

8.24

7.55

6.82

6.04

5.18

4.21

3.13

2.00

r

-5.00

-4.38

-3.99

-3.77

-3.60

-3.48

-3.28

-3.13

-2.67

-2.38

-2.18

-2.03

-1.90

-1.80

-1.72

-1.66

-1.61

-1.59

-1.58

-1.59

-1.62

-1.67

-1.76

-1.87

-2.02

-2.22

-2.47

-2.79

-3.19

-3.69

-4.34

-5.17

-6.27

-7.76

-9.91

-13.26

-19.33

-33.68

S

.000

.018

.029

.036

.041

.044

.050

.055

.069

.078

.085

.091

.096

.100

.105

.108

.112

.116

.119

.122

.126

.129

.132

.135

.138

.141

.143

.146

.149

.151

.154

.156

.158

.161

.163

.165

.166

.168

T

0

9.2

14.9

18.3

20.7

22.6

25.6

27.9

35.5

40.5

44.5

47.9

51.0

53.9

56.7

59.4

62.0

64.7

67.4

70.1

72.9

75.8

78.8

81.9

85.2

88.6

92.3

96.1

100.2

104.6

109.4

114.5

120.2

126.5

133.8

142.6

154.2

172.1

u = Horizontal velocity component normalized to circular

satellite velocity.

Z= Dimensionless function proportional to density times

velocity.

G = Deceleration in earth g's.

r = Flight path angle relative to local horizontal in degrees.

S = Circumferential distance traveled.

T = Time elapsed in seconds.
60 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

parallel to the flight path. The calculations are

carried out for two minimum dimensions, 20 meters

and 40 meters. (2) Density of the nickel-iron meteorite is 8 gm/cc. (3) The meteorite has no aerodynamic lift, either positive or negative (i.e., ballistic

entry). The lift-to-drag ratio (L/D) is therefore

zero. (4) The drag coefficient CD^\.b over the entire flight path. (5) The variation of atmospheric

density with height is exponential and \A/? «^ 30

everywhere in the earth's atmosphere. (6) r?« radius

of the earth = 6 X 108 cm. (7) For shallow angle

entries, the (normalized) horizontal velocity component, u, approximately equals the meteorite's

entire velocity.

Now MIA — Sh gm/cm2, where h is the average

depth of the meteorites (in cm) in the direction

parallel to the flight path. Therefore M/CVA =

5M gm/cm2. Also Po = 0.0012 gm/cm3. Substituting in equation (2) we have:

_ 0.0012 gm/cm3 X (6 X 10

 8 cm)

~ 10.6 X 30 xTgm/cm2

_ 2264 dimensionless,

for Ji = 40 m = 4 X 10

 3 cm, (Z/u)0 = 0.57,

for h = 20 m = 2 X 10

 3 cm, (Z/u)0 = 1.14.

(3)

(4)

Table 3 displays the trajectory parameters of a

body with zero lift, entering the earth's atmosphere

at an initial velocity of 13 km/sec and an initial

angle of —5.00° (the negative sign merely denoting

that the body is descending). From this table we see

that a meteorite characterized by (Z/u)o = 0.57

would impact the earth's surface at a velocity of

7.4 km/sec and an angle of —1.65°, 75 seconds after

first encountering the atmosphere. If (Z/u)0= 1.14,

the meteorite would impact at 4.4 km/sec and

— 2.8°, 96 seconds after first encountering the atmosphere. It might at first seem paradoxical that the

impact angle can be less than the initial entry angle

since the trajectory must always steepen (in an absolute sense) due to the combined effects of gravity

and aerodynamic deceleration. However, this may

indeed be the case for an impact angle measured

zvith respect to the local horizontal since the earth's

surface curves away from the trajectory path. Both

sets of parameters define points within the intact

ricochet domain as delineated in Figures 2 and 3.

Using the complete tables of Chapman and KapTABLE 4.—Computer-generated trajectory parameters and conditions at second impact for an iron

meteorite of h = 40 meters ricocheting with velocities Vj and angle Tl

(km I sec)

5.3

4.5

4.5

5.0

6.0

6.0

7.0

7.0

8.0

8.0

(degrees)

1.3

1.9

1.5

1.0

0.5

0.8

0.5

0.7

0.4

0.7

Range

(km)

161

153

125

114

106

152

172

211

233

306

Max. height

(km)

1.1

1.4

0.9

0.6

0.3

0.6

0.5

0.9

0.7

1.5

(km /sec)

3.9

3.4

3.5

4.0

4.8

4.4

4.9

4.6

5.0

4.5

(degrees)

-1.8

-2.4

-1.9

-1.3

-0.7

-1.1

-0.8

-1.2

-0.9

-1.6

phahn (1961), a number of such points can be

plotted, generating the family of lines shown in

Figures 2 and 3. Each line contains all the impact

velocities and angles (of interest here) for a single

initial encounter velocity. Lines corresponding to

encounter velocities of 11.2, 13, 16, and 20 km/sec

are plotted. An encounter velocity of 11.2 km/sec

(escape velocity) is, of course, the lower limit for

an incoming meteorite and we consider velocities

between 13 and 16 km/sec to be the most likely

range for large iron meteorites. Clearly, at least for

all encounter velocities less than 20 km/sec, a significant portion of the generated lines lie in the

intact ricochet domain.

For all impact velocities below about 8 km/sec,

the associated impact angle is less than ^5° for a

meteorite of ft = 20 m and less than,—-4° for a meteorite of h = 40 m. Combining these data, with those

shown in Figure 1, we see that the only possible

rebound angles are less than 3° and most are less

than 2°. We have used these rebound angles to

compute the after-ricochet trajectories of a meteorite of ft = 40 m, and the conditions at second

impact. The computer-generated results are shown

in Table 4. In all cases there is a significant reduction in velocity at second impact and, in every case

but one, the second impact angle is less than 2°. The

velocities at second impact would actually be somewhat less than those shown since we did not consider any energy (and velocity) loss due to the

initial impact and ricochet. Atmospheric decelera-
NUMBER 14 61

tion after rebound is most effective for the higher

velocity projectiles, so there is not a great deal of

difference between the velocities and angles of the

various cases at second impact—velocities varying

from 3.4 to 5.0 km/sec and impact angles from

— 0.6° to —2.4°. At these lower velocities and very

low incident angles we feel that such a meteorite

would most likely tumble and skid to rest without

ricocheting a second time. Since aluminum projectiles vertically impacting sand targets at 2.5 km/

sec remain essentially intact (although severely deformed), we expect a nickel-iron meteorite to survive such a skid to rest essentially intact.

Probabilities of Impact Survival

If certain pre-atmospheric trajectories will permit

the impact survival of a Chinguetti-size meteorite,

then there must be an envelope or entry corridor

containing these trajectories. An unguided, extraterrestrial body on a collison course with the earth

may or may not encounter this corridor. To a first

approximation, the probability of a "favorable"

encounter is merely the ratio of the cross-sectional

area of the annular ring defining the entry corridor

to the cross-sectional area of the earth itself:

= log1 z) X 16 km (7)

2Ar,

irr (6)

where /\r is the width of the annular ring and r is

the earth's radius. To be sure, the equation is not

precise, nor is it strictly the equation of applicability since the earth's gravity field creates an effective capture Cross-section and an annular entry

corridor both of which are larger than the comparable terms in equation (6). A precise derivation,

however, is complex and, considering the approximations and assumptions already made, the increase in precision would be meaningless. The first

approximation is at worst within a factor of 2 of a

more precise derivation—for a meteorite with the

lowest possible geocentric velocity (11.2 km/sec).

The approximation improves as geocentric velocities increase.

For an exponential atmosphere, /\r between any

two pre-atmospheric trajectories can be determined

from the ratio of their conic perigee parameters

since these parameters vary directly with air density

(equation 1). The atmospheric density changes by

a factor of 10 for every 16 km change in altitude

and the corridor width is simply:

The upper limit to any entry corridor will be a

trajectory resulting in just enough atmospheric

braking to transfer the incoming body to an unstable elliptical orbit, which will decay and lead to

atmospheric entry on a subsequent pass. For all

practical purposes this atmospheric entry will be

identical to that for a body with circular satellite

velocity, regardless of the initial encounter velocity.

(Thus all the curves in Figures 2 and 3 degenerate

to the same point). Beyond this limiting trajectory

the incoming body will swing around the earth on

a nonreturn hyperbolic trajectory. The nonreturn

boundaries for zero-lift bodies with initial velocities of 13 and 16 km/sec are characterized by Fp's

of 0.036 and 0.10, respectively (Chapman, 1960,

fig. 14). The lower corridor boundary can be any

arbitrarily chosen trajectory whatsoever. For example, Table 3 describes the atmospheric behavior of incoming bodies with initial velocities of

13 km/sec and pre-atmospheric trajectories characterized by Fp = 0.466. The ratio 0.466/0.036 = 12.9

= 101-

11

, so

Ar=l.ll X 16 = 17.8 km (8)

The concomitant, approximate probability of an

unguided, incoming body (with initial velocity of

13 km/sec) encountering this corridor is

2 X 17.8

6 X 10

 3: 0.006. (9)

This probability can be related to survival as follows: In Figure 3, the 13 km/sec curve encompasses

possible impact velocities and angles for a meteorite of ft = 40 m. Table 3 was used to generate one

point on that line—the point labeled .006. For that

class of meteorites encountering the earth, characterized by h=40 m and ^=1 3 km/sec, 0.6 percent will impact at velocities and angles given by

the segment of the 13 km/sec curve lying between

the .006 point and the atmospheric braking point.

All the other numbered points in Figures 2 and 3

were derived in the same way and have the same

meaning.

Discussion and Conclusions

From the foregoing sections it should be clear

that meteoritic masses very much greater than 1000
62 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

tons can survive a terrestrial impact under certain

conditions. In fact, mass is not strictly the governing parameter and a meteorite even more massive

than the specific Chinguetti-size bodies considered

herein could also survive a terrestrial impact, provided the critical parameter—its linear dimension

parallel to the atmospheric flight path—remains

modest. The probability of survival, however, will

decrease with increasing mass because of the need

for a meteorite to assume a favorable flight attitude

in the atmosphere. If a meteorite has a stable flight

attitude, it will be with the minimum dimension

oriented parallel to the flight path. For the present

study we have assumed that if all dimensions are

small enough to permit significant deceleration by

the atmosphere, then the meteorite will become

oriented in its stable attitude prior to maximum

deceleration. This holds for the maximum dimension considered (100 m) on most shallow-angle entry

trajectories. As the other dimensions increase beyond this, the pre-atmospheric orientations that will

lead to stable atmospheric orientation are reduced

and thus the survival probability decreases, although it never goes to zero as long as the minimum dimension is fixed.

With respect to the specific question of the possible existence of the Chinguetti meteorite, we reiterate the fact that the curves, boundaries and

probabilities displayed in Figures 2 and 3 are all

approximate. Nevertheless, the data are surely precise enough for order of magnitude conclusions.

Bearing this in mind we estimate the survival probability of a Chinguetti-size meteorite (whose geocentric velocity lies somewhere between 11.2 and

20 km/sec) to be between 0.1 and 1 percent. Put

another way, such a body has between one chance

in 100 and one chance in 1000 of surviving a terrestrial impact. Now, based very crudely on the number of more recent, known and probable terrestrial

impact craters due to meteorites with kinetic energies similar to the hypothetical Chinguetti body,

the upper limit to the encounter frequency of such

bodies with the earth's land surface cannot exceed

one per 10

 6 years (over the past few tens of million

years). This means that the expected survival (and

potentially recoverable) rate can be no higher than

one every 10

 8 to 10 9 years. Because the complete

oxidation (and thus destruction) of large iron

meteorites on the earth's surface is accomplished in

a time that is short compared to 100 million years,

we are led to the following conclusions. First, the

Chinguetti meteorite can exist. Second, from a

purely statistical aspect, the odds are heavily against

its existence. Of course, the specific existence or

nonexistence of the Chinguetti meteorite is not

purely a statistical problem, since it involves a reported observation. Thus there are only two possible probabilities: Either the observer, Gaston Rip

ert, was mistaken (or lied), or his report was correct.

In the former case, the probability that the Chinguetti meteorite exists is 0. In the latter case, the

probability is 1. No other probability calculations

are meaningful, nor is it possible to discriminate

between 0 and 1 at this point. The combination of

survival and weathering rates, however, does tell

us, clearly and irrevocably, that if the Chinguetti

meteorite does indeed exist, it must be, now and

forever in the history of mankind, unique.

Literature Cited

Chapman, D. R.

1959. An Approximate Analytical Method for Studying

Entry into Planetary Atmospheres. NASA Technical

Report, R-ll: 44 pages.

1960. An Analysis of the Corridor and Guidance Requirements for Supercircular Entry into Planetary

Atmospheres. NASA Technical Report, R-55: 47

pages.

Chapman, D. R., and A. K. Kapphahn

1961. Tables of Z Functions for Atmospheric Entry

Analysis. NASA Technical Report, R-106: 271 pages.

Hawkins, G. S.

1964. Meteors, Comets and Meteorites. 134 pages. New

York: McGraw Hill.

Heidi, F.

1964. Meteorites. 144 pages. Chicago: The University of

Chicago Press.

Lacroix, A.

1924. On a New Type of Meteoric Iron Found in the

Desert of Adrar in Mauritania. Comptes Rendus,

179:303-313.

Mason, B.

1962. Meteorites. 274 pages. New York: John Wiley and

Sons.

Monod, Th.

1952. Le probleme de la meteorite de Chinguetti. Bulletin

de la Direction des Mines, Gouvernement General

de I'Afrique Occidentale Francaise, 15 (2):405-412.

[Translated by L. F. Brady, "The Problem of the

[French West Africa] Chinguetti Meteorite [CN =

0127,202:]", and published, in 1955, in Meteoritics,

1 (3): 308-314.]

Wood, J. A.

1968. Meteorites and the Origin of Planets. 117 pages.

New York: McGraw Hill.
Preliminary Data on Eight Observed-Fall Chondritic Meteorites

Roy S. Clarke, Jr., Eugene Jarosewich,

and Albert F. Noonan

ABSTRACT

Eight observed-fall meteorites, five olivine-bronzite

chondrites and three olivine- hypersthene chondrites,

have been chemically analyzed and assigned a Van

Schmus-Wood petrographic classification. The

names, dates of fall, and classification of the meteorites are as follows; Ankober, 7 July 1942, H4;

Schenectady, 12 April 1968, H4; Dwaleni, 12 October 1970, H4 dark fraction and H6 light fraction;

Kiffa, 23 October 1970, H5; Kabo (Gwarzo), 25

April 1971, H4 dark fraction and H5 light fraction;

Tathlith, 5 October 1967, L6; Malakal, 9-15 August 1970, L5; Wethersfield, 8 April 1971, L6.

Introduction

During the past several years we have obtained a

number of newly fallen chondritic meteorites.

These specimens, or samples from them, have been

made available as promptly as possible to investigators engaged in time-dependent studies. Distribution of samples for other purposes has also been

made, depending upon availability of specimen

material. In an effort to support these outside studies, as well as to fulfill our curatorial responsibilities, we have undertaken preliminary examinations

of each meteorite. Typically, this includes obtaining as much information as possible about the

circumstances of fall and recovery of the meteorite,

performing a bulk chemical analysis, a preliminary

petrographic examination, and an electron microprobe examination of the major minerals. Our

Roy S. Clarke, Jr., Eugene Jarosewich, and Albert F. Noonan,

Department of Mineral Sciences, National Museum of Natural

History, Smithsonian Institution, Washington, D.C. 20560.

objective is sound classification, and the data is

circulated promptly to those who have need for it.

This paper summarizes data on eight observed-fall

chondrites.

The meteorites studied are listed by date of fall

in Table 1, together with their geographic location, date and time of fall, and the weight of

material recovered. Bulk chemical analyses and calculated normative mineral compositions are given

in Table 2. In Table 2 the meteorites are listed in

order of date of fall within the two major classification groups. The first five meteorites, Ankober,

Schenectady, Dwaleni, Kiffa, and Kabo are all

olivine-bronzite chondrites (H-group meteorites).

The last three meteorites, Tathlith, Malakal, and

Wethersfield are olivine-hypersthene chondrites

(L-group meteorites).

RELATED LITERATURE.—A number of papers have

been published giving cosmic-ray exposure ages and

rare gas measurements on meteorites from our list

of eight. References are given here, with the names

of the meteorites studied, for papers that are not

mentioned in our discussion: Bogard, et al. (1973),

Tathlith, Malakal, Dwaleni, Kiffa, Wethersfield,

and Kabo; Cressy (1970), Tathlith; Fireman and

Goebel (1970), Ankober; Fireman and Spannagel

(1971), Dwaleni; Reynolds, et al. (1971), Dwaleni;

Smith and Firemen (1973), Dwaleni, Kabo, Kiffa,

Malakal, and Wethersfield; Tobailem and Lalou

(1972), Kiffa; Heimann, Parekh, and Herr (1974),

Malakal,

ACKNOWLEDGMENTS.—The Smithsonian Institution's Center for Short-Lived Phenomena has been

responsible for obtaining our specimens of the Malakal, Dwaleni, Kiffa, and Kabo meteorites. We are

indebted to the Center's director, Robert A. Citron,

and to David Squires for their assistance. Joseph A.

63
64 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

TABLE I.—Recovery information on eight observed-fall chondrites (listed by date of fall)

Name

Ankober, Ethiopia

Tathlith, Saudi Arabia

Schenectady, New York

Malakal, Sudan

Dwaleni, Swaziland

Kiffa, Mauritania . . .

Wethersfield, Connecticut ... .

Kabo, Nigeria . . ... .

Location

9°32'N, 39°43'E

19°21'N, 43°44'E

(recovery site, both ±3')

42°51'39"N, 73°57'1"W

9°30'N, 31°45'E

27°12'S, 31°19'E

16°35'N, 11°21'W

41°42'N, 72°39'E

11°51'N, 8°13'E

Date

7 Jul 42

5 Oct 67

12 Apr 68

9-15 Aug 70

12 Oct 70

23 Oct 70

8 Apr 71

25 Apr 71

Time

10:00 a.m.

local time

5:15-5:30 a.m.

local time

8:30 p.m.

local time

Not known

10:30 hours

South African time

About 2:55 p.m.

GMT

2-6 a.m.

local time

(0700-1100 hrs. GMT)

About 4:30 p.m.

local time

(15.30 GMT)

Recovered Weight

7 kg

^V2kg

283 g

>2kg

3.2 kg

'Vl 5 kg

350 g

>10kg

Nelen did preliminary electron microprobe examinations on several of these meteorites. A grant from

the National Aeronautics and Space Administration provided funds for the purchase of the

Ankober and Wethersfield meteorites, and to pay recovery expenses for the Kabo meteorite. Dr. Robert

Hutchison, British Museum (Natural History) read

the manuscript and provided us with several helpful suggestions.

Meteorite Descriptions

The procedures and techniques used in this study

are standard for this type of investigation. Chemical analyses were perfomed following the general

procedures described earlier (Jarosewich, 1966).

Normative mineral compositions were calculated

from the chemical data. Olivine and pyroxene compositions were determined using the electron microprobe. Individual mineral grains were selected,

and Fe, Ca, and Mg were determined simultaneously. The number of grains analyzed depended

both on the homogeneity of the sample and on

their availability in the sections at hand. Olivine

compositions are reported as mole percent fayalite

(Fa) and pyroxene compositions are mole percent

ferrosilite (Fs). A petrographic classification is given

for each meteorite following the procedure of Van

Schmus and Wood (1967).

In the following sections, brief descriptions of

each of the meteorites are given in the order in

which they are listed in Table 2.

ANKOBER, BOLEDE, ETHIOPIA

The Ankober meteorite fall of 7 July 1942 was

observed and attracted local attention at the time.

We first heard of it more than 10 years later, when

Professor Guglielmo Sensi (1953) of the Pasteur Institue, Addis Ababa, wrote in behalf of the owner,

Ato Assafa Abye. Professor Sensi reported that the

meteorite had been incandescent in the air and

that it had fallen into a field of whitish clay causing no damage. A more dramatic version of the fall

attributed to Ato Assafa Abye reflects the excited

state of the local inhabitants: "After having

touched the earth, it sank to a depth of about one

meter, giving forth steam. The natives of the region

dug at the ground to remove it, but it was still

burning so much they could not take it immediately. They therefore left it in place, saying that it

must be a shell fired by the English." In early 1954

we received a specimen of the meteorite (USNM

2609) and its identification was confirmed by E. P.

Henderson. In 1967 Robert Citron, at that time

manager of the Smithsonian Institution Astrophysical Observing Station in Ethiopia, obtained the

main mass of the meteorite (USNM 3399). The

essentially complete individual stone of 6955 g was

subsequently deposited in the meteorite collection

in Washington.
NUMBER 14 65

TABLE 2.—Analytical data on observed-fall chondrites (values in weight percent unless otherwise indicated;

chemical analyses, Eugene Jarosewich; microprobe Fa-Fs determinations, Albert F. Noonan; classifications

according to Van Schmus and Wood, 1967)

Constituent

Ankober Schenectady Dwaleni Kiffa Kabo Tathlith Malakal Wethersfield

USNM 3399 USNM 5722 USNM 5447 USNM 5490 USNM5611 USNM 5448 USNM 5446 USNM 5596

H4 H4 H4fi6 H5 H4JI5 L6 L5 L6

Fe

Ni

Co

FeS

SiO3

TiO2

Al-A

Cr2O3

FeO

MnO

MgO

CaO

Na2O

K2O

P2O5

H2O+

H 2 O -

C

Total

Total Fe ... .

Olivine

Orthopyroxene

Diopside ... .

Albite

Anorthite ... .

Orthoclase . . .

Chromite

Ilmenite

Apatite

Nickel-Iron ..

Troilite

Fa

Fs

ANALYSES

13.96*

1.71

0.10

5.29

35.25

0.12

2.32

0.55

13.05*

0.32

22.86

1.72

0.84

0.12

0.33

0.45

0.36

0.10

99.55

27.47

43.6

18.8

3.4

7.1

2.2

0.7

0.8

0.2

0.8

15.8

5.3

19

17

15.01*

1.72

0.09

5.29

36.20

0.12

2.25

0.55

11.77*

0.32

23.00

1.77

0.83

0.10

0.29

0.69

0.23

0.12

100.35

27.52

38.7

23.2

3.8

7.0

2.1

0.6

0.8

0.2

0.7

16.8

5.3

19

17

17.23

1.75

0.09

5.21

36.49

0.12

2.30

0.51

9.52

0.27

23.16

1.72

0.88

0.09

0.22

0.18

0.03

0.04

99.81

28.41

33.9

25.8

4.0

7.4

2.1

0.5

0.8

0.2

0.5

19.1

5.2

17.65

1.77

0.09

5.62

36.14

0.12

2.14

0.52

9.15

0.31

23.26

1.77

0.82

0.10

0.22

0.00

0.10

0.01

99.79

28.33

17.56

1.80

0.09

4.82

36.54

0.12

2.15

0.53

9.60

0.33

23.24

1.72

0.82

0.08

0.28

7.61

1.14

0.06

6.58

39.44

0.14

2.40

0.52

13.84

0.33

24.35

1.88

0.99

0.11

0.21

0.03

0.01

99.72

28.09

NORMS

33.6

25.6

4.4

6.9

1.9

0.6

0.8

0.2

0.5

19.5

5.6

33.1

27.5

3.8

6.9

2.0

0.5

0.8

0.2

0.7

19.4

4.8

0.11

0.03

99.74

22.55

43.3

23.6

5.0

8.4

1.8

0.6

0.8

0.3

0.5

8.8

6.6

OLIVINE-PYROXENE COMPOSITIONS (mole percent)

20 L 18 19 L 26

16-19D

17 L

15-18 D

16

19 L

19D

17L

14-20D

21

7.56

1.18

0.05

4.30

40.38

0.14

2.14

0.50

15.32

0.28

24.88

1.85

0.95

0.10

0.17

<0.1

0.03

0.03

99.86

22.30

45.4

24.6

5.5

8.0

1.3

0.6

0.7

0.3

0.4

8.8

4.3

25

21

7.00

1.25

0.06

5.46

39.42

0.12

2.26

0.50

15.48

0.34

24.64

1.82

1.05

0.11

0.18

0.00

0.10

0.01

99.80

22.50

49.0

19.5

5.4

8.9

1.1

0.6

0.7

0.2

0.4

8.3

5.5

25

21

•Metallic Fe values are low and calculated FeO values are high in the Ankober and Schenectady analyses. This is primarily

due to oxidation of the sample prior to analysis. The brown color of the analysis powder and the high total water values are

consistent with this interpretation.

L = light fraction, D = dark fraction.

The stone is blocky in shape and about 90 percent of its surface is covered with fusion crust.

Late-stage spalling of fusion crust was restricted to

edges and corners where the essentially flat surfaces of the meteorite intersect. The stone appears

to have tumbled during flight and there is no ob-
66 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

vious anterior surface. One of the main surfaces is

markedly less smooth than the other surfaces. This

suggests a break-up at an early stage during atmospheric passage and the probability that the Ankober fall produced at least two individuals. The

fusion crust is brown in color, probably due to

oxidation by atmospheric moisture. It is assumed

that the stone has been protected from the weather

since shortly after its recovery, but we have no certain information on this prior to our obtaining the

specimen.

Freshly cut surfaces of Ankober quickly become

brown in color due to limonitic staining. Slices are

compact and hard, due largely to the metal forming

a continuous structural framework. Under low magnification (X 10) cut and broken surfaces are seen

to have a surprisingly open structure. Large numbers of submillimeter size cavities are present, into

which chondrules, euhedral crystals, and crystal

and chondrule fragments protrude. The meteorite

has a very uniform texture with no obvious brecciation or veining.

In thin section Ankober is seen to consist of distinct complete and broken chondrules in a matrix

of fine-grained silicates and metallic phases. Chondrules do not normally exceed one millimeter in

diameter, but a few unusually large ones up to 6

mm across were observed. Minerals present include

olivine, bronzite, clinobronzite, taenite, kamacite,

and troilite, with minor amounts of chromite,

whitlockite, and copper. Forty microprobe analyses

indicated a constant silicate composition of Fa 19

for olivine and Fs 17 for the low-Ca pyroxene. Abundant clinobronzite occurs both in chondrules and

matrix, often with devitrified glass. Ankober is classified as an H4 chondrite.

SCHENECTADY, SCHENECTADY COUNTY, NEW YORK

The Schenectady meteorite fall of 12 April 1968

produced an individual stone that was recovered

following a widely observed fireball. Details of the

fall and recovery have been reported by Fleischer,

et al. (1970). These authors also classified the meteorite, presented rare gas data, radioactive-ages and

cosmic-ray track information. The meteorite is the

property of The Schenectady Museum, Schenectady,

New York, and it was loaned to us for study in

August of 1969.

The physical characteristics of Schenectady are

similar to those described for Ankober. Exposure to

moisture from the air and during sawing has resulted in limonitic staining. The fusion crust however, is still black. The stone is compact and

hard, but under low magnification (X 10) many

small cavities can be seen. The openness of the

structure, however, is less than that observed in

Ankober. The stone has a uniform texture, free of

brecciation or veining.

Chondrules are abundant, distinct, and as large

as two millimeters in diameter. They are seen in

thin section to be in a relatively coarse-grained

matrix. The chondrules are composed of olivine,

orthobronzite, minor clinobronzite, and devitrified

glass. Forty-five microprobe analyses show the principal silicate minerals to be essentially homogeneous, with an olivine composition of Faa9 and a

pyroxene composition of Fs]7. Other minerals identified were taenite, kamacite, troilite, chromite,

whitlockite, and copper. The concentration of copper was unusually high with as many as 20 grains

found in one polished section. Schenectady is classified as an H4 chondrite.

DWALENI, SWAZILAND

Loud explosions accompanied the fall of the

Dawleni meteorite near the Swaziland-Transvaal

border on 12 October 1970. Three essentially completely fusion-crusted individuals were recovered

promptly from a 12 km

 2 area centering on the location given in Table 1. The individuals weighing

2.37, 0.51, and 0.35 kg were recovered from 15 to

18 cm below ground level in moist soil. We received

two pieces of the 0.35 kg stone (156 g and 10 g) on

3 November 1970. This sample material and information on the fall and recovery were sent to us by

J. G. Urie, Acting Director, Geological Survey and

Mines Department, Mbabane.

The Dwaleni chondrite is a compact rock with a

pronounced light-dark structure (Figure 1). The one

surface available to us shows approximately equal

areas of light and dark material, with thin dark

veins penetrating both types. The light-colored

areas are of uniform composition, have sharp outline and are tightly bound to the darker material.

Bogard, et al. (1973:2429) have noted that the dark

fraction of Dwaleni is unusually rich in rare gases.

Both light and dark materials undoubtedly have

similar bulk compositions, but minor differences in
NUMBER 14 67

FIGURE 1.—The Dwaleni, Swaziland, chondrite. A broken

surface showing light-dark structure and veining. One and a

half times actual size.

individual mineral compositions between these two

materials were noted. The lighter material contains

relatively large crystals of homogeneous olivine,

bronzite, and plagioclase. Chondrules are absent or

indistinct. Twenty-five grain analyses gave olivine,

pyroxene, and plagioclase compositions of Fa2o, Fs17

and An12. The petrographic classification of this

material is H6. The dark material, however, contains olivine and pyroxene of slightly higher

magnesium content and of somewhat variable composition. Eighteen grains analyses gave olivine and

bronzite compositions of Fa1G_19 and Fs15_18. Chondrules up to one millimeter in diameter are well

defined and contain turbid glass. The petrographic

classification of the dark material is H4. Kamacite,

taenite, troilite and minor chromite, and copper

occur in Dwaleni, mostly in the light-colored fraction.

KIFFA, MAURITANIA

At 2:55 p.m. GMT on 23 October 1970, detonations were heard and a smoke cloud observed in the

neighborhood of the town of Kiffa. About 10 a.m.

the next morning a meteorite specimen was found

by a child 8 km southwest of the town. It had made

a shallow hole about 20 cm deep in fine sand. The

meteorite shattered into many pieces on landing

and less than 1.5 kg was recovered. We received a

36 g piece on 17 February 1971 from M. Henri

Gruenwald, Chef de Service Geologique, Direction

Des Mines et de la Geologie, Nouakchott. M.

Gruenwald was also our source of information on

the fall and recovery of the meteorite.

The Kiffa meteorite is a friable gray chondrite

with distinct chondrules reaching a maximum diameter of approximately 2 mm. The chondrules

can be separated with ease from the fine-grained

white matrix, which appears to cement the chondrules and metal phases together. The texture is

quite uniform and there are no obvious foreign inclusions. Olivine and bronzite are the principal

silicate minerals in both chondrules and matrix.

Clinobronzite is rare. Twenty microprobe analyses

show chondrule olivine and pyroxene to be constant in composition, the fayalite and ferrosilite

value being Fa18 and Fs1(i, respectively. The white

matrix is composed, at least in part, of what appears

to be comminuted chondrules and devitrified glass.

In addition to olivine and bronzite, clinobronzite,

kamacite, taenite, troilite, chromite, and whitlockite were identified. Although chondrules are distinct, Kiffa is classified an H5 chondrite principally

on the basis of silicate homogeneity and the presence of only minor clinopyroxene.

KABO, GWARZO DISTRICT, KANO STATE, NIGERIA

The name Gwarzo has been used as a synonym

for Kabo.

The Kabo meteorite shower of 25 April 1971

attracted considerable local attention, and at least

four stones with a total weight of over 10 kg were

recovered. We received a 134 g sample on 9 June

1971. Both the sample and a description of the fall

and recovery were provided by Professor M. O.

Oyawoye, Geology Department, University of Ibadan. A detailed description of this meteorite has

been prepared by Hutchison and coworkers (Hutchison, et al., 1973).

Kabo is an ordinary chondrite with a subtle

light-dark structure. Bogard, et al. (1973) have

shown that its dark fraction contains an enrichment

of several trapped rare gases. Veining and distorted

metal grains in Kabo seem to be preferentially associated with the dark fraction. Chondrules, which
68 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

range up to two millimeters in diameter in both

fractions, are well defined in the dark fraction and

less well denned in the light fraction. Clinobronzite

occurs in both the light and dark fractions.

The minerals identified in Kabo are olivine,

bronzite, clinobronzite, kamacite, taenite, troilite,

chromite, ilmenite, whitlockite, chlorapatite, and

copper. Thirty grain analyses in the dark fraction

show pyroxene variability over the composition

range Fs14_20. The olivines, however, are essentially

homogeneous with a composition of Fa19. Glass occurs as fragments and in chondrules in minor

amounts, indicating that the dark fraction is less

equilibrated than the light fraction. Thirty olivine

and pyroxene grain analyses in the light fraction

indicate homogeneous compositions of Fa19 and

Fs17. The textural and compositional differences result in an H4 classification for the dark fraction and

an H5 classification for the light fraction.

TATHLITH, SAUDI ARABIA

The Tathlith meteorite fell early in the morning

on 5 October 1967 about 15 km from the village of

Tathlith. A single blocky-shaped, fusion-crusted

individual was recovered immediately. The exact

weight of the stone is not known to us, but estimates

based on photographs indicate that it weighed

about 2 kg (Figure 2). We received a 205 g slice of

Tathlith from Glen F. Brown, Chief, U.S. Geological Survey Field Party, Jiddah, Saudi Arabia on 22

November 1967. It had been identified as a meteorite by Gerhard W. Leo in the U. S. Geological

Survey Laboratories in Jiddah. The main mass of

the meteorite is believed to be in the possession of

the Emir of Abha.

Tathlith is a highly recrystallized gray chondrite

of uniform texture. Chondrules range in size up to

3 mm in diameter and are easily discernible on a

cut or broken surface. In thin section, however, the

chondrules appear relict and intergrown with granular plagioclase and metal. Minerals identified are

olivine, hypersthene, clinohypersthene, plagioclase,

kamacite, taenite, troilite, chromite, and copper.

Twenty grain analyses show the major silicates to

be homogeneous with olivine composition of Fa26

and hypersthene of Fs2i- The plagioclase is also

homogeneous with a composition of An10. Small

amounts of clinohypersthene, which are probably

a

it^yy^H

'•i-i

FIGURE 2.—The Tathlith, Saudi Arabia, meteorite, a, Cut

surface from which our 205 g specimen was removed, b,

Meteorite sitting on cut surface. Scale in inches. Photographs

by Gerhard W. Leo, U.S. Geological Survey.

remnant, occur in some of the larger chondrules.

Tathlith is an L6 chondrite.

MALAKAL, UPPER NILE PROVINCE, SUDAN

The fall of the Malakal meteorite during the

first half of August 1970 into an active military

area has been described by Dawoud and Vail

(1971). The meteorite fragment that reached Khar-
NUMBER 14 69

toum on 15 August 1970, weighed about 2 kg, and

photographs of that piece indicate that it is a part

of a considerably larger stone. It is not known if

other fragments were recovered. We received a 194 g

piece and 4.4 g of fragments from Professor J. R.

Vail of the University of Khartoum on 3 November

1970. A comprehensive description of the Malakal

meteorite has recently been published by El Rabaa,

etal. (1974).

Malakal is a unique meteorite from the point of

view of its cosmic-ray history. Cressy and Rancitelli

(1974) note that cosmic-ray produced

 2(iAl and 58Mn

are anomalously high in Malakal. They conclude

that the meteorite must have experienced a twostage irradiation, and that during the earlier stage

Malakal was exposed to a cosmic-ray flux several

times larger than that incident on other chondrites

or that measured by space probes.

Malakal is a moderately veined and brecciated

hypersthene chondrite, with the dark and apparently shock-produced vein material also occurring in patches. Kamacite and troilite also appear

to have been partially shock melted. Their interfaces with each other are frequently lacy and

diffuse, as are their interfaces with surrounding

silicates. Abundant spherules of metal or sulfide are

observed within the silicates near the metallic

phases. Chondrules are present, ranging up to 5 mm

in diameter, and the silicate matrix is moderately

recrystallized. The minerals identified are olivine,

hypersthene, kamacite, taenite, troilite, ilmenite,

chromite, and whitlockite. Twenty grain analyses

show the major silicates to be homogeneous with

olivine composition of Fa25 and pyroxene of Fs2i.

Malakal is classified as an L5 chondrite.

WETHERSFIELD,, HARTFORD COUNTY,, CONNECTICUT

The Wethersfield meteorite fell into the home of

Mr. and Mrs. Paul J. Cassarino during the early

morning hours of 8 April 1971. It penetrated a roof

of asbestos shingles and three-quarter-inch plywood,

then passed through four inches of insulating material and nearly went through a half-inch sheetrock

ceiling in a second floor room. Debris on the floor

of the room called attention to the presence of a

350 g meteorite precariously suspended in the

broken ceiling. Richard E. McCrosky of the Smithsonian Astrophysical Observatory, Cambridge,

visited the Cassarino's and obtained the specimen

FIGURE 3.—The Wethersfield, Connecticut, chondrite. The

bottom left side of the photograph shows posterior fusion

crust and spalled areas of crust. The bottom center area

shows a broken surface and extensive interior veining.

for scientific study and preservation. He also canvassed the surrounding area and made numerous

inquiries about the possibility of other pieces having been found. Only the one specimen was recovered, and no observations were reported that

would allow fixing the time of fall more precisely.

The meteorite as found was largely covered with

a dark fusion crust. Areas where the fusion crust

had spalled late in flight covered 10 to 15 percent

of the surface. The largest single surface covering

nearly half of the specimen, was smooth and

rounded and appeared to have been a leading

surface during atmospheric flight. The other surfaces were more irregular and the opposite surface

appears to have been a posterior surface. Its fusion

crust is lighter in color, more vesicular, and it has

small areas of the darker anterior fusion crust deposited on it. This area of posterior fusion crust is

shown in the central area of Figure 3.

Wethersfield is a gray, highly recrystallized chondrite with black veins and patches of black material

(Figure 3). This black material appears to have

been produced by shock. Relict chondrules range

up to 2 mm in diameter, with a few large ones

approaching 5 mm. Fifteen microprobe grain analyses show the silicates to be homogeneous, with an

olivine composition of Fa25 and hypersthene of

Fs2i. Other minerals identified were kamacite,

taenite, troilite, chromite, and whitlockite. It is

classified as an L6 chondrite.
70 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

Literature Cited

Bogard, D. D., M. A. Reynolds, and L. A. Simms

1973. Noble Gas Concentrations and Cosmic Ray Exposure

Ages of Eight Recently Fallen Chondrites. Geochimica et Cosmochimica Acta, 37:2417-2433.

Cressy, Philip J. Jr.

1970. Multiparameter Analysis of Gamma Radiation from

the Barwell, St. Severin and Tathlith Meteorites.

Geochimica et Cosmochimica Acta, 34:771-779.

Cressy, P. J., Jr., and L. A. Rancitelli

1974. The Unique Cosmic-Ray History of the Malakal

Chondrite. Earth and Planetary Science Letters, 22:

275-283.

Dawoud, A. S., and J. R. Vail

1971. Malakal Meteorite, Sudan. Nature: Physical Science,

229:212-213.

El Rabaa, S. M., A. M. Daminova, M. I. Dyakonova, L. G.

Kvasha, L. K. Levskii, and A. V. Fisenko

1974. The Results of the Investigation of the Malakal

Chondrite. Meteoritika, 33:83-89.

Fireman, E. L., and R. Goebel

1970. Argon 37 and Argon 39 in Recently Fallen Meteorites and Cosmic-Ray Variations. Journal of Geophysical Research, 75:2115-2124.

Fireman, Edward L., and Gert Spannagel

1971. Fresh Meteorites in 1970 and the Cosmic-Ray

Gradient. Chemie der Erde, 30:83-101.

Fleischer, R. L., E. Lifshin, P. B. Price, R. T. Woods, R. W.

Carter, and E. L. Fireman

1970. Schenectady Meteorite. Icarus, 12:402-406.

Heimann, M., P. P. Parekh, and W. Herr

1974. . A Comparative Study on ^Al and

 MMn in Eighteen

Chondrites. Geochimica et Cosmochimica Acta, 38:

217-234.

Hutchison, R., D. E. Ajakaiye, C. J. Elliott, and F. A. Fry

1973. The Kabo, Nigeria, Meteorite Fall. Mineralogical

Magazine, 39:340-345.

Jarosewich, E.

1966. Chemical Analyses of Ten Stony Meteorites. Geochimica et Cosmochimica Acta, 30:1261-1265.

Reynolds, M. A., D. D. Bogard, and C. M. Polo

1971. Dwaleni—A New Gas-Rich Chondrite (Abstract).

E.O.S., 52:269.

Sensi, Guglielmo

1953. [Letter from Professor Sensi to the Smithsonian

Institution.] Accession file 202751, Office of the

Registrar, Smithsonian Institution.

Smith, S., and E. L. Fireman

1973. Ages of Eight Recently Fallen Meteorites. Journal of

Geophysical Research, 78:3249-3259.

Tobailem, Jacques, and Claude Lalou

1972. Age d'exposition de la meteorite Kiffa. Comptes

Rendus des Seances de UAcadimie des Sciences,

Series B, 274 (21): 1185-1187.

Van Schmus, W. R., and J. A. Wood

1967. A Chemical-Petrologic Classification for the Chondritic Meteorites. Geochimica et Cosmochimica Acta,

31:747-765.
List of Meteorites in the National Museum of Natural History,

Smithsonian Institution

Compiled by Brian Mason

ABSTRACT

A brief history of the meteorite collection in the

National Museum of Natural History is followed

by a list with data of locality, type, and weight of

each specimen.

Introduction

Meteorites formed part of the original collections

of the Smithsonian Institution. James Smithson's

bequest, besides the endowment fund, included

(Goode, 1897:305) "a cabinet, which . . . proves to

consist of a choice and beautiful collection of minerals, comprising probably eight or ten thousand

specimens. . . . The cabinet also contains a valuable

suite of meteoric stones, which appear to be suites

of most of the important meteorites which have

fallen in Europe during several centuries." In 1854

the then Secretary, Joseph Henry (1854:18), recorded: "The laboratory of the Institution during

the past year has been used by Professor J. Lawrence

Smith in the examination of American minerals.

. . . He also made a series of analyses of meteorites,

among which were fourteen specimens belonging to

the cabinet of James Smithson." Unfortunately, the

specific meteorites from the Smithson collection

are not identified, and the meteorite collection was

apparently destroyed, along with the rest of Smithson's cabinet, in the 1865 fire.

In 1880 G. P. Merrill, in a manuscript report,

Brian Mason, Department of Mineral Sciences, National

Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560.

noted only six meteorites in the catalog: Imilac,

Vaca Muerta, New Concord, Parnallee, Searsmont,

and Cold Bokkeveld. The Tucson iron, which

should have formed the chief attraction, was not

cataloged, although brought to Washington in

1863. The Casas Grandes iron was also received

around 1880, being transferred to the Smithsonian

Institution along with much other material from

the Philadelphia Centennial Exhibition. However,

the collection grew rapidly during the next decade,

largely through the efforts of F. W. Clarke, who

was appointed honorary curator in 1883. In 1889

he published a catalog of the meteorite collection

as of October 1888, in which he lists 128 distinct

falls and finds; in addition, there were 217 meteorites in the Shephard collection, which was deposited in the museum by Shephard's son in 1886

(and ultimately bequeathed to the Smithsonian

Institution in 1915). Considerable duplication existed between the two collections, and many of the

specimens in both collections were small fragments.

Since that time the meteorite collection has

grown steadily. In 1902, W. Tassin brought the

Clarke catalog up to date; the Shephard meteorites

were listed along with the museum's collection,

and the combined collections contained 348 falls

and finds. The most recent published catalog is

that by G. P. Merrill, "Handbook and Descriptive

Catalogue of the Meteorite Collections in the

United States National Museum." The collection

at that time comprised 412 independent falls and

finds. In the Annual Report of the Smithsonian

Institution, E. P. Henderson (1948) noted that the

collection had grown to 767 meteorites.

The present collection contains representative

material of some 1300 meteorites, or about twothirds of all known meteorites. The current catalog

71
72 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

in the Department of Mineral Sciences lists over

5700 individual specimens. This collection ranks in

size and comprehensiveness with that of the British

Museum (Natural History).

ACKNOWLEDGMENTS.—I wish to thank Mr. R. S.

Clarke, Jr., and Mr. A. F. Noonan for much assistance in compiling this list, and Dr. W. R. Van

Schmus for some unpublished data on the classification of individual chondrites.

Literature Cited

Clarke, F. W.

1889. The Meteorite Collection of the U.S. National Museum: A Catalogue of Meteorites Represented November 1, 1886. Report of the Smithsonian Institution, 1885-86, part 2:255-265.

Goode, G. B.

1897. The Smithsonian Institution, 1846-1896. Washington.

Henderson, E. P.

1948. American Meteorites and the National Collection.

Annual Report of the Board of Regents of the

Smithsonian Institution, pages 257-268.

Henry, J.

1854. Report of the Secretary. Ninth Annual Report of

the Board of Regents of the Smithsonian Institution. 463 pages.

Merrill, George P.

1916. Handbook and Descriptive Catalogue of the Meteorite Collections in the United States National

Museum. United States National Museum Bulletin,

94.

Tassin, W.

1902. Descriptive Catalogue of the Meteorite Collection in

the United States National Museum to January 1,

1902. Report of the United States National Museum for 1900, pages 671-698.

CHONDRITES:

(Type, where

known, is indicated by a

following

digit)

ACHONDRITES:

Enstatite

Bronzite

Hypersthene

Amphoterite

Carbonaceous

Aubrite

Diogenite

Chassignite

Ureilite

Angrite

Nakhlite

Howardite

Eucrite

E

H

L

LL

C

Ae

Ah

Ac

Au

Aa

An

Aho

Aeu

Abbreviations

STONY-IRONS:

IRONS:

Pallasite

Mesosiderite

Siderophyre

Lodranite

Hexahedrite

Octahedrite

Coarsest octahedrite

Coarse octahedrite

Medium octahedrite

Fine octahedrite

Finest octahedrite

Plessitic octahedrite

Ataxite

Anomalous

P

M

S

Lo

Hx

O

Ogg

og

Om

Of

Off

Opl

D

Anom

List

Weights are given in grams unless otherwise indicated;

"s" indicates that only a thin or polished section is present

Name

Aarhus

Abancay

Abee

Abernathy

Accalana

Achilles

Achiras

Adams County

Adargas

ad-Dahbubah

Adelie Land

Adhi Kot

Admire

Locality

Denmark

Peru

Canada

Texas

Australia

Kansas

Argentina

Colorado

Mexico

Saudi Arabia

Antarctica

Pakistan

Kansas

Class

H

Of

E4

L6

L3

H5

L6

H5

Om

H5

L5

E3

P

Weight

s

9.8

2950

83

14

546

6.8

569

24

40 kg

69

22

22 kg

Name

Adrian

Agen

Aggie Creek

Aguada

Ahumada

Ainsworth

Akpohon

Akron (1961)

Alais

Alamogordo

Alamosa

Albareto

Albin

Locality

Texas

France

Alaska

Argentina

Mexico

Nebraska

Canada

Colorado

France

New Mexico

Colorado

Italy

Wyoming

Class

H4

H5

Om

L6

P

Ogg

Om

L6

Cl

H5

L6

L4

P

Weight

1090

163

984

8.0

834

1635

64

70

0.6

905

1784

1.7

3200
NUMBE

R 14

Name

Aleppo

Alessandria

Alexander County

al-Ghanim (iron)

al-Ghanim (stone)

Alfianello

Algoma

Alikatnima

Allegan

Allende

Al Rais

Alt Bela

Altonah

Amates

Ambapur Nagla

Amherst No. 1

Amherst No. 2

Anderson

Andover

Andura

Angelica

Angers

Angra dos Reis (stone)

Ankober

Anoka

Anthony

Antofagasta

Apoala

Appley Bridge

Arapahoe

Arcadia

Archie

Arispe

Arlington

Arltunga

Armel

ar-Rakhbah

Arriba No. 1

Arroyo Aguiar

Artracoona

Asheville

Ashfork

Ashmore

ash-Shalfar

Assam

Assisi

as-Su'aydan

Aswan

Atarra

Atemajac

Athens

Atlanta

Atoka

Atwood

Auburn

Augustinovka

Aumale

Aumieres

Aurora

Locality

Syria

Italy

North Carolina

Saudi Arabia

Saudi Arabia

Italy

Wisconsin

Australia

Michigan

Mexico

Saudi Arabia

Czechoslovakia

Utah

Mexico

India

Nebraska

Nebraska

Ohio

Maine

India

Wisconsin

France

Brazil

Ethiopia

Minnesota

Kansas

Chile

Mexico

Great Britain

Colorado

Nebraska

Missouri

Mexico

Minnesota

Australia

Colorado

Saudi Arabia

Colorado

Argentina

Australia

North Carolina

Arizona

Texas

Saudi Arabia

India

Italy

Saudi Arabia

Egypt

India

Mexico

Alabama

Louisiana

Oklahoma

Colorado

Alabama

USSR

Algeria

France

New Mexico

Class L6H5 Og O? H6 L6 OmDH5 C3

C2 OmOf Og H5 L6L6 PL6H6 OmL6 Aa H4 Of H5 POm

LL6

L5

LL6

H6

Og

Om

DL

5OL5H5 L6 OmOg H5 H5 L5H5 H5 OmL4L6

LL6

E5

L6

L6

Ogg

Om

L6

L6H4

Weight

162

37

12

500

3755

680223218 k

g

380 kg

132

10

10 kg

14

45

8017

473

48

2791

9.0

331

0.7

8.5

6964

132

8711

16 kg

324

545

422

1676

3760

178 kg

6140

979

301

395

1142

2.9

375

6.2

39

16

9357

29

5530

11

378

206

235

432

161

235

99

81

16

78

Name

Ausson

Avanhandava

Babb's Mill

(Troost's Iron)

Bachmut

Bacubirito

Bahjoi

Bald Mountain

Baldwyn

Balfour Downs

Bali

Ballinger

Ballinoo

Bandong

Bansur

Banswal

Baquedano

Barbotan

Barea

Baroti

Barranca Blanca

Barratta

Bartlett

Barwell

Barwise

Bath

Bath Furnace

Bear Creek

Beardsley

Bear Lodge

Beaver Creek

Beddgelert

Beenham

Bella Rocca

Belle Plaine

Bells

Bellsbank

Benares

Bencubbin

Bendego

Benld

Bennett County

Benton

Bereba

Beuste

Bhola

Bholgati

Bialystok

Bielokrynitschie

Billings

Billygoat Donga

Binda

Bingera

Bir Hadi

Bischtiibe

Bishop Canyon

Bishopville

Bishunpur

Locality

France

Brazil

Tennessee

USSR

Mexico

India

North Carolina

Mississippi

Australia

Cameroon

Texas

Australia

Java

India

India

Chile

France

Spain

India

Chile

Australia

Texas

Great Britain

Texas

South Dakota

Kentucky

Colorado

Kansas

Wyoming

Canada

Great Britain

New Mexico

Mexico

Kansas

Texas

South Africa

India

Australia

Brazil

Illinois

South Dakota

Canada

Upper Volta

France

Bangladesh

India

Poland

USSR

Missouri

Australia

Australia

Australia

Saudi Arabia

USSR

Colorado

South Carolina

India

Class L5H5 DL6

Off Og L4 L6Og C3 Og

Opl

LL6

L6L5 OmH5 ML6

Anom

L4OmL5 H5 H4 L6OmH5 OmH4 H5 L5OmL6

C2Hx

LL6

Anom

Og

H6

Hx

LL6

Aeu

L5

L

Aho

Aho

H4

Om

L6

Aho

Hx

H5

Og

Of

Ae

LL3

73

Weight

223

162

1339

997

497

222

0.5

911

154

459

1415

56

0.5

5.7

864

354

132

6.6

84

4256

670

1463

290

1086

388

275

926

3265

731

17

4166

666

90

0.5

343

88

7021

1980

6.3

8135

225

153

116

1.6

16

56

434

0.6

228

197

525

3358

226

63042
74 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

Name

Bitburg

Bjelaja Zerkov

Bjurbole

Black Moshannon Park

Black Mountain

Blackwell

Blanket

Blansko

Blithfield

Bluff

Bocas

Bodaibo

Boelus

Boerne

Bogou

Boguslavka

Bolrumilitz

Bolivia

Bondoc Peninsula

Bonita Springs

Boogaldi

Bori

Borkut

Bowden

Bowesmont

Boxhole

Brady

Brahin

Braunau

Breece

Breitscheid

Bremervorde

Brenham

Brewster

Bridgewater

Briggsdale

Briscoe

Bristol

Britstown

Broken Bow

Brownfield (1937)

Brownfield (1964)

Bruderheim

Bruno

Budulan

Bununu

Burdett

Burgavli

Bur-Gheluai

Burkett

Burlington

Burnabbie

Burrika

Buschof

Bushman Land

Bushnell

Bustee

Butler

Butsura

Locality

Germany

USSR

Finland

Pennsylvania

North Carolina

Oklahoma

Texas

Czechoslovakia

Canada

Texas

Mexico

USSR

Nebraska

Texas

Upper Volta

USSR

Czechoslovakia

Bolivia

Philippines

Florida

Australia

India

USSR

South Africa

North Dakota

Australia

Texas

USSR

Czechoslovakia

New Mexico

Germany

Germany

Kansas

Kansas

North Carolina

Colorado

Texas

Tennessee

South Africa

Nebraska

Texas

Texas

Canada

Canada

USSR

Nigeria

Kansas

USSR

Somalia

Texas

New York

Australia

Australia

USSR

South Africa

Nebraska

India

Missouri

India

Class

Of

H6

L4

L

Og

L5

L6

H6

E6

L5

L6

Of

LL6

H6

Og

Hx

Og

Og

M

H5

Of

L6

L5

H5

L6

Om

L6

P

Hx

Om

H5

H3

P

L6

Om

Om

L5

Of

Opl

H4

H3

H5

L6

Hx

M

Aho

H5

Og

H5

Og

Om

H5

L6

L6

Of

H4

Ae

Opl

H6

Weight

168

10

3509

29

18

2362

1790

2.3

129

8585

2

261

675

537

3107

185

325

20 kg

28 kg

34 kg

79

136

8.4

6.5

116

7346

60

20

241

541

s

33

89 kg

986

54

60

260

126

19

283

1182

168

5515

17

97

331

203

130

3513

1173

1325

65

0.6

14

2865

50

78

639

18

Name

Cabezo de Mayo

Cabin Creek

Cacaria

Cachari

Cadell

Calico Rock

Calliham

Cambria

Campbellsville

Campo del Cielo

Camp Verde

Canellas

Cangas de Onis

Canon City

Canton

Canyon City

Canyon Diablo

Cape Girardeau

Cape of Good Hope

Caperr

Cape York

Carbo

Cardanumbi

Carlton

Caroline

Carraweena

Carthage

Cartoonkana

Casas Grandes

Casey County

Cashion

Casilda

Casimiro de Abreu

Castalia

Castine

Cavour

Cedar (Kansas)

Cedar (Texas)

Cedartown

Cee Vee

Central Missouri

Cereseto

Chainpur

Chamberlin

Chandakapur

Channing

Chantonnay

Charcas

Charlotte

Charsonville

Chassigny

Chateau-Renard

Chaves

Chebankol

Cherokee Springs

Chesterville

Chico

Chico Mountains

Chicora

Locality

Spain

Arkansas

Mexico

Argentina

Australia

Arkansas

Texas

New York

Kentucky

Argentina

Arizona

Spain

Spain

Colorado

Georgia

California

Arizona

Missouri

South Africa

Argentina

Greenland

Mexico

Australia

Texas

Australia

Australia

Tennessee

Australia

Mexico

Kentucky

Oklahoma

Argentina

Brazil

North Carolina

Maine

South Dakota

Kansas

Texas

Georgia

Texas

Missouri

Italy

India

Texas

India

Texas

France

Mexico

Tennessee

France

France

France

Portugal

USSR

South Carolina

South Carolina

New Mexico

Texas

Pennsylvania

Class

L6

Om

Om

Aeu

L6

Hx

L6

Of

Om

Og

Og

H5

H5

H5

Om

Om

Og

H6

D

Om

Om

Om

L5

Of

H5

L3

Om

L6

Om

Og

H4

H5

Om

H5

L6

H6

H6

H4

Hx

H5

Ogg

H5

LL3

H5

L5

H5

L6

Om

Of

H6

Ac

L6

Aho

Og

LL6

Hx

L

Hx

LL6

Weight

207

34

165

1650

71

539

230

351

9521

196 kg

541

6.5

1103

55

409

284

1675 kg

4

209

36

8178

24 kg

0.6

1486

13

44

1399

s

1317 kg

92

71

203

212

17

0.2

9285

191

2181

9940

130

5072

65

114

98

32

1530

371

182

182

83

23

727

s

57

7885

103

s

173

272
NUMBER 14

Name

Chihuahua City

Chilkoot

Chinautla

Chinga

Chinguetti

Chulafinee

Chupaderos

Cincinnati

Clareton

Clark County

Clayton ville

Cleveland

Clover Springs

Clovis No. 1

Coahuila

Cobija

Cockarrow Creek

Cockburn

Cocklebiddy

Cocunda

Colby

Cold Bay

Cold Bokkeveld

Coldwater (iron)

Coldwater (stone)

Colfax

Collescipoli

Colomera

Comanche (iron)

Concho

Cookeville

Coolac

Coolamon

Coolidge

Coomandook

Coonana

Coon Butte

Coopertown

Coorara

Cope

Copiapo

Cortez

Cosby's Creek

Costilla Peak

Cotesfield

Covert

Cowra

Coya Norte

Crab Orchard

Cranberry Plains

Cranbourne

Cranganore

Cratheus

Credo

Crescent

Cronstad

Cross Roads

Crumlin

Cruz del Aire

Locality

Mexico

Alaska

Guatemala

USSR

Maurctania

Alabama

Mexico

Ohio

Wyoming

Kentucky

Texas

Tennessee

Arizona

New Mexico

Mexico

Chile

Australia

Australia

Australia

Australia

Wisconsin

Alaska

South Africa

Kansas

Kansas

North Carolina

Italy

Spain

Texas

Texas

Tennessee

Australia

Australia

Kansas

Australia

Australia

Arizona

Tennessee

Australia

Colorado

Chile

Colorado

Tennessee

New Mexico

Nebraska

Kansas

Australia

Chile

Tennessee

Virginia

Australia

India

Brazil

Australia

Oklahoma

South Africa

North Carolina

Ireland

Mexico

Class

Anom

Om

Of

D

M

Om

Om

Hx

L6

Om

L5

Om

M

H3

Hx

H6

L6

L6

H5

L6

L6

P

C2

O

H5

Om

H5

Anom

Og

L6

Og

Og

L6

C4

H6

H4

L6

Og

L6

H5

Anom

H6

Og

Om

L6

H5

Opl

Hx

M

Of

Og

L6

Of

L6

C2

H5

H5

L5

Of

Weight

363

5524

162

1613

409

. 119

2516

32

208

2069

198

819

1041

284 kg

147 kg

202

3.2

1850

119

s

3906

287

37

4768

5472

312

127

133

550

138

459

2067

s

203

11

s

199

1149

7.6

4147

174

54

1375

1849

17

2966

61

4850

2047

7.9

700 kg

10

42

7.4

s

12

6.5

35

351

Name

Cuernavaca

Cubertson

Cullison

Cumberland Falls

Cumpas

Cushing

Cynthiana

Dalgaranga

Dalgety Downs

Dalhart

Dalton

Dandapur

Daniel's Kuil

Davis Mountains

Dayton

Deal

Deelfontein

Deep Springs

Delegate

Del Rio

Densmore

Den ton County

Denver

Deport

Descubridora

Dexter

Dhurmsala

Dimboola

Dimitrovgrad

Dimmitt

Dingo Pup Donga

Dix

Djati-Pengilon

Dokachi

Doroninsk

Dorrigo

Douar Mghila

Doyleville

Drake Creek

Dresden (Canada)

Dresden (Kansas)

Drum Mountains

Duchesne

Duel Hill (1854)

Dungannon

Durala

Duruma

Dwaleni

D wight

Dyarrl Island

Eagle Station

Edjudina

Edmonson

Edmonton (Canada)

Edmonton (Kentucky)

Efremovka

Ehole

Locality

Mexico

Nebraska

Kansas

Kentucky

Mexico

Oklahoma

Kentucky

Australia

Australia

Texas

Georgia

India

South Africa

Texas

Ohio

New Jersey

South Africa

North Carolina

Australia

Texas

Kansas

Texas

Colorado

Texas

Mexico

Texas

India

Australia

Yugoslavia

Texas

Australia

Nebraska

Java

Bangladesh

USSR

Australia

Morocco

Colorado

Tennessee

Canada

Kansas

Utah

Utah

North Carolina

Virginia

India

Kenya

Swaziland

Kansas

New Guinea

Kentucky

Australia

Texas

Canada

Kentucky

USSR

Angola

Class

Om

H4

H4

Ae

Om

H4

L4

M

L5

L5

Om

L6

E6

Om

Off

L6

Og

D

Om

D

L6

Om

L6

Og

Om

Om

LL6

H5

Om

H4

Au

L

H6

H5

H6

Opl

LL6

H5

L6

H6

H5

Om

Of

Of

Og

L6

L6

H6

L6

M

P

H4

L6

Hx

Of

C3

H5

Weight

738

12

2421

8640

2212

519

643

159

125 kg

65

49 kg

57

5

117

24 kg

3

105

318

202

237

42 kg

8

208

4455

6021

212

681

46

219

6285

4.0

8905

464

16

7.5

39

0.5

17

152

27

212

522 kg

2780

138

1009

59

1.5

115

174

8

345

0.8

281

584

8277

269

1528
76 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

Name

Eichstadt

Ekeby

Elba

Elbogen

El Burro

El Capitan

Elenovka

Eli Elwah

Ellemeet

Ellerslie

Elm Creek

El Perdido

Elsinora

Elyria

Emery

Emmaville

Emmitsburg

Enigma

Enon

Ensisheim

Ergheo

Erie

Erxleben

Essebi

Estacado

Estherville

Esu

Eustis

Eva

Faith

Farley

Farmington

Farmville

Farnum

Faucett

Fayetteville

Felix

Fenbark

Filomena

Finmarken

Finney

Fisher

Fleming

Floyd

Follinge

Forest City

Forest Vale

Forksville

Forrest

Forrest Lakes

Forsyth

Forsyth County

Fort Pierre

Four Corners

Franceville

Frankfort (iron)

Frankfort (stone)

Franklin

Locality

Germany

Sweden

Colorado

Czechoslovakia

Mexico

New Mexico

USSR

Australia

Holland

Australia

Kansas

Argentina

Australia

Kansas

South Dakota

Australia

Maryland

Georgia

Ohio

France

Somalia

Colorado

Germany

Zaire

Texas

Iowa

Sudan

Florida

Oklahoma

South Dakota

New Mexico

Kansas

North Carolina

Nebraska

Missouri

Arkansas

Alabama

Australia

Chile

Norway

Texas

Minnesota

Colorado

New Mexico

Sweden

Iowa

Australia

Virginia

Australia

Australia

Georgia

North Carolina

South Dakota

New Mexico

Colorado

Kentucky

Alabama

Kentucky

Class Weight Name

H5 1 Freda

H4 18 Fremont Butte

H5 94 Frenchman Bay

Om 94 Fukutomi

Ogg 34 kg Futtehpur

Om 4831

L5 219 Gambat

L6 55 Garland

Ah s Garnett

L5 28 Garraf

H4 1185 Geidam

H5 39 Georgetown

H5 87 Ghubara

Om 234 Gibeon

M 1002 Gifu

Aeu s Gilgoin

Om 7 Girgenti

H4 94 Giroux

Anom 44 Gladstone (iron)

LL6 225 Gladstone (stone)

L5 1082 Glasgow

L 1275 Glorieta Mountain

H 6

 31 Gnadenfrei

C2 61 Goalpara

H6 10 kg Gobabeb

M 10 kg Goodland

H s Goose Lake

H 4

 480 Grady (1933)

L5 300 Grady (1937)

Grand Rapids

H5 434 Grant

H5 930 Grant County

L5 2620 Grassland

H4 5941 Great Bear Lake

L5 150 Greenbrier County

H5 6209 Gressk

H4 161 Gretna

C3 1286 Grosnaja

H5 4.0 Grossliebenthal

Hx 20 kg Gruneberg

P 977 Gruver

L5 277 Guarena

L6 6500 Guffey

H3 68 Guibga

H4 256 Guidder

Off 14 Gun Creek

H5 36 kg Gundaring

H4 147 Gunnadorah

L6 1995 Gutersloh

H5 1.7

LL5 s Haig

L6 9.5 Hainholz

Hx 1121 Hale Center No. 1

Om 99 Hale Center No. 2

Om 7255 Hallingeberg

Om 297 Hamilton

Om 1638 Hamlet

Aho 4.7 Hammond

H5 207 Hammond Downs

Locality Class Weight

North Dakota D 255

Colorado L4 162

Australia H3 82

Japan L5 9.7

India L6 19

Pakistan L6 29

Utah Ah 102

Kansas H4 286

Spain L6 53

Nigeria H5 5.5

Colorado H6 687

Saudi Arabia L5 9

South-West Africa Of 263 kg

Japan L6 18

Australia H5 4285

Italy L6 8939

Canada P 2381

Australia Og 21 kg

New Mexico H6 3250

Kentucky Om 4047

New Mexico Om Hkg

Germany H5 0.8

India Au 163

Southwest Africa H4 25

Kansas L4 174

California Om 1165 kg

New Mexico L 1768

New Mexico H3 772

Michigan Om 3526

New Mexico Om 481 kg

Kansas L6 696

Texas L4 114

Canada H6 40

West Virginia Om 473

USSR Hx 1935

Kansas L5 32 kg

USSR C3 4.7

USSR L6 49

Poland H4 16

Texas H4 1256

Spain H6 416

Colorado D 8200

Upper Volta L5 250

Cameroon LL5 0.4

Arizona Om 1204

Australia Og 237

Australia H5 1.2

Germany H4 22

Australia Om 450

Germany M 382

Texas L5 188

Texas H4 324

Sweden L3 144

Australia L6 201

Indiana LL4 1543

Wisconsin Om 293

Australia H4 15 kg
NUMBE

R 14

Name

Haraiya

Hardwick

Harleton

Harriman

Harrison County

Harrisonville

Havana

Haven

Havero

Haviland

Hawk Springs

Hedeskoga

Hedjaz

Helt Township

Hentmry

Hendersonville

Hermitage Plains

Hessle

Hex River Mountains

Hildreth

Hill City

Hoba

Hobbs

Hokmark

Holbrook

Holland's Store

Holly

Holyoke

Homestead

Honolulu

Hope

Hopper

Horace

Horse Creek

Hraschina

Huckitta

Hugoton

Huizopa

Hungen

Hvittis

Ibbenbiiren

Ibitira

Ider

Idutywa

Ilimaes (pallasite)

Ilinskaya Stanitza

Imilac

Imperial

Indarch

Indianola

Indian Valley

Indio Rico

Inman

Ipiringa

Iquique

Iredell

Iron Creek

Locality

India

Minnesota

Texas

Tennessee

Indiana

Missouri

Illinois

Kansas

Finland

Kansas

Wyoming

Sweden

Saudi Arabia

Indiana

Australia

North Carolina

Australia

Sweden

South Africa

Nebraska

Kansas

South-West

Africa

New Mexico

Sweden

Arizona

Georgia

Colorado

Colorado

Iowa

Hawaii

Arkansas

Virginia

Kansas

Colorado

Yugoslavia

Australia

Kansas

Mexico

Germany

Finland

Germany

Brazil

Alabama

South Africa

Chile

USSR

Chile

California

USSR

Nebraska

Virginia

Argentina

Kansas

Brazil

Chile

Texas

Canada

Class

Aeu

L4

L6OmL6L6 Of H6 Au H5 H5 H5 L

Ogg

Om

L5

L6H5 Hx L5 Of DH4 L4 L6Hx H4 H4 L5L5Og OmH5 Hx OmPH5 Of H6 E6 Ah

Aeu

Om

H5

PO

m

PH

4

E4

L5Hx H6 L4H6 D

Ogg

Om

Weight

2.2

1091

440012 k

g

19

10 kg

12

21

1.8

84

88

26

107

135

227 kg

2695

130

1863

582

173

10 kg

4203

224

12

8454

5437

222

5616

32

885

25

464

140

1.0

403

258

2790

21

1909

1.6

90 kg

50

155

184

19 kg

4

2840

225

489

4.7

1410

168

97

122

Name

Itapicuru-Mirim

Ivanpah

Ivuna

Jackalsfontein

Jackson County

Jajh deh Kot Lalu

Jamestown

Jelica

Jenkins

Jenny's Creek

Jerome

Jhung

Joe Wright Mountain

Johnson City

Johnstown

Jonzac

Judesegeri

Juromenha

Juvinas

Kaalijarv

Kaba

Kabo

Kainsaz

Kakangari

Kalaba

Kaldoonera Hill

Kalkaska x

Kamiomi

Kamsagar

Kandahar

Kansas City

Kapoeta

Kappakoola

Karakol

Karatu

Karee Kloof

Karkh

Karoonda

Kaufman

Kearney

Keen Mountain

Kelly

Kendall County

Kennard

Kenton County

Kerilis

Kermichel

Kernouve'

Kesen

Keyes

Khairpur

Khanpur

Kharkov

Khohar

Khor Temiki

Kiel

Kielpa

Locality

Brazil

California

Tanzania

South Africa

Tennessee

Pakistan

North Dakota

Yugoslavia

Missouri

West Virginia

Kansas

Pakistan

Arkansas

Kansas

Colorado

France

India

Portugal

France

USSR

Hungary

Nigeria

USSR

India

Zaire

Australia

Michigan

Japan

India

Afghanistan

Missouri

Sudan

Australia

USSR

Tanzania

South Africa

Pakistan

Australia

Texas

Nebraska

Virginia

Colorado

Texas

Nebraska

Kentucky

France

France

France

Japan

Oklahoma

Pakistan

India

USSR

India

Sudan

Germany

Australia

Class H5 OmCl L6OmE6Of

LL6

Og

Og

L4

L5OmL6Ah

Aeu

H6

D

Aeu

Og

C3

H5

C3

C3?

H4

H6

Om

H4

L6

L6H5

Aho

H6

LL6

LL6

Og

L6

C4

L5H5 Hx

LL4

Anom

H5

Om

H5

L6H6 H4 L6 E6

LL5

L6

L3

Ae

L6

H5

Weight

9.7

3115

122

30

46

18

329

231

55 kg

14

166

22

571

1955

1028

0.2

16

16

172

4.3

0.7

8026

0.5

11

1.4

7595

9.6

123

283

0.9

0.7

4572749

123

168

1008

5629

3512

2044

156

2691

2.4

42

1135

2105

1781

2730269290

6.2

351
78 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

Name

Kiffa

Killeter

Kimble County

Kingfisher

Kingoonya

Kingston

Kissij

Kittakittaooloo

Klein-Wenden

Klondike

Knowles

Knyahinya

Kodaikanal

Kopjes Vlei

Koraleigh

Krahenberg

Kramer Creek

Krasnoi-Ugol

Krasnoyarsk

Kress

Krymka

Kuleschovka

Kulnine

Kumerina

Kunashak

Kuttippuram

Kyancutta

Kybunga

Kyle

Kyushu

La Becasse

Laborel

La Caille

Ladder Creek

Lafayette

La Grange

L'Aigle

Lakangaon

Lake Bonney

Lake Brown

Lake Grace

Lake Labyrinth

Lake Murray

Laketon

Lakewood

La Lande

Lance

Langon

Landes

Langhalsen

Lanton

La Porte

La Primitiva

Las Vegas

Laundry East

Laundry Rockhole

Laundry West

Laurens County

Locality

Mauritania

Ireland

Texas

Oklahoma

Australia

New Mexico

USSR

Australia

Germany

Canada

Oklahoma

USSR

India

South Africa

Australia

Germany

Colorado

USSR

USSR

Texas

USSR

USSR

Australia

Australia

USSR

India

Australia

Australia

Texas

Japan

France

France

France

Kansas

Indiana

Kentucky

France

India

Australia

Australia

Australia

Australia

Oklahoma

Texas

New Mexico

New Mexico

France

France

West Virginia

Sweden

Missouri

Indiana

Chile

Nevada

Australia

Australia

Australia

South Carolina

Class

H4

H6

H6

L5

L4

Om

H5

H4

H6

D

Om

L5

Off

Hx

L6

LL5

L4

L6

P

L6

LL3

L6

L6

Opl

L6

L6

Om

L5

L6

L6

L6

H5

Om

L6

An

Of

L6

Aeu

L6

L6

L6

LL6

Ogg

L6

L6

L5

C3

H6

O

L6

Om

Om

Hx

Og

H3

H5

L4

Of

Weight

25

2.5

4130

2260

2.4

333

22

10

67

158

58

1575

283

64

s

4.4

38

5.5

910

113

136

11

170

339

175

120

754

94

253

216

81

17

107

5700

637

2168

448

10

s

0.2

335

1085

80

124

523

158

185

73

492

76

558

1491

93

2791

1.0

3.1

2.9

12

Name

Lawrence

Leedey

Leeds

Lenarto

Leon

Leoville

Le Pressoir

Les Ormes

Lesves

Lexington County

Lick Creek

Lillaverke

Lime Creek

Limerick

Lincoln County

Linville

Linwood

Lissa

Little Piney

Little River

Livingston (Montana)

Livingston (Tennessee)

Lixna

Locust Grove

Lodran

Logan

Lombard

Lonaconing

Long Island

Loomis

Loop

Loreto

Los Reyes

Lost City

Losttown

Lowicz

Loyola

Lua

Lubbock

Lucky Hill

Luis Lopez

Lumpkin

Lundsgard

Luotolax

Lutschaunig's Stone

Macau

Macibini

Madoc

Madrid

Mafra

Magura

Mainz

Malakal

Malotas

Malvern

Manbhoom

Mangwendi

Mantos Blancos

Locality

Kansas

Oklahoma

Canada

Czechoslovakia

Kansas

Kansas

France

France

Belgium

South Carolina

North Carolina

Sweden

Alabama

Ireland

Colorado

North Carolina

Nebraska

Czechoslovakia

Missouri

Kansas

Montana

Tennessee

USSR

Georgia

Pakistan

Oklahoma

Montana

Maryland

Kansas

Nebraska

Texas

Mexico

Mexico

Oklahoma

Georgia

Poland

doubtful

India

Texas

Jamaica

New Mexico

Georgia

Sweden

Finland

Chile

Brazil

South Africa

Canada

Spain

Brazil

Czechoslovakia

Germany

Sudan

Argentina

South Africa

India

Rhodesia

Chile

Class

L6

L6

Og

Om

H5

C2

L6

L5

L6

Og

Hx

H5

D

H5

L6

D

Og

L6

L5

H6

Om

Om

H4

Hx

Lo

H5

Hx

Og

L6

L6

L6

Om

Om

H5

Om

M

L5

L5

L5

Om

Om

L6

L6

Aho

L6

H5

Aeu

Om

L6

L4

Og

L5

L5

H5

Aho

LL6

LL6

Of

Weight

328

97

20

208

17 kg

482

3.6

0.3

1.5

2617

9.7

150

2.9

210

71

15

33 kg

118

78

170

294

123

58

2166

13

336

62

24

2696

229

149

89 kg

377

16 kg

71

82

1772

25

390

40

174

31

97

0.5

73

72

15

11

3.5

9

672

2

160

206

19

15

17

356
NUMBER 14

Name

Mapleton

Maria Elena (1935)

Marion

Marjalahti

Marshall County

Marsland

Mart

Matatiele

Mauerkirchen

Mayday

Mayodan

Maziba

Mbosi

McKinney

Mejillones

Melrose

Menow

Merceditas

Mem

Mertzon

Merua

Mesa Verde Park

Messina

Metsakyla

Mezo-Madaras

Miami

Mighei

Milena

Miller (Arkansas)

Miller (Kansas)

Mills

Milly Milly

Minas Gerais

Mincy

Misshof

Misteca

Moab

Mocs

Modoc

Mokoia

Molina

Molong

Monahans

Monroe

Monte Milone

Monze

Moonbi

Mooranoppin

Moore County

Mooresfort

Moorleah

Morito

Morland

Mornans

Morradal

Morrill

Morristown

Morven

Mosca

Locality

Iowa

Chile

Iowa

Finland

Kentucky

Nebraska

Texas

South Africa

Austria

Kansas

North Carolina

Uganda

Tanzania

Texas

Chile

New Mexico

Germany

Chile

Denmark

Texas

India

Colorado

Italy

Finland

Romania

Texas

USSR

Yugoslavia

Arkansas

Kansas

New Mexico

Australia

Brazil

Missouri

USSR

Mexico

Utah

Romania

Kansas

New Zealand

Spain

Australia

Texas

North Carolina

Italy

Zambia

Australia

Australia

North Carolina

Ireland

Australia

Mexico

Kansas

France

Norway

Nebraska

Tennessee

New Zealand

Colorado

Class

Om

Om

L6

P

Om

H5

Of

Og

L6

H

Hx

L6

Om

L4

Hx

L5

H4

Om

L6

Om

H5

Om

L5

H4

L3

H

C2

L6

H5

H

H6

Om

L

M

H5

Og

O

L6

L6

C3

L5

P

Opl

H4

L

L6

Om

Og

Aeu

H5

L6

Om

H6

H5

D

Om

M

H5

L6

Weight

3728

11kg

1717

452

67

244

454

69

73

5

13 kg

390

779

5208

12 kg

2782

110

724

220

3319

197

3439

3.4

s

335

1160

620

99

53

41

367

283

10

308

158

344

253

3346

5623

6.4

1189

864

913

252

0.6

265

286

149

460

161

s

636

517

32

58

87

1757

112

6136

Name

Mosquero

Mossgiel

Moti-ka-nagla

Motpena

Motta di Conti

Mount Ayliff

Mount Browne

Mount Dooling

Mount Dyrring

Mount Edith

Mount Egerton

Mount Joy

Mount Magnet

Mount Morris

Mount Ouray

Mount Padbury

Mount Sir Charles

Mount Stirling

Mount Vernon

Muddoor

Mulga (North)

Mulga (South)

Mundrabilla

Mungindi

Muonionalusta

Murchison

Murfreesboro

Murnpeowie

Muroc Dry Lake

Murphy

Murray

Muzzaffarpur

Nagaria

Nagy-Vazsony

Nakhla

Nakhon Pathom

Nanjemoy

Naoki

Nardoo No. 1

Nardoo No. 2

Narellan

Naretha

Narraburra

Nas

Nashville (Kansas)

Nashville (North

Carolina)

Navajo

Nazareth (iron)

Nedagolla

Needles

Neenach

Negrillos

Nejed

Nejo

Nelson County

Nenntmannsdorf

Neptune Mountains

Locality

New Mexico

Australia

India

Australia

Italy

South Africa

Australia

Australia

Australia

Australia

Australia

Pennsylvania

Australia

Wisconsin

Colorado

Australia

Australia

Australia

Kentucky

India

Australia

Australia

Australia

Australia

Sweden

Australia

Tennessee

Australia

California

North Carolina

Kentucky

India

India

Hungary

Egypt

Thailand

Maryland

India

Australia

Australia

Australia

Australia

Australia

Sweden

Kansas

North Carolina

Arizona

Texas

India

California

California

Chile

Saudi Arabia

Ethiopia

Kentucky

Germany

Antarctica

Class

H4

L4

H6

L6

H

Og

H6

Ogg

P

Om

Ae

Ogg

Opl

E6?

Om

M

Of

Og

P

H5

H6

H4

Om

Of

Of

C2

Om

Anom

L

Hx

C2

Opl

Aeu

Og

An

L6

H6

H6

H5

L6

L6

L4

Om

LL6

L6

O

Ogg

Om

Anom

Of

L6

Hx

Om

L6

Ogg

Ogg

Og

Weight

1629

560

77

98

2.4

95

486

370

672

1577

3731

2833

100

557

84

8147

21

383

134 kg

26

278

0.4

217 kg

573

419

30 kg

125

191

43

582

5830

5

s

36

644

852

79

227

75

109

33

2.7

321

17

23 kg

2676

517

315

28

10 kg

2210

15 kg

2931

183

1207

15

997
80 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

Name

Nerft

Ness County

Netschaevo

New Almelo

New Baltimore

New Concord

New Leipzig

Newport

New Westville

Ngawi

N'Goureyma

Nikolskoe

N'Kandhla

Nobleborough

Nocoleche

Nogoya

Nora Creina

Norcateur •

Nordheim

Norfolk

Norfork

Norristown

North East Reid

North Forrest

North Haig

North Reid

North West Forrest

Norton County

Novo-Urei

Nuevo Laredo

Nulles

Nyirabrany

Oak

Oakley (iron)

Oakley (stone)

Oberlin

Obernkirchen

Ochansk

Odessa

Oesede

Oesel

Ogallala

Ogi

Ojuelos Altos

Okano

Okechobee

Okirai

Olivenza

Ollague

Olmedilla de Alarcon

Orange River (iron)

Orgueil

Orlovka

Ornans

Oro Grande

Oroville

Orvinio

Oscuro Mountains

Locality

USSR

Kansas

USSR

Kansas

Pennsylvania

Ohio

North Dakota

Arkansas

Ohio

Java

Mali

USSR

South Africa

Maine

Australia

Argentina

Australia

Kansas

Texas

Virginia

Arkansas

Georgia

Australia

Australia

Australia

Australia

Australia

Kansas

USSR

Mexico

Spain

Hungary

Australia

Idaho

Kansas

Kansas

Germany

USSR

Texas

Germany

USSR

Nebraska

Japan

Spain

Japan

Florida

Japan

Spain

Bolivia

Spain

South Africa

France

USSR

France

New Mexico

California

Italy

New Mexico

Class

L6

L6

Om

L5

Anom

L6

Og

P

Of

LL3

Anom

L4

Om

Aeu

Anom

C2

L4

L6

D

Om

Om

Om

H5

H4

Au

LL5

E6

Ae

Au

Aeu

H6

LL5

L5

Og

H6

LL5

Of

H4

Og

H5

L6

Og

H6

L

Hx

L4

H5

LL5

P

H

Om

Cl

H

C3

H5

Om

L6

Og

Weight

71

5810

267

1557

3216

8700

17 kg

222

3318

103

1519

32

146

0.1

203

4.5

8.5

133

1094

110

60

196

1.9

3.8

8.2

4.7

11

1797

93

132

124

s

0.8

111kg

1614

195

302

1668

128 kg

137

28

118

40

191

20

968

31

938

296

314

120

183

127

3.8

9.1

401

59

102

Name

Osseo

Otis

Ottawa

Oubari

Ovid

Owens Valley

Ozona

Ozren

Pacula

Palo Blanco Creek

Pan de Azucar

Pantar

Para de Minas

Paragould

Paranaiba

Parnallee

Pasamonte

Patos de Minas

Patrimonio

Patwar

Pavlodar

Pavlograd

Pavlovka

Peace River

Peckelsheim

Peck's Spring

Peetz

Pena Blanca Springs

Penokee

Perpeti

Perryville

Persimmon Creek

Pervomaisky

Pesyanoe

Petersburg

Petropavlovka

Pevensey

Phillips County

Piancaldoli

Pickens County

Piedade do Bargre

Pierceville (iron)

Pierceville (stone)

Pillistfer

Pima County

Pine River

Pinnaroo

Pinon

Pipe Creek

Pitts

Plains

Plainview (1917)

Plantersville

Pleasanton

Plymouth

Pohlitz

Ponca Creek

Portales No. 3

Locality

Canada

Kansas

Kansas

Libya

Colorado

California

Texas

Yugoslavia

Mexico

New Mexico

Chile

Philippines

Brazil

Arkansas

Brazil

India

New Mexico

Brazil

Brazil

Pakistan

USSR

USSR

USSR

Canada

Germany

Texas

Colorado

Texas

Kansas

Pakistan

Missouri

North Carolina

USSR

USSR

Tennessee

USSR

Australia

Colorado

Italy

Georgia

Brazil

Kansas

Kansas

USSR

Arizona

Wisconsin

Australia

New Mexico

Texas

Georgia

Texas

Texas

Texas

Kansas

Indiana

Germany

Nebraska

New Mexico

Class

Og

L6

LL6

L4

H

Om

H

Og

L6

Aeu

Og

H5

Of

LL5

L6

LL3

Aeu

Hx

L

M

P

L6

Aho

L6

Ah

L5

L6

Ae

H

L6

Opl

Opl

L6

Ae

Aeu

H

LL5

P

L3

H

Om

Om?

L

E6

Hx

Om

M

D

H6

Of

H5

H5

H6

H5

Om

L5

Ogg

L

Weight

37 kg

215

12

151

251

157 kg

1658

17

44

s

101

112

223

31kg

322

520

1585

827

14

592

12

97

8

551

2.2

629

810

457

3552

35

14 kg

3519

446

67

42

118

14

368

s

67

398

808

183

66

150

297

1132

1240

312

1022

363

24 kg

1862

204

619

0.1

29

156
NUMBE

R 14

Name

Port Orford

Potter

Prairie Dog Creek

Prambanan

Pribram

Pricetown

Providence

Puente del Zacate

Pulaski County

Pulsora

Pultusk

Puquios

Puripica

Putinga

Putnam County

Quartz Mountain

Queen's Mercy

Quenggouk

Quillagua

Quinn Canvon

Raco

Rafruti

Rakovka

Ramsdorf

Ranchapur

Rancho de la Pila

Rancho de la Presa

Rangala

Ransom

Ras Tanura

Rawlinna

Reager

Red River

Reed City

Reid

Reliegos

RenazzO

Rhine Villa

Richardton

Richland

Richmond

Rich Mountain

Rifle

Rio Loa

Rio Negro

Rochester

Rodeo

Roebourne

Rolla (1936)

Rolla (1939)

Rosario

Rosebud

Rose City

Rowena

Rowton

Roy (1933)

Roy (1934)

Ruff's Mountain

Locality

Oregon

Nebraska

Kansas

Java

Czechoslovakia

Ohio

Kentucky

Mexico

Georgia

India

Poland

Chile

Chile

Brazil

Georgia

Nevada

South Africa

Burma

Chile

Nevada

Argentina

Switzerland

USSR

Germany

India

Mexico

Mexico

India

Kansas

Saudi Arabia

Australia

Kansas

Texas

Michigan

Australia

Spain

Italy

Australia

North Dakota

Texas

Virginia

North Carolina

Colorado

Chile

Brazil

Indiana

Mexico

Australia

Kansas

Kansas

Honduras

Texas

Michigan

Australia

Great Britain

New Mexico

New Mexico

South Carolina

Class PL6H3

Off H5 L6OmOmOg H5 H5 OmHx L6Of OmH6 H4 Hx OmH5 DL6 L6H4 OmHLH4 HH5 LOmOg HL

C2Og H5 Hx L5L6Og Hx L4HOmOmHHOg HH5 H6 OmL5L6Om

Weight 24

1930

314

2.3

140

3.0

5492

2332

112

5.8

3263

90

15 kg

962

2736

57

424

35

741

45

133

22232059541226

295

5.9

2.8

37

79

1877

4.0

26

26

114

5155

1026

18

112

4367

940

6653

1998

4018

414

10

1905

35877832

8607

4528

4762

Name

Rupota

Rush County

Rush Creek

Russel Gulch

Sacramento Mountains

St. Caprais-de-Quinsac

St. Francois County

St. Genevieve County

St. Germain-du-Pinel

St. Lawrence

St. Louis

St. Mark's

St. Mary's County

St. Mesmin

St. Michel

St. Peter

Saint-Sauveur

St. Severin

Salaices

Salina

Saline

Salla

Salles

Salta

Salt Lake City

Salt River

Sams Valley

San Angelo

San Cristobal

Sanderson

Sandia Mountains

Sandtown

San Emigdio

San Francisco

Mountains

San Jose

San Juan Capistrano

Santa Apolonia

Santa Catharina

Santa Cruz

Santa Isabel

Santa Luzia

Santa Rosa

Santa Rosalia

Santiago Papasquiero

Sao Jose do Rio Preto

Sao Juliao de Moreira

Saratov

Sardis

Sarepta

Savannah

Schenectady

Schonenberg

Schwetz

Scott City

Scottsville

Scurry

Seagraves

Locality

Tanzania

Indiana

Colorado

Colorado

New Mexico

France

Missouri

Missouri

France

Texas

Missouri

South Africa

Maryland

France

Finland

Kansas

France

France

Mexico

Utah

Kansas

Finland

France

Argentina

Utah

Kentucky

Oregon

Texas

Chile

Texas

New Mexico

Arkansas

California

Arizona

Mexico

California

Mexico

Brazil

Mexico

Argentina

Brazil

Colombia

Mexico

Mexico

Brazil

Portugal

USSR

Georgia

USSR

Tennessee

New York

Germany

Poland

Kansas

Kentucky

Texas

Texas

Class L6HL6OmOmLOg Of H

LL6

H4

E5

LL3

LL6

L6

L5

E4

LL6

H4

Om

H5

LH

6

PH

5

Opl

Om

Om

DO

m

Ogg

Om

H4

Of

H5

H6

Om

D

C2L6

Ogg

Anom

P

Anom

L5

Ogg

L4Og Og OmH5 L6OmH5 Hx H5 H4

81

Weight

975

4020

3170

72

6550

0.4

236

1380

53

100

2.4

258

s

86

231

549

7.8

2463

395

221

897

318

50

24 kg

2.5

112

19

3443

136

471

1672

100

490

1334

14218

5689

11kg

s

29

23 kg

5751

63

1176

7.5

2150

513

800 kg

25427 k

g

30

8.8

165

228

1042

26

13 kg
82 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

Name

Searsmont

Seelasgen

Segowlie

Seguin

Seibert

Seligman

Selma

Semarkona

Seminole

Sena

Seneca

Seneca Township

Seres

Serre de Mage

Sevrukovo

Seymour

Shalka

Shallowater

Sharps

Shaw

Shelburne

Shergotty

Shingle Springs

Shrewsbury

Shytal

Siena

Sierra Gorda

Sierra Sandon

Signal Mountain

Sikhote-Alin

Silver Bell

Silver Crown

Silverton

Simdndium

Sindhri

Sinnai

Sioux County

Sitathali

Ski

Sleeper Camp

Slobodka (1818)

Slobodka (1838)

Smith Center

Smithland

Smithonia

Smith's Mountain

Smithsonian Iron

Smithville

Social Circle

Soko-Banja

Somervell County

Soper

Soroti

South Bend

South Byron

South Dahna

South Oman

Spearman

Springwater

Locality

Maine

Poland

India

Kansas

Colorado

Arizona

Alabama

India

Texas

Spain

Kansas

Michigan

Greece

Brazil

USSR

Missouri

India

Texas

Virginia

Colorado

Canada

India

California

Pennsylvania

Pakistan

Italy

Chile

Chile

Mexico

USSR

Arizona

Wyoming

Australia

South Africa

Pakistan

Italy

Nebraska

India

Norway

Australia

USSR

USSR

Kansas

Kentucky

Georgia

North Carolina

Tennessee

Georgia

Yugoslavia

Texas

Oklahoma

Uganda

Indiana

New York

Arabia

Arabia

Texas

Canada

Class

H5

Og

L6

H

H

Og

H4

LL3

H4

H4

H

Of

H4

Aeu

L5

Og

Ah

Ae

H3

L6

U>

Aeu

D

Om

L6

LL5

Hx

Og

Of

Ogg

Ogg

Og

L6

M

H5

H

Aeu

H5

L6

L6

L4

L

L6

D

Hx

Om

Ogg

Og

Of

LL4

P

Anom

Off

P

D

O

E

Om

P

Weight

90

407

61

49

131

147

157

245

457

167

265

9372

2.0

25

23

1320

88

1017

401

1596

735

270

32

395

27

15

17 kg

72

41

4107

192

170

69

9.1

46

17

154

13

1.2

3.3

3.5

4.0

91

133

590

57

3400

3708

22 kg

337

80

1122

154

2.8

465

142 kg

13

870

2647

Name

Stalldalen

Stannern

Staunton

Stavropol

Steinbach

Stonington

Sublette

Success

Suchy Dul

Sultanpur

Supuhee

Susuman

Sutton

Suwahib (Buwah)

Sweetwater

Sylacauga

Tabor

Tadjera

Taiban

Tamarugal

Tambo Quemado

Tane

Tanokami Mountain

Tatahouine

Tathlith

Tawallah Valley

Tazewell

Tell

Temple

Tenham

Tennasilm

Ternera

Texline

Thiel Mountains

Thomson

Thoreau

Thule

Thunda

Thurlow

Tiberrhamine

Tieraco Creek

Tieschitz

Tilden

Timochin

Tirupati

Tjabe

Tjerebon

Tlacotepec

Tobe

Tocopilla

Toluca

Tomatlan

Tombigbee River

Tomhannock Creek

Tonganoxie

Tonk

Torrington

Toubil River .

Locality

Sweden

Czechoslovakia

Virginia

USSR

Germany

Colorado

Kansas

Arkansas

Czechoslovakia

India

India

USSR

Nebraska

Saudi Arabia

Texas

Alabama

Czechoslovakia

Algeria

New Mexico

Chile

Peru

Japan

Japan

Tunisia

Saudi Arabia

Australia

Tennessee

Texas

Texas

Australia

USSR

Chile

Texas

Antarctica

Georgia

New Mexico

Greenland

Australia

Canada

Algeria

Australia

Czechoslovakia

Illinois

USSR

India

Java

Java

Mexico

Colorado

Chile

Mexico

Mexico

Alabama

New York

Kansas

India

Wyoming

USSR

Class

H5

Aeu

Og

L6

S

H

L

L6

H5

L6

H6

Om

H5

H3

H5

H

H5

L5

L5

Om

Om

L5

Og

Ah

L6

D

Off

L6

L

L6

L4

D

H5

P

L6

Og

Om

Om

Om

L6

Om

H3

L6

H5

H

H

L5

D

H4

Hx

Og

H6

Hx

H5

Om

Cl

H

Om

Weight

192

497

6101

52

427

100

62

3503

1.8

71

89

74

305

5

1018

1682

65

69

438

17 kg

970

586

91

14

246

1267

1642

180

169

5535

4838

31

646

28 kg

217

294

449

209

403

100

4038

31

903

64

16

39

s

2400

5454

1467

109 kg

168

3001

31

231

3

116

175
NUMBER 14

Name

Tourinnes-la-Grosse

Travis County

Trenton

Trenzano

Treysa

Trifir

Troup

Tryon

Tucson

Tulia

Turtle River

Twin City

Tysnes Island

Uberaba

Ucera

Udei Station

Ularring

Ulysses

Umm Ruaba

Union

Union County

Ute Creek

Utrecht

Utzenstorf

Uwet

Uwharrie

Vaca Muerta

Valdinizza

Valkeala

Valley Wells

Vavilovka

Vengerovo

Vera

Veramin

Verkhne Udinsk

Vernon County

Victoria West

View Hill

Vigarano

Vincent

Vishnupur

Vouille

Wabar

Waconda

Waingaroraia

Waldo

Waldron Ridge

Walker County

Wallapai

Walltown

Walters

Warrenton

Waterville

Wathena

Weatherford

Weaver Mountains

Locality

Belgium

Texas

Wisconsin

Italy

Germany

Mali

Texas

Nebraska

Arizona

Texas

Minnesota

Georgia

Norway

Brazil

Venezuela

Nigeria

Australia

Kansas

Sudan

Chile

Georgia

New Mexico

Holland

Switzerland

Nigeria

North Carolina

Chile

Italy

Finland

California

USSR

USSR

Argentina

Iran

USSR

Wisconsin

South Africa

New Zealand

Italy

Australia

India

France

Saudi Arabia

Kansas

New Zealand

Kansas

Tennessee

Alabama

Arizona

Kentucky

Oklahoma

Missouri

Washington

Kansas

Oklahoma

Arizona

Class

L6

H5

Om

H6

Om

L

L6

L

Anom

H5

Om

D

H4

H5

H5

Om

L6

H

L5

Hx

Ogg

H4

L6

H

Hx

Om

M

L6

L6

L6

LL6

H5

L4

M

Om

H

Of

Om

C3

L5

LL6

L

Om

L6

Om

L

Og

Hx

Of

L

L6

C3

Anom

Hx

Anom

D

Weight

69

1480

391kg

285

195

3.0

114

2028

911kg

4917

387

3400

104

103

205

202

1.2

334

64

172

84

177

40

105

1105

1287

1449

850

s

11

3.0

34

50

52

36

9.3

34

1883

2051

s

24

161

299

1189

600

94

70

291

303 kg

3.7

25 kg

36

197

429

1216

773

Name

Webb

Weekeroo

Weldona

Welland

Wellington

Wellman

Wessely

Western Arkansas

West Forrest

Weston

West Reid

Weathersfield

Whitman

Wichita County

Wilbia

Wildara

Wiley

Willamette

Willaroy

Williamstown

Willow Creek

Willowdale

Wilmot

Wiluna

Wingellina

Winona

Witchellina

Wold Cottage

Wolf Creek

Wonyulg-unna

Woodbine

Wood's Mountain

Woodward County

Woolgorong

Wynella

Yambo No. 1

Yambo No. 2

Yandama

Yanhuitlan

Yardymly

Yatoor

Yayjinna

Yenberrie

Yonozu

York (iron)

Youndegin

Ysleta

Yurtuk

Zaborzika

Zacatecas (1972)

Zacatecas (1969)

Zavid

Zebrak

Zhovtnevyi

Zomba

Zsadany

Zvonkov

Locality

Australia

Australia

Colorado

Canada

Texas

Texas

Czechoslovakia

Arkansas

Australia

Connecticut

Australia

Connecticut

Nebraska

Texas

Australia

Australia

Colorado

Oregon

Australia

Kentucky

Wyoming

Kansas

Kansas

Australia

Australia

Arizona

Australia

Great Britain

Australia

Australia

Illinois

North Carolina

Oklahoma

Australia

Australia

Zaire

Zaire

Australia

Mexico

USSR

India

Australia

Australia

Japan

Nebraska

Australia

Texas

USSR

USSR

Mexico

Mexico

Yugoslavia

Czechoslovakia

USSR

Malawi

Romania

USSR

Class

L6

Og

H

Om

H

H5

H

Of

H5

H4

H6

L5

H

Og

H5

H5

Opl

Om

H3

Om

Og

H

H6

H4

H4

E6?

H4

L6

Om

Om

Of

Of

H4

L6

H4

H

L3

L6

Of

Og

H5

L6

Og

H4

Om

Og

Anom

Aho

L

Anom

Om

L6

H5

H

L6

H

H

Weight

3.1

11kg

1070

213

4224

543

0.2

1672

2.3

181

0.8

290

21

2251

3.8

s

189

2721

187

1223

4866

74

133

284

s

224

156

57

350 kg

577

48 kg

1786

44 kg

362

431

4.0

3.2

377

1200

81

222

14

3836

44

30

5756

19

33

4.1

444

6600

234

73

703

270

13

40
Chemical Analyses of Two Microprobe Standards

Eugene Jarosewich

ABSTRACT

Chemical analyses are given for two materials for

use as microprobe standards: volcanic glass from

the Mid-Atlantic Ridge and hornblende from

Arenal Volcano, Costa Rica.

There has been increasing need for well-analyzed

microprobe standards because, as with any instrumental method, a standard compositionally similar

to an unknown is the most likely to give reliable

results. The key requirements for microprobe standards can be found in the literature in general and

some are briefly summarized in an earlier paper

(Jarosewich, 1972).

The chemical analyses were performed employing

analytical methods described by Hillebrand, et al.

(1953) and Peck (1964) except for the determination

of sodium and potassium. The latter elements were

determined by flame photometry. Data for two new

microprobe standards follow.

ARENAL HORNBLENDE USNM 111356.—A green

hornblende xenocryst from an andesitic basalt

scoria was collected by Dr. W. Melson from the

September 1968 eruption of Arenal Volcano, Costa

Rica. The sample was crushed and sieved and the

60-100 mesh fraction purified using a heavy liquid

(D 3.19-3.21) followed by Franz magnetic separation. The purified sample contains less than 0.5

percent grains with adhering groundmass. An electron microprobe check indicates the sample to be

Eugene Jarosewich, Department of Mineral Sciences, National

Museum of Natural History, Smithsonian Institution, Washington, D. C. 20560.

TABLE 1.—Chemical analyses of two microprobe

standards (analyst: E. Jarosewich)

Constituent

SiO2

A12O3

Fe2O3

FeO

MgO

CaO

Na2O

K2O

H2O+

H 2 O -

TiO2

P2O5

MnO

Total

Total Fe

Basaltic Glass

Arenal Hornblende Juan de Fuca Ridge

(USNM 111356) (USNM 111240152)

41.46

15.47

5.60

6.43

14.24

11.55

1.91

0.21

1.21

<0.01

1.41

<0.01

0.15

99.64

8.91

50.81

14.06

2.23

9.83

6.71

11.12

2.62

0.19

n.d.

0.02

1.85

0.17

0.22

99.83

9.20

n.d. = not determined.

homogeneous within the limits of analytical error.

BASALTIC GLASS USNM 111240/52.—This sample

was dredged from the median, flat-floored valley of

the southern part of the Juan de Fuca Ridge (44°

40'N, 130°30'W, 2195-2220 m). Approximately 2

percent of the sample is composed of inclusions,

primarily plagioclase and olivine. Because the average combined chemical composition of these inclusions is similar to the composition of the glass and

because they are present in small amount, the bulk

chemistry of the sample is essentially the same as

85
86 SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

the glass. Electron microprobe analyses shows the 1953. Applied Inorganic Analysis. 2nd edition, 1034 pages.

glass to be extremely homogeneous in major and

 Ne w York :

 J° h n Wile?

 an d Sons

-

. , / s> J Jarosewich, E.

minor element content. .„„„ „, . , . , , r . ... , , ,,. ,

1974. Chemical Analyses or Five Minerals tor microprobe

Standards. Smithsonian Contributions to the Earth

Literature Cited Sciences, 9:83-84.

Peck, L. C.

Hillebrand, W. F., G. E. F. Lundell, H. A. Bright, and J. I. 1964. Systematic Analysis of Silicates. U. S. Geological SurHoffman vey Bulletin, 1170:66.
Preparation of Multiple Microprobe Samples

Grover C. Moreland and Richard Johnson

ABSTRACT

Several microprobe samples may be prepared simultaneously using a new technique described here.

With judicious choice of samples the same technique may be used to prepare microprobe standard

discs.

hardener. This mixture is stirred on the 40° to 45°

C hot plate until it reaches a watery consistency.

Each sample is now inserted in its appropriately

numbered hole. Then using a dissecting needle,

place some of the epoxy mixture on the plexiglass

disc and with the needle push some of the mixture

over the edge of each hole. The epoxy will run

down the wall of the hole, hit the cover glass, and

A preparation technique has been developed

whereby it is possible to prepare several probe

samples simultaneously. The bask: mount is a

plexiglass disc y4 inch thick cut from a 1-inch rod.

Holes of any convenient size are drilled through

the disc and the holes numbered with a scriber. As

many as 19 samples can be mounted and prepared

simultaneously (Figure 1).

A white 3X 5 inch card is fastened to a hot plate

with masking tape; this card provides a visual contrast against which the sample can be easily seen.

A carefully cleaned one inch cover glass is placed

on the white card, and the sample disc placed on

the cover glass. A weight is added to insure good

contact between the disc and the cover glass, and

the hot plate temperature adjusted to 40° to 45° C

(100°-115° F). Rubber cement is now painted

around the edge of the coverglass-plexiglass disc

sandwich, and the mount is left on the hot plate

for 5 to 10 minutes, or until cured as shown by a

brown color.

A mixture of epoxide and expoxide hardener

is now prepared (Buehler 20-8130 epoxide and

20-8132 hardener or equivalent). A convenient

amount is 4.8 gms of epoxide and 0.8 gm of

Grover C. Moreland and Richard Johnson, Department of

Mineral Sciences, National Museum of Natural History,

Smithsonian Institution, Washington, D. C. 20560.

E D

FIGURE 1.—Schematic of plexiglass disc. (A = Dissecting needle,

B = epoxy mixture, C = cross-section of plexiglass disc, D =

coverglass, E = mineral grain, F = hole drilled in plexiglass

disc.)

rise. This procedure should leave the specimen

in contact with the cover glass, with epoxy around

and above it, but very little if any beneath it. One

can check under a stereomicroscope to see that the

sample is resting on the cover glass (i.e., at the bottom of the hole) and that no air bubbles have

formed. If these conditions are not met then the

samples can be pushed down and air bubbles freed

87
SMITHSONIAN CONTRIBUTIONS TO EARTH SCIENCES

using a small dissecting needle. One then covers

the entire upper (numbered) side of the disc with

epoxy, thus insuring that the numbers will not be

accidentally obliterated during the subsequent steps

of preparation and during later use of the disc.

The epoxy mixture should be allowed to dry on

the hot plate for about 30 minutes at 50° C (125°

F). The card-coverglass-plexiglass disc assembly is

then placed in a 50° C oven for about 10 hours. The

assembly is then removed from the oven and the

card separated from the remainder of the unit.

The samples are exposed by grinding off the cover

glass on an 850 rpm lap with a slurry of water and

$:600 aluminum oxide. Being careful to keep the

lap damp, grind the disc for 2 to 3 minutes or

until the samples are exposed. Also grind the numbered side, being careful not to grind off the numbers. The disc should now be washed thoroughly

with soap and water and dried.

The samples are now brought to a rough polish

by covering a 600 rpm wheel with a double thickness of brown wrapping paper that has been

covered with polishing oil and 3 micron diamond

compound. (The diamond compound regularly used

is VB-3, produced by the Glennel Corp. of West

Chester, Pennsylvania.) The disc should be moved

counter to the rotation of the wheel; a lapping time

of about 5 minutes is usually required. After washing and drying the polish is examined under a reflected light microscope. If necessary repeat the

lapping until the only scratches visible are those

made by the 3 micron polishing compound. The

numbered side of the disc should also be polished to

make the numbers visible.

Next, the disc is lapped on a 150 rpm wheel

covered with a polishing cloth. The polishing cloth

is covered with water to which 0.05 micron alumina

is sparingly added until a damp-dry condition is

reached. The disc is moved for 30 turns counter to

the rotation of the wheel. The disc, same side down,

is rotated 180° and given another 30 turns on the

wheel. Once again it is washed and dried.

Finally the disc is lapped on a 50 rpm wheel

covered with a clean polishing cloth, giving it only

5 turns with light pressure, counter to the rotation

of the wheel. This final polishing is to remove any

possible contamination due to smearing.

The disc is now washed and dried and examined

under a reflected light microscope at about 80

magnification. The 3 micron scratches should no

longer be visible and one should see only highly

polished, optically fiat grains.

One should exercise care in choosing specimens

to be mounted in one disc as some very soft

material may smear upon polishing and hence

cause contamination of the rest of the specimens.

Tests were made here on eight samples of varying

hardness (metallic zinc, gold, magnesium, aluminum, silver, platinum. Ni-Fe-Co alloy, and lead

sulfide (galena)), and mounted and polished on a

single disc. A check was made by electron microprobe to determine any effects of smearing from

one sample to another due to the polishing technique. For each sample (sulfur in the case of the

galena) the background level above and below the

peak was determined. Each sample was then probed

for Zn, Au, Mg, Al, Ag, Pt, Fe, Co, Ni, and S. Sulfur

was the only element that showed a measurable

concentration in some of the other samples on the

disc, hence the galena did contaminate the other

samples.

Preliminary tests have shown that with judicious

choice of samples, microprobe standard discs may

be prepared using this technique, thus effecting a

considerable saving in time and materials over the

one-at-a-time method of polishing microprobe standards.

ACKNOWLEDGMENT.—We wish to thank Charles

Obermeyer and William Potts for their assistance in

the preparation of this paper.

U.S. GOVERNMENT PRINTING OFFICE: 197S 546-367/32