Lower Eocene Phosphatized 

Globigerina Ooze from 

Sylvania· Guyot 

By EDWIN L. HAMILTON and ROBERT W. REX 

BIKINI AND NEARBY ATOLLS, MARSHALL ISLANDS 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 260-W 

A study of the mode of occurrence, 

mineralog;, and paleontolog; of 

fossil Globigerina oozes from 

Sylvania' Guyot 

· .. ·,·. 

. . 

UNITED ST.ATES GOV.ERNMENT. PR{NTING OFFICE, WASHINGTON : 1959 
UNITED STATES DEPARTMENT OF THE INTERIOR 

FRED A. SEATON, Secretary 

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director 

This P,Ublication has been cataloged by the U.S. Geological Survey Library as follows: 

Hamilton, Edwin Lee, 1914-

Lower Eocene phosphatized Globigerina ooze from Sylvania Guyot, by Edwin L. Hamilton and Robert W. Rex. 

Washington, U.S. Govt. Print. Off., 1959. 

iii, 785-797 p. 5 plates, map. 30 em. (U. S. Geological Survey. 

Professional paper 260-W) 

"Bikini and nearby atolls, Marshall Islands." 

Bibliography: p. 794-798. 

1. Globigerinidae, Fossil. 2. Deep-sea deposits. 3. PaleontologyMarshall Islands-Sylvania Guyot. I. Rex, Robert W., 1929-

joint author. II. Title. (Series: U. S. Geological Survey. Professional paper 260-W) 

563.1 

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

Washington 25, D. C. 
Abstract-------------------------------------------

Introduction ______ ------- __ ------------------------

Occurrence of fossilife.rous materiaL ____ - - ___ - ____ - - --- Mid-Pacific station 43 A ________________________ _ 

Mid-P.acific statiOii 4·~ D ________________________ _ 

Mid-Pacifio station 43 DD ______________________ _ 

Description of planktot~ic Foraminifera _______________ _ 

Mid-Pacific station 43 A ________________________ _ 

Mid-Paoific station 43 D _______ - __ ------- __ ------ Mid-Pacific station 43 DD ________________ _, _____ _ 

CONTENTS 

Pnge 

785 

785 

786 

786 

787 

787 

788 

788 

788 

788 

Discussion and conclusions __________________________ _ 

Age and affinitie's of the fossil faunas _____________ _ 

Mid-Pacific station 43 A ____________________ _ 

Mid-Pacific station 43 D ____________________ _ 

Mid-Pacific .station 43 D D __________________ _ 

Significance of the fossil faunas __________________ _ 

Systematic descriptions _____________________________ _ 

Selected bibliography _______________________________ _ 

Index _____________________ .. ______________________ _ 

ILLUSTRATIONS 

[Plates 250-25! foJlow index) 

PLATE 250. Volcanic tuff-breccia containing Eocene Globigerina ooze. 

251. Photomicrograph of Eocene planktonic Foraminifera. 

252. Lower Eocene plankto.nic fauna. 

253. Miocene and lower Eo.cene planktonic fauna. 

254. Upper Miocene planktonic fa1,1na. 

FIGURE 255. Map of Bikini Atoll and Sylvania Guyot_ ___ -________ Page 785 

III 

Page 

788 

788 

788 

789 

789 

789 

790 

794 

7~)7 
~ I 

;.~· 

• 

BIKINI AND NEARBY ATOLLS, MARSHALL ISLANDS 

LOWER EOCENE PHOSPHATIZED GLOBIGERINA OOZE FROM SYLVANIA GUYOT t 2 

BY ·EDWIN L. 'HAMILTON ~. and· RoBERT.'W. REx 4 · 

. .ABST~CT . 

Dredge hauls on the top .. of Sylvania Guyot, the seamount 

·adjacent to Bikini Atoli, Marshall Isl~nds, ~ere made by 1950 

Mid-Pacific Expedition of the Scripps Institution of Oceanog-

'raphy and the U. S. Navy Electronics Laboratory. Sylvania · 

10 0 10 20 

has a very flat top at about 705 fathoms and is ·connected .to 12"1-J-4-\-f":"-b'/--.J__-H.f-f?<:~-"-------=~----r-~-1 

Bikini Atoll by a sac;ldle.at a depth of 790 fathoms; the adjacent ()()' 

sea floor is deep.er than 2,500 fathoms. 

The dredge haul from Mid-Pacific station 43 A included 

tuff-breccia with cracks filled with a phosphatized fauna of 

earliest Eocene age dominated by Globorotalia velascoensis and 

G .. aragonens.is; the nearest· faunal affinity of this assemblage, 

the oldest in the northern Marshall Islands, is with si~ilarly 

occurring faunas from the Mid-Pacific .Mountains about 1,000 

miles to the east and with faunas from the Paleocene .'and 

Eocene deposits of the Tampico Embayment region of Mexico. 

In the dredge hauls from Mid-Pacific stations 43 . D and 

.43 DD, the fossil pla.nktor.ic. fauna ·was from the ·Miocene. 

The material from 43 D is correlated with the Glob.ige'rinatella 

insueta zone of ·the Caribbean; the material is about the same 

age as that found on Saipan. · · . · · 

The new evidence ·from Sylvania Guyot fits well into that 

previously determined and indicates the probability that in 

Late Cretaceous or earliest Tertiary time Sylvania was eroded 

to a flat bank; Bikini Atoll at this time .w.as probably ~. young~r 

and higher feature whlch had been little erode~. Fast subsi~­

ence in the Late Cretaceous or early Tertiary left Sylvania 

Guyot as"a reiatively' deepiy submerged flat bank ~hile Bikini 

Atoll was at, or above, the surface. Subsequent submergence· 

was relatively slow, so that a great ·reef grew on ~ikini Atoll 

while planktonic Foraminifera were being deposited on the top 

of Sylvania 9'uyot. 

INTRODUCTION 

From 1946 to 1952 the most concentrated field study 

of co1~al atolls ever attempted took place in the northern 

Ma~shall Islands. Most of these studies are presented 

in other chapters of Professional Paper 260. As part 

of this effort the pei'Sonn~l of the 1950 Mid-Pacific 

Expedition sponsored by the U. S. Navy Electronjcs 

Laboratory and Scripps Institution of Oceanography 

n1ade dredge hauls on Sylvania Guyot, the flat-topped 

seamount which lies northwest of Bikini J\toll. Sylvania Guyot and Bikini Atoll form a single twin-peaked 

massif which is connected by a saddle at a depth of 790 

fathoms (fig. 255). Sylvall:ia Guyot has a very .flat top 

• U.S. Navy Eloctronfcs Laboratory Prof. Contr. no. 42. 

a Scripps Institution of Oceanography, Untv. of CaUl,, Contr., New ~E!f~()S, 

aU. S. Navy Electronics Laboratory. · · 

tScrlpps JAsmu~ton of O~e~o~r~phr, "{Jpl:verslty of Call.fotnla ... 

l!V 

u•L-----"---1...-~-------~-----_j 164°25' 16~ 0()1 166•00' 

FIGURE 255.-Map of B1k1n1 Atoll and Sylvania Guyot showing the locations at 

· which drodge hau~ were made. · 

with depths of about 705 fathoms; it is about 14 by 30 

miles across the top and is larger than Bikini Atoll. 

. The geology of Bikini Atoll and Sylvania Guyot and 

details on the dredge hauls of this paper have been 

discussed by Emery, Tracey, and Ladd (1954) and 

will not .be completely repeated here. 

One of the 1950 dredge hauls (MP 43 ·A) was ·made on 

· Jt north spur of Sylvania Guyot at depths of from 1,030 

to 810 fathoms, near the rounded edge of the flat top 

of the seamount (fig. 255). The dredged material 

consisted mostly of yellow and brown tuff-breccia 

covered by crusts of manganese oxide ·and containing 

irregular cracks filled with cemented Foraminifera 

.· (pl. 250); .1 rock was 24 inches long and weighed about 

· 200 pounds and was covered by a }fs-K inch crust of 

manganese o:\ide. Nfacdonald (Emery, Tracey, and 

Ladd, 1954, p. 120-121) identified this material as a 

friable tuff-breccia containing rock fragments in a. fine 

matrix. Much of the tuff was altered to clay minerals. 

Macdonald believed this material was pyroclastic and 

was probably formed in waters much. shall~wer t~an 

. that from which the material was dredged. The fossil 

planktonic Foraminifera from the cracks and pockets 

of this tuff-breccia are from the earliest Eocene. 

A second dredge haul (MP 43 D) was made on the 

· ~9\lth~~.st sid~ of Sylvani~ Guyot, just below t~e J:>reak 

785 
786 BIKINI AND NEARBY ATOLLS, MARSHALL ISLANDS 

in slope, at depths between 1,150 and 820 fathoms 

(fig. 255). Part of this material' was described by 

Macdonald as a much altered basaltic lava covered by 

a shell.of manganese oxide. 

In this latter material, uncemented Miocene Globigerina. ooze was found in a small crack under the 

manganese. 

4 third dredge haul (MP 43 DD; fig. 255), made on. 

a south s.pur of Sylvania at 880 '·fathoms., . yielded a 

small "boulder" of partly indurated Globigerina ooze . 

covered with a coat of manganese oxide. The plank- · 

tonic Foraminifera of this indurated ooze are probably ' 

uppermost Miocene, but M. N. Bramlette (personal 

communication) thinks that the ·material may be 

Pliocene, on the basis of the coccoliths in the ooze. 

This paper is concerned with the mode of occurrence, , 

mineralogy, and paleontology .~f these fossil Globigerina : 

oozes from the top of Sylvania Guyot and .the signifi-. 

cance of this material in· the geologic· history of the 

area. T~is material is important in ·the geologic , 

history of the Pacific· Basin ·because the early Eocene ' 

fauna is· the oldest in th~ ... northern Marshall Islands · 

area and is aboiit. th~ .same age as the fossil Foraminifera : 

on the submerged flat tops of the . ancient islands of ; 

the Mid-Pacific Mountains to the east. . . . . 

Acknowledgments.~The writers appreciate th:e help-: 

ful. information . and .. coinmerits ·.from . G ... Arrhenius, ' 

0. L. Bandy, H. M. Bolli, M. N. Bramlette, E. C .. 

Buffington, W. S. Cole, K. 0. Emery, E. D. Goldberg,· 

L. I. Gordon, H. W. Menard, D. G. Moore, F. L. · 

Parker, F. B. Phlegm·, and Lawrence Weiss. The, 

dtii\vings of the fossil Foraminifera were made ·by 

M·a~gtierite L. Hagar. 

The mineralogical study w·as by R. W. Rex and was· 

supported by. contract between the University of California, 'Scripps· Institution of Oceanography, and the 

Office of Naval Research. The foraminiferal studies 

were by E. L. Hamilton. 

. OCCURRENCE OF FOSSILIFEROUS MATERIAL 

MID-PACIFIC STATION 43 A 

Vesicles and cracks in the palagonitized tuff from 

dredged material often contain buff Foraminifera embedded in· a buff matrix. Detailed X-ray analysis and 

qualitative chemical tests of this buff material indicated 

'that it is nearly pure apatite with only a small amount 

of calcium cm~bor~ate remaining. No chert. crack 

fillings were noted (Macdonald in Emery, Tracey, and, 

Ladd, 1954, p. 120). The process of phosphatization 

of the Foraminifera and other calcium · carbonate 

particles is most complete for the matrix and least 

complete for foraminiferal tests and coccolith· plates.: 

· Much of the phosphatized ooze has a dense buff crust,: 

· especially in areas 'where crusts of· hydrogenous~ 

ferruginous manganese oxide have been deposited. 

The transition from apatite to crust of ferruginous 

manganese oxide is visually sha_:rp; however, very small 

(1-30 microns) apatite partic)es form the principal 

noilferruginous manganese oxide part of this size 

range of the black crusts. The nonferrriginous mang·~~~se part of the crust is 15 percent by weigh't of which 

2 .. p.ercent is apatite. 

. Detailed studies of the crystal structure, morphology, 

and· surface area of the ferruginous manganese crust 

_min~rals h_ave been made by Buser and Grutt~r (1956). 

The iron; according to these ··authors, is present as 

amorphous hydroxide and goethite, and the manganese, 

as delta-Mn02 (Buser and Grutter, 1956, p. 51). The 

chemical composition of· the ferruginous manganese 

crust from MP 43 A has been reported by Gold berg 

(1954,.p. 252). . . 

The parag~netic. sequence "\vhich is suggested is as 

fol_lows: · 

1. Depositio~ of For~minifera .and coccolith calcium 

carbonat·e· remains in vesicles and chicks in the palagonitized" tuff-breccia (pl. 250). · . 

... ·.2a. ·Phosphatization o{ the· .·calcium . carbonate by 

orthophosphate :ion substitutiop for carbonate in the 

.solid calcium -carbonate; -probably according . to· the 

riiec.hanism described by Clark and Turner (1955); 

this is essentially a replacement· phenomenon.. ' 

2b. Dissolu.tion of surface material in some cracks 

with reprecipitation. of apatite , to produce ·a dense 

crust over ·the loosely cemented ooze. This stage 

may have occurred before stage 2a, so that the solution 

and redepositio'n of calcium carbonate produced ·th:e 

h~rd crust. Evidence· determining which ·step came 

.first was not observed. · · ·, ' 

3. Sedimentation change from biogenous· carbon.ate 

to hydrogenous ferruginous manganese crust containing 

a small quantity of 1- to 30-micron apatite particles. 

The X-ray powd.er diffraction pattern of these apatite 

particles is indis~inguishable by_ spectrometer technique 

from the apatized Foraminifer·a. In addition, the 

presence of these apatite particles s·uggests that there are 

at 'least two mechanisms for production of apatite in 

equilibrium' with sea water. Clark and Turner (1955, 

p. 665), in their discussion of the kinetically slow orthophosphate ion-solid calcium carbonate reaction, describe 

the first mechanism which is essentially a replacement 

of deposited calcium carbonate. If the foraminiferal 

form is preserved this mechanism is indicated. The 

sec;ond is . a direct deposition of apatite particles from 

sea water. Because no calcium carbonate remains 

·with the apatite of the ferruginous manganese crust 

and some does remain in the phosphatized ooze, it is 

concluded that calcium carbonate either was not deposited or was redissolved during deposition of the 
... 

-~ 

LOWER EOCENE .PHOSPHATIZED GLOBIGERINA OOZE 787 

ferruginous ·manganese crust. For this reason it seems 

improbable that the apatite in the ferruginous manganese crust could form after deposition· from phosphatization of biogenous calcium carbonate. However, 

no evidence is available to indicate the precise mechanism of production of the apatite particles deposited 

directly from sea water. These -particles do not show 

the small crystallite size characteristic of fishbone fragtnents or teeth. G. Arrhenius, M. N. Bramlette, and 

E. Picciotto (1957) have pointed out that the. small 

apatite crystallites of fish debris which settle on ferruginous 1nanganese crusts may dissolve and recrystallize 

as larger grains thereby decreasing their surface energy. 

The new apatite would then be in equilibrium with 

sea water, and the rare earths and thorium originally 

scavenged by the fish debris is sorbed on the ferruginous 

manganese phase. 

The d spacings for the powder diffraction pattern of 

the apatized Foraminifera are given in the following table 

with corresponding values for apatized· Foraminifera 

from Horizon Guyot and apatizecl biogenous calcium 

carbonate from Cape Johnson Guyot in the Mid-Pacific 

. Mountains (for locations and geology see Hamilton,· 

1956). The powder-diffraction patterns from these 

. seamounts are remar~ably similar and differ only very 

: slightly from a California continental-shelf phosphorite. 

The X-ray pattern corresponds to those of dehrnite and 

. franpolite (McConnell, 1938, p. 5), two different varieties ·of. apatite. Further chemical studies .would .be 

necessary to ascertain which of these two varieties is. 

the form present. Fluorapatite does not fit the marine 

apatite pattern as well as does francolite or dehrnit·e~ 

· Dietz, Emery, and Shepard (1942, p. 818) suggested 

that the California continental-shelf phosphorite be 

· called francolite, basing their conclusion on the powder 

. diffraction pattern and a fluorine content of about 3 

percent. Dehrnite is a hydroxyapatite rich in sodium 

carbonate, and it n1ay be that marine apatite precipitates as hydroxyapatite, the common. aqueous precipitate (Clark, 1955, p. 1696), and then undergoes slow 

fluorine for hydroxyl substitution to gradually change 

t.o francolite. · 

X-my d·1:jJraction analyses of apatite f1·orn seamo·unts and banks of the Notth Pacific com.pared w·ith delm1.1:te, fra·ilCoWe, and jl:uor-apat1'te 

All d values In A. Measurements made \\•lth Norelco· Diffractometer, CuKa,'NI filter, scanning H0 20 per minute, 1° slits, 4 second time constant, and employing at·otat- . . lng sample bolder] · . 

Sylvania Guyot, Oape Johnson 

MP-43A Guyot, MP-37C 

·Phosphorite, F. P. Horizon Guyot, · S. 183-5, Coro- Dehrnlte Francolite Fluor-apatite 

MP-25 F-2 nado "Bank1 San (McConnell, 1938)1 (McConnell, 1938)• (McConnell, 1938)1 

Diego, Calli. 

h, k, l d I d I ·d I 

---

t2~ ------------------- 3.45 4 3.45 "4 3.45 

102 ------------------- 3.17 3 3.17 2 3.17 120, 210) ______________ 3.05 2 3.05 2 3.05 

(300 fJ)- ---------------. 2.95 1 2.95 !''11211) ............... 2. 7D 10 2. 79 10 2. 79 

112 ------------------- 2. 77 8 2. 77 6 2. 77 

300~ -------.-.------.-- 2.69 5 2.69 6 2.69 

202 ------------------- 2.62 3 2.62 3 2.62 

301 ------------------- 2. 51 1 2.50 1 2. 51 

122, 212~-------------- 2.28 1 ....................... 2.29 

130,310 -------------- 2.24 2 2.24 -----·-·a-· 2. 24 ml :1.~ :.::::::::::::: 2.13 1 2.13 1 2.13 

2.06 1 2.06 1 2.06 

203 ------------------- 2.00 1 2.00 

222 ------------------- 1. 93 2 1. 93 3 1. 93 182, 812! .............. 1. 88 1 1.88 2 1.88 

123,213 -------------- 1.84 3 1. 84 3 1. 84 

231,321 -------------- 1. 79 1 1. 79 2 1. 79 

!~g~ -~:~::::::: :::::::: 1. 76 1 1. 76 2 1. 76 1. 74 1 1. 74 2 1. 74 

004) ---------·--------- 1. 72 2 1.72 2 1. 73 

232, 322)-- ------------ 1.63 1 1. 63 1 1. 63 

• McConnell's d spacings given here rounded.off at second decimal place. 

It should be noted that the paragenetic sequence and 

mineralogy of this material from Sylvania Guyot is 

identical with that for the phosphatized ooze from 

Horizon Guyot some 1,500 miles to the east. For the 

phosphatization of an expanse of ooze to take place, it 

is necessary that there be a cessation or marked diminution of the rate of accumulation; this is especially 

true if there. has been a manganese crust deposited over 

the indurated material which is the case on Hess Guyot 

and Guyot 19171 in the Mid-P*\.vific Mountains. 

6 

2 

3 

1 

10 

7 

8 

4 

1 

1 

3 

1 

1 

1 

3 

2 

4 

2 

2 

2 

2 

1 

d I d I d I d I 

------------------------ 3.44 6 3.43 1 3.43 2 3.43 2 3.17 2 3.16 0. 5 3.16 0. 5 --------·- ...................... 3.05 2 3.04 3 3.04 2 3.06 3 

-----i7ii" 2.96 .5 2.96 .5 . 2.98 .5 

10 } 2. 77 10 2. 77 >IO 2.80 >IO 

2. 77 7 2. i7 4 2.69 6 2.69 6 2.68 7 2. 70 6 2.62 3 2.61 3 2.62 4 2.62 3 

-------·-- ...................... 2. 51 .5 2. 51 .5 2.52· . 5 2. 28 1 2.28 .5 2.28 1 2.2\.l .5 

2.24 3 2.23 4 2.24 3 2.25 2 2.13 1 2.12 2 2.13 2 2.14 1 2.06 1 2.05 . 5 2.06 1 2.06 1 1.99 1 ---------- -------·-- 2.00 1 2.00 . 5 

1. 93 3 1. 93 6 1. 93 3 1. 9.4 3 1. 88 2 1.88 2 1.88 1 1.88 1 1.83 3 1.83 6 1. 84 3 1.84 6 1. 79 1 1. 79 2 1. 79 2 1:80 3 1. 76 1 1. 76 2 1. 76 2 1. 77 3 

1. 74 1 1. 74 2 1. 74 2 1. 75 3 

1. 72 2 1. 72 2 1.72 2 1.72 3 ........................ ..................... 1. 63 1 1.63 .5 I. 64 1 

MID-PACIFIC STATION 43 D 

The Globigerina ooze in the cracks of the altered 

basalt of MP 43 D has been altered to phosphatic 

minerals in the same manner as the material from ~t[p 

43 A. This indicates that phosphatization was going 

on in the Miocene in the same manner as in the early 

Eocene. 

MID-PACIFIC STATION 43 DD 

This partly indurated, uppermost Miocene calcium 

c&rbonate oo~e w~s in the form of a. small boulder about 
788 BI:IpNI AND NEARBY ATOLLS, MARSHALL ISLANDS 

8 inches in diameter and was protected by a shell ·of 

manganese oxide about 6~10 millimeters thick. This 

material has not been phosphatized. 

DESCRIPTION OF. THE PLANKTONIC FORAMINIFERA 

;MID-PACIFIC STATION 43 A 

The cracks and pockets inside the tuff-breccia from 

matel(ial dredged in haul M·P 43 A contained the following fos.sil planktonic Foraminifera: · · 

Globigerina apertura Cushman 

aff. G. colla'ctea (Finlay) 

eocaena GUmbel 

mckannai White 

orbiformis Cole 

pseudobu,lloides Plummer 

rotundata d'Orbigny var. jacksonensis Bandy 

topilensis Cushman 

triloculinoides Plummer 

Globorbtalia aragonensis Nuttall 

centralis Cushman and Bermudez 

c1·assata (Cushman) 

crassata densa (Cushman) 

membranacea (Ehrenberg) 

. velascoensis (Cu~hman). 

· · whitei ·weiss 

wilco:tensis Cushman and Ponton 

One crack contained an unusually well.,.preserved 

party phosppatized ·planktonic. fauna. The C:J;"~ck was 

ab.out half filled with the fossiliferous mate:rial. The 

top surface of the filling had an excellently preserved 

fauna which was lightly cemented together in the top 

part and was incorp.orated into the more indurated 

material on the bottom (pl. 251). The species of the 

ll1.aterial were easily identified. A distinctive feature 

<?f this fauna was that numerous specimens of Globoroialia ve{ascoensis (Cushman) and G. aragonensis Nuttall 

appeared together; this .allowed excellent age dating, as 

described below. The fauna of this and the other cracks 

was a Globorotalia-Globigerina planktonic fauna with 

very few benthonic species. The strongly keeled 

Globorotalia dominated the fauna. 

The systematic descriptions of this, and the other 

fossil faunas will be found at the end of the paper 

together with plates which illustrate the ma:in index 

species. 

MID-PACIFIC STATION 43 D 

·The pocket, or crack, in the altered basalt and 

under the manganese crust, from material dredged in 

haul MP 43 D contained the following fossil planktonic 

Foraminifera: 

Globigerina apertura Cushman 

bulloides d'Orbigny 

ciperoensis Bolli . 

dissimilis Cushman and Bermudez 

ouchitaensis Howe and Wa1lace var. senilis Bandy 

Globigerina rotundata d'Orbigny var. jacksonensis Bandy 

venezuelana Hedberg 

Globigerinoides bispherica Todd 

ruora (d'Orbigny) 

8ac_culifera (Brady) 

. subquadrata Bronniman 

triloba (Reuss) 

.. ·As can· be seen from the above list this was a Globi._ 

gerina-Globigerino,£des fauna; ~ distinctive feature is 

that no species of Globorotalia were identified; which is 

':iiJ, sharp contrast with the fauna· previously described 

from the Eocene. Stainforth (1949, p. 419) stated 

that .· the appearance of large-apertured species of 

Globigerinoides may be taken as evidence of postmiddle 

Oligocene; this mass aspect is certainly true of the 

Sylvania Guyot (MP 43 D) material. 

MID-PACIFIC STATION 48 DD 

The unindurated calcium carbonate ooze from 

dredge haul MP 43 DD contained the following fossil 

Fo~a:minifera in addition to most of the planktonic 

sp_ecies which occur in ·the Recent material from the 

area . 

Globigerina altispira Cushman and Jarvis · 

·Globorotalia menardii (d'Orbigny) var. fijiensis Cushman 

menardii (d'Orbigny) var.·multicamerata Cushrilan and· Jarvis 

Sphaeroidinella multiloba LeRoy 

rutschi Cushman and Renz 

f!emdnulirz,~ (S9hwager) 

With the exception of the above species, this fauna 

. looks like the modern tropical planktoni'c fauna exp'ectable in the area. 

DISCUSSION A~D CONCLUSIONS 

AGE AND. AFFINITIES ·oF THE· FOSSIL· FAUNAS 

When the prolific, fossil, planktonic foraminiferal 

faunas of the Mid-Pacific Mountains were discovered, 

it was realized that these forms, so familiar in land 

deposits, were actually present all over the · Pacific 

Basin and should be looked for and expected in ancient 

sea-floor deposits (Hamilton, 1953). The present study 

confirms this expectation and again presents the utility 

of the planktonic smaller Foraminifera in long-range 

time correlations. 

MID-PACIFIC STATION .43 A 

Studies of the mass aspects of fossil planktonic faunas 

by Henson (1938), Glaessner (1945), Tromp (1949), 

Reiss (1955), and others indicate that the GlobotruncanaGUmbelina faunas of the Upper Cretaceous are replaced 

by the Globigerina-Gumbelina faunas of the Danian. 

In the Paleocene (Midway) and lower Eocene (Wilcox), 

the keeled Globorotalias. ar~ strongly represented, and 

the fauna is, in general, dominantly made up of Globorotalia-Globigerina species, which is the faunal type of 

the Sylvania samples from MP 43 A. 

.. 
-. 

-· 

LOWER EOCENE PHOSPHATIZED GLOBIGERINA OOZE 789 

Several worldwide index species are represented in 

the MP 43 A fauna. The two most important, and 

the ones whose overlapping total ranges allow a rather 

precise age determination, are Globorotalia velascoensis 

(Cushman) and Globorotalia aragonensis Nuttall. G. 

velascoensis was described by Cushman from the Velasco 

shale of the Tampico Embayment region of Mexico. 

G. aragonensis was described by Nuttall from the 

Aragon formation of Mexico. Since their first description, both species have been noted in the Middle East, 

Mediterranean, Gulf of Mexico and Caribbean areas, 

and from seamounts in the Mid-Pacific. The range of 

G. velascoensis is possibly uppermost Cretaceous, definitely Paleocene, and probably lower Eocene. G. aragonensis is a restricted lower Eocene to middle Eocene 

form. rrhe fact that these two forms are found together 

in an apparently uncontaminated fauna (in one crack 

filling) places the age of the fauna at about the boundary 

between the Paleocene (Midway) and the Eocene (Wilcox). The remainder of the planktonic species, from 

cracks and pockets, tend to favor an age dating just 

into the earliest Eocene, although it is uncertain whether 

all the listed species lived at the same time. 

The nearest affinity of this Sylvania Eocene fauna is 

with the fossil planktonic species of the lvfid-Pacific 

Mountains to the east (Han1ilton, 1953). In the MidPacific Mountains, planktonic Foraminifera of Paleocene and Eocene age occur on the tops of four flattopped seamounts. On Horizon Guyot almost the identical fauna (as noted above for Sylvania) occurs in the 

cracks of n1anganese-coated volcanic rocks. Other than 

the l\1id-Pacific faunas, the nearest faunal affinity of 

the Eocene Sylvania species is with those of the Paleocene and Eocene deposits of the Tmnpico Embayment 

region of l\1exico. 

MID-PACIFIC STATION 4,3 D 

The fossil planktonic fauna from the. pocket within 

. the altered basalt of. MP 43 D is correlated with the 

Globigerinatella insueta zone of the Carribbean area on 

the basis of the ranges of the contained species. The 

G. insueta zone was originally placed in the lower part 

of the upper Oligocene of the Caribbean area (for 

example, Stainforth, 1948a, and 1948b), but recent 

work both in Europe and in the Caribbean area (Kugler, 

1954; Akers, 1955; Drooger, 1956; Akers and Drooger, 

1957; Blow, 1957; and Bolli, 1957) indicate that this 

zone is in the lower to middle Miocene of the Caribbean. 

The appearance in the Sylvania Guyot fauna of 

Globigerinoides bispherica Todd and G. subquadrata 

Bronnimann is of particular interest. These two 

species were recently named by Todd and Bronnimann 

(in Todd and others, 1954); they occur. in the Miocene 

of the Cm·ibbean region and in deposits on Saipan, and 

484266-59-2 

G. bispherica has been noted in the Mediterranean area 

(Drooger, 1956). The chances of finding these species 

in a single rock from a haul of dredged material on the 

top of a seamount are such that their discovery in this 

areally intermediate location is almost more than hoped 

for (Todd and others 1954, p. 679). The discovery of 

these two index species on Saipan extended the usefulness of the Globigerinatella insueta zone of the Caribbean 

area into the central Pacific; their discovery on Sylvania 

Guyot and in the Mediterranean (Drooger, 1956) 

emphasizes the importance of the species of this zone in 

worldwide correlations. 

MID-PACIFIC STATION 4o3 DD 

The fossil planktonic fauna from the manganesecoated calcium carbonate material obtained in dredge 

haul MP 43 DD is correlated with the late Miocene 

on the basis of the overlapping ranges of Globigerina 

altispira, Sphaeroidinella multiloba, S. rutschi, S. 

seminulina, S. dehiscens, and Pulleniatina obliquiloculata 

(for example see Grimsdale, 1951). M. N. Bramlette 

(oral communication) after an examination of the 

coccoliths prefers an early Pliocene dating, but adds, 

correctly, that the exact ranges of the coccoliths, as 

well as the Foraminifera, are not well enough known to 

state the exact age more precisely. ·Most sf:>ecies of 

the modern planktonic fauna had appem·ed by the 

early Miocene; therefore planktonic foraminiferal 

faunas younger than that must be dated on relatively 

few species. It appears from this study and examination of the literature (for example Phleger, Parker, and 

Peirson, 1953, p. 85, and Grimsdale, 1951) that the best 

chance to date the upper Miocene in planktonic assemblages is with the species named above and their 

overlap in ranges with more modern elements of the 

fauna such asS. dehiscens, and P. obliquiloculata. 

SIGNIFICANCE OF THE FOSSIL FAUNAS 

In the central North Pacific Basin, there are now 

·several age da.tings of seamounts and events. From 

the borings at Eniwetok Atoll (Ladd, and others, 1953; 

Cole, 1958), it is known that Eocene (Tertiary b) 

shallow-water calcm·eous deposits lie just above the 

olivine basalt. 

At Bikini Atoll, the deep bore hole to 2,556 feet bottomed in the Oligocene (?); but in footnotes (Emery, 

Tracey, and Ladd, 1954, p. 83) and in the papers 

by Cole (1954) and Todd and Post (1954), it is noted 

that there is a distinct possibility that the top of the 

Eocene was reached. A revision of the Bikini Atoll 

evidence by Cole (1958), however, indicates Tertiary e 

(Aquitanian). · · 

Cushman, Todd, and Post (1954) note the presence of 

Tertiary Foraminifera in a core (No. 1176) taken in the 
790 BIKINI .AND NEARBY ATOLLS, MARSHALL ISLANDS 

saddle. between Bikini Atoll and Sylvania Guyot (fig. 

255). It was supposed that these species may have been 

redeposited from the slopes of Bikini Atoll above, but 

now that older material has been found on Sylvania 

Guyot and Tertiary fossil material has been found at 

the surface in the Mid-Pacific Mountains, there is a 

distinct possibility that this material was in place and 

not redeposited. 

· Macdonald (in Emery, Tracey, and Ladd, 1954, p. 

123) notes that the presence of fresh glass in the volcanic 

rocks oil Sylvania Guyot indicates that the rocks are 

not older than the late Paleozoic and that they, being 

pyroclastic rocks, were. erupted in waters much shallower than the water from which they were dredged. 

The early Eocene fauna from a crack in the tuff-· 

breccia boulder (MP 43 A) near the break in slope on 

top of Sylvania Guyot places the age of the fiat top of 

the volcanic peak at not younger than earliest Eocene. 

In the Mid-Pacific Mountains, about 1,000-1,500 

miles to the east of the Marshall Islands, Eocene ooze 

was found in surficial material on the top of Horizon 

Guyot, and Paleocene ooze was found on the top of Hess 

Guyot, at or near the surface of the sediment (Hamilton, 

1953, 1956). The dating of an ooze on the top of a seamount merely indicates that the surface was there at a 

certain time and available to receive sediment; it is 

definitely a "not-younger-than" type of dating and may 

be far from the actual time when the seamount was 

formed, or, .in the case of the fiat-topped seamounts, 

when the seamount was at the surface of the sea. For 

example: Hess Guyot in the Mid-Pacific Mountains was 

·at the surface of the sea in the Cretaceous (Aptian to 

. Cenomanian), but the oldest ooze collected from the 

surface of the fiat top was laid down about 40 million 

years later during the late Paleocene. 

At Eniwetok Atoll the sample from 2,780-2,790 

feet contained the first Eocene species according to 

Cole, so that there is about 1,900 feet of Eocene material 

above the basalt basement of the atoll (at about 4,600 

feet). This is comparable to the Bikini Atoll bore hole, 

where at 2,556 feet the hole bottomed in Tertiary e 

(Aquitanian). At this point the hole was about 2,400 

feet above the volcanic basement as determined by 

seismic techniques; if these assumptions are true then it 

seems likely that there is about 2,400 feet of Oligocene 

and Eocene (and perhaps older rock) above the base-

. ment which is about the same situation as at Eniwetok 

Atoll. 

The finding of early Tertiary Foraminifera in the tuffbreccia· on Sylvania Guyot is another block of evidence 

in the structure forming the geologic history of the 

Pacific Basin and especially the northern Marshall 

Islands. This new evidence fits very well into all of the 

other information previously reported. 

The best postulated history for the Bikini AtollSylvania Guyot feature is still about the same as that 

formulated by Emery, Tracey, and Ladd (1954, p. 

126-131). The new evidence can be assimilated easily 

into the history, so that the events might have been 

somewhat as follows: 

The Bikini Atoll-Sylvania Guyot feature was a 

twin-peaked volcanic mass (Raitt, 1954) in Late 

Cretaceous or earliest Tertiary time. Sylvania Guyot, 

the older peak, had been eroded to a bank, and possibly 

corals had begun to grow and form banks among the 

erosional debris, much of which was pyroclastic. The 

marginal ridges around parts of Sylvania Guyot could 

thus be explained; a similar marginal ridge was noted 

on Hess Guyot (Hamilton, 1956, p. 15) but only 1 

dredge haul out of 6 on Hess Guyot contained· reef 

coral. Bikini Atoll at this time was younger and 

higher and had been relatively little eroded. Subsidence in Late Cretaceous or early Tertiary time was 

too fast to permit coral to continue to stay at the 

surface (which is the favored hypothesis for the sunken, 

coral-bearing guyots of the Mid-Pacific Mountains). 

This would have left Bikini Atoll at or above the 

surface while Sylvania Guyot was a relatively deeply 

submerged bank-too deep for coral growth and below 

the depth of profuse bottom life. Subsequent submergence must have been relatively slow because a 

great reef probably began to grow on the foundation of 

Bikini Atoll in early Tertiary time while, at the same 

time, planktonic Foraminifera were being deposited in 

the cracks of the pyroclastic rocks on Sylvania Guyot . 

Nonaccumulation of sediment around the rims of 

Sylvania Guyot and in the saddle between Sylvania 

Guyot and Bikini Atoll left old rocks and sediment 

deposits at the seamount surface, some of which became 

phosphatized. This is, in general, the same situation 

as in the Mid-Pacific Mountains. 

After the start of deposition on Sylvania Guyot in 

the early Tertiary one might expect to find later deposits 

clear through the Tertiary to Recent time.. The 

Miocene faunas are not, therefore, unexpected. 

It may be very significant in the geologic history of 

the north-central Pacific Basin that roughly the same 

events were transpiring at about the same time in the 

Bikini Atoll-8ylvania Guyot area, in the Mid-Pacific 

Mountains to the east, and at Eniwetok Atoll to the 

west. 

SYSTEMATIC DESCRIPTIONS 

The bulk of the material will be deposited in the U.S. 

National Museum, Washington, D. C. 

~-
LOWER EOCENE PHOSPHATIZED GLOBIGERINA OOZE 791 

Family GLOBIGERINIDAE 

Genus GLOBIGERINA d'Orbigny, 1826 

Globigerina altispira Cushman and Jarvis, 1936& 

Plate 254, figures 1-3 

Globigerina altispira Cushman and Jarvis, 1936, Cushman Lab 

Foram. Res., Contr., v. 12, p. 5, pl. 1, figs. 13, 14. 

This species has been reported from the Miocene of 

Jamaica and Haiti, and from the upper Oligocene and· 

Miocene of the Dominican Republic. Grimsdale (1951) 

reports the species from the Middle East, and it· was reported as rare in a mixed-fauna core from the MidPacific Mo~ntains. Phleger, Parker, and Peirson report this species in Miocene ooze from the Atlantic. 

This distinctive species appears to be a worldwide index 

fossil of some importance; it is common in the Miocene 

material from MP 43 DD. 

Globigerina apertura Cushman, 1918 

Plate 252, figure 7 

Globigerina apertura Cushman, 1918, U. S. Geol. Survey Bull. 

676, p. 57, pl. 12, fig. 8. 

This species has been reported from the Eocene to the 

Pleistocene of North America. and from the Eocene 

faunas of the Mid-Pacific Mountains. It is rare in the 

MP 43 A material. 

Globigerina bulloides d 'Orbigny, 1826 6 

Plate 253, figure 14 

Globigerina b'ltlloides d'Orbigny, 1826, Annals Sci. Naturelles, v. 7, 

p. 277, no. 1; Modeles no. 76 and young, no. 17. 

Phleger and Parker, 1951, Geol. Soc. America Mem. 46, 

p. 34, pl. 19, figs. 6, 7. 

A few forms referred to this species (as diagnosed from 

comparison with modern form~ such as those of the 

second citation) occur in the material from MP 43 D. 

Globigerina ciperoensis Bolli, 1954 

Plate 253, figures 23, 24 

Globigerina ciperoensis Bolli, 1954, Cushman Found. Foram. 

Res. Contr., v. 5, p. 1, figs. 3, 4, 5, and 6. 

Globigerina cf. G. concinna Reuss. Cushman and Stainforth, 

1945, Cushman Lab. Foram. Res. Spec. Pub. 14, p. 67, 

pl. 13, fig. 1. 

Bolli considers that the lower Oligocene form sometimes referred to as G. concinna Reuss is sufficiently dis~ 

tinctive to merit a new species name. This form is 

common in the material from MP 43 D. 

Globigerina aft'. G. collactea (Finlay), 1939 

Globorotalia collactea Finlay, 1909, New Zealand Royal Soc. 

Trans.v.69,pt.3,p.327,pl.29,figs. 164,165. 

A few forms which appear to be close to G. cullactea 

(Finlay) occur in the MP 43 A fauna. · 

o Oonus should bo Globoquadrina. • Reldontlfied os Globorotalia obeBa Bolll, 1957. 

Globigerina dissimilis Cushman and Bermudez, 1937 

Plate 253, figures 9,. 10 

Globigerina dissimilis Cushman and Bermudez, 1937, Cu~hman 

Lab. Foram. Res. Contr., v. 13, p. 25, pl. 3, figs. 4-6. 

A few forms referrable to this species occurred in the 

material from MP 43 D. 

Globigerina eocaena GUmbel, 1868 

.. Plate .252, .. figure 4 

Globigerina eocaena GUmbel, 1868, K. Bayer. Akad. Wiss. 

Munchen, Math.-Physik. Cl., Abh., Munchen, Deutschland, ·Band· 10· (1870). Abt. 2, p. 662, pl. .2, fig; 109a-b. 

This species is rare in. the Eocene (MP 43 A) fauna. 

Globigerina mckannai White, 1928 

Plate 252, ·figures 10, 11 

Globigerina mckannai White, 1928, Jour. Paleontology, v. 2, p. 

194, pl. 27, fig. 16. 

This species is rare in the Sylvania Guyot fauna 

(MP 43 A). It was common in the Eocene fauria from 

Horizon Guyot. 

Globigerina orbiformis Cole, 1927 

Plate 252, figure 6 

Globigerina orbiformis Cole, 1927, Am. Paleontology Bull., v. 14, 

no. 51, p. 33, pl. 5, fig. 7. 

This species is rare in the Sylvania fauna from MP 43 

A' as it was, also, in the Eocene material from Horizon 

Guyot. 

Globigerina ouachitaensis Howe and Wallace var. senilis ·Bandy, . 1949 

Plate 253, figure 4 

Globigerina ouachitaensis senilis Bandy, 1949, Am. Paleontology 

Bull., v. 32, p. 121, pl. 22, fig. 5. 

This variety occurs in the Eocene and middle Oligocene of the gulf coastal area and was found in the Eocene 

material from Horizon Guyot. It is rare in the material of MP 43 D. 

Globigerina p·seudobulloides Plummer, 1926 

Plate 252, figure .3 

Globigerina pseudobulloides Plummer, 1926, Texas Univ. Bull. 

2644, p. 133, pi. 8, figs. 9a-c. 

This species is common in J>aleocene deposits around 

the world and is recorded by Nuttall from the Eocene 

of Mexico. It is rare in the MP 43 ·.A material. In· the 

Paleocene ooze from Hess Guyot this form was common. 

Globigerina rotundaia d'Orbigny var. jacksonensis Bandy, 1949 

Plate 252, figure 1 

Globigerina rotundatajacksonensis Bandy, 1949, Am. Paleontology 

Bull., v. 32, no. 131, p. 121, pl. 23, figs. 6a-c. 

This form is rare in· the Sylvania G~yot faunas.· . ' . . 
792 BIKINI" AND NEARBY ATOLLS, MARSHALL ISLANDS 

Globigerina topilensis Cushman, 1925 

Plate 252, figures 17, 21 

Globigerina topilensis Cushman, 1925, Cushman Lab. Foram. 

Res., Contr., v. 1, p. 7, pl. 1, fig. 9. 

Sylvania forms which appear to fall into this species 

are common in the crack fillings of the tuff-breccia of 

MP 43 A. 

Globigerina triloculinoides Plummer, 1926 

Plate 252, figure 2 

Globigerina triloculinoides Plummer, 1926, Texas·Univ. Bull. 2644, 

p. 134, pl. 8, figs. lOa-c. 

This Danian to 'lower Eocene species is rare in the 

fossil fauna from Sylvania guyot (l\1P 43 A). It was 

common in the Mid-Pacific Mountains faunas. 

Globigerina venezuelana Hedberg, 1937 

Plate 253, figures 15, 16 

Globigerina venezuelana Hedberg, 1937, Jour. Paleontology, v. 11, 

p. 681, pl. 92, fig. 7. . 

This species is recorded from the upper Eocene to the 

middle Miocene. It is common in the material from 

MP43 D. 

Genus GLOBIGERINOIDES Cushman, 1927 

Globigerinoides bispherica Todd 

Plate 253, figures 11-13 

Globigerinoides bishperica Todd, 1954, Am. Jour. Sci., v. 252, p. 

681, pl. 1, 4. 

This species, described from the "upper Oligocene" 

of Saipan is also a common form in the Mediterranean 

area and in the Globigerinatella insueta zone of the 

Caribbean. This form, and that of G. subquadrata 

Bronnimann, may well prove to be extremely important 

index fossils .for the lower Miocene now that worldwide 

distribution is shown. 

Globigerinoides rubra (d'Orbigny), 1839 

Plate 253, figure 5 

Globigerina rubra d'Orbigny, 1839, in de la Sagra, Histoire Phys. 

.Pol.·Nat. Cuba, p. 82, pl. 4, figs. 12-14. 

This abundant Recent form is sparsely represented 

in the· material from MP 43 D; it is common in the late 

Miocene.ooze (1\.fP 43 DD). 

Globigerinoides sacculifera (Brady), 1877 

Plate 253, figures 3, 20-22 

Globigerina sacculifera Brady, 1877, Geol. Mag., v. 4, p. 535. 

Brady, 1884, Dept. Sci. Results Voyage H. M.S. Challenger, 

Zool., v. 9, p. 604, pl. 80, fig. 4. 

This species. is common in the material from MP 43 D 

and in the upper Miocene fauna from MP 43 DD. 

Globigerinoides 'Sacciulifera var. fistulosa. (Schubert) I 1910 

Plate 254, figure i4 

Globigerina fistulosa Schubert, 1910, K. k. geol. Reichsanstalt 

Verh., no. 14, p. 324 (7), fig. 2 (in text). 

Schubert, 1911, K. k. geol. Reichsanstalt Abh., Band 20, 

pt. 4, p. 100, figs. 132-c (in text). 

This form, described from the Tertiary of New 

Guinea, is common in the upper Miocene material from 

MP43 DD. 

Globigerinoides subquadrata Bronnimann, 19~4 

Plate 253, figures 6-8 

Globigerinoides subquadrata Bronnimann, 1954, Am. Jour. Sci., 

v. 525, p. 680, pl. 1, figs. 5, 8. 

This species is abundant in the "upper Oligocene" of 

Saipan (Todd and others 1954) and is known from the 

Miocene of Trinidad and Venezuela. The form is 

common in the material from MP 43 D. 

Glo bigerinoides trilo ba (Reuss), 1850 

Plate 253, figures 17-19 

Globigerina triloba Reuss, 1850, K. Akad. Wiss. Wien, Math.-

Nat. Cl. 1., Denkschr., Wien, Osterreich, Ba.nd 1, 

p. 374, pl. 47, fig. 11. 

This form is common. in the material from MP 43 D. 

Genus ORBULINA d'Orbigny, 1839 

Orbulina bilobata (d'Orbigny), 1846 

Plate 254, figure 11 

Globigerina bilobata d'Orbigny, 1846, Foraminiferes fossiles du 

bassin tertiare de Vienne, Gide et Comp., Paris, France, 

p. 164, pl. 9, figs. 11-14. 

This form is rare in the upper Miocene material from 

MP 43 DD. 

Genus SPHAEROIDINELLA Cushman, 1927 

Sphaeroidinella multiloba LeRoy, 1944 

Plate 254, figure 7 

Sphaeroidinella multiloba LeRoy, 1944, Colorado School Mines 

Quart., v. 39, p. 91, pl. 4, figs. 7-9. 

A form which is tentatively assigned to this species is 

common in the l\.1iocene material from MP 43 ·DD. As 

noted by the writer (Hamilton, 1953, p. 228) and Miss 

Frances L. Parker (in Phleger, Parker,. and Peirson, 

iQ53, p. 18) this species, S. rutschi, and S. seminulina 

n1ay well be variations of a single· sp·ecies (especially 

true of S. seminulina and s.·rutschi). In I952·Hflmil.:. 

ton examined topotype material of spe.cin1eil.s ·of 

S. rutschi and S. sem.inulina sent to Miss Parker 

by the U. S. National Museum. In Miss .Parker's 

opinion and in that of Hamilton, the two species (in the 

material at hand) \Vere the same, with the possible 

exception that the wall of S. seminulina appear!3d to be 

thinner and more translucent and had a .r<?und po~e 
LOWER EOCENE PHOSPHATIZED. GLOBIGERINA OOZE 793 

structure which appeared· as white dots, whereas 

S. rutschi had the typical ·hexagonal pore structure of 

the Globigerinidae and a thicker, whiter wall. All these 

forms are important worldwide index species of the 

Upper Tertiary and fortunately have about the same 

reported range: S. multiloba from the lower to upper 

Miocene, S. seminulina from the upper Oligocene to 

the lower Pliocene, and S. rutschi from the middle 

Oligocene to the middle Nliocene. 

Sphaeroidinella rutschi.Cushman and Renz, 1941 

Plate 254, figure 6 

Sphaeroidinella rutschi Cushman and Renz, 1941, Cushman Lab. 

Foram. Res., Contr., v. 17, p. 25, pl. 4, figs. 5a-c. 

A few forms assigned to this species were noted in 

the Miocene material from MP 43 D D. See also the 

remarks under S. multiloba LeRoy. 

Sphaeroidinella seminulina (Schwager), 1866 

Plate 254, figures 4, 5 

Globigerina seminulina Schwager, 1866, Novara. Exped., Geol. 

Theil, v. 2, p. 256, pl. 7, fig. 112. 

This form occurs commonly in the Miocene material 

from MP 43 DD. For further remarks see the note 

under S. multiloba. 

Family·GLOBOROTALUDAE 

Genus GLOBOROTA~IA Cushman, 1927 

Globorotalia aragonensis Nuttall, 1930 

Plate 252, figures 14-16 

Globorotalia aragonensis Nuttall, 1930, Jour. Paleontology, v. 4, 

p. 288, pl. 24, figs. 6-8, 10, 11. 

This species is a worldwide index fossil for the early 

and middle Eocene; it has been reported from the 

Middle East, the gulf coast area, the Caribbean area, 

and the Mid-Pacific fiat-topped seamounts. It is 

common in the Sylvania guyot fauna and occurs in 

the same indurated crack filling (pl. 251) as G. 

velascoensis (Cushman). The overlapping range of 

this species with that of G. velascoensis places the age 

of the fauna as at about the boundary between the 

Paleocene and the Eocene. 

Globorotalia centralia Cushman and Bermudez, 1937 

Globorotalia centralia Cushman ·and Bermudez, 1937, Cushman 

Lab. Fo!am. Res., Co~tr., v. 13, p. 26, pl. 2, figs. 62-65. 

· Three speqimens of this form were found in the 

MP 43 A material. 

Globorotalia cra.ssata (Cushman) 

·Plate 252, figure 5 

Pulvinulina crassata Cushman, 1925, Am. Assoc. Petroleum 

Geologists Bull., v. 9, p. 300, pl. 7, fig. 4. 

Globorotalia crassata (Cushman). Cole, 1927, Am. Paleontology 

BulL, v. 14, no. 51, p. 34, pl. i, figs. 7-8. 

Cushman, 1939, Cushman Lab. Foram, Res., Contr., v. 15, 

p. 74, pl. 12, fig. 19 .. 

In connection with the Mid..,Pacific material,· plesiotype material of the last named citation was obtained 

from the U. S. National Museum and compared to 

the Mid-Pacific material. The species, as so diagnosed, 

· is common in the Paleocene and Eocene faunas of the 

Mid-Pacific Mountains and is common in the Sylvania 

guyot material. The original figure by Cushman is 

entirely inadequate to identify this species:· 

Globorotalia crassa.ta densa (Cushman) 

Plat~ 252, figur~s 8,9. 

Pulvinulina crassata· densa. (Cushman), 1925, Am., Assoc. 

Petroleum Geologists Bull., v. 9, p. 301; no fig. 

Globorotalia· crassata densa (Cushman), 1939, Cushman Lab. 

Foram. Res., Contr., v. 15, p. 74, pl. 12, fig. 20. · . 

Plesiotype material from the last-named citation 

was obtained from the U. S. National Museum for 

comparison with the Mid-Pacific material. The variety 

is common in the Mid-Pacific guyot faunas and is 

common in the Sylvania guyot material from MP 43 A. 

Globorotalia membrana.cea. (Ehrenberg), 1854 

Plate 252, figure 13 

Planulina membranacea Ehrenberg, 1854, Mikrogeologie, pl. 25, 

1A, fig. 41, pl. 26, fig. 43. 

One specimen of this Paleocene species was found in 

the Sylvania guyot material from.MP 43 A. 

Globorotalia. mena.rdii (d'Orbigny) va.r. fijiensis Cushman, 19~4 

Plate 254, figure 13 

Globorotalia menardiifijiensis Cushman, 1934, B. P. Bishop .Mus. 

Bull. 119, p. 136, pl. 17, fig. 5. 

This form·, named from the Tertiary of Suva, is r&re 

in the Miocene material from MP 43DD. 

Globorotalia mena.rdii (d 'Orbigny) va.r. multica.mera.ta. Cushman 

and Jarvis, 1930 

Plate 254, figure 12 

Globorotalia menardii multicamerata Cushman and Jarvis, 1930, 

Jour. Paleontology, v. 4, p. 367, pl. 34, fig. 8. 

This form, named from the Miocene of Jamaica, is 

rare in the Miocene material from MP 43DD. It was 

reported by Phleger, Parker,· and Peirson (1953, p. 20) 

from the Miocene of deep-sea cores in the Atlantic. 

Its geographic range is now extended to the Pacific. 

As noted by Phlegel,', P~rker, and Peir~on, only. 9ne 

report has been made from the Recent. If this: occurrence in deep water off Cuba is the result of transported 

ma.terial, then the fo.rm might be useful in dating the 

upper Tertiary. . · · 

Globorotalia tuniida. (Brady) cf. G. tumida. va.r. flexuosa (Koch), . 1923 . . ; . . . . ·· ... 

Plate 254, figures 8-10 . 

Pulvinulina flexuosa Koch, 1923, Eclogae Geol. Helv., Laus.anne, 

Suisse, v. 18, p. 357, p. 351, tfs., 9a-b, lOa-b. · 

The form illustrated may be compared to the variety, 

but further study is need~d to di.ff~renti&te th~ menanlii-
794"" BIKINI "AND- .NEARBY. ATOLLS; . MARSHALL ISLANDS 

tumida_ complex. :It" is probable that close study of this 

group will yield. species and varieties of stratigraphie 

importance, especially from the upper Miocene .to the 

Re.cent where such markers are sorely needed. 

Globorotalia velascoensis (Cushman), 1925 

Plate 252, figures 18-20 

Pulvinulina velascoensis Cushman, 1925, Cushman Lab. Foram. 

Res., Contr. v. 1, p. 19, pl. 3, figs. 5a-c. 

Globorotalia velascoensis (Cushman), 1927, Jour. 'Paleontology, 

v. 1, pl. 27, figs. 7-9.· 

"';this speqie~ is the best worldwide index fossil for the 

lower Tertiary. It has been noted in material from 

the Middle East, the gulf coast area, Caribbean area, 

and the Mid-Pacific Mountains. Its, geologic range is 

possibly uppermost Cretaceous, definitely Paleocene, 

and probably lower Eocene. The form noted in the 

Sylvania guyot material is very close to the type; it 

has the distinctive beaded and raised sutures on the 

dorsal side, as well as the open umbilicus. 

Globorotalia whitei Weiss, 1955 

Plate 253, figures 1, 2 

Globigerina crassajormis Galloway and Wissler. White, 1928, 

. Jour. Paleontolo-gy, v: 2, p. 193, pl. 27, fig. 14. 

Globorotalia -crassajormis (Galloway . and Wissler). Nuttall, 

. .. .1~35, .Jour. PaleontologY., v. 9, p. 130, pl. 1~, figs.. 21, 29. 

Globorotalia·whitei Weiss, 1955, Jour. Paleontology; v. 29, p: 18, 

pl. 6, figs. 1-3. · 

This ~~w species, as _diagnosed by Weiss~ is known 

from .the Paleocene and lower Eocene of Peru, the 

Upper Cretaceous and Paleocene of Mexico, and the 

Eocene of Venezuela. This species is rare in the lowermost Eocene fauna from Sylvania guyot, but this new 

locality indicates a widespread distribution. Specimens fro~ the Sylvania· guyot fauna were sent to 

Weiss, who affirmed that they were identical with his 

type material. · · 

Globorotalia wilcoxensis Cushman, 1932 

Plate 252, figure 12 

Globorotalia wilcoxensis Cushman and Ponton, 1932, Cushman 

· Lab. Foram. Res., Contr. v. 8, p. 71, pl. 9, fig. 10. 

This form is rare in the Sylvania material. 

SELECTED BIBLIOGRAPHY 

Akers, W. H., 1955·, Some planktonic Foraminifera of the American gulf coast and suggested correlations with the Caribbean 

· Tertiary: Jour. Paleontology, v. 29, p. 647-664. 

Akers, W. H., and Drooger, C. ·W., 1957, Miogypsinids, planktonic Foraminifera, ·an_d .gulf coast .Oligocene-Miocene correlations: Am. Assoc. Petroleum Geologists Bull., v. 41, 

p. 656-678.· 

Arrhenius, a·., Bramlette, M_. N., and Picciotto, E., 1957, 

Localization of radioactive and stable heavy nuclides in 

·ocean sediments: Nature, v. 180, p. 85-86. 

Blow, W. H.; 1957,_ Transatlantic correlation o_f Mio~ene sediments: Micropaleontology, v. 3, p. 77-79. 

Bolli, H. M., 1957; Planktonic Foraminifera from the Oliga.ceneMiocene Cipero-Lengua formations of Trinidad: U. S. 

Natl. Mus. Bull. 215. 

Buser, W. and Grutter, A., 1956, Uber die Natur der Manganknollen, Schweiz: Mineralogische ~nd Petrographische 

Mitteilungen, v. 36, p. 49-62. 

Clark, J. 8., 1955, Solubility criteria for the existence of hydroxyapatite: Canadian Jour. Chemistry, v. 33, p. 1696-1700. 

Clark, J. S., and Turner, R. C.~ 1955, Reactions between ·solid 

calcium carbonate and orthophosphate eolutions: Canadian 

Jour. Chemistry, v. 33, p. 665-671. · 

Cole, W. S., 1954, Larger Foraminifera and smaller diagnostic 

Foraminifera from Bikini drill holes: U. S. Geol. Survey_ 

Prof. Paper 260-0. 

--- 1958, Larger Foraminifera from Eniwetok drill holes: 

U.S. Geol. Survey Prof. Paper 260-:V. 

Cushman, J. H., Todd, Ruth, and Post, R. J., 1954, Recent 

Foraminifera of the Marshall Islands: U. S. Geol. Survey 

Prof. Paper 260-H. 

Dietz, R. S., Emery, K. 0., and Shepard, F. P., 1942, Phosphorite deposits on the sea floor off southern California: 

Geol. Soc. America Bull., v. 53, p. 815-848. · 

Drooger, C. W., 1956, Transatlantic correlation of the Oligo-

. Miocene by means of Foraminifera: Micropaleontology, 

. v. 2, p. 183-192. 

Emery, K. 0., Tracey, J. 1., Jr., and Ladd, H. S., 1954, Geology 

of Bikini and nearby atolls, Pt. 1, Geology: U. S. Geol. 

Survey Prof. Paper 260-A. 

Glaessner, M. F., l945, Principles of micropaleontology, Oxford 

Univ. Press;· London. 

Goldberg, E. D., 1954, Marine geochemistry I. Chemical 

scavengers of the sea: Jour. Geology, v. 62, 249-265. 

Grimsdale, T. F., 1951, Correlation, age determination, and the 

. · .. ~ertiary pelagic Foraminifera: Proc. Third World Petroleum Cong., sec. 1, p. :463-47~. , 

Hamilton, E. L., 1953, Upper Cretaceous, Tertiary, and :Itecent 

planktonic Foraminifera from Mid-Pacific flat-topped seamounts: Jour. Paleontology, v. 27, p. 204-237. 

--·- 1956, Sunken. islands of the Mid-Pacific Mountains: 

Geol. .Soc. America Mem. 64. 

Henson, F·. R .. S., {938, Stratigraphical correlation by small 

Foraminifera in Palestine and adjoining countries: Geol. 

Mag. v. 75, p. 227-233. · · 

Kugler, H. G., 1954, The Miocene-Oligocene boundary in the 

Caribbean region: Geol. Mag., v. 91, p. 410-414. 

Ladd, H. S., and others, 1953, ·Drilling on Eniwetok AtolJ, 

Marshall Islands: Am. Assoc. Petroleum Geologists Bull., 

v. 37, p. 2257-2280. 

McConnell, D. M., 1938, A structural investigation of the isomorphism of the apatite group: Am. Mineralogist, v. 23, 

.p. 1-19. 

Phleger, F. B, Parker, F. L., and Peirson, J. F., 1953, North 

Atlantic· Foraminifera: Repts Swedish Deep-Sea. Exped., 

v.7,no. 1 

Raitt, R. W., 1954, Seismic refraction studies at Bikini and 

Kwajalein Atolls and Sylvania Guyot: U. S. Geol. Survey 

Prof. Paper 260-K. . . Reiss, Z., 1955, Micropaleontology and the Cretaceous-Tertiary 

boundary in Israel: Israel Res. Council Bull., Sec. B, v. 5B, 

p. 105-120. 

Stainforth, R. M., i948a, Applied micropaleontology in coastal 

·Ecuador: ·Jour. Paleontology, v, 22, _p. 113-151. · 
~-

LOWER EOCENE PHOSPHATIZED GLOBIGERINA OOZE 795 

----1948b, Description, correlation, and paleoecology of 

Tertiary Cipero marl fot;mation, Trividad, B. W. I.: Am. 

Assoc. Petroleum Geologists Bull., v. 32, p. 1292-1330. 

---1949, Foraminifera in the Upper Tertiary of Egypt: 

Jour. Paleontology, v. 23, p. 419-422. 

Todd, Ruth, and others, 1954, Probable occurrence of Oligocene 

on Saipan: Am. Jour. Sci., v. 252, p. 673-682 

Todd, Ruth, and Post, R. J., 1954, Smaller Foraminifera from 

Bikini drill holes: U. S. Geol. Survey Prof. Paper 260-N. 

Tromp, S. W., 1949, The determination of the CretaceousEocene boundary * * * in the Near East: Jour. Paleontology, v. 23, p. 673-676. 
... 
INDEX 

[Italic numbers indicate descriptions) 

Page 

Acknowledgements •••••••••• __ ••••••••••..•••..•.•••••••• --•..••.•••••• ---... 786 

Ago of rocks ••••••• ----------.••• ------------------------------------------- 789-790 

altlapira, Globigerina. ------------------------------------------- 788, 789, 791, pl. 254 

Analyses, X-ray diffraction •••••••••••••••••.••••••••••••••••••••••. ---------- 787 

Apatite ••••••••••••••••••••••••••••• -----••• --•••• _ •••••.••• ----••••• ----.---- 786 

apertura, Globigerina ••••••••••••••••••••••••••••••.••••••••••••••••• 788, 791, pl. 252 

aragimensia, Globorotalia ••••••••• -------------------------------- 788, 789, ?93, pl. 252 

Bibliography ••••• ------- __ -------••• ----•••••••.•• _ •••••• _--------_----- ___ 794-795 

bilobata, Globigerina •• ---•• __ •••• --•• ----- __ -----••.• -----••• ------------•• ---- 792 

Orbulina ••••••••••••• -----••••••••••••• __ .-----•••••••.• ------------- 79!, pl. 254 

blapherica, Globigerinoidea •••••••••••••••••••.••••••••••••••••••• 788,789, 79B, pl. 253 

bulloides, Globigerlna ••••••••••••• __ ---••••• _ •• ----••• __ •• --.••••• __ •• 788, 791, pl. 253 

centralia, Globorotalia ••••••••• -------••• __ •••••• ----•••••• --•••. __ -----•••• -- 788, 793 

cfperoenala, Globigerina •••••••••••••••••••••••••••••••.•• ------------- 788,791, pl. 253 

Coccoliths.--------------•• ----_---------._ ••••• ------ __ -------••••• ---------- 786 

collactea, Globlgerina •••• ----- ____ •• _______ ••••••••• ______ ---•• ______ -------- 788, 791 

conclnna, Globlgerlna ••••• __ ---- __ ••• __ • ---••.•• ----------•.•.. --------------.. 791 

Condusions •• -------------••••••• ----------. ___ ---- _____ -------------.----- 788-790 

crassaformis, Globlgerina ••••••• -----.-----------------------------· •• --.------ 794 

Globorotalia •••••••••••••••••••••••••••••. --------------------------------- 794 

crassata, Globorotalia.------------------------------------------------ 788, 799, pl. 252 

Pulolnulina ••••• -------•••••••• ----••••••••••••••••.•••.•..•••••••• ---. •• • 793 

crassata densa, Globorotalia •••••• ------------------------------------- 788, 79!1, pl. 252 

Puloinullna •••••• ---•••••••••••••••••••••••••••••••••• __ . __ ..• •• • • • • • • • • • • 793 

dehiscena, Sphaeroidinella ••••••••••••••••••••• ----••• ---.•• --••• -----•••• --•. -- 789 

denaa, Globorotalia craaaata •••••• ------------------------------------ 788, ?9!1, pl. 252 

Pulointtllna craaaata ••• ---•• --••••••••••• ----••• -----------... •• • •• •• .• •• • 793 

Description of planktonic Foraminifera ••••• ---------------------------------- 788 

Discussion •••••• ----•••• __ ••• -----••• ____ •••• ----••• __ ••• --•• --•••••• ____ ••• 788-790 

diaslmilfB, Globigerl'na ••••••••••••••••••••••• ------------------------ 788, 791, pl. 253 

Dredge lH\Uls. (See Mid-Pacific station.) 

Enlwetok AtolL •••••••••••• --------------••• -----•••• ----------------.------ 789, 790 

f.Ocaena, Globigerina ••••••••••••••••••••••••. ------------------------ 788,791, pl. 252 

fijiensla, Globorotalia menardiL •• ------------------------------------ 788, 799, pl. 254 

jiatulosa, Globigerlnoides •••••••••••• ---.•••••.••••••••••••••••••• ---•• --•••• --. 792 

Globlgerlnoides aacculifera ••••••••••••.••••••••••••••••••••••••••••••• 79B, pl. 254 

jle:tttosa, Globorotalia tumida ••••• ----------------------------------·--·-- 799, pl. 254 

Puloinullna ••••••• ----••••••••••••.•••••••••••••...••••• -••••••••••• ----.• 793 

Globigerina altf8pira _____________________________________________ 788,789,791, pl. 254 

apertura·------------------------------------------------------- 788,791, pl. 252 

bllobata ••••••••••••••••••• ----•.••••••••.••••••••••• -.--.---•• -----------. 792 

bulloides •• ------·----------------------------------------------- 788,791, pl. 253 

ciperoensls •••••••••••••••••••••••••••••••••••••••••••••••••••••• 788, 791, pl. 253 

collactea ••••••••••••••• ---••••••• ------•••••• --------.---.--•••• -- __ . __ •• 788, 791 

concinna •••••• ----•• -------------------.-----••••••• ----•••• -------------. 791 

crassaformls •••••••••••••• ---••••••••••••••• ---- __ •••• ----••• __ -------.. •• • 794 

dlssimflis ••• ---------------------------------------------------- 788, 791, pl. 253 

eocaena. -------------------------------------------------------- 788, 791, pl. 252 

mckannai. ••••••• ----------------------------------------------- 788, 791, pl. 252 

orblformla .•••••••••• ---------------------------------------------------- 788, 791 

ouchitaensla aenllia •••• ------------------------------------------ 788, 791, pl. 253 

oozo. ------------·-------------------------------------------------- pis. 250, 251 

pseudobttlloldea ••• ---------------------------------------------- 788, 791, pl. 252 

rotundatajacksonensla ••••••••••••••••••••••••••••••••••••••••••• 788,791, pl. 252 

aemlnulina ••• -----.------------------------------------------------------ 793 

topilensla ••••••••••••••••••••••••••••••••••••••••••••••••••••••• 788, 79B, pl. 252 

trllocullnoldea ••••••••••••••••••••••••••••••••••••••••••••••••••• 788, 79B, pl. 252 

~~eneztulana •••••• ---------------------------------------------- 788, 79B, pl. 253 

Globlgerinatella lnauda zone ••••••••• ------•.• ----------.-------••• ------------ 789 

Page 

Globigerinoides bf8pherica ________________________________________ 788, 789, 79S, pl. 253 

jistuloaa •••••••••••••..•••••..••.••••••••••••..•.•••••••••••••••• _ .• ---... 792 

rubra .••• ------------------------------------------------------- 788, 79S, pl. 253 

sacculi/era .• ---._----------------------------------------------- 788, 79S, pl. 253 

fistuloaa ••••••.• -------------------------------------------------- ?9B, pl. 254 

subquadrata •••••••••• --------------------------------------- 788,789, 79B, pl. 253 

triloba •• ••• : •••••. ----------.--------------------.-------------- 788, 79B, pl. 253 

Globorotalia •••••....•.•••. ----•••••••••••••••••••• ---.--•••••••••••• ------••• pl. 251 aragonensia _________________________________________________ 788, 789, 79!1, pl. 252 

centralia .. --------•• -----------------•• ------•• ------------------.------ 788, 798 

craasajormia •••••••••••• ---••••••••••••.••••• --.--•.••••••• --.•••••. ---- __ • 794 

crassata ••••••••.•..• ------------------------------------------- 788, 79!1, pl. 252 

densa .••••.••• __ ---------.•••••••• ---------------•.. ------.•• ------- 788, 799 

membranacea ••••••.• ------------------------------------------- 788, ?99, pl. 252 

menardii fi}iensia •.••••••. _ •••.• ------------------••..• -----••••• 788, 799, pl. 254 

muUicamerata ••••••••••.••. __ .•...•••••••.... ---••••••.••••.• 788, 799, pl. 254 

tumida jlexuosa •..••• ------------------------------------------------ 798, pl. 254 

oelascoensis ••.•••.••..•••••.....••••••..•. ----•. ---...•.• 788, 789, 793, 794, pl. 252 

white!. •••••• ---•••••.• ---------•••• ---...•••••.••.....•• ---.---- 788, 794, pl. 253 

·wilco:tensis .....•..••• -------•• ------------------••.•••••..••. ---- 788, ?94, pl. 252 

Globotruncana-Gtlmbelina faunas •. ___ ..•••••••.•. ----••• -----................. 788 

insueta zone, Globigerinatella •• -----------· -----·----•• --------••• ------------- 789 

Introduction •••• ----------------------------------------------------.------ 785-786 

jacksonensis, Globigerina rotundata •• --------------------------------- 788,791, pl. 252 

Macdonald, Identification by-----------------------------------------.------- 785 mckannai, Globigerina ________________________________________________ 788,791, pl. 252 

Manganese oxide ••• _ •..• --•••• ----------.• ---••.•• --.-----.-----.• __ .-------. 785 membranacea, Globorotcilia ___________________________________________ 788, 79!1, pl. 252 

Planulina ••• ------------------------------------------------------------- 793 menardii fi}iensis, Globorotalia ________________________________________ 788, 79!1, pl. 254 

menardii multicamerata, Globorotalia •• ------------------------------- 788,799, pl. 254 

Mid-Pacific Mountains •• -------------------------------------- __ .------------ 790 

Mid-Pacific station 43A _. _. ------------------------------------- ____ • -------- 785 

description of Foraminifera at •• ------------------------------------------ 788 

discussion and oonclusions ..•••• ----------------------------- _ ---.------ 788-789 

occurrence of fossiliferous material at·----------------------------------- 786-787 

Mid-Pacific station 43 D----------------------------------------------.------- 785 

description of Foraminifera __________________________________ ----.-------- 788 

discussion and oonclusions.--------------------------------- _ ---- _ -------- 789 

occurrence of fossiliferous material at·------------------------------------- 787 

Mid-Pacific station 43 DD----------~----------------------------------------- 786 

description of Foraminifera at •.. ------------------------------------------ 788 

discussion and conclusions.----------------------------------------------- 789 occurrence of fossiliferous material at ____________________________________ 787-788 

multicamerata, Globorotalia menardii-------------------------------- 788, 799, pl. 254 

muUiloba, Sphaeroidinella-------------------------------------- 788, 789, 79B, pl. 254 

obliquiloculata, Pulleniatina. _ ------------------------------------. ___ . -------- 789 

Occurrence or fossiliferous materiaL.--------------------------------_------ 786-788 

orbiformis, Globigerina .•. ------------------------------------------- 788, 7P1, pl. 252 

Orbulina bilobata ••.•..•• ----------------------------------------- ____ . __ 79B, pl. 254 ouchitaensis senilf8, Globiuerina ____________________________________ 788, 791, pl. 253 

Paragenetlc sequence. ____ ------------------. __ ------ __ ---. __ ••••• _____ ••••••• 786 

Planulina membranacea •• ---------------------------------------- ____ . -------- 793 

pseudobulloides, Globigerina .••••••••• ------------------------------ 738, 791, pl. 252 Pulleniatina obliqufloculata ______________________________________ ______ -------- 789 

Pulvinulina crassata. _. ------------------------------------------ _____ -------- 793 

crassata densa ________________ ------------------ __ ••• -------------.-------- 793 

jlexuosa •. ------------ __ ••.••• _____ . _. _ ---- _. ---. _. ____ •• _. __ . _ •• ___ ------- 793 

rJelascoensf8 •••••.••• ------------------------------------ ___ ---. ____ -------- 794 

797 
798 INDEX 

Page 

rotundata jack8onensis, Globigerina-------------------------------- 788, 791, pl. 252 

rubra, Globigerinoides.--------------------------------------------- 788, 79B, pl. 253 

rutschi, Sphaeroidinella.-------- 7 -------------------------------- 788, 789, 79B, pl. 254 

sacculi/era, Globigerinoides .. ------ _ ------ _ •. _ ------ ____ -- __ -- ______ • 788, 792, pl. 253 

sacculi/era fistulosa, Globigerinoides.. •. _______________________ . _________ 79B, pl. 254 

seminulina, Globigerina .• _ ---------------------------------------------------- 793 Sphaeroidinella ••••••••••• __________ •• _________________ 788, 789, 792, 799, pl. 254 

senilis, Globigerina ouchitaensis _______________________________________ 788,791, pl. 253 

Significance of fossil faunas .••• --------------------------------------------- 789-790 alminulina, Sphaeroidinella .• ________________________________________ 788,789,792, 79j 

Sphaeroidinella dehillcens. ------ ____ ----- _ ---- _ -- ____ -------------------------- 789 

muUiloba.-------------------------------------------------·- 788,789,791, pl. 254 

rttlschi. -------------------------------------------------- 788,789,792,793, pl. 254 seminulina .•.• __________________________________________ 788, 789,792,793, pl. 254 

0 

Page 

subquadrata, Globigerinoides •••. ---------------------------------- 788,789, 79B,·pl. 253 

Systematic descriptions ••.••• ----------.•.• ___ •. --------•. ------------------ 79G-794 

topilensiB, Globigerina ••.•. ------------------------------------------- 788, 79S, pl. 252 triloba, Globigerinoides _______________________________________________ 788,79£, pl. 253 

triloculinoides, Globigerina ... ---------------------------------------- 788, 79B, pl. 252 

tumidajlexuosa, Globorotalia.------------------~------------------------- 799, pl. 254 

velascoensiB, Globorotalia ...•.. ------------------------------- 788,789,793,794, pl. 252 Pulvinulina •••.•..•....•..•• _. ___ ......•••.•...... _______ •••• _______ •• _ •• _ 794 

venezuelana, Globigerina •••...•...•.. -------------------------------- 788, 79B, pl. 253 

whitei, Globorotalia·------------------------------------------------- 788,794, pl. 253 

wilcoxensis, Globorotalia ••••... --------------------------------------- 788,794, pl. 252 
~· 

PLATES 250-254 . 
PLATE 250 

FIGURE 1. Volcanic tuff-breccia with cracks filled with white,. partly phosphatized Eocene Globigerina ooze 

(MP 43 A). At the lower right1 note the· black crust ·of ferruginous oxide covering both the 

tuff-breccia and the crack filling. X 2.4. 

2. Volcanic tuff-breccia with pockets and cracks filled, or partly filled, with partly phosphatized 

Eocene Globigerina ooze (MP 43 A). Note the pocket (lower right) containing indurated ooze 

and phillipsite crystals. X 3.0. 

·~ 

"' 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 260 PLATE 250 

VOLCANIC TUFF-BRECCIA CONTAINING EOCENE GLOBIGERINA OOZE 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 260 PLATE 251 

PHOTOMICROGRAPH OF EOCENE PLANKTONIC FORAMINIFERA 
•• 

PLATE 251 

Photomicrograph of Eocene planktonic Foraminifera on the top surface of an indurated,·partly phosphatized 

Globigerina ooze crack filling (MP 43 A). Black material near the center is ferruginous manganese ox-ide. 

Approximately X 60. Keeled Globorotalia, typical of lower Tertiary faunas. are indicated by arrows. 
PLATE 252 

FIGURE 1. Globigerina rotundata d'Orbigny var. jacksonensis Bandy. X 50 (p. 791). 

2. Globigerina triloculinoides Plummer. X 66 (p. 792). 

3. Globigerina pseudobulloides Plummer. X 82 (p. 791). 

4. Globigerina eocaena GUmbel. X 85 (p. 791). 

5. Globorotalia crassata (Cushman). X 74 (p. 793). 

6. Globigerina orbiformis Cole. X 53 (p. 791). 

7. ,Glo.bigerina apertura Cushman. X 76 (p. 791). 

8, 9. Globorotalia crassata:densa (Cushman). X 64 (p. 793). 

8, ventral view; 9·;- peripheral view. 

10, 11. Globigerina mckannai White. X 58 (p. 791). 

10, ventral view; 11, peripheral view. 

12. Globorotalia wilcoxensis Cushman and Ponton. X 56 (p. 794). 

13. Globorotalia membranacea (Ehrenberg). X 79 (p. 793). 

14, 15, 16. Globorotalia aragonensis Nuttall. X 55 (p. 793). 

14, dorsal view; 15, ventral view; 16, peripheral view. 

17, 21. Globigerina topilensis Cushman. (p. 792). 

17, X 21;21, X 60. 

18, 19, 20. Globorotalia velascoensis (Cushman). X 54 (p. 794). 

18, dorsal view; 19, ventral view; 20, peripheral view. 
,_ 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 260 PLATE 252 

2 

1 3 4 

6 

5 7 8 9 

10 11 12 13 

17 

14 15 16 

21 

LOWER EOCENE PLANKTONIC FAUNA 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 260 PLATE 253 

1 2 

3 

4 5 

6 7 8 9 10 

11 12 13 

15 16 17 18 19 

23 24 

22 

MIOCENE AND LOWER EOCENE PLANKTONIC FAUNA 
l>LATE 253 

FIGURES 1, 2. Globorotalia whitei Weiss. X 66 (p. 794). From lower Eocene fauna of MP 43 A. 

1, ventral view; 2, peripheral view. 

3. Globigerinoides sacculi/era (Brady). X 75 (p. 792). 

4. Globigerina ouchitaensis Howe and Wallace var. senilis Bandy. X .58 (p. 791). 

5. Globigerinoides rubra (d'Orbigny). X 63 (p. 792). 

6, 7, 8. Globigerinoides 81lbquadrata Bronnimann. X 57 (p. 792). 

6, ventral view; 7, dorsal view; 8, peripheral view. 

9, 10. Globigerina dissimilis Cushman and Bermudez. X 60 (p. 791). 

9, ventral view; 10, peripheral view. 

11, 12, 13. Globigerinoides bispherica Todd. X 64 (p. 792). 

11, ventral view; 12, dorsal view; 13, peripheral view. 

14. Globigerina bulloides d'Orbigny. X 77 (p. 791). 

15, 16. Globigerina venezuelana Hedberg. X 73 (p. 792). 

15, ventral view; 16, peripheral view of another specimen. 

17, 18, 19. Globigerinoides triloba (Reuss). X 62 (p. 792). 

17, ventral views; 18, peripheral view; 19, dorsal view. 

20, 21, 22. Globigerinoides sacculi/era (Brady). X 72 (p. 792). 

20, ventral view; 21, dorsal view; 22, peripheral view. 

23, 24. Globigerina ciperoensis Bolli. X 62 (p. 791). 

23, ventral view; 24, dorsal view. 
PLATE 254 

FIGURES 1, 2, 3. Globigerina altispira Cushman and Jarvis. X 60 (p. 791). 

1, ventral view; 2; peripheral view; 3, dorsal view. 

4, 5. Sphaeroidinella seminulina (Schwager.). X 66 (p. 793). 

4, ventral view; 5, dorsal view. 

6. Sphaeroidinella rutschi Cushman and Renz. X 77 (p .. 793). 

7. Sphaeroidinella multiloba LeRoy. X 65 (p. 792). 

8, 9, 10. Globorotalia tumida (Brady) cf. G. tumida fiexuosa (Koch). X 66 (p. 793). 

8, ventral view; 9, dorsal view; 10, peripheral view. 

11. Orbulina bilobata (d'Orbigny). X 49 (p. 792). 

12. Globorotalia menardii (d'Orbigny) var. m1tlticamerata Cushman and Jarvi~. X 61 (p. 793). 

13. Globorotalia menardii (d'Orbigny) var. jijiensis Cushman. X 46 (p. 793). 

14. Globigerinoides sacculifera (Brady) var. jistulosa (Schubert). X 68 (p. 792). 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 260 PLATE 254 

1 2 3 

4 5 6 

7 

11 

8 9 10 

12 13 

UPPER MIOCENE PLANKTONIC FAUNA