bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduced Meteoritic Iron Oxide
Authors: Buddhue John Davis
Published: June 2012

Weighed pieces of Canyon Diablo, Arizona, oxide were reduced to metal by heating in hydrogen. In two cases, the oxide was analyzed before reduction, and the resulting metal was analyzed after reduction. From the data obtained, it is possible to calculate the oxygen content of the original oxide by three different methods. The results are in fair agreement, and indicate an oxygen content of about 29%.
Miscellaneous Notes on Meteorites from Holbrook, Richardton, Xiquipilco, and Mount Elden*
Authors: Buddhue John Davis
Published: June 2012

From time to time, minor observations have been made on meteorites. These included the following: A Holbrook, Arizona, aerolite contained 0.23% of water‐soluble salt, which included 0.02% of sulfate and a trace of calcium. The same stone had a variable moisture content, which depended upon the relative humidity of its surroundings. A Richardton, North Dakota, aerolite contained only 0.033% of moisture. A Xiquipilco, Mexico, siderite probably contained a trace of nitride. An analysis is given of the taenite in a Mount Elden, Arizona, siderite. Much of the graphite in this mass appeared to be cliftonite or otherwise crystalline.
Some Remarks on the Origin of Earthly Meteorites*
Authors: Leonard Frederick C.
Published: June 2012

In general, fallen meteorites are probably of planetary origin, whereas consumed meteorites, perhaps in most cases, if not in all, are of cometary origin. The latter variety of bodies are evidently of insufficient mass to escape total vaporization within the Earth's atmosphere. Since no comet—and probably no meteorite, either—has ever been showed to have been traveling on an unmistakably hyperbolic heliocentric orbit, if Earthly meteorites are of planetary and cometary origin, their elliptic heliocentric orbits and their origin within the Solar System are readily explained.
The Albuquerque, Bernalillo County, New Mexico, Siderite (ECN =+ 1068,350)
Authors: Beck Carl W. , La Paz Lincoln
Published: June 2012

Abstract

In this paper are given details concerning the acquisition of an iron meteorite (siderite) found approximately 13 miles west‐southwest of Albuquerque, in Bernalillo County, New Mexico (equatorial coördinate number (ECN) = + 1068,350). The total mass recovered to date is a single specimen weighing 157.3 gm. Mineralogical, chemical, and radiochemical studies have been made, and, on the basis of these investigations, the meteorite is classified as a medium octahedrite (Om). The original belief that this meteorite might be a stray specimen of the Canyon Diablo, Arizona, fall is refuted by the mineralogical, chemical, and radiochemical findings, especially the last two.
The Discovery of an Additional Sams Valley, Oregon, Meteorite (ECN =+ 1229,425)
Authors: Morley Russell A.
Published: June 2012

Abstract

The discovery, in the summer of 1949, of an additional Sams Valley, Oregon, meteorite (ECN = + 1229,425; cl. = Om) on the Frank B. Payne property, near Beagle, Jackson County, Oregon, in the Trail Quadrangle, is announced. This meteorite was found by Mr. Payne's father in the late 1800′s, but has never before been reported. It is now on display in the Jacksonville Museum. The specimen measures 12.5 × 4.5 × 4 cm. (overall dimensions), and has a specific gravity (sp. gr.) of 6.82 and a hardness of 5.5–6.0, and weighs about 1028 gm.
A Proposed Curriculum in Meteoritics for College Students*
Authors: Leonard Frederick C.
Published: June 2012

Abstract

A proposed new undergraduate curriculum or “major” in meteoritics—which would be simply a “combined major” in astronomy and mineralogy—is outlined as it would probably work out at the present time at the University of California, Los Angeles, and similar institutions.
Fire from Heaven?*
Authors: Wylie C. C.
Published: June 2012

Abstract

When heat is reported in connection with the fall of any ordinary meteorite, it is always found that the alleged meteorite is not a meteorite at all, but rather a “meteorong”!
THE LEONIDS BY RADAR—1957 TO 19681
Authors: McIntosh Bruce A. , Millman Peter M.
Published: June 2012

Radar observations of the Leonid meteor shower, made near Ottawa during the years from 1957 to 1968 inclusive, are analyzed and reduced to give comparative flux rates. A strength classification has been made in terms of the ratio of shower rates to background rates. The relative strengths found by radar, showing marked variability from year to year, are confirmed by analysis of available visual observations.

There is also great variation in the distribution of particle sizes. The high rates of the 1966 return were accompanied by a relatively high percentage of small particles. In 1965 there was a much higher proportion of large particles, and the high rates of 1961 showed a mass or size distribution intermediate between that of 1966 and of 1965.
THE VALDINIZZA METEORITE: MINERALOGY, CHEMISTRY AND MICROTEXTURES
Authors: Levi‐Donati G. R. , Jarosewich Eugene
Published: June 2012

The principal data are collected about the fall and the distribution of the fragments of the Valdinizza, Italy, meteorite. A complete individual, weighing 872 g, preserved in the United States National Museum, Washington, D. C., is described in some detail. The mineralogical composition is olivine, Fa25; hypersthene, Fs23; plagioclase, An10; maskelynite; nickel‐iron; troilite; chromite; ilmenite and possibly a phosphate mineral. Valdinizza is a fairly typical hypersthene chondrite, belonging to the type 6 chondrites of Van Schmus and Wood (1967); its structure shows evidence of a period of high‐temperature recrystallization; interesting features of shock‐metamorphism are notable, the microtexture deformations suggesting a high level of stress
THE SEMINOLE, GAINES CO., TEXAS, METEORITE
Authors: Huss G. I. , Buseck P. R. , Moore C. B.
Published: June 2012

The Seminole Meteorite was found near Seminole, Texas in 1961 and recognized as a meteorite in 1963. Two fragments weighing a total of 41.1 kg were recovered. Analyses showed these to be fragments of a single black olivine‐bronzite, or H4‐group chondrite, showing brecciation and a moderate number of individual chondrules
POTENTIOSTATIC STUDY OF IRON METEORITE CORROSION
Authors: Tackett Stanford L. , Goudy Andrew J.
Published: June 2012

A potentiostat was used to study the electrolytic corrosion of iron meteorites in a neutral solution. Low current densities were chosen so that the observed potentials would more closely approximate the theoretical Nernst values. Iron, nickel, and cobalt ions, the products of corrosion, were soluble in the electrolyte solution, and were determined after each electrolysis by atomic absorption spectrophotometry. Kamacite and taenite dissolved as individual phases, with kamacite dissolving preferentially. Cobalt dissolved along with iron and nickel from each phase. There is a direct relationship between nickel content and the potential at which a meteorite first starts to dissolve; the higher the nickel content, the more resistant the meteorite is to corrosion. None of the six meteorites observed started to dissolve at a lower potential than pure iron, nor at a higher potential than pure nickel
THE RANSOM METEORITES
Authors: Read William F.
Published: June 2012

A number of stony meteorite specimens, presumably from a single fall, have been recovered from an area about 5–6 miles north of Ransom, Kansas. This paper presents a map of discovery locations, so far as known. Megascopic appearance, external and internal, of a typical (?) specimen is described. The Ransom meteorite has already been classified as an olivine‐bronzite chondrite — chemical group H of Van Schmus and Wood. Features observed in thin section are characteristic of petrologic type 4
THE TIMMERSOI†, NIGER, HYPERSTHENE CHONDRITE
Authors: Smith D. G. W. , Bell J. D. , Frisch T.
Published: June 2012

The Timmersoi meteorite, a new type L5 hypersthene chondrite from the Niger Republic is described and microprobe analyses of its olivine, orthopyroxene, clinopyroxene, plagioclase, kamacite, taenite, troilite, chromite, whitlockite, chlorapatite and limonite presented. Veins and patches of black “glassy” material are regarded as products of shock melting. In places this material contains immiscible droplets of troilite each with one or more well‐formed crystals of taenite. Calculations indicate equilibrium between olivine and orthopyroxene with a temperature of equilibration of about 850 °C.
THE MINERALOGY OF METEORITES
Authors: Mason Brian
Published: June 2012

During the past decade the number of minerals recognized in meteorites has doubled, from about 40 in 1962 to over 80 in 1972. The great expansion in our knowledge can be largely ascribed to the introduction of the electron‐beam microprobe as a research tool, enabling the quantitative analysis of microscopic grains in polished sections. While most of these discoveries are of minerals present in minute amounts, their identification has elucidated many aspects of meteorite formation. Of particular interest are five phosphate minerals, three of them unknown in terrestrial rocks; a chromium nitride and a silicon oxynitride; lonsdaleite and chaoite, new polymorphs of carbon; ringwoodite and majorite, the spinel and garnet analogs of olivine and pyroxene respectively; a number of calcium‐ and aluminum‐rich silicates in the Allende meteorite, a Type III carbonaceous chondrite which fell in 1969; and several alkali‐rich silicates found as inclusions in iron meteorites. Knowledge of the compositional range of the common minerals olivine, pyroxene, and plagioclase has also been greatly increased by recent researches
METASTABLE GROWTH PATTERNS IN SOME TERRESTRIAL AND LUNAR ROCKS
Authors: Drever Harald I. , Johnston Robert
Published: June 2012

With reference to new information on the textures in some terrestrial mafic and ultramafic igneous rocks of Tertiary age, textural patterns attributable to metastable crystallization are described, illustrated and reviewed. The igneous textural terminology, employed in the descriptive text, is reviewed and the use of certain new terms is advocated. Compared with these textural patterns are the skeletal crystal growth and intergrowth in igneous rock samples obtained, mainly by the Apollo 12 Mission, from the moon. Both orientated and unorientated metastable growth yield characteristic dendritic or skeletal olivine crystals, and a texture which has been termed “intrafasciculate” is also attributed to metastable crystallization of plagioclase and pyroxene. The three principal terrestrial textures defined and described are ‘Willow Lake’ texture, intrafasciculate texture and harrisitic texture. The term “thermotactic” is preferred to ‘Willow Lake’ or ‘crescumulate’ to define a texture with orientation of crystal growth in the direction of the thermal gradient

Attention is drawn to the importance in petrogenesis of such metastable crystallization, as inferred from crystal growth and textural observations. It is apparent that analogous ‘metastable’ textures occur through a remarkable range in geological context

More detailed work is advocated on the pegmatitic eucrites and peridotites of Rhum. Since the evidence suggests that these rocks represent hydrous ultrabasic liquids, not cumulates, the conditions governing the growth of olivine in them must differ from those of any lunar analog
SOLID SOLUTION, SUBSOLIDUS REDUCTION AND COMPOSITIONAL CHARACTERISTICS OF SPINELS IN SOME APOLLO 15 BASALTS
Authors: Haggerty Stephen E.
Published: June 2012

Compositional data for spinels in the chromite‐hercynite‐ulvöspinel system from three large basalts and for spinels in 48 basalt particles in four soil samples show: (1) that the range of compositions are comparable to those of spinels in Apollo 12 basalts; (2) that the spinel series is complete between 0.75 FeCr2O4 0.25 FeAl2O4 and Fe2TiO4; (3) that the Apollo 12 bimodal distribution is present insofar as chromite‐rich and ulvöspinel‐rich phases are more commonly present than compositions intermediate between these two end members; (4) well defined ionic relationships exist for those cations displaying high octahedral site preference energies in the spinel structure (viz. Cr vs Al and Ti vs Cr+ Al); (5) cations displaying low site preference energies (Fe2+, Mg) show poor correlation; and (6) the absence of a simple relationship between the divalent ions (Fe2+ and Mg), and the paucity (10% of 356 analyses) of intermediate compositions suggests a strong dependence on the structural stability of intermediate members of a normal (hercynite, chromite) — inverse (ulvöspinel) solid solution series
MAJOR ELEMENT COMPOSITION OF GLASSES IN THREE APOLLO 15 SOILS
Authors: Reid Arch M. , Warner Jeff , Ridley W. I. , Brown R. W.
Published: June 2012

Approximately 180 glasses in each of three Apollo 15 soils have been analyzed for nine elements. Cluster analysis techniques allow the recognition of preferred glass compositions that are equated with parent rock compositions

Green glass rich in Fe and Mg, poor in Al and Ti may be derived from deep seated pyroxenitic material now present at the Apennine Front. Fra Mauro basalt (KREEP) is most abundant in the LM soil and is tentatively identified as ray material from the Aristillus‐Autolycus area. Highland basalt (anorthositic gabbro), believed to be derived from the lunar highlands, has the same composition as at other landing sites, but is less abundant. The Apennine Front is probably not true highland material but may contain a substantial amount of material with the composition of Fra Mauro basalt, but lacking the high‐K content. Glasses with mare basalt compositions are present in the soils and four subgroups are recognized, one of which is compositionally equivalent to the large Apollo 15 basalt samples
PARTICLES AROUND BOXHOLE METEORITE CRATER
Authors: Hodge Paul W. , Wright Frances W.
Published: June 2012

A sampling program of soil surrounding the Boxhole meteorite crater reveals very much smaller amounts of meteoritic material in the soil than found for other craters, such as Henbury and Canyon Diablo. Microprobe analyses of individual small particles show the presence of four spherules with Ni‐Fe ratios in agreement with that for the parent meteorite.
GROSSULAR IN THE ALLENDE (TYPE III CARBONACEOUS) METEORITE*
Authors: Fuchs Louis H.
Published: June 2012

Grossular garnet has been observed in several white inclusions in the Allende meteorite. Compositions range from Gro9sPy5 to Gro88Py12 in five inclusions. Its mottled appearance indicates that it crystallized from a glass of near‐grossular composition and not by a solid state reaction between wollastonite, anorthite and melilite. These grossular‐bearing inclusions either condensed directly as metastable liquids from the solar nebula or if initial solid condensates were liquefied by some subsequent heating process. In either case, a prolonged residence time in a thermal blanket appears necessary to effect crystallization of the grossular.
THE CHEMICAL COMPOSITION OF MAJOR ELEMENTS AND HEAVY TRACE METALS IN CHONDRITES PARAMBÙ AND MARILIA
Authors: Shima M. , Jochum K.P. , Sighinolfi G.P. , Hintenberger H.
Published: June 2012

The chemical composition of the newly observed fallen chondrites Parambù, 1967, and Marilia, 1971, was determined. Wet chemical methods were used for major elements analyses and the abundances of heavy trace elements from tungsten to uranium were determined by spark source mass spectrometry.

The chemical composition confirmed the classification of Marilia as an H‐group chondrite by Avanzo et al. (1973): Parambù was classified as an LL‐group chondrite.
THE LOCATION OF METEORITE IMPACTS BY SEISMIC METHODS
Authors: Nicholls David C. , Stewart Ian C. F.
Published: June 2012

Photographic methods for the location of meteorite falls are restricted to hours of darkness and limited by weather conditions, resulting in a low detection rate. The importance of rapid recovery of newly‐fallen meteorites leads to the consideration of seismic methods for the location of impact points. The purpose of this paper is to discuss the degree to which seismic networks can augment the detection of meteorites by conventional means. Factors involved in the generation of seismic waves are considered. The present sophistication of experimental and computational techniques in seismology should enable a microearthquake detection network to locate within 2 km the impacts of larger meteorites. The detection limits are determined by meteorite size and the configuration and instrumentation of the seismograph network.
YAMATO METEORITES COLLECTED IN ANTARCTICA IN 1969
Authors: Nagata Takesi
Published: June 2012

The meteoritic community has been tantalized by reports of extensive meteorite finds in Antarctica by members of the Japanese Antarctic Research Expedition. The National Institute of Polar Research has published this introduction and review of the Yamato meteorites collected in Antarctica in 1969.

This welcome review reveals that nine meteorite fragments of meteoritic material were found in the region of the Yamato Mountains. Four pieces greater than 60 g in weight have been identified as an enstatite chondrite, a hypersthene achondrite, a type III carbonaceous chondrite and a bronzite chondrite. In 1973 eleven additional suspected meteorites were recovered. Preliminary results show that three bronzite chondrites and one achondrite are among the new finds. In 1974 over 600 pieces of meteorite‐like rock have been collected.

The volume contains five articles on the original 1969 material. These include a general discussion on their discovery including photographs of the individuals, and notes on the chemical, mineralogical and petrological characteristics of the four large samples. Two articles deal with detailed mineralogic and magnetic properties of these specimens.

Information on these interesting finds is welcome. Information on the 1969 and 1974 material is anxiously awaited.
OLIVINE MICROPORPHYRY IN THE ST. MESMIN CHONDRITE
Authors: Dodd Robert T. , Jarosewich Eugene
Published: June 2012

Olivine microporphyry, of metal‐ and troilite‐poor LL‐group composition and composed chiefly of olivine (58 vol. %), pyroxenes (18%, including orthopyroxene, pigeonite, and subcalcic augite), and quartz‐oligoclase glass (22%), occurs in and locally intrudes clasts in the St. Mesmin chondrite (LL‐group breccia). Its crystallization history resembles that of many Apollo 12 lunar basalts, modified somewhat by a lower bulk Fe/Mg ratio and a higher (Fe+Mg)/Ca ratio.

The microporphyry crystallized from a melt which was emplaced during a period of brecciation or between two episodes of brecciation, but after the thermal metamorphism recorded in other components of the breccia. This melt originated by complete melting of normal LL‐group material with loss of Fe, Ni, and S, or, less likely, by fusion of such material (LL‐7?) which had lost these elements during prior anatexis. Comparison of the St. Mesmin microporphyry with similar material in the Parnallee chondrite (Binns, 1968) suggests that the latter was derived from a different parent, perhaps of C‐1 chondritic composition.
PIANCALDOLI METEORITE: CHEMISTRY, MINERALOGY AND PETROLOGY
Authors: Carapezza Marcello , Nuccio P. Mario , Valenza Mariano
Published: June 2012

The fall occurred near Piancaldoli, Florence, Italy, at 19.14 U.T. on the 10th August 1968. The fireball broke up in the atmosphere producing a cloud like a balloon.

The trajectory and the terminal point were calculated, leading to the recovery of three small meteoritic fragments, found on the roof of a house. Chemical analysis gave the following results: SiO2 40.80; TiO2 0.15; Al2O3 2. 70; Cr2O3 0.47; FeO 17.20; MnO 0.07; MgO 25.18; CaO 1.95; Na2O 0.64; K2O 0.07; P2O5 0.20; NiS 0.93; FeS 6.24; Fe° 2.40; Ni° 0.40; Co 0.05; sum 99.45.

In the lithic portion of the meteorite the following minerals were found: both clino and orthopyroxenes (En = 76 to 98%), olivines (Fo = 66 to 98%), troilite, pyrrhotite, pentlandite, kamacite, ilmenite, apatite, merillite, schreibersite, chromite and Henderson phase.

From all the mineralogical and petrological data, we conclude that the Piancaldoli meteorite is an “unequilibrated ordinary chondrite,” LL3. The microbrecciated structure of the rock and some shock features were observed, while the rock as a whole is unshocked, suggesting that these features were caused by impact events which took place during the accretion of the parent body.
EVIDENCE FOR THE PRESENCE OF LOW MOLECULAR WEIGHT ALCOHOLS AND CARBONYL COMPOUNDS IN THE MURCHISON METEORITE†
Authors: Jungclaus G.A. , Yuen G.U. , Moore C.B. , Lawless J.G.
Published: June 2012

Alcohols, aldehydes and ketones identified in the Murchison C2 chondrite include: methanol, ethanol, 2‐propanol, butyl alcohols, formaldehyde, acetaldehyde, propionaldehyde, acetone, 2‐butanone, 3‐pentanone and 2‐pentanone.
WAS THE FORMATION OF LUNAR CRATER GIORDANO BRUNO WITNESSED IN 1178? LOOK AGAIN.
Authors: Nininger H.H. , Huss Glenn I
Published: June 2012

The assumption that five men witnessed the formation of the lunar crater Giordano Bruno on June 18, 1178, is analyzed. The difficulties inherent in this interpretation are discussed. The only tenable solution — that of a meteor passing before the moon — is presented.
ELGYGYTGYN CRATER, SIBERIA: PROBABLE SOURCE OF AUSTRALASIAN TEKTITE FIELD (and Bediasites from Popigai)
Authors: Dietz Robert S.
Published: June 2012

Elgygytgyn crater (lat. 67–30 N, long. 172–00 E) in remote northeastern Siberia is proposed as the meteorite impact site from which the Australasian tektite strewnfield was splashed. The following points support this interpretation: 1, Elgygytgyn very likely is an impact crater and is of adequate size, 18 km across, to generate tektites; 2, the apex of the strewnfield points towards this crater; 3, the terrane is Mesozoic which fits the age of the tektite parental material from Sr/Rb data; 4, compositional and specific gravity lineations within the strewnfield are directed, in part, toward this crater; 5, the high velocity tektites, australites, are distal with respect to this crater while the low velocity tektites, splash forms and Muong Nong tektites, are proximal; 6, the loess deposits and mixed acid/basic rocks of the impact site provide a suitable subgraywacke‐type source material; 7, the erosional state of Elgygytgyn suggests that its age may well be in accordance with that of the Australasian tektite event, i.e., 700,000 years.
EXPERIMENTAL VAPORIZATION OF THE HOLBROOK CHONDRITE
Authors: Gooding James L. , Muenow David W.
Published: June 2012

Knudsen cell‐quadrupole mass spectrometry has been used to quantitatively determine the composition of the vapor phase produced by heating samples of the Holbrook chondrite to 1300 °C. Maximum observed vapor pressures (atm) of metals are 10−5.3 ± 0.3 Na, 10−5.8 ± 0.3 K, 10−5.3 ± 0.3 Fe, and 10−6.6 ± 0.3 Ni at 1200 °C. S2 (with minor SO2), H2O, and CO2 were also observed in the high‐temperature gas phase. Release of intrinsically derived volatiles produced abundant vesicles in the heated sample residues. Some possible implications for chondrite evolution are briefly discussed
ADELAIDE AND BENCH CRATER — MEMBERS OF A NEW SUBGROUP OF THE CARBONACEOUS CHONDRITES
Authors: Fitzgerald M.J. , Jones J.B.
Published: June 2012

The composition and mineralogy of Bench Crater and a new carbonaceous chondrite (Adelaide) are compared. They, Kakangari and possibly certain carbonaceous xenoliths from other meteorites constitute a distinct chemical subgroup of the carbonaceous chondrites characterized primarily by a calcium‐to‐aluminium ratio (atomic) of about 0.5. It is proposed to call this group the Kakangari (CK) group
SOLAR GASES IN METEORITES: THE ORIGIN OF CHONDRITES AND C1 CARBONACEOUS CHONDRITES
Authors: Heymann D.
Published: June 2012

Because of their short cosmic ray exposure ages, chondritic meteorites are more likely to have been broken off from parent bodies in Earth‐crossing orbits than from parent bodies in the asteroid belt. The radii of the objects now in the vicinity of the Earth (Apollo and Amor objects) are too small to be unfragmented asteroids of the theory for the origin of gas‐rich meteorites of Anders. Because of the abundant evidence for very heavy shock and reheating among L‐ and H‐chondrites, I conclude that the asteroidal origin for the ordinary chondrites is still the most likely. A cometary origin for the CI chondrites is examined. Regolith and megaregolith do not necessarily have to be formed by impacts on the cometary nucleus. The short‐period comet Encke receives about 1/10 the solar‐wind flux of a belt asteroid at 2.5 AU in its present orbit. The thickness of the megaregolith (C1 chondrites) is estimated between 0.1 and 0.3 km. Stirring of the megaregolith without substantial loss of dust from the comet might occur when the comet is transitional between “active” and “dead.” The consolidation of C1‐ “dust” into rock is somewhat problematic, but if liquid water and water vapor have played a role, then a crust rich in solar gases might form in the outer regions of a comet. A testable alternative explanation is suggested, namely that the solar gases in the C1 chondrites do not come from the Sun.
THE ADELAIDE METEORITE
Authors: Davy R. , Whitehead S.G. , Pitt G.
Published: June 2012

A preliminary description and chemical analysis of the newly‐discovered Adelaide meteorite is given. This meteorite is a C2 chondrite with C3 affinities. However, the meteorite is unlike both C2 and C3 chondrites in having a Ca/Al ratio of 0.47. The subtype is ambiguous but is closer to the Vigarno than the Ornans subtype. The meteorite is unusual in that it contains primary magnetite. In many other respects this meteorite resembles the Allende meteorite
NOBLE GAS ANOMALIES AND SYNTHESIS OF THE CHEMICAL ELEMENTS
Authors: Sabu D.D. , Manuel O.K.
Published: June 2012

There are two types of planetary noble gases: One, containing isotopically “anomalous” argon, krypton and xenon but isotopically “normal” helium and neon, was derived from outer stellar regions. The other, consisting almost entirely of isotopically “normal” argon, krypton and xenon, with little or no helium or neon, was derived from inner stellar regions.

Mixing of nucleosynthesis products from different regions of a supernova is responsible for the observed correlations between elemental and isotopic ratios of planetary noble gases in different classes of meteorites. The solar system condensed directly from the chemically and isotopically heterogeneous debris of a single supernova.

There is no convincing evidence, however, of separate nucleogenetic components in neon. Fractionation and spallation can account for all previously identified components of trapped meteoritic neon, Ne‐A, Ne‐B, Ne‐C, Ne‐D, Ne‐E, Ne‐Al, Ne‐A2, Ne‐E(L), Ne‐E(H) and Ne‐O, and this same mechanism also explains differences between the isotopic compositions of meteoritic, atmospheric, and solar wind neon.

Variations in the abundance pattern of planetary noble gases are primarily the result of stellar fusion reactions and physical adsorption, rather than gas solubility.
THE LOOP CHONDRITE: PETROLOGY, MINERAL CHEMISTRY, AND OPAQUE MINERALOGY
Authors: Boctor Nabil Z. , Kullerud Gunnar
Published: June 2012

The Loop meteorite was found in 1962 in Gaines County, Texas, at a location very close to that where the Ashmore chondrite was found in 1969. The two specimens were assumed to be fragments of the same meteorite.

The Loop meteorite is a type L6 chondrite composed of olivine (Fo75.4Fa24.6), orthopyroxene (En77.6Wo1.5Fs20.9), clinopyroxene (En47.5Wo45.1Fs7.4), plagioclase (Ab84.3Or5.5An10.2), Fe‐Ni metal, troilite, and chromite. Fe‐Ni metal is represented by kamacite (5.8‐6.4 wt % Ni, 0.88‐1.00 wt % Co), taenite (30.0–52.9 wt % Ni, 0.16‐0.34 wt % Co), and plessite (16.8–28.5 wt % Ni, 0.38‐0.54 wt % Co). Native copper occurs as rare inclusions in Fe‐Ni metal. Both chondrules and matrix have similar mineral compositions.

The mineral chemistry of the Loop meteorite is quite different from that of the Ashmore, which was classified as an H5 chondrite by Bryan and Kullerud (1975). Therefore, the Ashmore and Loop meteorites are two different chondrites, even though they were recovered from the same geographic location.
CILIMUS: A NEW CHONDRITE FALL
Authors: Miller Joy , Nelen J. , Fredriksson K. , Darsoprajitno S. , Padmanagara S.
Published: June 2012

Cilimus is a new Indonesian chondrite. Its mineralogy and chemistry categorize it as a veined, intermediate‐to‐white hypersthene or L‐5 chondrite. Black veins and impact‐produced glasses including maskelynite show evidence that Cilimus has been severely shocked.
THE TAMBAKWATU CHONDRITE
Authors: Fredriksson K. , Miller J. , Nelen J. , Darsa S.
Published: June 2012

According to its petrography, uniform olivine, Fa23.8, and pyroxene, Fs20.4, a total iron content of 22.9 wt % Fe, 16.4 wt % FeO and an FeO/FeO + MgO ratio of 24.7 mol %, the Tambakwatu is a veined, intermediate hypersthene (Cia) or L6 chondrite.
THE DERRICK PEAK, ANTARCTICA, IRON METEORITES
Authors: Clarke Roy S.
Published: June 2012

Sixteen iron meteorite specimens, Derrick Peak A78001 through DRPA78016, were recovered from the slopes of Derrick Peak, Antarctica, in 1978. Recovery from a relatively small area combined with their strikingly similar appearances suggest they represent a single fall. The metallographic structure of the two specimens that have been cut is dominated by regions of swathing kamacite enclosing coarse schreibersite and schreibersite‐troilite inclusions. Patches of coarsest octahedrite Widmanstätten structure are interspersed. Specimens DRPA78008 and DRPA78009 have been analyzed: 6.64, 6.59 wt % Ni; 0.51, 0.46 wt % Co; 0.35, 0.34 wt % P. The specimens are coarsest octahedrites of chemical group IIB.
GRAIN‐SIZE DISTRIBUTION AND MORPHOLOGY OF METAL IN E‐CHONDRITES
Authors: Easton A.J.
Published: June 2012

The size distribution and morphology of metal grains have been examined in 11 sections of types I and II E‐chondrites. The changes in the grain‐size distribution and morphology of metal grains correspond with the petrologic types and define a series that reflects increase in thermal metamorphism in the following order: type I, Kota Kota‐Indarch‐South Oman‐St. Mark's; and type II, Jajh deh Kot Lalu‐Atlanta‐Daniel's Kuil‐Hvittis‐Pillistfer‐Khairpur‐Blithfield. Concentrations of metal grains adjacent to the perimeters of chondrules are observable throughout the sequence and delineate relic chondritic structure in six of the seven type II E‐chondrites; relic structures are absent from Blithfield.
INTEROBJECT STRUCTURE OF UNGROUPED IRON METEORITES AS REVEALED BY ADVANCED CLUSTERING: METHODS AND CHEMICAL FEATURES
Authors: Esbensen Kim H. , Kaufman L. , Massart D.L.
Published: June 2012

Using the MASLOC clustering strategy, 61 ungrouped iron meteorites are probed for physico‐chemical clusters. The existing classification of 13 resolved chemical groups is used as an internal coherence reference.

Results include tentative establishment of a new group: ID (7 members), with chemical features similar to those of the non‐magnetic groups IAB and IIICD. Six additional pairings, all with magmatic chemical signatures, are also recognized.
THE MARYVILLE METEORITE: A 1983 FALL OF AN L6 CHONDRITE
Authors: Shervais John W. , Taylor Lawrence A. , Cirlin Eun‐Hee , Jarosewich Eugene , Laul J.C.
Published: June 2012

The Maryville chondrite fell on January 28, 1983 in eastern Tennessee. Compositions of olivine (Fa 24.5), orthopyroxene (Fs 20.8), plagioclase (An 10.6), along with the bulk composition and siderophile concentrations, indicate L‐group classification. The presence of highly equilibrated minerals, strongly recrystallized matrix, and the development of large, clear plagioclase grains suggest petrologic type 6 classification. Subsequent to metamorphism the meteorite was subjected to high transient pressures that converted some feldspar to glass, deformed the silicates, and caused small amounts of melting to occur. The effects of this shock event correspond to shock facies “d” or “e”.
THE CLASSIFICATION OF THE BENARES CHONDRITE
Authors: Mason Brian
Published: June 2012

The Benares meteorite is an LL4 chondrite, not LL6 as recorded in the literature. Some specimens labelled Benares are misidentified.
Carbonates and Sulfates in CI Chondrites: Formation by Aqueous Activity on the Parent Body
Authors: Fredriksson Kurt , Kerridge John F.
Published: June 2012

Abstract— Compositions and morphologies of dolomites, breunnerites, Ca‐carbonates, Ca‐sulfates and Mg, Ni, Na‐sulfates, and their petrologic interrelations, in four CI chondrites are consistent with their having been formed by aqueous activity on the CI parent body. Radiochronometric data indicate that this activity took place very early in Solar‐System history. No evidence for original (“primitive”) condensates seems to be present. However, alteration apparently took place without change in bulk meteorite composition.
Carbon, Oxygen, Silicon, Sulphur, Calcium, and Iron Determinations in Twenty‐four Dark Clasts and One Dark Inclusion of the Allende Meteorite by 12C(d,p)13C Nuclear Reaction and PIXE
Authors: Heymann D. , Makjanic J. , Van der Stap C. C. A. H. , Vis R. D. , Verheul H.
Published: June 2012

Abstract— A study of carbon contents of millimeter‐sized dark clasts and of one dark inclusion of the Allende meteorite with the 13C(d,P0)13C method has been undertaken. The results show that C in dark Allende areas varies, perhaps in a “clustered” fashion, from near 0.3%, which is essentially the bulk C‐content of the meteorite, to at least 2.1% in the dark rim of a dark inclusion. At least one cluster has now been identified with C‐contents in the range 0.4%‐0.5%. Raman spectra of C in the dark inclusion ADIR 4E1‐fu and in matrix have also been determined. These are identical. Our results are consistent with a comparatively low temperature origin of essentially all elemental carbon in Allende.
Pyroxene thermobarometry in LL‐group chondrites and implications for parent body metamorphism
Authors: McSween Harry Y. , Patchen Allan D.
Published: June 2012

Abstract— Geothermometry based on the compositions of clinopyroxenes in type 6 and 7 LL chondrites gives coherent results, but the estimated temperatures from coexisting orthopyroxenes are consistently lower than for clinopyroxenes. Orthopyroxene thermometry is suspect because of compositional effects of polymorphic inversions and/or unknown kinetic factors. Lack of clinopyroxene equilibration precludes accurate estimation of peak metamorphic temperatures for type 4 and 5 chondrites. There is no apparent correlation between Al content (a pressure‐dependent variable) and equilibration temperature in chondritic pyroxenes. This finding, which is at variance with a previously published conclusion that temperature and pressure are correlated in metamorphosed chondrites, may have important implications for asteroid thermal models.
Carbon in glass inclusions in the Allende meteorite
Authors: Makjanic J. , Touret J. L. R. , Vis R. D. , Verheul H.
Published: June 2012

Abstract— Olivines in chondrules of the Allende CV3 carbonaceous chondrite contain two types of micron sized silicate melt inclusions: clear glass (type I) and devitrified glass (type II) inclusions. Many of the type I inclusions contain a gas bubble of variable size. Type II inclusions can be transparent (IIa), with or without a gas bubble, and brown (type IIb), with a gas bubble. A number of inclusions were measured with the Raman microprobe to detect possible presence of carbon. Carbon in the form of graphite was detected only in type II inclusions. Compositions of 11 inclusions were determined with the electron microprobe and proton microprobe in search for possible explanation of this preference of carbon for devitrified inclusions. All of the measured inclusions are rich in Si, Al and Ca. No significant differences between the compositions of the two types of inclusions were found. The data suggest that the inclusions formed from the melt trapped in growing olivine crystals, which themselves crystallized from a silicon rich, gas bearing melt. There is no coherent relation between the occurrence of graphite and the gas abundance in the original melt, as indicated by the sizes of gas bubbles. Therefore, carbon was not combined in a gaseous species (e.g., CO). It must have been preferentially dissolved in some domains of the melt.
Volatile compounds in shergottite and nakhlite meteorites
Authors: Gooding James L. , Aggrey Kwesi E. , Muenow David W.
Published: June 2012

Abstract— Vacuum pyrolysis and quadrupole mass spectrometry were used to measure evolved‐gas profiles and total concentrations of H2O, CO2, CO, SO2, S2, H2S, HCl, Cl, and hydrocarbons in both exterior and interior samples of shergottites (ALHA77005, EETA79001, and Shergotty), a nakhlite (Nakhla), and eucrites (ALHA81001, EETA79004, and Pasamonte). Eucrites were analyzed as control samples to monitor effects of terrestrial weathering and contamination, relative to properties sought for the shergottite‐nakhlite parent body. In contrast with eucrites, shergottites and Nakhla contain large proportions of their sulfur as oxidized sulfur compounds. Sulfate occurs in all shergottite and Nakhla samples and carbonate was confirmed in EETA79001 and Nakhla. Carbonate and sulfate abundances are inversely correlated but total chlorine abundance varies directly with fractional sulfate abundance. Most of the volatile compounds seem to be anhydrous, based on low bulk water contents in the meteorites (<0.1% H2O), although Nakhla might contain significant water that is chemically associated with chlorine. Traces of saturated and unsaturated hydrocarbons in some samples are most likely terrestrial contaminants. The indigenous volatile compounds indicate that the shergottite‐nakhlite parent body was highly oxidizing and supported aqueous geochemistry during at least part of its history.
FeO‐rich rims and veins in Allende forsterite: Evidence for high temperature condensation at oxidizing conditions
Authors: Weinbruch S. , Palme H. , Müller W. F. , El Goresy A.
Published: June 2012

Abstract— Forsteritic olivine grains in the Allende meteorite are commonly rimmed by FeO‐rich olivine. New evidence is presented in this paper that the fayalitic rims formed by condensation from a gas and not by thermal equilibration of forsterite with FeO‐rich metal or FeO‐rich olivine in the interior of a parent body. A similar origin is inferred for fayalitic veins within forsterite crystals.

A good correlation of FeO with MnO was observed along profiles from forsteritic cores to fayalite‐rich rims, excluding oxidation of metal as a source of rim FeO. The fayalite content of the rim is generally lower than that of the adjacent matrix olivines excluding formation of FeO‐rich rims by equilibration with present matrix. This is also supported by systematic differences in Cr between rim and matrix olivines.

Chromites, associated with FeO‐rich olivine, were found at the boundary between forsterite and fayalite‐rich rim, within the rim itself and in fayalitic veins. Condensation of chromite from a gas phase is likely for the latter two occurrences since no other suitable source of Cr is available. Chromite at the forsterite‐fayalite interface was formed by diffusion of Cr from forsterite. Increasingly oxidizing conditions, apparently enabled formation of chromite.

The steep compositional gradient between forsterite and fayalite provides severe constraints on the thermal history of forsterite grains. The width of oxidized zones (halos) around metal inclusions in the interior of forsterite grains are not compatible with this steep gradient. Their development requires longer diffusion times than would be allowed by the rims, indicating that these forsterite grains must have had an independent history of oxidation prior to formation of the rim.

Condensation calculations indicate that FeO‐rich olivine can be formed by condensation from a gas with enhanced oxygen fugacity. Increasing the oxygen fugacity would provide conditions allowing the thermodynamic stability of chromite.

High temperatures and oxidizing conditions must have prevailed for some time in that part of the solar nebula where the Allende meteorite formed.
Implications for cratering mechanics from a study of the Footwall Breccia of the Sudbury impact structure, Canada
Authors: Lakomy R.
Published: June 2012

Abstract— The Footwall Breccia layer in the North Range of the Sudbury impact structure is up to 150 m thick. It has been analyzed for several aspects: shock metamorphism of clasts, matrix texture, mineralogy, and geochemistry with respect to major and trace element compositions. The matrix of this heterolithic breccia contains mineral and lithic fragments, which have suffered shock pressures exceeding 10 GPa, along with clasts of breccia dikes originating from the crater basement. The matrix in a zone near the upper contact of the breccia layer is dominated by a dioritic composition with intersertal textures, whereas beneath this zone the matrix is characterized by poikilitic to granular textures and a tonalitic to granitic composition. Major and trace element analyses of adjacent slices of a thin‐slab profile from the breccia show that the matrix is chemically inhomogeneous within a range of 3 mm. The breccia layer has been thermally annealed by the overlying Sudbury Igneous Complex, which is interpreted as a coherent impact melt sheet. The Rb‐Sr isochron age of 1.825 ± 0.021 Ga for the matrix is a cooling age after partial melting of fine grained clastic material by the melt system. Two‐pyroxene thermometry calculations give temperatures in excess of 1000 °C for this thermal overprinting. Clasts were affected by recrystallization, melting, and reactions with the surrounding matrix at that time. The crystallization of the molten matrix resulted in the observed variety of igneous textures. Results of clast population statistics for the Footwall Breccia along with both geochemical considerations and the Sr‐Nd isotopic signature of the matrix indicate that the breccia constituents exclusively derived from the Levack gneiss complex, which forms the local country rock to the breccia layer in the Levack area. K‐feldspar‐rich domains, which tend to replace parts of matrix and felsic gneiss fragments have been formed due to metasomatic activities during the Penokean orogeny, ∼ 1.7 Ga ago.

The available observations suggest that the Sudbury structure represents the remnant of a multi‐ring basin with an apparent diameter between 180 and 200 km and a diameter of the transient cavity of about 100 km. For a crater of the size of the Sudbury basin a maximum depth of excavation of ∼21 km and a depth of shock‐melted target rocks of ∼27 km are obtained. In the Sudbury crater, the Footwall Breccia layer represents a part of the uplifted crater floor directly underlying the thick coherent impact melt sheet.
Cosmic spherules in the geologic record
Authors: Taylor Susan , Brownlee Donald E.
Published: June 2012

Abstract— Cosmic spherules obtained from the Greenland ice cap, deep‐sea sediments, and ancient oceanic deposits of Eocene and Jurassic age were chemically and texturally compared. The proportions of spherule types were found to change as a function of time, with the number of iron spherules increasing as the age of the sample increased. It is not yet possible, however, to determine if the variation in spherule types represents a real change in the meteoroid complex or is a result of differential weathering of the spherules in the Earth's environment.

The age of these spherules ranges from less than 3000 years to about 190 million years. Although only a few spherules older than 500 000 years are chemically unaltered, textural information is available even from the oldest spherules and, by comparison with contemporary spherules, gives some insight into the original compositions of the particles.
Minor/major element variation within and among diogenite and howardite orthopyroxenite groups
Authors: Berkley John L. , Boynton Nancy J.
Published: June 2012

Abstract— Diogenites are orthopyroxenites that may contain chromite and olivine as accessory minerals. Howardite breccias contain orthopyroxenite clasts with similar properties compared to monomict diogenites. We used statistical methods and variation plots of major and minor elements in orthopyroxene and chromite to show whether or not howardite orthopyroxenites are related to monomict diogenites, and to assess their petrogenesis. Our results fail to establish any evidence that monomict diogenites are significantly different from howardite orthopyroxenites in terms of major and minor elements. We also found no differences between Antarctic diogenites and non‐Antarctic diogenites. Although element variation plots show compelling evidence that most diogenites originated by igneous fractionation, linear trends among the various diogenites and howardite orthopyroxenite clasts are either non‐existent or ill‐defined. This militates against an origin from a single magma body, but suggests an origin from multiple magma bodies in the parent planetoid.
S‐asteroids 387 Aquitania and 980 Anacostia: Possible fragments of the breakup of a spinel‐bearing parent body with C03/CV3 affinities
Authors: Burbine Thomas H. , Gaffey Michael J. , Bell Jeffrey F.
Published: June 2012

Abstract— Asteroids 387 Aquitania and 980 Anacostia are anomalous members of the S‐class. Their reflectance spectra exhibit a strong broad absorption feature longwards of 1.5 μm and no significant feature near 1 μm. Their spectra indicate the presence of spinel, an aluminum‐magnesium oxide mineral commonly present in inclusions in CV3 and CO3 meteorites. Spinel probably makes up only a small percentage of the surface assemblages of these asteroids, but its spectral effect may be enhanced by its presence in fine‐grained white inclusions in immature asteroid regoliths. It is speculated that Aquitania and Anacostia represent material formed in the same nebular zone as the CV3 and CO3 chondrites but either: A) at an earlier time in the nebula when such inclusions might have been a relatively larger fraction of the nebular grain population, or B) in local regions where nebular processes (e.g., settling to the midplane) had concentrated such inclusions. The close similarity of two orbital elements (a, i) suggests that Aquitania and Anacostia may be members of a partially dispersed asteroid family produced by the early disruption of a spinel‐bearing parent body.
Fuc Bin–an L5 chondrite fall from Vietnam
Authors: Mitreikina O. B. , Zinovieva N. G. , Granovsky L. B. , Krot A. N.
Published: June 2012

Abstract— A stony meteorite fell near the Fuc Bin village, Vietnam, in July, 1971. Based on optical microscopy, scanning electron microscopy and electron probe microanalysis, the meteorite is classified as an L5 chondrite that contains olivine (Fa23.6), low‐Ca pyroxene (Fs20.3 Wo1.3), high‐Ca pyroxene (Fs7.5 Wo44.2), plagioclase (Ab83.8 Or5), chlorapatite, merrillite and opaque minerals: chromite, troilite, kamacite, taenite, tetrataenite and native copper.