CALIFORNIA STATE UNIVERSITY, NORTHRIDGE
BENTHIC FORAMINIFERA AND PALEOBATHYMETRY
OF THE EOCENE LLAJAS FORMATION,
SOUTHWESTERN SANTA SUSANA MOUNTAINS, CALIFORNIA
A thesis submitted in partial satisfaction of the requirements for the degree of Master of Science in
Geology
by
Herman Bodo Schymiczek
August, 1983 The Thesis of Herman B. Schymiczek is approved:
California State University, Northridge ACKNOWLEDGEMENTS
This investigation has had the benefit of the assistance, cooperation, advice, and discussions of many individuals, and for all of it I am deeply grateful. My deepest thanks goes to my friend and mentor, Dr. Richard L.
Squires, Cal State University, Northridge, for his advice and patience, without which this project could not have been completed. Squires provided thicknesses and aided also in collecting of the microfossil samples. The type section traverse used by Squires {1981, 1983b) is the same one used in this report. Dr. Robert G. Douglas, University of Southern California, provided several outstanding discussions as to paleobathymetric interpretations. The skills and techniques required for this investigation were provided by the expert instruction of Dr. Benjamin N. Akpati, Cal State University,
Northridge.
Alvin A. Almgren, Roy Fulwider, Mark Filewicz, Merton Hill, III, all of the Union Oil Company, reviewed and confirmed many of my identifications as well as providing information from their own studies of the Llajas Formation.
Gary Taylor, Cal State University, Northridge, helped in ostracod identification and provided some of the photomicrographs used for the plates.
Gerald Haigh, Wiff Haigh, and the Marr Ranch granted permission for access into the study area. Richard Chow, Cal State University, Northridge, provided instruction and assistance in the use of the scanning electron microscope. All of the figures and tables were skillfully drafted by Dale Dow.
I am especially indebted to Nancy Pratt and Diana Gary for typing the manuscript and for their patience with my countless revisions. My thanks to the Getty Oil Company for their support.
iii Despite the invaluable contributions of those listed above, they are in no way to be held responsible for any identifications, interpretations, or conclusions made in this investigation.
iv CONTENTS
Page
ABSTRACT vii
INTRODUCTION 1
PREVIOUS WORK 5
METHODS 7
GEOLOGIC SETTING 9
PALEONTOLOGY 12
AGE 16
PALEOBATHYMETRY 21
INTRODUCTION 21
DIVERSITY 22
BENTHIC FORAMINIFERAL SUBORDER TRENDS 23
HYALINE SUPERFAMILY TRENDS 26
GENERA AND SPECIES TRENDS 26
ASSOCIATED MICROFOSSIL TRENDS 28
SYSTEM A TIC MATERIALS AND METHODS 31
SYSTEM A TIC PALEONTOLOGY 32
REFERENCES CITED 68
v LIST OF ILLUSTRATIONS
Figure Page
1. Index map of study area 2
2. Stratigraphic column of the Llajas Formation 3
3. Generalized historical development of stratigraphic nomenclature for the Santa Susana, Llajas, and Sespe Formations 6
4. Sample locations along the type section of the Llajas Formation 8
5. Location of study area relative to the Ventura Basin setting 10
6. Foraminiferal diversity variations in the Llajas Formation 25
7. Distribution of foraminiferal suborders in the Llajas Formation 25
8. Distribution of hyaline foraminifer superfamilies present in the Llajas Formation 27
9. Paleobathymetric curve for the Llajas Formation 30
Table
1. Checklist of foraminifers found in the Llajas Formation 13
2. Known age ranges for benthic foraminifers in the Llajas Formation 19
Plate
1. Foraminifers of the Llajas Formation 79
2. Foraminifers of the Llajas Formation 8l
3. Foraminiferas of the Llajas Formation 83
4. Pseudophragmina clarki, equatorial section 85
vi ABSTRACT
BENTHIC FORAMINIFERA AND PALEOBATHYMETRY
OF THE EOCENE LLAJAS FORMATION,
SOUTHWESTERN SANTA SUSANA MOUNTAINS, CALIFORNIA
by
Herman Bodo Schymiczek
Master of Science of Geology
The late early to middle Eocene Llajas Formation, southwestern Santa
Susana Mountains, California, contains an abundant and diverse benthic foraminiferal fauna. At least 37 genera and 68 species were identified. Most of the· foraminifers are well preserved and unabraded, with little mixing of faunas, suggesting minimal post-mortem transport. However, shallow water faunas found in the slope facies show signs of abrasion and fragmentation.
The age of the Llajas Formation, based on benthic Foraminifera, ranges from lower Ulatisian for the lower one third, through upper Ulatisian for the remainder of the formation. The most recently accepted age of the Ulatisian is lower to lower middle Eocene, and my studies support this.
Variations in foraminiferal assemblages within the section suggest paleobathymetries ranging from inner neritic to upper bathyal during deposition of the Llajas Formation. Expressed as the number of species per
vii sample, diversity ranges from 4 species per sample from the middle neritic portion of the shallow marine facies to a high of 44 species per sample from the upper bathyal portion of the outer shelf to slope facies. Agglutinated
Foraminifera have the greatest abundance and diversity in the upper bathyal portion of the section, whereas porcelaneous types are most abundant and diverse in the middle and outer neritic portion of the section. The hyaline suborder predominates throughout the section. Planktonic foraminifers, diatoms, radiolarians, and calcareous nannofossils all increase in abundance with increasing depth, while ostracodes decrease in abundance with increasing depth. Inner to middle neritic conditions are indicated in the lower and upper portion of the section, indicating transgressive and regressive phases of deposition.
viii INTRODUCTION
The Llajas Formation in Simi Valley contains a diverse and well preserved benthic foraminiferal fauna, but very few studies on the micropaleontology have been published to date. The purposes of this study are to update and illustrate the taxa, to provide synonymies of the species, and to make the first paleobathymetric interpretation based on the contained microfauna. With this completed, one can make a more meaningful comparison of the microfauna and depositional environments of the Llajas
Formation with other formations of similar age along the West Coast.
The Llajas Formation crops out in the southwestern Santa Susana
Mountains and southern part of Simi Valley (Fig. 1). Most of the outcrops on the south side of Simi Valley are poorly exposed. The best exposure is the 545 m-thick type section in Chivo Canyon (Fig. 1), where there is a 95 percent exposed section. This section was chosen as the main area of study for this reason. At the type section, the Llajas Formation is unconformable over the upper Paleocene to lower Eocene Santa Susana Formation, and it is unconformably overlain by the upper Eocene to Oligocene Sespe Formation
(Fig. 2).
The basal portion of the Llajas Formation consists of an unfossiliferous conglomerate interpreted to be deposited as a coastal alluvial fan (Squires,
1981). The remainder of the formation consists mostly of very fine-grained sandstone deposited in a shallow-marine environment with minor amounts of siltstone deposited in an outer shelf environment. Microfossils, along with megafossils, tend to be concentrated in numerous beds that are mostly channel-fill deposits. Also present in the formation is a relatively thin
1 2
_Figure 1 Index map of Ventura County with location of study area. 3
EARLY Sespe NONMARINE LATE Formation EOCENE .. z SHALLOW MARINE 0 Regressive Phase -~ en z ALLUVIAL FAN EARLY Susana EOCENE Formation MARINE FIGURE 2 Stratigraphic column of the Llajas Formation in the vacinity of the type section showing age (in part) and facies of Squires (1981) . '· ' ~.. 4 interval of slope siltstone and turbidite-filled channels within the slope siltstone (Squires, 1981). PREVIOUS WORK Most of the previous geologic studies of the Llajas Formation deal with the stratigraphy and megafossils. The more notable previous stratigraphic works are those by Cushman and McMasters (1936), Stipp (1943), and Squires (1981). Notable megapaleontologic works are those by Waring (1917), Clark (1921, 1926), and Squires (1983a, 1983b). Because the name "Llajas Formation" was not formalized until 1936 by Cushman and McMasters, early workers (Waring, 1917; Kew, 1924; Clark, 1921, 1926; McMasters 1933; and others) referred to the strata equivalent to the Llajas Formation by various names (Fig. 3). Most previous micropaleontological studies of the Llajas Formation deal with the age, taxonomy, and description of benthic foraminifers (Schenck, 1929; McMasters, 1933; Cushman and McMasters, 1936; Laiming, 1940, 1943). The most detailed study was done on a core taken from Getty Oil Company "Tapo Fee" No. 42 well (Cushman and McMasters, 1936). This core was used as part of the formalization of the name "Llajas Formation", and it has since been lost. This well produced oil until 1973, when it was plugged and abandoned. Recently, the emphasis has been to interpret the depositional environments of the Llajas Formation based on sedimentology and megafossils (Squires, 1981) and on microfauna (Schymiczek, 1983a), and to relate this information to available subsurface data (Schymiczek, 1983b). Filewicz and Hill (1983) have recently inferred the age of Llajas Formation based on calcareous nannofossils. 5 CUSHMAN AND McMASTERS. 1936 WARING, 1917 KEW, 1924 ClARK, 1926 i~TIPP. 1943, S UIRES 1981 SESPE FORMATION tiOT DISCUSSED SESPE FORMATION TEJON FORMATION TEJON FORMATION i LLAJAS i FORMATION I TEJON GROUP MEGA NOS OOMENGINE FORMATION i FORMATION . I I I I I SANTA SUSANA SANTA SUSANA MARTINEZ FORMATION FORMATION FORMATION MARTINEZ FORMATION FIGURE 3 Generalized historical development of stratigraphic nomen clature for the Santa Susana, Llajas, and Sespe Formations. 0"\ METHODS Surface samples were collected from the type section of the Llajas Formation in Chivo Canyon (Fig. 4) along Squires' (1981) measured section. Sample locations (Fig. 4) were determined by Jacob-staff measurements relative to the base of the formation. The sandstone classification follows the usage of Folk (1974), and particle size designation conforms to Wentworth (1922). Sample preparation follows that of Kummel (1965). The bulk material was disaggregated with solvent (kerosene) and/or tri-sodium phosphate (TSP), and washed through a 0.062 mm screen. Well indurated samples were disaggregated with concentrated hydrogen peroxide (15%). No standard amount of material was picked and no statistical counts were made. Organic remains were picked from the washed residues and mounted for identification. Large orbitoid foraminifers were thin sectioned in equatorial, vertical tangential-peripheral, parallel, and oblique views to reveal the internal morphology. Such sections are necessary for proper identification (Schenck and Agguerevere, 1926). Specimens of benthic foraminifers were classified according to Loeblich and Tappan's (1964) system. All identifications were made by the author. However, A. A. Almgren of the Union Oil Company, Ventura, confirmed certain specific indentifications. 7 8 FIGURE 4 Sample locations along Squires' (1981) traverse of the type section. Base map from the Santa Susana 7~' Quad rangle (U.S.G.S.). Numbering is a combination of Cal State University, Northridge (beginning with numerals) and my own (beginning with letters) systems. GEOLOGIC SETTING The study area is part of a subprovince of the Ventura basin, the deepest structural depression of several Neogene basins included in the Transverse Ranges (Yeats, 1976). The Ventura basin extends from the San Gabriel fault westward down the Santa Clara Valley and across the Santa Barbara Channel to the continental slope (Fig. 5). Onshore, the Ventura basin can be divided into several tectonic subprovinces which includes the Simi Valley subprovince (Nagle and Parker, 1971), a portion of which is the study area (Fig. 5). The major structural element of the subprovince is the Simi Valley syncline. Simi Valley is notable in that it contains exposures of Paleogene rocks along the west coast of North America. Paleogene strata were unconformably deposited on Upper Cretaceous rocks in environments ranging from nonmarine to deep marine. Studies made prior to 19 50 dealt mainly with stratigraphic and megapaleontologic investigations. Until recently, there has been much confusion as to age relations due to the lack of details concerning geologic mapping, sedimentologic studies, and stratigraphic nomenclature. A reinvestigation of the nomenclature and biostratigraphy of the stratigraphic units in Simi Valley is presently being undertaken as a Pacific Section, Society of Economic Paleontologists and Mineralogists guidebook for 198 3. Detailed facies descriptions and inferred depositional environments of the Llajas Formation based on the sedimentology and megapaleontology have been presented by Squires (1981). The recognized facies are: 1) coastal alluvial-fan, 2) shallow marine, and 3) outer shelf to slope with included turdidite-filled channels. 9 ~I '--~ i VENTU~COU~\ i ~N 0 I '\~~ o., ....~~=~~:-'~ A.tv ~ ' ~ ~~· I ~ ' 'uoo ~A.u1..-,.· vI sANTA--- -=-----YNEz·~~-~-..,~ \~ <'..l'.''0 1"• 10 MILES Figure 5 Location of study area relative to the Ventura Basin setting. ,_ 0 11 The coastal alluvial-fan facies consists of lenticular conglomerate (80%) and sandstone (20%), and it makes up the basal 35m of the formation at the type section. The shallow-marine facies consists mostly of alternating laminated and bioturbated sandstone with scattered occurrences of fossils concentrated in channel-fill deposits. This facies can be divided into a transgressive phase in the lower portion of the section, and a regressive phase in the upper portion. These transgressive and regressive portions of the shallow-marine facies are separated by micaceous siltstone and minor sandstone of the outer shelf to slope facies. The Llajas Formation is in disconformable contact with the Santa Susana Formation below, and it is unconformably overlain by the Sespe Formation above. No attempt was made to further analyze the sedimentology of the formation in this study. Facies described by Squires (1981) are presented here to provide a background for later discussions on paleoecology. A summary of his conclusions are presented in Figure 2. The Llajas Formation is not widely distributed in the Ventura basin and is restricted to the eastern portion. Lateral-age equivalents in other parts of the basin include all or parts of the Juncal and Matilija Formations (Ingle, 1981). Subsurface analyses (Nagle and Parker, 1971) indicate that the Santa Susana Formation has been removed progressively by erosion to the west, and the Llajas Formation "directly overlies the basal Paleocene conglomerate in the western part of the Oxnard shelf". PALEONTOLOGY Megafossils found in the Llajas Formation have long been recognized as one of the best preserved and most diverse middle Eocene assemblages on the Pacific Coast (Waring, 1917; Clark, 1921, 1926; Schenck, 1926; Vokes, 1939; Turner, 1938; Stewart, 1927, 1930). Of the megafossils recently recorded (Squires, 1983a, in press) mollusks make up 90% of the fauna. Microfossils are present in all portions of the Llajas Formation, with the exception of the coastal alluvial-fan facies. Most of the foraminifers are well preserved and unabraded. Some have been fragmented and abraded, especially the few shallow-marine forms present in the outer shelf to slope facies. Alteration of the microfossils due to recrystallization and post lithification dissolution is evident in some of the samples, especially mica-rich samples from the outer shelf to slope facies and just below the Sespe contact. Planktonic foraminifers are very rare and poorly preserved, and are of little use in age and paleobathymetric interpretations. Thirty-seven genera of benthic foraminifers are represented by at least 68 species (Table 1). Microfossils other than benthic foraminifers are not included on the checklist, and include ostracodes, microscopic-sized mollusks, scaphopods, byrozoans, echinoid spines, fish teeth and jawbones, scolecodonts (annelid worm teeth), diatoms, radiolarians, and calcareous nannofossils (Filewicz and Hill, 1983). Sample numbering is a combination of my own system and California State University, Northridge (CSUN) megafossil localities (Fig. 4, Table 1). The different facies (Squires, 1981) present in the Llajas Formation contain characteristic foraminiferal faunas. The following genera 12 13 "'~"';;;;-.;;;.,~;;'/) \ t-~'f;. to.' .$)}-- ~ ~ ~ ~ ~ \ ....~ >:;, ~ -:::. ~ ~<" \ Q) _.l -l ~ ,.., ...... 'd>..... Amtul.opa.te.tUna .&p. l( AnomaU!la ga.ga~~~ 9 ' l( Anoma.Una umboturta. ? y A.&teM..aeM.na .6.imie.YL6.U. l( l( l( l( l( l( l( l( l( l( l( )( )( Ba.th!£.6.i.ohon e.ocPYiil'a IY Bi 6.ilr..bta .6 p. I~ Bui..i.m{.na .6 p. IY J( Ca.M.i.de.Ua d.<.boUen.i>.U. l( c.<.b.<.c.i.de.-6 coaUnge.YL6.U. ? l( X C.i.b.i.ude.h plf.O.e.CIJJL60JUM ? l( )( )( .:t.b-t&de.-6 a.u. C. -,v: orffformaaJt.i.anM )( )( C.i.b.<.c.i.d 1!..6 "'and.<.e.t~ e.YL6.U. IY C.i.b.i.c.i.de.-6 .6P. )( )( )( l( X Ve.nta.Una cole..<. l( l( l( Ve.n.ta.Una c.onvnun.i..6 l( VentaUna. ck. V. C.Orm!Ut''; J. l( Ve.n.ta.Una coo peJLeYL6 .i.-6 ? l( Venta.Uua. tequmen ? J( Vettta.Una c.6. D• .i>heJLbolln.i. Vettta.Una. .6~:>. l( l( V.U.eollb.u. c6. v. obvotuta. l( vu c.o~r.b.u. "'p. l( X Etpkid.<.um caUklltt.i.eum l( l( l( l( f.oott.i.de.-6 ia.clu.ouetMiJ. X Epo tt.i.d 1!..6 totM f l( l( Epott.i.de.-6 mex.i.cat!U6 l( l( l( l( l( Epott.<.de.-6 .6p. l( l( l( l( )( l( )( (;fnhJnohivon /,,.PPnirin. ? l( Gio bo but-imina. .6 p. l( GtoboMtaUa .61:>. l( )( )( GtobuUna .61:>. )( Gr/lr.O.icii.tta .6 p. )( l( Ha.6tageM..ne.Ua .i>p. l( La'!e.tta eUA.p.t..i..ea ? )( Laqe.na. ma.ILQlttat4 f lx Lagena. .i>p. LetttA.euUna. atto -limbatut. f l( l.en:Ucu..Una allt.tpodum l( l( te.n:UeuUna a.llt.<.eul.ata. texattM l( )( -Le.n.t..i..cuUna e6. L. COttVe.IL!Je.YL6 l( l( l( L• vor.; ~" P; ,~ il1nJivtfli"ll. l( l( l( l( l( l( l( l( IX TABLE 1 Checklist of foraminifers found in the Llajas Formation. Sample locations are shown in increasing stratigraphic order. 14 \~ ~~~~17-~~ ,'\\\\~~if ~ 'G> .~~B .>:P~ ~\ \ (j'\ \ (01 i"" ("' "' C1' o> ~ !-- rf'..... lvttic.u.UtUt timbo~ tt6 X X X X lo .. ~J,.,/,'""' Piml,nlu< J,,,.j,p""""L '• X X X X X Le.tt.Uc.u.Una. d. L. ma.t{.i X X X Le.tt.Uc.u.Una. d. l. !l.6 eudoM.tu..ta. X X X X letttic.u.Unct P6 eudo voJt.te.x X X X X lo .. ~}M1Pi>1tr :f'llh#,J.,tr:f'IIA X X X X X Le.tt.Uc.u.Una. wea.veM. ? X I""~ ,,..,p;.,, utnPnl. • X fn.,1'inuP.'na. ~P. X X X X X X X X X X X X X X Ma.ltnJ.w1htl1 c.~ 1.1. :l'mni rln X l.ln!t nJ .,,JJ~' 1111 A 1'1. X X MaJr.q.ittu.Unop~.U, Clllt.va..tuJt.M ? X No do~ aM.a. lAte i uqa..ta. X X X X X X X X X X X X No do~ aM.a. PUILu.la. X Nonume.Ua. U..o!Wte.Me. ? X Nummu.Ut 1!..6 · c.u.4 hmani. X X oo.una. ~pheM.c.a. 1 X Pla.nu.la!t.ia. :tltunc.a.na. X Planu.la!t.ia. ~ p. X P.tanu.Una c.~. P. l"oc_oomi.A X p.f.anu.Una. ~p. X P~ eudo plvw.qm.i.tUt c..f.aJr.IU X X X X Qu..i.nque.!oc.uU.na a.ngu..i.IUI. X X l)u..i.nq ue.f.oc.u.UM .tae.viqa..ta. X Qu..i.nq ue.!o c.uUna. .:tllianq u.f.ttM.6 X Qu..i.nque..f.oc.u.Una. ye.quae.M.iA X Qu..i.nque..f.oc.ulina ~p. X X X X X X JlonnhiiY An. X Rhabdamm.i.na eoc.e.ni.c.a. X X X X stU..U..tomif.la ue.ne.aae.M.U. ? X T e x.tu.la!t.ia. ~ ". X u,, '""' '"Ol'll.r.A moxic.antt6 nudic.o~.ta..ta X X X X X X X X X X Vag-UtuUno ~. TABLE 1 (Continued) Checklist of foraminifers found in the Llajas Formation. Sample locations are shown in increasing stratigraphic order. 15 characterize the shallow-marine facies: Lenticulina (13 species), Quingueloculina (4 species), Vaginulinopsis (3 species), Elphidium (1 species), Nummulites (1 species), and Pseudophragmina (1 species). Ostracodes, microscopic-sized mollusks, and bryozoans are all common, as well as Nodosaria latejugata, a shallow-marine representative of that genus. Assemblages from the shallow-marine facies are characterized by low diversity but highly abundant populations. Most of the foraminifers from this facies are very well preserved with few signs of abrasion or fragmentation. The greatest concentrations are in shallow, broadly lenticular channels. Although containing the most abundant and diverse assemblages in the subsurface (Filewicz and Fulwider, personal communications), the outer shelf to slope facies is generally barren in the surface section with the exception of a few samples. Being highly micaceous, this portion of the section allows the lateral movement of rain-water, which selectively removes calcareous material by dissolution. Those surface samples with high clay content contained sparse to very diverse assemblages. Iron oxide and siliceous casts of Foraminifera tests are common. The few displaced shallow-marine forms show the greatest effects of abrasion, fragmentation, and dissolution. The outer shelf to slope facies is charaterized by assemblages which are highly diverse and abundant. Genera commonly found include Dentalina (6 species), Cibicides (4 species), Nodosaria (3 species), Eponides (3 species), Lagena (2 species), Cassidella (1 species), and Nonionella (1 species). Other microfossils restricted to this facies are diatoms, calcareous nannofossils, radiolarians, and rare planktic foraminifers. AGE The Llajas Formation is disconformable over the marine Santa Susana Formation (Squires, 1981). Mallory (1959) reported that the upper part of the Santa Susana Formation is correlative with the Pacific Coast provincial benthic foraminiferal Penutian Stage, which he considered to be of early Eocene age. One must use caution when making this correlation because in a number of sections in California, Penutian foraminifers are found with calcareous nannofossils indicative of late Paleocene age (Poore, 1979, 1980), thus such stages may be time transgressive. Early workers considered the lower portion of the Llajas Formation to be equivalent to the Pacific Coast provincial molluscan "Capay Stage" (Clark and Vokes, 1936; Merriam and Turner, 1937; Weaver and others, 1944). Mallory (1959) considered the Penutian Stage to be equivalent to the "Capay Stage". The age of the Llajas Formation based on the contained molluscan fauna has been recently documented (Saul, 1983; Squires, 1983b, in press) to be late early to middle Eocene ("Capay Stage" to "Domengine" Stage). Benthic foraminifers which are indicative of the Ulatisian Stage have been reported by Mallory (19 59) from the middle and upper portions of the Llajas Formation. The Ulatisian is equivalent to the molluscan "Domengine Stage". The "Domengine Stage11 is considered to be of early middle Eocene age (Givens and Kennedy, 1979). Mallory (1959) reported the presence of his Amphimorphina californica zone (upper Ulatisian) from the upper part of the Llajas Formation. The upper Ulatisian Stage includes the uppermost part of the "Domengine Stage" as well as the lowermost part of the molluscan "Transition Stage" (middle Eocene) (Givens and Kennedy, 1979). The 16 17 "Transition Stage" has not been recognized in the Llajas Formation (Squires, 1983a). Laiming (1943), in his tentative scheme of informal and poorly defined "zones", reported an age of upper "Capay" and "Domengine" for the Llajas Formation based on the occurrence of Marginulina mexicana var. B. (=Vaginulinopsis mexicana nudicostata), Cibicides coalingensis, and Amphimorphina californica. This age is equivalent to the informal foraminiferal zones B-2, B-1, and B-lA (Laiming, 1939, 1941, 1943). Cushman and McMasters (1936) considered the Llajas Formation to be middle_ Eocene, based on a single specimen of Dictyconus sp., which at that time was thought to occur only in strata of that age. Dictyconus has since been shown to occur from Lower Cretaceous to upper Eocene (Loeblich and Tappan, 1964). Cushman and McMasters misidentified this genus, which is actually a species of Annulopatellina. Using Mallory's (19 59) benthic foraminiferal zones, I assign the Llajas Formation as ranging in age from lower Ulatisian, for the lower one third, through upper Ulatisian, for the remainder of the formation. The lower Ulatisian age is based on several foraminifers from samples collected by this author. These include the last known occurrence of Eponides cf. E. lotus, and the first appearance of Dentalina cf. D. sherborni, Nummulites cushmani, Lenticulina limbosus, and Lenticulina weaveri. The upper Ulatisian age of the contained fauna include last-known occurrences of Elphidium californicum, Nodosaria latejugata, Nummulites cushmani, Planulina truncana, Vaginulinopsis mexicana vacavillensis, the first appearance of Lenticulina limbosus hockleyensis and Lenticulina welchi, and the occurrence of Cibicides sandiegensis and Quinqueloculina triangularis, which are restricted to this age 18 (Table 2). Laiming's (1943) informal foraminiferal B-1 zone, considered equivalent of lower "Domengine", can be recognized by the occurrence of Cibicides coalingensis and Marginulina mexicana var. B (= Vaginulinopsis mexicana nudicostata). Several ambiguities in Mallory's (1959) zonations have been pointed out by Gibson and Steineck (1972). These problems become evident upon examination of the Llajas fauna. For example, Pseudophragmina clarki is listed by Mallory (19 59) as occurring only in the upper Ulatisian, but is found with both upper and (more commonly) lower Ulatisian faunas from samples collected by this author. The discrepancy probably stems from the misidentification by Cushman and McMasters (1936) of P. clarki as P. cloptoni (= ~· advena), which is listed (Mallory, 1959) as being restricted to the lower Ulatisian. It is evident then, that the range of P. clarki should be extended to include all of the Ulatisian. Also, Lenticulina antipodum is listed by Mallory (1959) as occurring in strata no younger than lower Ulatisian, but is found (rarely) with upper Ulatisian faunas from samples collected by this author. This may be due to reworking, but the unabraded nature of the specimens suggests that the range of this species should extend into the upper Ulatisian. Other foraminifers which occur sporadically throughout the Llajas Formation but are associated with ages other than Ulatisian (Mallory, 1959) include ~inulinopsis saundersi (upper Narizian), Cibicides praecursorius (Ynesian), and Lenticulina mayi (upper Narizian). Many of the problems related to benthic foraminiferal stages on the West Coast are undoubtedly due to the paleoecologic controls on type sections for these stages, as well as endemism of various species. These factors, therefore, make correlations problematic. In addition, species common to 19 Ynezian Bulitian Penutian Ulatisian Narizian lower upper o<~er upper lower upper lower UPPer lower UDDer Anoma..U.na aa~~.zaneM .i.6 ? J( J( J( J( J( ll Anomatina umbonata ? J( J( J( J( J( J( Bathy~~phon eaeeniea J( J( J( X J( J( J( J( J( C<.bi:udu p~Laeel.lltAo!LW f J( J( J( J( J( J( _X "J( Cibi.Udu ~ a.nd<.egeM~ J( Oen.ta.Una eo.f.ei. X X X X X J( J( J( J( Oenta..U.na eo1711111miA J( J( X X X X " J( J( Venta..U.na e6. V. ~heJt.boJt.~ J( J( J( J( Etp~cU.wn eili!toJt.~eum X J( J( J( J( Epo~du totw. f J( J( J( Epo~du meuea.rtLI-6 J( J( X X X J( X J( Gtob.i.a~na bu.Uo~u f X J( J( J( J( J( L~eu.Uno. a.Uo-UmbatUll J( X X X J( X L~euli..na anti.podum X J( J( J( J( J( Lenti.euli..na all..ti.euf.ata .texanU/l X J( X J( X J( X L~c.u.Una eonveJt.geM J( X X J( X J( J( J( J( J( Lentic.u.Una .inoJt.natU/1 J( J( J( X J( J( J( J( J( J( LentieliUna Umbo~Ull X J( J( X Lenti.eutina Umbo~Ull hoek.{et/~~ J( J( X Lentieuli..na e 6. L. may~ J( J( J( X Lentieuli..na p6 eudovoJt..tu X J( J( J( X J( X L~eutUta .tuJt.b.i.natU/l J( J( J( J( J( X Lentic.u.Una WMV~ 1 J( J( X J( J( J( J( L~eutina we!~ X J( J( MMg.inu.Unop6.i4 eUJt.va:twuu. ? J( J( J( J( X J( J( J( Nodo~alt.la la.tejugata J( J( X X X X X J( Nodo~alt.la pynula X J( X J( No~nella. 6loun~e ? X Nummu.Utu CUllhmaM X X X J( X P~ eudo phit.agmUta. cl.aJt.IU J( X QuhtquUoeu.Una .tUang~ X Qu,l.nqueloeaUna yeguae~~ X X X Vag~nuli..nop~~ meueana muUea~.ta.ta X X X X X " Vag~nuli..nop~~ meueana vaeav~e~~ X X J( X X X J( Vag~u.f..inop6~ 4aunde!L4.i. X X X X TABLE 2 Known age ranges for benthic foraminifers in the Llajas Formation, using Mallory's (1959) system. 20 various areas have different stratigraphic ranges (McDougall, 1980), and it has been recognized by some authors that many, if not all, of the provinci Cenozoic benthic-foraminiferal stages are time transgressive when viewed against a planktonic biostratigraphic framework (Bandy, 1960, 1967; Ingle, 1967; Bandy, 1971; Steineck and Gibson, 1971; Gibson, 1973; Bukry, Brabb, and Vedder, 1973, 1977; Hardenbol and Berggren, 1978; Poore, 1979, 1980; Ingle, 1980). Equivalent planktonic foraminiferal zones are roughly the PlO for the upper Ulatisian and P9 for the lower Ulatisian (Poore, 1980). The actual age of the Ulatisian is both problematic and controversial (Steineck and Gibson, 1971; Phillips, 1982). For example, the upper one third of the type Lodo Formation is Ulatisian (middle Eocene) in age based on benthic foraminifers (Mallory, 1959), upper lower Eocene based on planktonic foraminifers, and lower Eocene based on nannoplankton {Steineck and Gibson, 1971). By correlating the provincial benthic-foraminiferal stages to the current alignment of standard planktonic biozones and datum planes with the radiometric and paleomagnetic time scales, the Ulatisian ranges from lower to lower middle Eocene (Berggren, 1969; Ingle, 1980). Due to the presence of a "Capay Stage" and "Domengine Stage" molluscan fauna (Squires, 1983), the presence of an informal B-1 zone (Laiming, 1943), the presence of a latest early(?} to mlddle Eocene nannozone (Filewicz and Hill, 1983), and the most recently accepted age of the Ulatisian, the Llajas Formation is considered here to be late early to middle Eocene in age. PALEOBATHYMETRY Introduction Microfauna! variations in the Llajas Formation are compared with Holocene variations related to depth observed along the East Pacific margin from data compiled by Bandy and Arnal (1957), Bandy (1961), Bandy and Rudolfo (1964-), Smith (1963, 1964-), and Uchio (1960). These studies were chosen because the environmental setting of the East Pacific margin closely resembles that suggested for the Eocene of the west coast of North America (Addicott, 1967; Lohmar and Warme, 1979, Nilsen and McKee, 1979). Comparisons are also made with the Holocene variations observed in the Gulf of Mexico (Phleger, 1951; Pflum and Frerichs, 1976), and generalized Holocene microfauna! variations discussed by Bandy and Arnal (1960), Bandy (1964-), and Murray (1973). Variations in benthic foraminiferal diversity, and suborder and superfamily distributions, are related to bathymetry in most of these studies. These types of variations and distributions in the Llajas Formation are used for comparison wth those found in Holocene assemblages. Models used to explain distribution patterns of Cretaceous faunas {Sliter, 1972) are applied to microfaunas present in the Llajas Formation, as well. Facies designations of Squires (1981) follow those used in preceding sections. The reader should keep in mind that besides depth, variations in microfaunas can take place due to differences in temperature, salinity, circulation, nutrient supply, substrata, and other variations in the physio chemical environment. Studies in silled basins off southern California, where water qualty is the same from the sill, down to the basin floor (Emery, 1960), show that the distributions are related to water-mass properties and sediment 21 22 properties (which is usually related to bathymetry, but not to depth per ~ according to Douglas (1979)). Post-burial alterations of assemblages due to dissolution, even with only a few centimeters of sediment (Berger, 1979), can make paleobathymetric interpretations difficult. Post-mortem transport of shallow-water assemblages into deep water (indigenous vs. exotic assemblages (Fagerstrom, 1964)) can also hinder interpretations. The presence of articulated ostracodes and microscopic-sized bivalves along with mostly unfragmented and unabraded shallow-water benthic foraminifers suggests that these assemblages have not been transported very far. The condition of megafossils present also indicates minimal transport (Squires, 1981). Microscopic-sized worm burrows, which were slightly better cemented than the surrounding sediment, are also found with the shallow-marine assemblages. These worm burrows could not have been transported far, and, therefore, they support the conclusion that the shallow-marine assemblages are essentially in place. Very few of the samples show signs of dissolution, thereby indicating minimal alterations due to leaching. Variations of foraminiferal assemblages (Figs. 6-8) indicate paleobathymetries ranging from inner neritic (intertidal to 30m) to upper bathyal (200m to 600m) during deposition of the Llajas Formation. Inner to middle neritic conditions are indicated in the lower and upper portions of the section, suggesting transgressive and regressive phases of deposition. Sedimentologic evidence (Squires, 1981) indicates aerial conditions as a coastal alluvial fan for the basal conglomerate which is barren of fossils. Diversity Expressed as the number of species per sample, diversity varies in a systematic manner with the interpreted paleobathymetry in the study area 23 (Fig. 6). The number of species per sample from the Llajas Formation ranges from 4 species per sample from the middle neritic (shallow-marine facies) to a high of 44 species per sample from the upper bathyal (outer shelf to slope facies). Values from the middle neritic range from 4 to 17 species per sample. Outer neritic samples range from 15 to 20 species per sample. Values remained relatively constant for inner and middle neritic and upper bathyal samples (Fig. 6). Minor, but noticeable, peaks occur in middle neritic samples near the inner neritic boundary. The microfossil diversity trend exhibited in the Llajas Formation is similar to known trends in the Holocene. In the Holocene, the number of species per sample increases across the shelf and in the lower bathyal and abyssal zones, whereas the upper and middle bathyal zones are areas of decreased values (Bandy and Arnal, 1957; Bandy and Rudolfo, 1964; Smith, 1963; Uchio, 1960; Buzas and Gibson, 1969). The Llajas Formation data show two major differences when compared to the Holocene. These differences are: 1) the number of species per sample is lower in the Llajas Formation than in the Holocene, and, 2) the maximum shelf/upper slope (outer neritic) values are displaced in the Llajas Formation from the outer neritic to the upper bathyal zone. These differences are probably due to post-mortem depositional and diagenetic effects that have altered the assemblages from the Llajas Formation more than Holocene assemblages. Differences in sample size and statistical methods used in modern studies may also be a cause of variation. Benthic foraminiferal suborder trends In the study section, in Chivo Canyon, the diversity of agglutinated foraminifers (suborder Textulariina) increases with depth; the porcelaneous foraminifers (suborder Miliolina) generally decrease with depth; and the 24 hyaline foraminifers (suborder Rotaliina) predominate throughout (Fig. 7). The Textulariina never make up more than 10 percent of the species present. They are typically absent from the interpreted neritic portions (shallow-marine facies) of the section. Agglutinated species increase in both abundance and diversity in the outer neritic and upper bathyal (outer shelf to slope facies) portions of the section (Fig. 7). The porcelaneous suborder is somewhat more diverse than the agglutinated suborder, but it still constitutes a small percent of the benthic foraminiferal fauna, never making up more than 20 percent. They are most abundant in the deeper .portions of the middle neritic and in the outer neritic. Major peaks in diversity also occur in the shallow portions of the middle neritic (Fig. 7). Although porcelaneous tests have been observed to have extensive depth distributions relative to the living range in Holocene assemblages (Uchio, 1960), they are absent in the upper bathyal portion of the Llajas Formation. This could be accounted for by either a general lack of downslope post-mortem transport or by selective removal of porcelaneous tests by leaching. The rarity of non-porcelaneous shallow water faunas in the upper bathyal portion of the section supports the lack of downslope transport interpretation. The abundance and diversity of the hyaline suborder remains high and predominates the faunas throughout the section. Trends associated with the hyaline suborder are more meaningful when the assemblages are analyzed at the superfamilial, generic, or specific levels. These trends are discussed below. The agglutinated, porcelaneous, and hyaline suborder trends of the Llajas Formation are comparable to the general trends exhibited by these 25 SAMPLE LOCATION 0 545 I I 50 NO. OF SPECIES 40 PER 30 20 SAMPLE INFERR£0 u ~ -' t.41DDLE NERITIC u ,._ ...... ,.. u .... i£ a: I ... w ... i£ MIDDLE NERITIC z .. i£ PAL£0BATH YltiETRY "'z IXl "'z "'z lr lr lr lr lr "'z "'.... "'a. ..."' z :::> a. :::> "'z 0 :::> 0 ~ OUTER SHELF TO SHALLOW MA"INE FACIES (TRANSGRESSIVE) SHALLOW MARINE FACIES SLOPE FACIES I (AE'GRE SSIVE) I FIGURE 6 Foraminiferal diversity variations in the Llajas Formation. Scale on the graph is in meters (0-545) . SAMPLE LOCATION SUBORDERS 0 545 75 AGGLUTINATED 50 25 __...... _ ..... 75 PORCELANEOUS 50 25 ...... --"\....__. _../'\ ~ ~ ~ ~ --..... 75 ../ HYALINE 50 25 ~ ~ ;i NERITIC u /NFERREO ,_ .... ,.. ~IDDLEu l: - i= i£ lr .... ':::: a: 0: "'z MIDDLE NEll IT IC z"' .. z PALEOBATHYMETRY "' "'z "' 4: lr lr a: w w 0: ...... a. ... z "':::> a. :::> "'z ~ 0 :::> 0 ~ OUTER SHELF TO SHALLOW MARINE FACIES I SHALLOW MARINE FACIES (TRANSGRESSIVE) I SLOPE FACIES (REGRESSIVE) ' FIGURE 7 Distribution of foraminifer suborders in the Llajas Forma tion. Scale on the graph is in meters (0-545). 26 groups in Holocene assemblages (Bandy, 1960, 1964; Murray, 1973; Sliter and Baker, 1972). The agglutinated suborder increases in diversity with depth, whereas the porcelaneous suborder may be common in inner shelf and in, some cases, outer shelf assemblages, becoming increasingly rare with depth. The hyaline suborder predominates throughout. Hyaline superfamily trends Six hyaline superfamilies are present in the Llajas Formation: Nodosaracea, Buliminacea, Discorbacea, Rotolinacea, Orbitoidacea, and Cassidulinacea (Fig. 8). Discorbacea and Rotolinacea are most common in the middle neritic portion of the section, decreasing in the outer neritic and upper bathyal portion of the section. Buliminacea and Cassidulinacea are present only in the deeper portions of the outer neritic and upper bathyal. Orbitoidacea shows variations, but species are found in all parts of the section. Nodosaracea also shows variations, but species are predominant throughout the section, usually making up 50 percent or more of the faunas present (Fig. 8). Genera and species trends Many generic and specific trends can be recognized in the Llajas Formation. The middle neritic (shallow-marine facies) is characterized by abundant lenticulinids, elphidiums, and eurybathyal species. Nodosaria latejugata, Asterigerina simiensis, Pseudophragmina clarki, and varieties of Vaginulinopsis mexicana are common in this facies. Outer neritic (outer shelf) assemblages are more diverse than the middle neritic (shallow marine facies) assemblages, containing numerous species of Lenticulina, Dentalina, and Eponides. Lenticulina inornatus and Eponides mexicanus are common members of the outer neritic assemblages. Nummulites (Operculina) cushmani is one of 27 0 545 SUPERFAMILY I SAMPLE LOCATION I 75 NODOSARACEA 50 25 75 BULIMINACEA 50 25 /"'"\. 75 DISCORBACEA 50 25 ..._r- __..... \! ""'- 75 ROTOLINACEA 50 25 . _, A / 75 ORBITOIDACEA 50 25 r " ~ 75 CASSIDULINACEA 50 25 _...... , - INFERREO 0 0 NERITIC 0 1- c/. ~IDDLE 1- >- 0 :t: - E ii: ii: 1- ':::: 0: < 0: z MIDDLE NERITIC "'z Ill PALEOBArHYMErHY "' "'z "'z 0: 0: 0: 0: - 0: 1- "'0.. 1-"' "'z "'::> 0.. ::> "'z ~ 0 ::> 0 ~ OUTER SHELF TO SHALLOW MARINE FACIES SHALLOW MARINE FACIES (TRANSGRESSlVE) I SLOPE FACIES (REGRESSIVE) FIGURE 8 Distribution of hyaline foraminifer superfamilies pre sent in the Llajas Formation. Scale on the graph is in meters (0-545) . 28 the dominant forms in the shallower portions of the outer neritic portions of the section. The upper-bathyal {outer shelf to slope facies) assemblages contain the most diverse genera. These include numerous Dentalina, Lagena, and Cibicides. Cassidella dibollensis and Nonionella florinense are the most common species in these assemblages although far from predominant. Gyroidinids and other deeper water species first appear in this facies. Associated microfossil trends Associated microfossils in the Llajas Formation other than benthic foraminifera are commonly occurring ostracodes, microscopic-sized mollusks {bivalves, gastropods, scaphopods), bryozoans, and echinoid spines, and rarely occurring fish teeth and jawbones, annelid worm teeth {scolecodonts), planktonic foraminifers, radiolarians, diatoms, microscopic-sized worm burrows (trace fossils), and calcareous nannofossils. Some of these microfossils show no recognizable trends {fish teeth and jawbones, echinoid spines, annelid worm teeth) because of random distribution or extreme rarity. Others are restricted to samples from the shallow-marine facies (ostracodes, microscopic-sized mollusks, bryozoans). Diatoms and calcareous nannofossils are found only in the outer shelf to slope facies. Some of the calcareous nannofossils are reworked Cretaceous species {Hill, personal communication). The types of ostracodes {Cytheridea sp., Bairdia sp.) present in the shallow-marine facies have similar depth distributions as in Holocene assemblages (Bandy and Arnal, 1957; Pflum and Frerichs, 1976). The increase in planktonic foraminifers, radiolarians, diatoms, and calcareous nannofossils with depth is analogous to Holocene trends {Bandy, 1960; Bandy and Arnal, 1969; Bandy and Rudolfo, 1964; Ingle, 1967, Pflum and Frerichs, 1976). A 29 paleobathymetric curve related to the stratigraphic column of the Llajas Formation is presented as a summary (Fig. 9). 30 EARLY Sespe NONMARINE LATE Formation METERS EOCENE o8!~§§§- ..z SHALLOW MARINE 0... Regressive Phase (/) -z < \ w ...a: z I w LIJ () OUTER SHELF TO SLOPE z r--... 0 0 f-. w z With Turbidite-filled 1-- ~ LIJ w :!: Channels -1 0 0 0 I 0 ~ ~ 0 1- k >- LIJ :IE -1 z SHALLOW MARINE "'.. 0: 0 Transgressive Phase "' <( z w LIJ :!: w 0 1- 0 <( • -1 ALLUVIAL FAN EARLY Susana EOCENE Formation MARINE FIGURE 9 Interpreted paleobathymetry of the Llajas Formation in the vacinity of the type section. SYSTEM A TIC MATERIALS AND METHODS No attempt has been made to compile complete synonomies, as they are readily available in other works (Mallory, 1959). Rather, only those references which are useful for identification purposes are given for each species from west coast Paleogene strata. References which were used for identification purposes, but from localities other than the west coast are also presented. Comments as to the relative abundance, preservation, and stratigraphic position have been included. Facies used are those of Squires (1981). The systematic arrangement of the family grouping follows that of Loeblich and Tappan (1964). Provincial stages are those of Mallory (1959), as are the provincial ranges of individual species. Thin sections used for the identification of Pseudophragmina clarki are stored at the Natural History Museum of Los Angeles County, Invertebrate Paleontology Section (hypotypes LACMIP 6500 and 6501). All other mounted and identified specimens are stored at the California State University, Northridge (CSUN) Paleontology Museum. 31 SYSTEMATIC PALEONTOLOGY Phylum PROTIST A Haeckel, 1863 Subphylum SARCODINA Schmarda, 1871 Order FORAMINIFERIDA Eichwald, 1830 Suborder TEXTULARIINA Delage and Herouard, 1896 Superfamily AMMODISCACEA Reuss, 1862 Family ASTRORHIZIDAE Brady, 1881 Subfamily ASTRORHIZINAE Brady, 1881 Genus RHABDAMMINA M. Sars, 1869 Type species: Rhabdammina abyssorum M. Sars, 1869 (OD) Rhabdammina eocenica Cushman and G. D. Hanna. Rhabdammina eocenica Cushman and Hanna, 1927: 209, pl. 13, fig. 33. Mallory, 1959: 104, pl. 1, figs. 1, 2; pl. 27 fig. 1. Weaver and Weaver, 1962: 53, pl. 1, figs. 2, 3. Provincial Range: Not known. Local Occurrence: Outer shelf to slope facies. Remarks: This species is rare, and always fragmented as it is very fragile. Subfamily RHIZAMMINA Rhumbler, 1895 Genus BA THYSIPHON M. Sars, 1872 Type species: Bathysiphon filiformis M. Sars, 1872 (OD) Bathysiphon eocenica Cushman and G. D. Hanna. Bathysiphon eocenica Cushman and Hanna, 1927: 210, pl. 13, figs. 2, 3. 33 Cushman and McMasters, 1936: 508, pl. 74, fig. 1. Cushman and Siegfus, 1942: 400, pl. 15, fig. 1. Cushman and Simonson, 1944: 193, pl. 30, fig. 1. Cushman and Stone, 1947: 2, pl. 1, fig. la. Cushman, 1951: 3, pl. 1, figs. 1, 2. Israelsky, 1951: 27, pl. 2, figs. 1-4. Hornaday, 1961: 206, pl. 1, fig. 2. Weaver, 1962: 403, pl. 1, fig. 3. Weaver and Weaver, 1962: 53, pl. 1, fig. 4. Bathysiphon eocenicus (Cushman and G. D. Hanna); Mallory, 1959: 105, pl. 1, fig. 4. Provincial Range: Lower Ynezian - upper Narizian. Local Occurrence: Outer shelf to slope facies. Remarks: This species is rare and very fragile. It is always fragmented. Superfamily LITUOLACEA de Blainville, 1825 Family HORMOSINIDAE Haeckel, 1894 Subfamily HORMOSININAE Haeckel, 1894 Genus REOPHAX Montfort, 1808 Type species: Reophax scorpiurus Montfort, 1808 (OD) Reophax sp. Local Occurrence: Outer shelf to slope facies. Remarks: This genus is very rare and poorly preserved in the Llajas Formation. Family TEXTULARIIDAE Ehrenberg, 1838 Subfamily TEXTULARIINAE Ehrenberg, 1838 34 Genus TEXTULARIA Defrance, 1824 Type species: Textularia sagittula Defrance, 1824 (OD) Textularia sp. Local Occurrence: Shallow-marine facies. Remarks: This genus is represented by a single, poorly preserved specimen. Suborder MILIOLINA Delage and Herouard, 1896 Superfamily MILIOLACEA Ehrenberg, 1839 Family MILIOLIDAE Ehrenberg, 1839 Subfamily QUINQUELOCULININAE Cushman, 1917 Genus QUINQUELOCULINA d'Orbigny, 1878 Type species: Quingueloculina seminulum (Linne, 1758) (SD) Quingueloculina anguina Terquem. Quinqueloculina anguina Terquem; Cushman, 1935: 63, pl. 2, figs. 18, 19a, b. Provincial Range: Not known. Local Occurrence: Shallow-marine facies. Remarks: This species is rare and always shows some signs of dissolution. Quinqueloculina laevigata d'Orbigny Quingueloculina laevigata d'Orbigny; Cushman, 1935: 63, pl. 2, figs. 13a, b, 14a, b, 15a, b. 35 Provincial Range: Not known. Local Occurrence: Shallow-marine facies. Remarks: This species is somewhat more common and better preserved than Q. anguina. Quinqueloculina triangularis d'Orbigny Plate l, Figure A Quingueloculina triangularis d'Orbigny; Cushman and M. A. Hanna, 1927: 57-58, figs. 8, 9. Mallory, 1959: 130, pl. 36, fig. 5a-c. Provincial Range: Upper Ulatisian. Local Occurrence: Shallow-marine facies (regressive phase). Remarks: Although rare, this species is always very well preserved. Quingueloculina yeguaensis Weinzierl and Applin Quingueloculina yeguaensis Weinzierl and Applin, 1929: 393, pl. 44, fig. 4a, b. Cushman and Thomas, 1930: 34, pl. 3, figs. 1, 2. Howe, 1939: 33, pl. 2, fig. 8. Israelsky, 1939: pl. 2, figs. 2, 3. Mallory, 1959: 131, pl. 5, fig. 12a, b. (non) Quingueloculina seminulum (Linne); Stadnichenko, 1927 (misidentification): 226, pl. 38, fig. 28. Provincial Range: Upper Penutian to upper Ulatisian. Local Occurrence: Shallow-marine facies. Remarks: This species is the most common and widespread member of this genus in the Llajas Formation. 36 Quingueloculina sp. Local Occurrence: Shallow-marine facies. Remarks: Many specimens which show badly etched surfaces due to dissolution have been recovered. Suborder ROT ALliN A Delage and Herouard, 1896 Superfamily NODOSARIACEA Ehrenberg, 1838 Family NODOSARIINAE Ehrenberg, 1838 Genus NODOSARIA Lemark, 1812 Type species: Nodosaria radicula (Linne, 1758) (SD) Nodosaria latejugata ~umbel Plate 1, Figures B, C Nodosaria latejugata Gumbel; Cushman and G. D. Hanna, 1927: 212, pl. 13, fig. 15. Cushman and M.A. Hanna, 1927: 52, pl. 5, figs. 1-3. Cushman and McMasters, 1936: 512, pl. 75, figs. 11, 12. Cushman, 1951: 23, pl. 7, figs. 1, 2. Mallory, 1959: 171, pls. 13, 28, 41. Weaver and Weaver, 1962: 64, pl. 7, figs. 16, 17. Nodosaria sp. Israelsky, 19 39: 57 5, pl. 3, fig. 11. (?) Marginulina cocoaensis Cushman; lsraelsky, 1939: 574, pl. 3, figs. 8, 9, 10. (non) Nodosaria raphanus (Linnaeus); Hanna, 1923 (misidentification): 321, pl. 58, fig. 1. Provincial Range: Lower Ynezian to upper Ulatisian. Local Occurrence: Shallow-marine facies. 37 Remarks: This is one of the most abundant and well preserved species found in the Llajas Formation. Nodosaria pyrula d'Orbigny Plate l, Figure D Nodosaria pyrula d'Orbigny; Cushman and Schenck, 1928: 308, pl. 43, fig. la. Howe, 1939: 101, pl. 5, fig. 16. Mallory, 1959: 172, pl. 13, fig. 19, pl. 41, fig. 2. Hornaday, 1961: 213, pl. 4, fig. 6. Weaver and Weaver, 1962: 64, pl. 7, fig. 18. Kleinpell and Weaver, 1963:171, pl. 7, figs. 5, 6. Hornaday, 1965:30, pl. 3, figs. 5, 6. Fairchild, 1969: 102, pl. 4, fig. 12. McDougall, 1980: 41, pl. 6, fig. 3. Nodosaria cf. N. pyrula d'Orbigny; Beck, 1943: 599, pl. 105, figs. 19-21. Provincial Range: Upper Penutian to upper Narizian. Local Occurrence: Outer shelf to slope facies. Remarks: This species is abundant and well preserved. Genus DENT ALINA Risso, 1826 Type species: Dentalina cuvieri (d'Obrigny, 1826) (OD) Dentalina colei Cushman and Dusenbury Vaginulina legumen (Linne) var. elegans Cole, 1927: 21, pl. 3, figs. 10, 11. Plummer, 1926: 110, pl. 6, fig. 1. Dentalina colei Cushman and Dusenbury, 1934: 54, pl. 7, figs. 10, 12. Toulmin, 1941: 584, pl. 79, fig. 12. Beck, 1943: 598, pl. 103, fig. 18. Cushman, 1944: 37, pl. 5, figs. 25-28. Cushman, 1951: 19, pl. 8, fig. 12. Mallory, 1959: 162, pl. 12, fig. 9, pl. 7, fig. 5. Fairchild, 1969: 105, pl. 5, fig. 17. Dentalina sp. Israelski, 1939: 376, pl. 3, fig. 12. 38 Provincial Range: Upper Ynezian to upper Narizian. Local Occurrence: Outer shelf to slope facies. Remarks: Although rare, this species is always well preserved. Dentalina communis (d'Orbigny) Nodosaria (Dentalina) communis (d'Orbingy), Cushman and M. A. Hanna, 1927: 52, pl. 4, figs. 11, 12. Cushman and G. D. Hanna, 1927: 214, pl. 13, fig. 16. Dentalina sp. Israelski, 1939: 576, pl. 3, fig. 13a. Dentalina communis (d'Obrigny), Beck, 1943: 598, pl. 105, fig. 22. Howe and W_allace, 1932: 93, pl. 6, fig. 8. Smith, 1957: 165, pl. 22, fig. 9. Mallory, 1959: 162, pl. 13, fig. ll, pl. 41, fig. 6. Weaver and Weaver, 1962: 64, pl. 7, fig. 6. Hornaday, 1965: 35, pl. 3, fig. 9. Provincial Range: Upper Ynezian- upper Narizian. Local Occurrence: Outer shelf to slope facies. Remarks: This species is well preserved when present, but rare. Dentalina cf. D. communis (d'Orbigny) Dentalina cf. D. communis (d'Orbigny), Cushman, 1946a: 14, pl. 3, fig. 8. Fairchild, 1969: 105, pl. 5, fig. 3. Provincial Range: Not known. Local Occurrence: Outer shelf to slope facies. Remarks: This species is very rare, and differs slightly from D. communis. 39 Dentalina cooperensis ? Cushman Dentalina cooperensis Cushman, 1933: 8, pl. 1, fig. 17. Cushman, 1935: 20, pl. 8, fig. 3, 4. Hornaday, 1961: 213, pl. 4, fig. 8. Fairchild, 1969: 105, pl. 5, fig. 4. Provincial Range: Not known. Local Occurrence: Outer shelf to slope facies. Remarks: This species is rare and poorly preserved, making positive identification impossible. Dentalina legumen ? Reuss Dentalina legumen Reuss, Cushman and Jarvis, 1932: 30, pl. 9, fig. 9. Cushman, 1946a: 65, pl. 23, figs. 1, 2. Mallory, 19 59: 165, pl. 12, figs. 21, 22. Provincial Range: Not defined. Local Occurrence: Outer shelf to slope facies. Remarks: Only a few poorly preserved specimens have been recovered from the outer shelf to slope facies. Dentalina cf. D. sherborni Bowen Dentalina cf. D. sherborni Bowen; Mallory, 19 59: 166, pl. 13, fig. 2. Weaver and Weaver, 1962: 64, pl. 7, figs. 9, 10. Provincial Range: Lower Ulatisian to lower Narizian. Local Occurrence: Outer shelf to slope facies. Remarks: This species is well preserved, but rare. 40 Dentalina sp. Local Occurrence: Shallow-marine and outer shelf to slope facies. Remarks: Many fragmented and poorly preserved specimens of this genus are found throughout the fossiliferous portions of the study section. They are never abundant. Genus LAGENA Walker and Jacob, 1798 Type Species: Lagena sulcata Walker and Jacob, 1798 (SD) Lagena elliptica ? Bandy Lagena elliptica Bandy, 1949: 167, pl. 7, fig.l6. Provincial Range: Not known. Local Occurrence: Outer shelf to slope facies. Remarks: This species is common, but not very well preserved. Lagena marginata? (Walker and Boys) Lagena marginata (Walker and Boys), Fairchild, 1969: 105, pl. 5, fig. 14. Provincial Range: Not known. Local Occurrence: Outer shelf to slope facies. Remarks: This species is rare and shows signs of dissolution, making identification difficult. Lagena sp. 41 Local Occurrence: Outer shelf to slope facies. Remarks: Several specimens of this genus have been recovered from the outer shelf to slope facies, but they were too poorly preserved for identification. Genus LENTICULINA Lemarck, 1804 Type species: Lenticulina rotulata Lemarck, 1804 (SD) Lenticulina alto-limbatus ? (Gumbel) Cristellaria alto-limbata (Gumbel); Cushman, 1926: 171, pl. 9, fig. 10. Cushman and Applin, 1926: 171-172, pl. 8, fig. 8a, b. Robulus alto-limbata (Gumbel); Howe and Wallace, 1932: 37, pl. 3, fig. 2a, b. Robulus alto-limbatus (Gumbel); Cushman, 1935: 67, pl. 6, fig. 2a, b. Cushman, 1939b: 15, pl. 6, fig. 2a, b. Howe, 1939: 99, pl. 4, fig. 18. Cushman and Siegfus, 1942: 404, pl. 15, figs. 19-21. Bandy, 1949: 58, pl. 8, fig. la, b. Mallory, 1959: 133, pl. 6, fig. 27, pl. 27, fig. ll. Hornaday, 1961: 209, pl. 2, figs. 11-13. Weaver and Weaver, 1962: 57, pl. 3, fig. 3. Lenticulina alto-limbatus (Gumbel); Curtis, 19 55: 77, pl. 30, figs. 11, 12. Fairchlld, 1969: 105, pl. 5, fig. 15. Provincial Range: Lower Penutian to upper Narizian. Local Occurrence: Shallow-marine and outer shelf to slope facies. Remarks: Found scattered throughout the study section, this locally abundant species is apparently more prone to dissolution than other members of this genus, making identification difficult. 42 Lenticulina antipodum (Stache) Robulus antipodum (Stache); Cushman and Dusenbury, 1934: 53, pl. 7, fig. 5a, b. Mallory, 1959: 134, pl. 6, fig. 12a, b. Provincial Range: Upper Ynezian - lower Ulatisian. Local Occurrence: Shallow-marine facies (transgressive phase). Remarks: This species is not common but always well preserved. Lenticulina articulata (Reuss) texanus? (Cushman and Applin) Plate l, Figure E Cristellaria articulata (Reuss) var. texana Cushman and Applin, 1926: 170, pl. 8, figs. 1, 2. Lenticulina articuiata (Reuss) var. texana (Cushman and Applin); Howe and Wallace, 1932: 91, pl. 5, figs. 1, 2. Fairchild, 1969: 105, pl. 5, fig. 19. Robulus articulata (Reuss), var. texanus (Cushman and Applin); Ellisor, 1933: 1336, pl. 2, fig. 3. Cushman, 1935: 65, pl. 4, figs. 16, 17. Mallory, 1959: 135, pl. 6, fig. 13a, b. Robulus texanus (Cushman and Applin); Beck, 1943: 595, pl. 103, figs. 1, 2, 4, 5. Bandy, 1949: 63, pl. 9, fig. 2a, b. Provincial Range: Upper Bulitian to upper Narizian. Local Occurrence: Shallow-marine facies. Remarks: Widespread and locally abundant, this species is usually well preserved. Lenticulina cf. L. convergens (Bornemann) 43 Lenticulina convergens (Bornemann); Cushman and Barksdale, 1930: 64, pl. 11, fig. 8a, b. Cushman and Dusenbury, 1934: 54, pl. 1, fig. 2. Fairchild, 1969: 105, pl. 5, fig. 11. Robulus convergens (Bornemann); Smith, 19 57; 157, pl. 20, fig. 5a, b. Provincial Range: Lower Ynezian to upper Narizian. Local Occurence: Shallow-marine and outer shelf to slope facies. Remarks: Rare, but widespread in the study section, this species usually shows signs of dissolution. Lenticulina inornatus (d'Orbigny) Plate 1, Figure F Cristellaria inornata d'Orbigny; Cushman and G. D. Hanna, 1927: 217, pl. 14, fig. 5. Robulus inornatus d'Orbigny; Cushman and M. A. Hanna, 1927: 51, pl. 4, fig. 4. ?Robulus inornatus (d'Orbigny); Cushman and Barksdale, 1930: 62, pl. 2, figs. 2, 3. Israelsky, 1939: 573, pl. 3, fig. 1. Robulus inornatus (d'Orbigny); Toulmin, 1941: 577, pl. 78, fig. 19. Beck, 1943: 595, pl. 104. Cushman and Stone, 1947: 5, pl. 1, fig. 8. Cushman, Stewart, and Stewart, 1947a: 60, pl. 7, fig. 3a, b, pl. 13, fig. 2a, b. Mallory, 19 59: 137' pl. 7' fig. 15, pl. 40, fig. 5. Provincial Rang_e: Lower Ynezian to upper Narizian. Local Occurrence: Shallow-marine and outer shelf to slope facies. Remarks: This species is common in the shallow marine facies. A few 44 poorly preserved specimens were found in the outer shelf to slope fades, as well. Lenticulina limbosus (Reuss) Plate I, Figure G Robulus limbosus (Reuss), Ellisor, 1933: 1336, pl. 2, fig. la, b. Cushman, 1935: 67, pl. 6, fig. 5. Cushman, 1946b: 6, pl. I, fig. 13. Bandy, 1949: 61, pl. 8, fig. 8. Mallory, 1959: 138, pl. 6, fig.14a, b. Weaver and Weaver, 1962: 58, pl. 4, fig. 4a, b. Provincial Range: Lower Ulatisian to upper Narizian. Local Occurrence: Shallow-marine and outer shelf to slope fades. Remarks: This species is rare, appearing in a few scattered samples. Lenticulina limbosus (Reuss) hockleyensis (Cushman and Applin) Plate l, Figure H CristeUaria limbosa (Reuss) hockleyensis Cushman and Applin, 1926: 171, pl. 8, figs. 3, 4. Robulus limbosus (Reuss) hockleyensis (Cushman and Applin); Ellisor, 1933: 1334, pl. 1, fig. lla, b. Cushman and Dusenbury, 1934: 52, pl. 7, fig. I. Cushman, 1935: 65, pl. 4, fig. 15a, b, pl. 6, fig. 3a, b. Cushman, 1939a: 53, pl. 9, fig. 21. Cushman and Simonson, 1944: 194, pl. 30, fig. 9. Smith, 1956: 89, pl. 10, fig. 5a, b. Mallory, 1959: 139, pl. 6, fig. 15a, b. Weaver and Weaver, 1962: 58, pl. 4, fig. 5a, b. (non) Robulus inornatus (d'Orbigny); Cushman, Stewart, and Stewart, 1949 (misidentification): 130, pl. 14, figs. 4, 5. 45 Lenticulina limbosus (Reuss) hockleyensis (Cushman and Applin); Fairchild, 1969: 107, pl. 6, fig. 2. Provincial Range: Upper Ulatisian- upper Narizian. Local Occurrence: Shallow-marine facies (regressive phase). Remarks: Although not as widespread as L. limbosus, this species is more abundant when present, and it is always very well preserved. Lenticulina cf. L. mayi (Cushman and Parker) Plate 1, Figure I Robulus mayi (Cushman and Parker); Howe and Wallace, 1932: 40, pl. 2, fig. 7. Mallory, 1959: 139, pl. 6, fig. lla, b. Weaver and Weaver, 1962: 58, pl. 4, fig. 6a, b. Provincial Range: Lower Ulatisian to upper Narizian. Local Occurrence: Shallow-marine facies. Remarks: Although rare, this species is usually well preserved. Lenticulina cf. L. pseudorotula (Asano) Plate 2, Figure A Lenticulina cf. L. pseudorotula (Asano); Fairchild, 1969: 106, pl. 6, fig. 3a, b. McDougall, 1980: 41, pl. 7, figs. 13, 14. Provincial Range: Not known. Local Occurence: Shallow-marine facies. Remarks: This is a rare, but well preserved species. 46 Lenticulina pseudovortex (Cole) Robulus pseudovortex Cole, 1927: 19, pl. 1, fig. 12. Cushman and McMasters, 1936: 510, pl. 74, fig. 12a, b. Cushman and Siegfus, 1942: 404, pl. 15, fig. 23. Cushman and Stone, 1949: 79, pl. 13, fig. 31. Bandy, 1949: 61, pl. 8, figs. 9, 10. Smith, 1957: 158, pl. 20, figs. 12a, b, 13a, b. Mallory, 1959: 141, pl. 7, figs. 2a, b, 3a, b, pl. 27, fig. 13a, b. Weaver and Weaver, 1962: 58, pl. 4, fig. 8a, b. Lenticulina pseudovortex (Cole); Fairchild, 1969: 109, pl. 7, fig. 2a, b. (non) Robulus gyroscalprum (Stache); Cushman and Dusenbury, (misidentified): 53, pl. 1, fig. 4. Provincial Range: Lower Bulitian to lower Narizian. Local Occurrence: Shallow-marine facies. Remarks: Rarely found and never abundant, this species is well preserved. Lenticulina turbinatus (Plummer) Cristellaria turbinatus (Plummer), 1926: 93, pl. 7, fig. 4. Robulus turbinatus (Plummer), Cushman, 1940: 55, pl. 9, fig. 17. Kline, 1943: pl. l, fig. 17. Cushman and Todd, 1946: 47, pl. 7, fig. ll. Cushman, 1951: 14, pl. 4, figs. 6-9. Mallory, 1959: 141, pl. 6, fig. 3a, b, pl. 27, fig. 14a, b. Weaver and Weaver, 1962: 61, pl. 5, fig. 3a, b. Provincial Range: Lower Bulitian - upper Ulatisian. Local Occurrence: Shallow-marine facies. Remarks: This species is relatively common in the study section, and 47 typically shows signs of dissolution. Lenticulina weaveri? (Beck) Robulus weaveri Beck, 1943: 595, pl. 103, figs. 3, &. Mallory, 1959: 143, pl. 7, fig. 14a, b. Weaver and Weaver, 1962: 61, pl. 5, fig. 4a, b. Provincial Range: Upper Bulitian - upper Narizian. Local Occurrence: Shallow-marine facies. Remarks: Rarely found and never abundant in the study section, this species usually shows signs of dissolution. Lenticulina welchi (Church) Robulus welchi Church, 1931: pl. C, figs. 13, 14. Cushman and Simonson, 1944: 195, pl. 30, fig. ll. Smith, 1957: 159, pl. 21, figs. 4a, b, 5a, b, 6a, b. Mallory, 1959: 143, pl. 7, fig.&. Hornaday, 1961: 210, pl. 3, fig. 3. Weaver and Weaver, 1962: 61, pl. 5, fig. 5a, b. Robulus welchi Church?; Cushman and Siegfus, 1942: 404, pl. 15, fig. 22. Lenticulina welchi (Church); McDougall, 1980: 41, pl. &, figs. 1-4. Provincial Range: Upper Ulatisian - upper Narizian. Local Occurrence: Shallow-marine facies. Remarks: This species is rare but mostly well preserved. Lenticulina sp. Local Occurrence: Shallow-marine and outer shelf to slope facies. 48 Remarks: Abraded and poorly preserved specimens of this genus are found scattered throughout the fossiliferous portions of the study section. Many of these are undoubtedly some of the species listed above, but others may also be present. Genus MARGINULINA d'Orbigny, 1826 Type species: Marginulina raphanus d'Orbigny, 1826 (SD). Marginulina cf. M. tumida Reuss Marginulina cf. M. tumida Reuss; Weaver and Weaver, 1962: 64, pl. 7, figs. 1, 2. Provincial Range: Not known. Local Occurrence: Outer shelf to slope facies. Remarks: Only a few poorly preserved individuals were found. Marginulina sp. Local Occurrence: Shallow-marine facies. Remarks: Only a few rare, poorly preserved specimens have been recovered from the study section. Genus MARGINULINOPSIS Silvestri, 1904 Type species: Marginulinopsis densicostata Thalmann, 1937 (SD) Marginulinopsis curvaturus? (Cushman) Marginulina curvatura Cushman, 1946a: 63, pl. 22, figs. 11, 12. Marginulinopsis curvaturus (Cushman); Mallory, 1959: 152, pl. 10, fig. lOa, 49 b. Provincial Range: Lower Ynezian to upper Ulatisian. Local Occurrence: Outer shelf to slope facies. Remarks: A few poorly preserved specimens, as well as a few iron oxide casts, have been found. Genus PLANULARIA Defrance, 1826 Type species: Planularia auris (Defrance, 1824) (OD) Planularia truncana (Gumbel) Cristellaria truncana Gumbel; Cushman and G. D. Hanna, 1927: 217, pl. 14, fig. 6. Planularia truncana (Gumbel); Cushman, 1935: 17, pl. 6, fig. 7a, b. Mallory, 19 59: 148, pl. 9, fig. 8a, b, pl. 27, fig. 17a, b. Vaginulinopsis truncana (Gumbel), Smith, 1957: 163, pl. 21, fig. 17a, b. Provincial Range: Lower Penutian to upper Ulatisian. Local Occurrence: Shallow-marine facies. Remarks: This species is rare but especially well preserved. Planularia sp. Local Occurrence: Shallow-marine facies. Remarks: A few fragmented specimens of this genus have been found in the study section. Genus VAGINULINOPSIS Silvestri, 1904 50 Type species: Vaginulinopsis soluta {Silvestri) var. carinata {Silvestri, 1898) {SD) Vaginulinopsis mexicana {Cushman) nudicostata {Cushman and G. D. Hanna) Plate 2, Figures B, C Cristellaria mexicana nudicostata Cushman and G. D. Hanna, 1927: 216, pl. 14, fig. 2. Marginulina mexicana nudicostata {Cushman and G. D. Hanna); Cushman and McMasters, 1936: 511, pl. 74, fig. 15. Marginulina mexicana {Cushman) var. B Laiming, 1941: 198, pl. 83, fig. 5. Vaginulina mexicana var. nudicostata {Cushman and G. D. Hanna); Smith; 1957: 162, pl. 22, fig. 3a, b. Mallory, 1959: 157, pl. 28, fig. la, b, pl. 40, fig. 2a, b. Provincial Range: Lower Bulitian to upper Ulatisian. Local Occurrence: Shallow-marine and outer shelf to slope facies. Remarks: This is one of the most common and well preserved species in the shallow marine facies. A few poorly preserved and abraded specimens have been found in the outer shelf to slope facies. Vaginulinopsis mexicana {Cushman) vacavillensis {Hanna) Plate 2, Figure E Cristellaria vacavillensis Hanna, 1923: 324, pl. 59, fig. 4a, b. Robu1us mexicanus {Cushman) var. nudicostata (Cushman and Hanna); Cushman and McMasters, 1936: 511, pl. 74, fig. 16. Marginulina mexicana {Cushman) var. A Laiming, 1941: 198, pl. 83, fig. 4a, b. 51 Vaginulinopsis vacavillensis (G. D. Hanna); Smith, 1957: 163, pl. 22, figs. 6-8. Vaginulinopsis mexicana (Cushman) var. vacavillensis (Hanna); Mallory, 19 59: 157' pl. 40, fig. 1. Provincial Range: Upper Ynesian to upper Ulatisian. Local Occurrence: Shallow-marine facies. Remarks: Nearly as common and abundant as V. mexicana nudicostata in the study section. Vaginulinopsis saundersi (Hanna and Hanna) Plate 2, Figure F Cristellaria saundersi Hanna and Hanna, 1924: 61, pl. 13, figs. 5, 6, 15. Marginulina mexicana (Cushman) var. C Laiming, 1943: 195, pl. 83, fig. 6a, b. Vaginulinopsis saundersi (Hanna and Hanna) subsp. rex Martin, 1943: 107, pl. 9, fig. 2a, b. Weaver and Weaver, 1962: 64, pl. 7, fig. 4. Vaginulinopsis saundersi (Hanna and Hanna); Beck, 1943: 598, pl. 105, figs. 1, 2, 4, 5, 10. Smith, 1957: 162, pl. 22, figs. 1, 2. Mallory, 1959: 157, pl. 11, fig. 10. McDougall, 1980: 42, pl. 10, figs. 8, 9. Provincial Range: Lower Ulatisian to upper Narizian. Local Occurrence: Shallow-marine facies. Remarks: Although not nearly as common as either variety of V. mexicana, it is always well preserved when found. 52 Family POLYMORPHINIDAE d'Orbigny, 1839 Subfamily POLYMORPHININAE d'Orbigny, 1839 Genus GLOBULINA d'Orbigny, 1826 Type species: Globulina gibba (d'Orbigny, 1826) (SO) Globulina sp. Local Occurrence: Outer shelf to slope facies. Remarks: A few iron oxide casts and poorly preserved specimens have been found. Family GLANOULINIOAE Reuss, 1860 Subfamily OOLININAE Loeblich and Tappan, 1961 Genus OOLINA d'Orbigny, 1839 Type species: Oolina laevigata d'Orbigny, 1839 (SO) Oolina spherica? Bandy Colina spherica Bandy, 1949: 167, pl. 7, fig. 20. Provincial Range: Not known. Local Occurrence: Outer shelf to slope facies. Remarks: A few poorly preserved specimens which most closely resemble this species have been found. Superfamily BULIMINACEA Jones, 187 5 Family EOUVIGERINIOEA Cushman, 1927 Genus STILISTOMELLA Guppy, 1843 Type species: Stilistomella rugosa Guppy, 1843 (OO) 53 Stilistomella cienegaensis? (Kleinpell). Stilistomella cienegaensis (Kleinpell); Fairchild, 1969: 115, pl. 10, fig. 13. Provincial Range: Not known. Local Occurrence: Outer shelf to slope facies. Remarks: Only a few fragmented individuals have been recovered. Family BULIMINIDAE Jones, 1875 Subfamily BULIMININAE Jones, 187 5 ·Genus BULIMINA d'Orbigny, 1826 Type species: Bulimina marginata d'Orbigny, 1826 (SD) Bulimina sp. Local Occurrence: Outer shelf to slope facies. Remarks: A few iron oxide casts and poorly preserved specimens have been found in the study section. Genus GLOBOBULIMINA Cushman, 1927 Type species: Globobulimina pacifica Cushman, 1927 (OD) Globobulimina sp. Local Occurrence: Outer shelf to slope facies. Remarks: A few poorly preserved specimens of this genus have been found. Superfamily DISCORBACEA Ehrenberg, 18 38 54 Family DISCORBIDAE, Ehrenberg, 1838 Subfamily DISCORBINAE Ehrenberg, 1838 Genus DISCORBIS Lemarck, 1804 Type species: Discorbis visicularis (Lemark, 1804) (OD) Discorbis cf. D. obvoluta (Terquem). Discorbis obvoluta (Terquem); Ellis and Messina, 1951: 482, figs. 33-35. Provincial Range: Not known. Local Occurrence: Shallow-marine facies. Remarks: Although present in only a few samples, it is very abundant and usually well preserved when found. Discorbis sp. Local occurrence: Shallow-marine and outer shelf to slope facies. Remarks: A few scattered, poorly preserved specimens of this genus have been found, but positive identification is not possible. Family ASTERIGERINIDAE d'Orbigny, 1839 Genus ASTERIGERINA d'Orbigny, 1839 Type species: Asterigerina carinata d'Orbigny, 1839 (SD) Asterigerina simiensis Cushman and McMasters Asterigerina simiensis Cushman and McMasters, 1936: 515, pl. 77, figs. 1- 4. Provincial Range: Not known. 55 Local Occurrence: Shallow-marine facies. Remarks: This species is widely dispersed throughout the shallow marine facies, but it is never abundant. Its test is very susceptible to dissolution, always showing badly etched surfaces as in the specimen figured by Cushman and McMasters (1936). To this author's knowledge, this species has been described only from the Llajas Formation. Superfamily ROT ALINACEA Ehrenberg, 1839 Family ELPHIDIIDAE Galloway, 1933 Subfamily ELPHIDIINAE Galloway, 1933 Genus ELPHIDIUM de Montfort, 1803 Type species: Elphidium macellum (Fichtel and Moll, 1798) (OD) E.lphidium californicum Cook Plate 2, Figure G Elphidium californicum Cook, 1950: 63, pl. 2, fig. 9a, b. Mallory, 1959: 148, pl. 15, fig. 10, pl. 33, fig. 8. McDougall, 1980: 45, pl. 20, figs. 4, 5. Elphidium cf. E. smithi Cushman and Dusenbury; Smith, 1957: 171-172, pl. 23, figs. 22, 23. Provincial Range: Upper Bulitian to upper Ulatisian. Local Occurrence: Shallow-marine facies. Remarks: This species is not common but is widespread in the shallow marine facies. It is always especially well preserved. Family NUMMULITIDAE de Blainville, 1825 Subfamily NUMMULITINAE de Blainville, 1825 56 Genus NUMMULITES Lemarck, 1801 Type species: Nummulites laevigata (Bruguiere, 1792) (SO) Nummulites cushmani (Cole) Plate 2, Figure H Operculina cushmani Cole, 1927: 23, pl. 2 fig. 13. Cushman and McMasters, 1936: 513, pl. 75, figs. 18-20, pl. 77, fig. 5. Mallory, 1959: 185, pl. 15, fig. 11. Provincial Range: Upper Bulitian to upper Ulatisian. Local Occurrence: Outer shelf to slope facies. Remarks: Although not very widely dispersed in the Llajas Formation, it is one of the most abundant when present. It is usually well preserved. Superfamily GLOBIGERINACEA Carpenter, Parker, and Jones, 1862 Family HETEROHELICIDAE Cushman, 1927 Subfamily HETEROHELICINAE Cushman, 1927 Genus BIFIRINA Parker and Jones, 1872 Type species: Bifirina saxipara (Ehrenberg, 1854) (OD) Bifirina sp. Local Occurrence: Outer shelf to slope facies. Remarks: Only a few poorly preserved specimens have been found. Family GLOBOROT ALIIDAE Cushman, 1927 Subfamily GLOBOROTALIINAE Cushman, 1927 Genus GLOBOROTALIA Cushman, 1927 57 Type species: Globorotalia tumida (Brady, 1877) (OD) Globorotalia sp. Local Occurrence: Outer shelf to slope facies. Remarks: A few poorly preserved specimens have been found. Family GLOBIGERINIDAE Carpenter, Parker, and Jones, 1862 Subfamily GLOBIGERININAE Carpenter, Parker, and Jones, 1862 Genus GLOBIGERINA d'Orbigny, 1826 Type species: G1obigerina bulloides d'Orbigny, 1826(50) G1obigerina bulloides? d'Orbigny Globigerina bulloides d'Orbigny; Howe and Wallace, 1932: 73, pl. 10, fig. 10. Mallory, 1959: 248, pl. 34, fig. 7a-c. Weaver, 1962: 415, pl. 7, fig. 4. Weaver and Weaver, 1962: 84, pl. 17, fig. 4a-c. Akpati, 1966: 138, pl. 9, fig. 5. Fairchild, 1969: 127, pl. 16, fig. 6. Provincial Range: Lower Penutian to Recent. Local Occurrence: Outer shelf to slope facies. Remarks: A few poorly preserved specimens and iron oxide casts have been found which most closly resemble this species. Genus HASTIGERINELLA Cushman, 1927 Type species: Hastigerinella digitata (Rhumbler, 1911) (OD) Hastigerinella sp. Local Occurrence: Outer shelf to slope facies. 58 Remarks: Members of this genus are extremely rare and poorly preserved in the Llajas Formation. Superfamily ORBITOIDACEA Schwager, 1876 Family EPONIDIDAE Hofker, 1951 Genus EPONIDES de Montfort, 1808 Type species: Eponides rapandus (Fichtel and Moll, 1798) (OD) Eponides jacksonensis (Cushman and Applin) Eponides jacksonensis (Cushman and Applin); Cushman, 1935: 46, pl. 19, figs. 4-8. Bandy, 1949: 181, pl. 14, fig. la-c. Provincial Range: Not known. Local Occurrence: Shallow-marine facies. Remarks: This species is rare and not very widespread ln the study section. Eponides lotus? (Schwager) Plate 2, Figure I Eponides lotus (Schwager); Bandy, 1949: 181, pl. 14, fig. 3a-c. Cushman, 1951: 52, pl. 14, fig. 2la, b. Provincial Range: Lower Penutian to lower Ulatisian. Local Occurrence: Shallow-marine facies (transgressive phase). Remarks: Although relatively rare in the study section, this species is always well preserved. 59 Eponides mexicanus (Cushman) Pulvinulina mexicana Cushman; Cushman and G. D. Hanna, 1927: 222, pl. 14, figs. 12-15. Eponides mexicana (Cushman); Cushman and M. A. Hanna, 1927: 54, pl. 5, figs. 8, 9. Howe, 1939: 109, pl. 9, figs. 31-33, pl. 10, figs. 1-3. Smith, 1957: 183, pl. 27, fig. lOa-c. Weaver and Weaver, 1962: 76, pl.l3, fig. 4a-c. Eponides guayabalensis Cole var. yeguaensis Weinzierl and Applin; Cushman and Dusenbury, 1934: 62, pl. 9, fig. la-c. Eponides yeguaensis Weinzierl and Applin; Cushman and McMasters, 1936: _514, pl. 76, fig. la-c. Beck, 1943: 608, pl. 108, figs. 1, 4. Eponides frizzelli Kleinpell, 1938: 318, pl. 2, figs. 12, 15, 16. Eponides kleinpelli Cushman and Frizzell, 1940: 42, pl. 8, fig. lla-c. Fairchild, 1969: 129, pl. 17, fig. 7. Eponides primus Martin, 1943: 23, pl. 9, fig. 4a-c. Eponides gaviotaensis Wilson, 1954: 43, pl. 16, figs. 11, 12. Hornaday, 1961: 224, pl. 10, fig. 1. Eponides mexicanus (Cushman); Curtis, 1955: 78, pl. 30, figs. 18, 19. Mallory, 1959: 237, pl. 37, fig. 11, pl. 41, fig. 9. McDougall, 1980: 45, pl. 23, figs. 4-9. (non) Rotalia soldanii (d'Orbigny); Hanna, 1923 (misidentification) 37 5, pl. 59' fig. 3. (non) Eponides lotus (Schwager), Israelsky, 19 39 (misidentification): 578, pl. 5, fig. la-c. Provincial Range: Lower Bulitian to upper Narizian. Local Occurrence: Shallow-marine and outer shelf to slope facies. 60 Remarks: Although never abundant, this species is widespread and well preserved in the study section. Eponides sp. Local Occurrence: Shallow-marine and outer shelf to slope facies. Remarks: Several poorly preserved members of this genus have been found scattered throughout the Llajas Formation. They are never abundant. Family CIBICIDIDAE Cushman, 1927 Subfamily PLANULININAE Bermudez, 1952 Genus PLANULINA d'Orbigny, 1826 Type species: Planulina ariminensis d'Orbigny, 1826 (SD) Planulina cf. P. cocoensis Cushman Plate 3, Figure A Planulina cocoensis Cushman; Bandy, 1949: 193, pl. 20, fig. 2. Provincial Range: Not known. Local Occurrence: Outer shelf to slope facies. Remarks: Although very rare, this species is relatively well preserved when found. Planulina sp. Local Occurrence: Outer shelf to slope facies. Remarks: Only rare, fragmented speciments have been recovered from 61 the study section. Subfamily CIBICIDINAE Cushman, 1927 Genus CIBICIDES de Montfort, 1808 Type species: Cibicides refulgens de Montfort, 1808 (OD) Cibicides coalingensis? Cushman and Hanna Plate 3, Figure B Cibicides coalingensis Cushman and Hanna, 1927: 221, pl. 14, figs. 7-9. Provincial Range: Not known. Local Occurrence: Outer shelf to slope facies and regressive phase, shallow marine facies. Remarks: This species is very rare, but relatively well preserved when found. Cibicides praecursorius? (Schwager) Plate 3, Figure C Cibicides praecursorius (Schwager); Cushman and Renz, 1942: 13, pl. 3, fig. 9a-c. Cushman, 1951: 65, pl. 19, figs. 1-6. Mallory, 1959: 269, pl. 32, fig. lOa-c. Applin, 1964: 70, pl. 4, figs. 9, 10. Provincial Range: Lower Ynezian to upper Ulatisian. Local Occurrence: Shallow-marine facies. Remarks: As with other members of this genus, this species is relatively rare in the study section. 62 Cibicides pseudoungarianus (Cushman) evolutus? Cushman and Hobson. Cibicides pseudoungarianus (Cushman) evolutus Cushman and Hobson, 1935: 64, pl. 9, fig. ll. Provincial Range: Not known. Local Occurrence: Shallow-marine facies. Remarks: This species is rare, but relatively well preserved. Cibicides aff. C. pseudoungarianus (Cushman). Cibicides aff. C. pseudoungarianus (Cushman); Fairchild, 1969: 135, pl. 20, figs. 1, 5, 6. Provincial Range: Not known. Local Occurrence: Shallow-marine facies. Remarks: This is a very rare species, with only a few scattered individuals found in the study section. Cibicides sandiegensis Cushman and Hanna Cibicides sandiegensis Cushman and M.A. Hanna, 1927: 55, pl. 5, figs. 1, 2. Mallory, 1959:270, pl. 25, fig. 7a-c. Provincial Range: Upper Ulatisian. Local Occurrence: Shallow-marine facies (Regressive phase). Remarks: This is another very rare species with only a few well preserved specimens found. 63 Cibicides sp. Local Occurrence: Shallow-marine and outer shelf to slope facies. Remarks: Several poorly preserved or fragmented members of this genus have been found scattered throughout the Llajas Formation. Family DISCOCYCLINIDAE Galloway, 1928 Genus PSEUDOPHRAGMINA Douville, 1923 Type species: Pseudphragmina floridana (Cushman, 1917) (OD) Pseudophragmina clarki (Cushman, 1920) Plate 4, Figure A Orbitolites, sp. A Arnold, 1910: 13, 108, pl. 3, fig. 6. Orthophragmina clarki Cushman, 1920: 41, pl. 7, figs. 4, 5. Discocyclina clarki (Cushman); Schenck, 1929: 221, figs. 1, 2, 5, text figure 7. Pseudophragmina clarki (Cushman); Schymiczek and Squires, 1981 (text). Squires, 198 3: fig. 5a-b. (non) DiscocycHna cloptoni Vaughn, Cushman and McMasters, 1936 (misidentification): 516, pl. 77, figs. 6-9. Provincial Range: Lower Ulatisian to upper Ulatisian. Local Occurrence: Shallow-marine facies (transgressive phase). Remarks: This is one of the most abundant, and certainly the largest species of Foraminifera found in the Llajas Formation. Superfamily CASSIDULINACEA d'Orbigny, 1839 64 Family ANNULOPATELLINIDAE Loeblich and Tappan, 1964 Genus ANNULOPATELLINA Parr and Collins, 1930 Type species: Annulopatellina annularis (Parker and Jones, 1860) (OD) Annulopatellina sp. Plate 3, Figure D Local Occurrence: Outer shelf to slope facies. Remarks: Members of this genus are rare and tend to be partially recrystallized, making identification to species level impossible. They are identical to those figured by Cushman and McMasters (1936), which were misidentified as Dictyconus sp. Family CAUCASINIDAE Bykova, 1959 Subfamily FURSENKOININAE Loeblich and Tappan, 1961 Genus CASSIDELLA Hofker, 1951 Type species: Cassidella tegulata (Reuss, 1846) (OD) Cassidella dibollensis (Cushman and Applin) Plate 3, Figure E Virgulina dibollensis Cushman and Applin, 1926: 168, pl. 7, fig. 7a-c. Howe and Wallace, 1932: 66, pl. 11, fig. 1. Cushman, 1935: 36, pl. 14, figs. la, b, 2, 3. Cushman, 1937: pi. 1, figs. 20-22. Mallory, 1959: pl. 40, fig. 12a, b. Provincial Range: Not known. Local Occurrence: Outer shelf to slope facies. Remarks: This is one of the most abundant and best preserved species found in the outer shelf to slope facies. 65 Family NONIONIDAE Schultze, 1854 Subfamily CHILOSTOMELLINAE Brady, 1881 Genus CHILOSTOMELLOIDES Cushman, 1926 Type species: Chilostomelloides oviformis (Sherborn and Chapman, 1886) (OD) Chilostomelloides sp. Local Occurrence: Outer shelf to slope facies. Remarks: Members of this genus are very rare and poorly preserved. Subfamily NONIONINAE Schultze, 1854 Genus NONIONELLA Cushman, 1926 I.xpe species: Nonionella miocenica Cushman, 1926 (OD) Nonionella florinense? (Cole) Plate 3, Figure F Nonion florinense Cole, 1927: 22, pl. 4. Cushman, 1939b: 3, pl. 1, figs. 17, 19. Nonion sp. Israelsky, 1939: 576, pl. 7, fig. 2a-c. Nonionella florinense (Cole); Mallory, 1959: 183, pl. 15, fig. 8a-c. (non) Nonionella frankei (Cushman); Smith, 1957 (misidentification): 171, pl. 23, fig. 21a, b. Provincial Range: Lower Ulatisian. Loca,l Occurrence: Outer shelf to slope facies. Remarks: This is one of the most abundant and well preserved species · from the outer shelf to slope facies. 66 Family ALABAMINIDAE Hofker, 1951 Genus GYROIDINA d'Orbigny, 1826 Type species: Gyroidina orbicularis d'Orbigny, 1926 (SD) Gyroidina sp. Local Occurrence: Shallow-marine and outer shelf to slope facies. Remarks: Members of this genus are very rare but widely dispersed in fossiliferous portions of the Llajas Formation. They are always poorly preserved. Family ANOMALINIDAE Cushman, 1927 Subfamily ANOMALININAE Cushman, 1927 Genus ANOMALINA d'Orbigny, 1826 Type species: Anomalina punctulata d'Orbigny, 1826 (SD) Anomalina garzaensis? Cushmand and Siegfus Anomalina garzaensis Cushman and Siegfus, 1939: 32, pl. 7, figs. 3a-c. Cushman and Siegfus, 1942: 422, pl. 18, figs. 6a-c. Graham and Classen, 1955: 30, pl. 5, figs. 12a-c. Mallory, 1959: 259, pl. 31, fig. la-c. Weaver, 1962: 90, pl. 20, fig. 3a-c. provincial Range: Lower Penutian- upper Narizian. Local Occurrence: Shallow-marine facies. Remarks: This species is rare but relatively well preserved when found. Anomalina umbonata? Cushman Anomalina umbonata Cushman, 1925: 300, pl. 7, figs. 5, 6. Cushman, 67 1927: 160, pl. 27, figs. 10, 11. Howe, 1939: 117, pl. 13, figs. 6-8. Israelski, 1939: 589, pl. 7, fig. 6. Mallory, 1959, 262, pl. 31, fig. 2a-c. Cibicides sp. D. Cushman and McMasters, 1936: 511, pl. 76, fig. 13a-c. Provincial Range: Lower Bulitian - lower Narizian. Local Occurrence: Shallow-marine facies. Remarks: This species is more rare than A. garzaensis, and it is not as well preserved. REFERENCES CITED Addicott, W. 0., 1967, Zoogeographic evidence for late Tertiary lateral slip on the San Andreas fault, California: U.S. Geological Survey, Professional Paper 593-D, p. 1-12. Akpati, B.N., 1966, Some Lower Paleocene Foraminifera from the Anita Formation, Santa Barbara County, California: Cushman Foundation of Foraminiferal Research Contributions, v. 17, pt. 4, p. 135-139. Applin, E. R., 1964, Some Middle Eocene, Lower Eocene and Paleocene foraminiferal faunas from west Florida: Cushman Foundation of Foraminiferal Research, Contributions, v. 15, pt. 2, p. 45-72. Arnold, Ralph, 1910, Paleontology of the Coalinga district, Fresno and Kings Counties, California: U.S. Geological Survey Bulletin 603, 173 p. Bandy, 0. L., 1949, Eocene and Obgocene Foraminifera from Little Stave Creek, Clark County, Alabama: Bulletin of American Paleontology, v. 32, no. 131, p. 1-153. Bandy, 0. L., 1960, The geologic significance of coiling in the foraminifera Globigerina pschyderma (Ehrenberg): Journal of Paleontology, v. 34, p. 671-681. Bandy, 0. L., 1961, Distribution of foraminifera, radiolaria and diatoms in sediments of the Gulf of California: Micropaleontology, v. 7, p.l-26. Bandy, 0. L., 1964, General correlation of foraminiferal structure with environment, in Imbrie, J., and Newell, N. D., eds., Approaches to paleoecology, John Wiley and Sons: New York, p. 7 5-90. Bandy, 0. L., 1967, Foraminiferal definition of the boundaries of the Pleistocene in southern California, in Sears, M., ed., Progress in Oceanography, v. 4: New York, Pergamon Press, p. 27-49. Bandy, 0. L., 1971, Neogene planktonic foraminiferal zones, California, and some geologic implications: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 12, p. 131-150. Bandy, 0. L., and Arnal, R. E., 1957, Distribution of Recent Foraminifera off the west coast of Central America: American Association of Petroleum Geologists Bulletin, v. 41, p. 2027-2053. Bandy, 0. L., and Arnal, R. E., 1960, Concepts of a foraminiferal paleoecology: American Association of Petroleum Geologists Bulletin, v. 44, p. 1921- 1932. Bandy, 0. L., and Arnal, R. E., 1969, Middle Tertiary basin development, San Joaquin Valley, California: Geological Society of America Bulletin, v. 80, p. 78 3-820. 69 Bandy, 0. L., and Rudolfo, K. S., 1964, Distribution of Foraminifera and sediments, Peru-Chile Trench area: Deep Sea Research, v. 11, p. 817- 837. Beck, R. S., 1943, Eocene Foraminifera from Cowlitz River, Lewis County, Washington: Journal of Paleontology, v. 17, p. 584-614. Berger, W. H., 1979, Preservation of foraminifera: Society of Economic Paleontologists and Mineralogists, Short Course No. 6, p. 105-155. Berggren, W. A., 1969, Cenzoic chronostratigraphy, planktonic foraminiferal zonation and the radiometric time scale: Nature, v. 224, p. 1072-1075. Bukry, D., Brabb, E. E., and Vedder, J. G., 1973, Correlation of Tertiary nannoplankton assemblages from the Coast and Peninsular Ranges of California: Preprint, Congreso Latino-americo de Geologica, Second, Caracas, p. 1-35. Bukry, D., Brabb, E. E., and Vedder, J. G., 1977, Correlation of Tertiary nannoplankton assemblages from the Coast and Peninsular Ranges of California: Congreso Latino-americo de Geologica, Memoir 3, p. 1461- 1483. Buzas, M. A., and Gibson, T. A., 1969, Species diversity: benthonic Foraminifera in the western North Atlantic: Science, v. 163, p. 72-75. Church, C. C., 1931, Foraminifera of the Kreyenhagen Shale, Mining in California: California Department of Natural Resources, Division of Mines, v. 27, p. 202-213. Clark, B. L., 1921, Stratigraphic and faunal relationships of the Meganos group, middle Eocene of California: Journal of Geology, v. 29, p. 125-165. Clark, B. L., 1926, The Domengine horizon, Middle Eocene of California: University of California Publications Geological Sciences, v. 16, p. 99- 118. Clark, B. L., and Vokes, H. E., 1936, Summary of marine Eocene sequence of western North America: Geological Society of America Bulletin, v. 47, p. 851-878. Cole, W. S., 1927, A foraminiferal fauna from the Guayabel Formation in Mexico: Bulletin of American Paleontology, v. 14, no. 51, p. 1-46. Cook, T. D., 19 50, Eocene Foraminifera from the Devils Den area, California (unpublished Masters thesis): Department of Paleontology, University of California, Berkeley, 116 p. Curtis, N. M., Jr., 1955, Paleoecology of the Viesca Member of the Weches Formation at Smithville, Texas: Journal of Paleontology, v. 29, no. 2, p. 263-282. 70 Cushman, J. A., 1920, The America species of Orthophragmina and Lepidocyclina: U. S. Geologic Survey Professional Paper 125-1, p. 39- 108. Cushman, J. A., 1925, An Eocene fauna from the Montezuma River, Mexico: American Association Petroleum Geologists Bulletin, v. 9, p. 298-303. Cushman, J. A., 1926, The Foraminifera of the Valasco Shale of the Tampico embayment: American Association of Petroleum Geologists Bulletin, v. 10, p. 581-612. Cushman, J. A., 1927, Some characteristic Mexican fossil Foraminifera: Journal of Paleontology, v. 1, pt. 2, p. 147-172. Cushman, J. A., 1933, New Foraminifera from the upper Jackson Eocene of the southeast coastal plain region of the United States: Cushman Laboratory of Foraminiferal Research, Contributions, v. 9, pt. 1, p. 1-21. Cushman, J. A., 1935, Upper Eocene Foraminifera of the southeastern United States: U. S. Geological Survey Professional Paper 181, 88 p. Cushman, J. A., 1937, A Monograph of the subfamily Virgulininae: Cushman Laboratory of Foraminiferal Research, Special Publication No. 9, 240 p. Cushman, J. A., 1939a, Eocene Foraminifera from submarine cores off the eastern coast of North America: Cushman Laboratory of Foraminiferal Research, Contributions, v. 15, p. 49-76. Cushman, J. A., 1939b, A Monograph of the Foraminiferal Family Nonionidae: U. s. Geological Survey Professional Paper 191, 100 p. Cushman, J. A., 1940, Midway Foraminifera from Alabama: Cushman Laboratory of Foraminiferal Research, Contributions, v. 16, pt. 3, p. 51- 73. Cushman, J. A., 1944, The foraminiferal fauna of the type locality of the Pecan Gap Chalk: Cushman Laboratory of Foraminiferal Research, Contributions, v. 20, pt. 1, p. 1-17. Cushman, J. A., 1946a, Upper Cretaceous Foraminifera of the Gulf Coastal region of the United States and adjacent areas: U. S. Geological Survey Professional Paper 206, 124 p. Cushman, J. A., 1946b, A rich foraminiferal fauna from the Cocoa Sand of Alabama: Cushman Laboratory of Foraminiferal Research, Special Publication 16, 40 p. Cushman, J. A., 1951, Paleocene Foraminifera of the Gulf Coastal region of the United States and adjacent areas: U. S. Geological Survey Professional Paper 232, 75 p. 71 Cushman, J. A., and Applin, E. R., 1926, Texas Jackson Foraminifera: American Association of Petroleum Geologists Bulletin, v. 10, p. 154- 189. Cushman, J. A., and Barksdale, J. D., 1930, Eocene Foraminifera from Martinez, California: Stanford University, Department of Geology Contributions, v. 1, p. 55-73. Cushman, J. A., and Dusenbury, A. N., Jr., 1934, Eocene Foraminifera of the Poway conglomerate of California: Cushman Laboratory of Foraminiferal Research, Contributions, v.IO, pt. 3, p. 51-65. Cushman, J. A., and Frizzell, Virgil, 1940, Two new species of Foraminifera from the Oligocene, Lincoln Formation, Washington: Cushman Laboratory of Foraminiferal Research, Contributions, v. 16, pt. 2, p. 42. Cushman, J. A., and Hanna, G. D., 1927, Foraminifera from the Eocene near Coalinga, California: California Academy of Sciences Proceedings, 4th series, v. 16, no. 8, p. 205-228. Cushman, J. A., and Hanna, M. A., 1927, Foraminifera from the Eocene near San Diego, California: San Diego Society Natural History Transactions, v. 5, no. 4, p. 45-64. Cushman, J. A., and Hobson, H. D., 1935, A foraminiferal faunule from the type San Lorenzo Formation, Santa Cruz County, California: Cushman Laboratory of Foraminiferal Research, Contributions, v. 11, pt. 3, p. 53- 64. Cushman, J. A., and Jarvis, P. W., 1932, Upper Cretaceous Foraminifera from Trinidad: U.S. Museum Natural History, Proceedings, v. 80, art. 14, 60 p. Cushman, J. A., and McMasters, J. H., 1936, Middle Eocene Foraminifera from the Llajas Formation, Ventura County, California: Journal of · Paleontology, v. 10, p. 497-517. Cushman, J. A., and Renz, H. H., 1942, Eocene, Midway, Foraminifera from Soldado Rock, Trinidad: Cushman Laboratory of Foraminiferal Research, Contribution, v. 18, pt. 1, p. 1-14. Cushman, J. A., and Schenck, H. G., 1928, Two foraminiferal faunules from the Oregon Tertiary: University of California Publications in Geological Science, v. 17, p. 305-324. Cushman, J. A., and Siegfus, S. S., 1939, Some new and interesting Foraminifera from the Krayenhagen Shales of California: Cushman Laboratory of Foraminiferal Research, Contributions, v. 15, p. 23-33. Cushman, J. A., and Siegfus, S. S., 1942, Foraminifera from the type area of the Kreyenhagen Shales of California: San Diego Society of Natural History, Transactions, v. 9, no. 34, p. 385-426. 72 Cushman, J. A., and Simonson, R. R., 1944-, Foraminifera from the Tumey Formation, Fresno County, California: Journal of Paleontology, v. 18, p. 186-203. Cushman, J. A., Stewart, R. E., and Stewart, K. C., 1947, Lower Coaledo (Upper Eocene) Foraminifera from Sunset Bay, Coos County, Oregon: State of Oregon, Department of Geological and Mining Industry Bulletin, v. 36, no. 4, p. 58-61. Cushman, J. A., Stewart, R. E., and Stewart, K. C., 194-9, Upper Eocene Foraminifera from the Toledo Formation, Toledo, Lincoln County, Oregon: State of Oregon, Department of Geological and Mining Industry Bulletin, v. 36, no. 4, p. 58-61. Cushman, J. A., and Stone, Benton, 194-7, An Eocene foraminiferal fauna from the Chira Shale, Peru: Cushman Laboratory of Foraminiferal Research, Contributions, v. 23, pt. 3, p. 57. Cushman, J. A., and Stone, Benton, 1949, Foraminifera from the Eocene Verdum Formation, Peru: Cushman Laboratory of Foraminiferal Research, Contributions, v. 25, pt. 4, p. 73-84. Cushman, J. A., and Thomas, N. L., 1930, Common Foraminifera of the East Texas Greensands: Journal of Paleontology, v. 4, no. 1, p. 33-41. Cushman, J. A., and Todd, M. R., 194-6, A foraminiferal fauna from the Paleocene of Arkansas: Cushman Laboratory of Foraminiferal Research, Contributions, v. 22, pt. 2, p. 4-5-65. Douglas, R. G., 1979, Benthic foraminiferal ecology and paleoecology: A review of Mineralogists, Short Course No. 6, p. 21-53. Ellis, B. F., and Messina, A. R., 1951, Catalogue of Foraminifera: American Museum of Natural History Special Publication, v. 18. Ellisor, A. C., 1933, Jackson group of formations in Texas, with notes on Frio and Vicksburg: American Association of Petroleum Geologists Bulletin, v. 17, p. 1293-1350. Emery, K. 0., 1960, The sea off southern California: a modern habitat of petroleum: John Wiley and Sons, New York, 366 p. Fagerstrom, A., 1964, Fossil communities in paleoecology: their recognition and significance: Geological Society of America Bulletin, v. 75, p. 1197- 1216. Fairchild, W. W., Wesendunk, R. R., and Weaver, D. W., 1969, Eocene and Oligocene Foraminifera from the Santa Cruz Mountains, California: University of California Publications in Geological Sciences, v. 81, 93 p. 73 Filewicz, M. V., and Hill, M. E., III, 1983, Calcareous nannofossil biostratigraphy of the Santa Susana and Llajas Formations, north side Simi Valley, in Squires, R. L., and Filewicz, M. V., eds., Cenozoic geology of theSimi Valley area, southern California: Pacific Section, Society of Economic Paleontologists and Mineralogists, Field Trip Guide. Folk, R. L., 1974, Petrology of sedimentary rocks: Austin, Hemphill, 182 p. Gibson, J. M., 1973, Foraminiferal biostratigraphy of the Anita Formation, western Santa Ynez Mountains, Santa Barbara County, California (unpublished Masters thesis): University of Southern California, Los Angeles, 319 p. Gibson, J. M., and Steineck, P. L., 1972, Age and correlation of the Ulatisian and Narizian Stages, California: Reply: Geological Society of America Bulletin, v. 7, p. 2225-2232. Givens, C. R., and Kennedy, M.P., 1979, Eocene molluscan stages and their correlation, San Diego area, California, in Abbott, P. L., ed., Eocene Depositional Systems, San Diego: PacificSection, Society of Economic Paleontologists and Mineralogists, Field Trip Guide, Geological Society of America Annual Meeting, p. 81-95. Graham, J. J., and Classen, W. J., 1955, a lower Eocene foraminiferal faunule from the Woodside area, San Mateo County, California: Cushman Laboratory of Foraminiferal Research, Contributions, v. 6, pt. 1, p. 1-55. Hanna, G. D., 1923, Some Eocene Foraminifera near Vacaville, California: University of California Publications in Geological Sciences, v. 14, p. 319-328. Hanna, G. D., and Hanna, M. A., 1924, Foraminifera from the Eocene of Cowlitz River, Lewis County, Washington: University of Washington Publication in Geology, v. 1, p. 57-64. Hardenbol, J., and Berggren, W. A., 1978, American Association of Petroleum Geologists, Studies in Geology No. 6, p. 213-234. Hornaday, G. R., 1961, Foraminifera from the Sacate Formation south of Refugio Pass, Santa Barbara County, California: University of California Publications in Geological Sciences, v. 37, p. 165-232. Hornaday, G. R., 1965, An Eocene foraminiferal faunule from the northwestern Santa Ynez Mountains, California: Cushman Foundation of Foraminiferal Research, Contributions, v. 6, pt. 1, no. 293, p. 29-39. Howe, H. v., 1939, Louisiana Cook Mountain Eocene Foraminifera: Louisiana Geological Survey Bulletin, v. 14, p. 1-122. 74 Howe, H. v., and Wallace, W. E., 1932, Foraminifera of the Jackson Eocene at Danville Landing on the Ouachita, Catahoula Parish, Louisiana: Louisiana Geological Survey Bulletin, v. 2, p. 7-118. Ingle, J. C., Jr., 1967, Foraminiferal biofacies and the Miocene-Pliocene boundary in southern California: Bulletins in American Paleontology, v. 52, p. 1-217. Ingle, J. C., Jr., 1980, Cenozoic paleobathymetry and depositional history of selected sequences within the southern California continental borderland, in Sliter, W.V ., ed., Studies in marine micropaleontology and paleoecology: Cushman Foundation of Foraminiferal Research, Special Publication 19, p. 163-195. Ingle, J. C., Jr., 1981, Cenozoic depositional history of the norther continental borderland of southern California and the origin of associated Miocene diatomites: Pacific Section, American Association of Petroleum Geologists, Guide to the Monterey Formation in the California Coastal area, Ventura to San Luis Obispo, p. 1-8. Israelsky, M. C., 1939, Notes on some Foraminifera from Marysville Buttes, California: Sixth Pacific Science Congress Proceedings, v. 2, p. 569- 580. Israelsky, M. C., 1951, Foraminifera of the Lodo Formation, central California: U. S. Geological Survey Professional Paper 240-A, p. 1-29. Kew, W. S. W., 1924, Geology and oil resources of a part of Los Angeles and Ventura Counties, California: U. S. Geological Survey Bulletin 7 53, 202 P· Kleinpell, R. M., 1924, Geology and oil resources of a part of Los Angeles and Ventura Counties, California: U. S. Geological Survey Bulletin 7 53, 202 P· Kleinpell, R. M., 1938, Miocene stratigraphy of California: American Association of Petroleum Geologists, Tulsa, Oklahoma, 450 p. Kleinpell, R. M., and Weaver, D. W., 1963, Oligocene biostratigraphy of the Santa Barbara Embayment, California (Parts 1 and 3): University of California Publications in Geological Sciences, v. 43, p. 1-77 and 163- 232. Kline, M. H., 1943, Clay County fossils: Midway Foraminifera and Ostracoda: Mississippi State Geological Survey Bulletin, v. 53, p. 1-98. Kummel, B., 1965, Handbook of paleontological techniques: W. H. Freeman Co., San Francisco, 400 p. Laiming, Boris, 1940, Some foraminieral correlations in the Eocene of San Joaquin Valley, California: Sixth Pacific Science Congress Proceedings, v. 2, p. 535-568. 75 Laiming, Boris, 1941, Foraminiferal correlations in Eocene of San Joaquin Valley, California: American Association of Petroleum Geologists Bulletin, v. 24, p. 1923-1939. Laiming, Boris, 1943, Eocene foraminiferal correlations in California: State of California Division of Mines Bulletin 118, p. 193-198. Loeblich, A. R., Jr., and Tappan, Helen, 1964, Sarcodina, chiefly "Thecamoebians" and Foraminiferida, in Moore, R. C., ed., Treatise on invertebrate paleontology: GeologicalSociety of America, New York, pt. C, v. 1-2, 900 p. Lohmar, J. M., and Warme, J. E., 1979, An Eocene shelf margin: San Diego County, California, in Armentrout, J. M., Cole, M.R., and Terbest, H., Jr., eds., Cenzoic Paleogeography of the Western United States: Pacific Section, Society of Economic Paleontologists and Mineralogists, Pacific Coast Paleogeography Symposium 3, p. 165-176. MaUory, V. S., 1959, Lower Tertiary biostratigraphy of the California Coast Ranges: American Association of Petroleum Geologists, Tulsa, Oklahoma, 416 p. Martin, L. T., 1943, Eocene Foraminifera from the type Lodo Formation, Fresno County, California: Stanford University Publications in Geological Sciences, v. 3, p. 93-125. McDougall, Kristin, 1980, Paleoecological evaluation of late Eocene biostratigraphic zonations of the Pacific coast of North America: Society of Economic Paleontologists and Mineralogists, Paleontology Monograph No. 2, 46 p. McMasters, J. H., 1933, Eocene Llajas Formation, Ventura County, California: Geological Society of America BuUetin (abs.), v. 44, p. 217-218. Merriam, C. W., and Turner, F. E., 1937, the Capay middle Eocene of northern California: University of California Publications in Geological Sciences, v. 24, p. 91-114. Murray, J. W., 1973, Distribution and Ecology of Living Benthic Foraminiferids: Crane, Russak, and Co., 274 p. Nagle, H. E., and Parker, E. S., 1971, Future oil and gas potential of onshore Ventura basin, California: American Association of Petroleum Geologists, Memoir 15, p. 254-297. Nilsen, T. H., and McKee, E. H., 1979, Paleogene paleogeography of the western United States, in Armentrout, J. M., Cole, W. S., and Terbest, H., Jr., eds., Cenozoic Paleogeography of the Western United States: Pacific Section Society of Economic Paleontologists and Mineralogists, Pacific Coast Paleogeography Symposium 3, p. 257-276. 76 Pfleum, C. E., and Frericks, W. E., 1976, Gulf of Mexico deep water foraminifers: Cushman Foundation of Foraminiferal Research, Special Publication 14, 125 p. Phillips, F. J., 1972, Age correlation of the Eocene Ulatisian and Narizian Stages, California: discussion: Geological Society of America Bulletin, v. 83, p. 2217-2224. Phleger, F. B., 1951, Ecology of foraminifera, northwest Gulf of Mexico. Part 1: Foraminiferal distribution: Geological Society of America Memoir 46, p. 1-88. Plummer, H. J., 1926, Foraminifera of the Midway Formation in Texas: University of Texas Bulletin 2644, p. 3-206. Poore, R. z., 1979, Correlations of Pacific Coast Paleogene benthic stages and calcareous plankton zonations California: Geological Society of America abstracts with Programs, v. 11, 122 p. Poore, R. z., 1980, Age and correlation of California Paleogene benthic foraminiferal stages: U. S. Geological Survey Professional Paper ll62-C, p. 1-8. Saul, L. R., 1983, Notes on Paleogene turritellas, venericardias, and molluscan stages of the Simi Valley area, California, in Squires, R. L., and Filewicz, M. V., eds. Cenzoic geology of the Simi Valley area, southern California: Pacific Section, Society of Economic Paleontologists and Mineralogists, Field Trip Guide. Schenck, H. H., 1929, Discocyclina in California: San Diego Society of Natural History Transactions, v. 5, no. 14, p. 211-240. Schenck, H. G., and Aguerrevere, S. E., 1926, Morphologic nomenclature of orbitoidal foraminifera: America Journal of Science, 5th Series, v. ll, no. 63, p. 251-256. Schymiczek, H. B., 1983a, Benthic Foraminifera and paleobathymetry of the Eocene Llajas Formation, north side of Simi Valley, California, in Squires, R. L., and Filewicz, M. V., eds., Cenozoic geology of the Simi Valley area, southern California: Pacific Section, Society of Economic Paleontologists and Mineralogists, Field Trip Guide. Schymiczek, H. B., 1983b, Depositional environments and petroleum occurrence, the Eocene Llajas Formation, southwestern Santa Susana Mountains, California: Program and abstracts, Pacific Sections, American Association of Petroleum Geologists, Society of Exploration Geophysicists, Society of Economic Paleontologists and Mineralogists (abs.), 58th annual, Sacramento, p. 52. 77 Schymiczek, H. B., and Squires, R. L., 1981, Biostratigraphy of Discocyclinid bearing beds, Eocene Llajas Formation, southwestern Santa Susana Mountains, California: American Association of Petroleum Geologists Bulletin (abs.), v. 65, p. 989. Sliter, W. V., 1972, Cretaceous foraminifers - depth habitats and their origin: Nature, v. 239, p. 514-515. Sliter, W. V., and Baker, R. A., 1972, Cretaceous bathymetric distribution of benthic foraminifers: Journal of Foraminiferal Research, v. 2, p. 167- 183. Smith, B. V., 1957, Lower Tertiary Foraminifera from Contra Costa County, California: University of California Publications in Geological Sciences, v. 32, p. 127-207. Smith, P. B., 1963, Quantitative and qualitative analysis of the Family Bolivinidae: U. S. Geological Survey Professional Paper 429-A, p. 1-39. Smith, P. B., 1964, Ecology of benthonic species: U. S. Geological Survey Professional Paper 429-B, p. l-55. Squires, R. L., 1981, A transitional alluvial to marine sequence, the Eocene Llajas Formation, southern California: Journal of Sedimentary Petrology, v. 51, p. 923-938. Squires, R. L., 1983a, New mollusks from the lower middle Eocene Llajas Formation, southern California: Journal of Paleontology, v. 57, p. 354- 362. Squires, R. L., 1983b, Eocene Llajas Formation, Simi Valley, southern California, in Squires, R. L., and Filewicz, M. V., eds., Cenozoic geology of the Simi Valley area, southern California: Pacific Section, Society of Economic Paleontologists and Mineralogists, Field Trip Guide. Squires, R. L., in press, Molluscan paleontology and biostratigraphy of the Eocene Llajas Formation, Simi Valley, California: Natural History Museum of Los Angeles County, Contributions in Science. Stadnickenko, M. M., 1927, The Foraminifera and Ostracoda of the marine Yegua of the type sections: Journal of Paleontology, v. 1, p. 226-233. Steineck, P. L., and Gibson, J. M., 1971, Age and correlation of the Eocene Ulatisian and Narizian Stages, California: Geological Society of America Bulletin: v. 82, p. 477-480. Stewart, R. B., 1927, Gabb's California fossil type gastropods: Academy Natural Sciences of Philadelphia Proceedings, v. 78, p. 287-44 7. 78 Stewart, R. B., 1930, Gabb's California Cretaceous and Tertiary type larnellibranchs: Academy of Natural Sciences of Philadelphia Special Publications No. 3, 314 p. Stipp, T. F., 1943, Simi oil field, in Geologic formations and economic development of the oil and gas fields of California: California Division of Mines Bulletin 118, pt. 3, p. 415-424. Toulmin, L. D., Jr., 1941, Eocene smaller Foraminifera from the Salt Mountain Limestone of Alabama: Journal of Paleontology, v. 15, p. 567-611. Turner, F. E., 1938, Stratigraphy and mollusca of the Eocene of western Oregon: Geological Society of America Special Paper 10, 130 p. Uchio, Takayasa, 1960, Ecology of living benthic foraminifera from the San Diego, California, area: Cushman Foundation of Foraminiferal Research, Special Publication 5, 71 p. Vokes, H. E., 1939, Molluscan faunas of the Domengine and Arroya Honda Formations of the California Eocene: New York Academy of Sciences Annual 38, 246 p. Waring, C. A., 1917, Stratigraphic and faunal relations of the Martinez to the Chico and Tejon of southern California: California Academy of Sciences Proceeding, 4th series, v. 7, p. 41-124. Weaver, D. W., 1962, Eocene Foraminifera from west of Refugio Pass, California: University of California Publications in Geological Sciences, v. 41, 96 p. Weaver, W. R., and Weaver, D. W., 1962, Upper Eocene Foraminifera from the southwestern Santa Ynez Mountains, California: University of California Publications in Geological Sciences, v. 41, 96 p. Weaver, C. E., et al., 1944, Correlation of the marine Cenozoic formations of western North America: Geological Society of America Bulletin, v. 55, p. 569-598. Weinzierl, L. L., and Applin, E. R., 1929, The Clairborne Formation on the Coastal Domes: Journal of Paleontology, v. 3, p. 384-440. Wentworth, C. H., 1922, A scale of grade and class terms for clastic sediments: Journal of Geology, v. 30, p. 377-392. Wilson, E. J., 1954, Foraminifera from the Gaviota Formation east of Gaviota Creek, California: University of California Publications in Geological Sciences, v. 30, p. 103-170. Yeats, R. s., 1976, Neogene tectonics of the central Ventura basin, California: Pacific Section, Socity of Economic Paleontologists and Mineralogists, Neogene Symposium, San Francisco, p. 19-32. 79 PLATE 1 A. Quingueloculina triangularis d'Orbigny X25 B. & C. Nodasaria latejugata Gumbel X20 D. Nodasaria pyrula d'Orbigny X40 E. Lenticulina articulata (Reuss) texanus ? (Cushman and Applin) X40 F. Lenticulina inornatus (d'Oribny) X40 G. Lenticulina limbosus (Reuss) X35 H. Lenticulina limboses (Reuss) hockleyensis Cushman and Applin X60 I. Lenticulina cf. L. mayi (Cushman and Parker) X60 80 A B c r;.\ ----_.1-,....rr- " (' --- i :\ ( " I ;.-- \ \j F D E . ' G H ' 81 PLATE 2 A. Lenticulina cf. L. pseudorotula (Asano) X40 B. & C. D. E. Vaginulinopsis mexicana (Cushman) vacavillensis (Hanna) X38 F. Vaginulinopsis saundersi (Hanna and Hanna) X40 G. Elphidium californicum Cook X56 H. Nummulites cushmani (Cole) X35 I. Eponides lotus? (Schwager) X60 82 A 8 c D E F H 83 PLATE 3 A. Planulina cf. P. cocoensis Cushman X80 B. Cibicides coalingensis? Cushman and Hanna X80 c. Cibicides praecursorius? (Schwager) X80 D. Annulopatallina sp. X50 E. Cassidella dibollensis (Cushman and Applin) X84 F. Nonionella florinense? (Cole) X84 84 A B ------ D E F 85 PLATE 4 A. Pseudophragmina clarki (Cushman) Equatorial Section, xl5. 86