THE DEPARTMENT OF NATURAL RESOURCES • • • • miSSISSIPPI geology

Bureau of Geology Volume 5, Number 4 2525 North West Street June 1985 • Jackson, Mississippi 39216

TAR PODS FROM THE YAZOO CLAY (UPPER ) AT CYNTHIA, MISSISSIPPI

David T. Dockery Ill Mississippi Bureau of Geology

INTRODUCTION

Workers at the Miss-Lite Aggregate clay pit in Cynthia, Hinds County, central Mississippi, notified the Mississippi Bureau of Geology on two separate occasions during July of 1985 when their bulldozer uncovered tar pods in the Yazoo Clay. According to the workers, these pods covered an area of about five feet in diameter. The writer was able to observe in situ only the "roots" or tar-filled fissures of the second of these pods (Figures 1 and 2). These fissures were generally less than a quarter of an inch in diameter, oblique, and multidirectional. They tapered to a feather edge before terminating and penetrated only about one foot of substrate below the excavated surface. Remains of the main pod body consisted of four- to five-inch long, somewhat tabular, tar fragments with conchoidal fracture. This tar is relatively pure with the exception of some clay inclusions. The clay-tar contact on some fragments indicates that the main pod body was lenticular and rested above a "root system" of tar-filled fissures. These fragments exhibit three distinct surface morphologies at the clay­ Figure 1. Oblique view of in situ, interconnected, tar­ tar boundary: (1) a basal surface that is smooth and filled fissures in the Yazoo Clay at the Miss-Lite clay pit slightly undulatory, (2) a lateral contact with lenticular in Cynthia, Hinds County. Mississippi. Photograph was lobes extending horizontally into the surrounding clay taken on July 18, 1985. Figure 3. Tar fragment showing horizontal lenticular lobes penetrating the surrounding clay.

Figure 2. Vertical view of in situ, tar-filled fissures in the Yazoo Clay. Photograph was taken on July 18, 1985.

(Figure 3), and (3) an upper and lateral contact with a lobate pillar structure (Figure 4) . The host clay sur­ rounding the tar pods is fossiliferous and of obvious marine origin. Dockery and Siesser (1984) placed the Yazoo Clay at the Cynthia pit In calcareous nanno­ Figure 4. Tar fragment showing the lobate pillar plankton zone NP21 and date it as upper Eocene in morphology of the upper surface. age. The tar pods occur in the lower part of unit one as given in their report. Hydrocarbons moving through vents on the upper Eocene, muddy, Yazoo shelf released their volatile ORIGIN OF THE TAR PODS IN THE YAZOO CLAY components within the soft sea-floor sediments before escaping into the aqueous environment. Above the Each of the two tar pods excavated was a small, vents, a lenticular residue of tar built up in the viscous lenticular, fissure-fed body centered about a single substrate and flowed laterally in a plastic state. This focal point. The tar is apparently a residue of escaping flow, though less viscous, slower, and on a miniature hydrocarbons. Deposition of the tar in both fissures scale, was somewhat like that of a submarine flow and lenticular pods demonstrates respectively both a as indicated by the lobate pillar surface morphology of compact, solid clay and a viscous clay matrix at the the tar. Tar also accumulated at the top of fissures time of hydrocarbon movement. This varied compac­ which fed the vents. tion of the host clay indicates that tar deposition Tar generated by oil seepage is common in the Gulf occurred syngenetically with sea-floor sedimentation of Mexico today. It is found as floating particles, as during late Eocene time. Thus, the tar pods are a globular masses washed up on beaches, and as mat­ product of an Eocene, submarine "paleo-oil seep." like masses on the sea floor. Geyer and Sweet (1973)

MISSISSIPPI GEOLOGY 2 illustrated an in situ submarine tar mass with a diameter fields in the area surrounding Cynthia include: (1) of two feet in Laguna de Tamiahua, Mexico, that is Jackson Gas Field, 6.4 miles to the south-southeast, similar in morphology to that postulated from tar producing gas from the Upper Jackson fragments excavated from the Yazoo Clay. While many Gas Rock, (2) Flora Field, 10.0 miles to the north, oil seeps and tar deposits in the Gulf are associated producing oil from the Jackson Gas Rock, (3) Browns­ with known petroleum reserves, Wilson and others ville Field, 7.8 miles to the west-northwest and above (1973) stated that most petroleum seepage is derived the Brownsville Salt Dome, producing oil from the directly from the source rock. In this case, oil seeps are Tertiary Wilcox Formation, and (4) Bolton Field, 11.0 not necessarily indicators of underlying petroleum miles to the west-southwest, producing oil from various reservoirs. Lower Cretaceous formations. Cynthia is situated on The tar pods excavated from the Yazoo Clay were the northern flank of the Jackson Dome, making this not associated with a plane, though small-scale structure the most likely source of hydrocarbons. If a faults (presumably due to slumping) do occur in the faulted reservoir were responsible for the "paleo-oil Cynthia clay pit. Geyer and Sweet (1973) stated that seeps" at Cynthia, it is possible that this reservoir was/ many present day oil seeps occur in areas where no is closer to the site than the oil and gas fields mentioned. faulting is evident. In a study of submarine gas seeps, Either this reservoir has yet to be discovered or its Watkins and Worzel (1978) observed apipelikewipeout reserves were vented out into the late Eocene ocean on 3.5-kHz soundings beneath a prominent seep. This that once covered the region. wipeout suggested a narrow cylindrical conduit for the upward movement of gas through the sedimentary REFERENCES CITED sequence. Such a conduit is postulated here for the movement of hydrocarbons that penetrated the Yazoo Dockery, David T., Ill, and William G. Siesser, 1984, Clay to form isolated tar deposits. Age of the upper Yazoo Formation in central Oil seeps on the Yazoo marine shelf at Cynthia were Mississippi: Mississippi Geology, v. 5, no. 1, p. probably produced by petroleum migrating from Upper 1-10, 1 pl. Cretaceous strata of the Jackson Dome. Hydrocarbons Geyer, Richard A., and William M. Sweet, Jr., 1973, either derived directly from their source beds or from a Natural hydrocarbon seepage in the Gulf of faulted Upper Cretaceous reservoir moved upward into Mexico: Gulf Coast Association of Geological (Cockfield and Moodys Branch formations) Societies Transactions, v. 23, p. 158-169. underlying the Yazoo Clay. Moving laterally within Watkins, Joel S., and J. LamarWorzel, 1978, Serendipity these aquifers, these hydrocarbons penetrated about gas seep area, south Texas offshore: American three hundred feet of compact clay through narrow, Association of Petroleum Geologists Bulletin, cylindrical, pressure-induced fissure systems and were v. 62, no. 6, p. 1067-1074. vented into the marine environment at isolated points. Wilson, A.D., P. H. Monaghan, A. Osanik, L. C. Price, The limited nature of the tar accumulation may be and M. A. Rogers, 1973, Estimate of annual input due to a limited amount of hydrocarbon seepage, the of petroleum to the marine environment from rarity of tar deposition at hydrocarbon seeps, or con­ natural marine seepage: Gulf Coast Association current transport of tar deposits to the surface and of Geological Societies Transactions, v. 23, p. subsequent deposition along the shoreline. Oil and gas 182-193.

3 JUNE 1985 PALEOECOLOGY OF SOME CLASSIC TERTIARY LOCALITIES IN THE AND PARIS BASINS OF

Cyrille Dolin Luc Dolin 16 rue des Ursulines 93200 Saint-Denis, France

and

Pierre Lozouet Laboratoire de Prehistoire et Paleoecologia du Quaternaire de I'E.P.H.E. lnstitut des Sciences de Ia Terre 6, Boulevard Gabriel 21000 Dijon, France

INTRODUCTION EOCENE OF THE AQUITAINE BASIN (BEARN BASIN - PAU AREA) The Aquitaine and Paris basins of France and the northern Gulf Basin of the southeastern United States The Aquitaine Basin is a coastal basin that contains contain excellent marine sequences. three east-west trending structural zones (Pomerol, Paleogene stages or groups within these basins have 1973, 1982): (1) a northern zone, (2) a median zone, been used as standards for worldwide stratigraphic and (3) the Pre-Pyrenean Trench (an extension of the correlations for over one hundred years. In the northern Aturian Gulf). This complex basin is not well under­ Gulf, the Eocene and marine sections are stood despite a recurrence of interest in the subject particularly well preserved along the eastern flank of within the geologic community. Tertiary invertebrate the Mississippi Embayment in Mississippi and south­ faunas within the Aquitaine Basin show many interest­ western Alabama. These marine sections can be closely ing relationships to those of the North American Gulf correlated with tt,ose of the Aquitaine and Paris basins realm. In this paper, data derived from studies of by means of calcareous nannoplankton as demon­ invertebrate faunal assemblages are analyzed to strated by Pujol (1979) , Siesser and Dockery (1985), determine the fossil communities and paleoecology for and others. several classic Eocene and Oligocene localities in the Comparative studies of the northern Gulf and French Beam and Adour subbasins of the Aquitaine Basin. Paleogene strata show parallel development of many These localities are the same as those studied by taxa and similarities 1n the paleoecology of benthic Siesser and Dockery (1985) so that the fossil com­ faunas. Such studies also demonstrate cyclical histories munities can be placed in the proper biostratigraphic of sea level fluctuation in widely separated basins as framework. well as the tectonic development of these basins. The Paleogene localities studied in the Bearn Basin Tectonic processes were more pronounced in the of the Pau area consist of the Acot and "Tuilerie" Aquitaine Basin, which was associated with the outcrops. A major tectonic feature that influenced the Pyrenean during the Eocene Epoch. Recon­ depositional history of these outcrops was the Pre­ structions of fossil communities from the diverse Pyrenean Trench. This trench extended eastward from Paleogene sedimentary facies of the Aquitaine and the Atlantic as far as the Corbieres in the late Paris basins provide useful models for paleoecological to early Eocene but retreated westward to the vicinity of studies of related environments in Mississippi's Eocene Ossun (between Pau and ) in the late ear1y and Oligocene sequence. Eocene. North to south barriers associated with diapiric

MISSISSIPPI GEOLOGY 4 MOULIN de CARREAU • • Mt. de MARSAN

• • MINEUR • oAX

• GAAS PEYRERE •

• PAU

• GAN

Figure 1. Tertiary localities in the Aquitaine Basin, southwestern France. salt movements {Pomerol, 1973) divided this trench coastal environments before their deposition at Acot. into a series of steps that hindered the transport of Shells having an ivory color comprise the fossil com­ detritus toward the Altantic. The Acot locality marks munity; however, only those fossils associated with the transition from the {represented articulated valves of the dominant bivalve Saturnia are by the 'Tuilerie" locality) to the deep axial zone. considered to be in situ. This community contains: Analyses of biofacies in the area of Gan {near Pau) are 1. Deposit feeders including the bivalves Nucula complex because of the gradual ecological transition {s.l.), Nucula (Lamellinucula}, Saturnia, Port­ of taxa between the fossil communities represented in landia, and Lithoradia, the gastropods Callio­ the Acot and 'Tuilerie" outcrops. These outcrops have tropis, Argyropeza, Tibia {s.s.)?, and Tibia (ct. many genera in common. The occurrences of some of Sulcogladius), and small echinoids. these genera, though characteristic, are reported here 2. Suspension feeders including the bivalves for the first time. Propeamussium (Parvamussium), Limatula, and Bathyarca, and some rare brachiopods and soli­ Acot parish of Gan tary corals. 3. Scavengers and predators including the gastro­ The outcrop at Acot contains a three-meter exposure pods Bonnellitia, Turridae {20 small species), of a compact, dark gray, silty clay lithofacies having Olividae, Ringicula, Cy/ichna, with rare occur­ an unvarying composition. Fossils are disseminated rences of Semicassis, ct. Muricopsis, Cymati­ sparsely throughout the section and in irregularly idae, Mitridae, and others, the plentiful scapha­ dispersed small pockets occurring fromonetooneand pods Dentalium (Compressidens), Cadulus one half meters above the base. Color seems to provide {s.s.), Cadu/us (Gadila), Entalina, and the a convenient clue as to the origin of fossils at Acot. carnivorous bivalves Cuspidaria, Verticordia, Fossils having a gray to black color include "Nipadites" and ct. Haliris. Also included in the Acot paleo­ {palm tree fruit) and many Archeogastropoda indicative community are rare occurrences of parasitic of rocky shores. These fossils were transported from gastropods.

5 JUNE 1985 The autecologic data known for the previously men­ malacophageous fish and/or cephalopods on the tioned genera agree with lithologic indications in gastropod Gisortia gigantea as cited by Dolin and placing the Acot fossil assemblage in the terrigenous Dolin (1 983). A specimen of the latter species is mud-shelf communities group of Peres (1 982). The illustrated in Plate 1. marine sediment associated with this fa unal group is The "Tuilerie" section contains a succession of fossil composed of silt and clay with rare admixtures of sand. assemblages that correspond to changing lithofacies Upon deposition. this sediment produces a relatively and indicate a regular decrease in water depth. Col­ mobile (fluid) mud. Because of the high sedimentation lectively the distribution of the successive communities· rate and very so f1 substrate consistency. hard bodies characteristic species according to feeding habits is as tend to be quickly buried (Peres. 1982). Consequently. follows. sessile species are largely absent. 1. Deposit feeders include the abundant gastro­ In spite of a stratig raphic gap. the Acot fauna closely pods Sigmesalia and and the more resembles that of the St.-Etienne d'Orthe upper Oligo­ uncommon gastropods Chedevi/lia. Diento­ cene fossil assemblage. These two assemblages show mochilus (Ectinochilus). and several allied many strikingly similar or substitutive genera and even genera or subgenera, Xenophora (many species), species. The St.-Etienne d'Orthe (and consequently and the bivalve Nipponulimopsis (or Gratis). Acot) fossil assemblage resembles the Hungarian 2. Suspension feeders other than those previous Egerian Hinia-Cadulus communities of Baldi (1973). cited include the epibiontic bivalves Chlamys, The fossil communities of Baldi (1973) agree with living Spondylus, Plicatula. and Oimya deshayesi, and communities described by Hartman (1963) from the endobiontic bivalves Pilar (Calpitaria), submarine canyons off southern California. This Aphrodina. Petalocardia. Corbula (Caryocor­ agreement supports Baldi's communities as useful bula). and Tel/ina (Peronidia) . According to models for paleoecological interpretations. Both living Baldi (1973). these bivalves indicate a slow rate and fossil communities indicate that the Acot fauna of sedimentation in calm. oxygenated water. developed along the unlighted deep circalittoral zone The sedimentation rate was sufficiently slow to of the Aturian Sea and probably penetrated the top of allow the settlement of a diversity of sessile the bathyal zone. Autecologic data on Argyropeza suspension feeders including the worm Serpula, (Houbrick. 1980) place the bathymetric range of this the gastropod Vermetus, the stalked crinoid fauna at 150 to 300 meters. Conocrinus, the bryozoan Lunulites, and the solitary corals Odoncyatus and ct. Trochocyatus. The "Tui lerie" parish of Gan 3. Scavengers and/or predators include the gastro­ pods Globulariidae, Hexaplex. Pterynotus. The west slope of the classical "Tuilerie" outcrop. Typhis (Siphonochelus). Cymatiidae, Fasciolari­ near Gan's railway station. exposed only a part of the idae. Olividae. Fusimitra, Volutidae. Hemiconus. 16-meter section cited by Dolin and Dolin (1983). This Turridae. and Pyramidellidae. ar1d the scapha­ section contained large foraminifers and consisted of: pods Dentalium (ct. Rhabdus) and Entalina. (1) a basal silty clay with a splintery breakage, (2) a Some parasitic gastropods are also present. middle dark and blue-gray silty clay with conchoidal Other less frequent gastropods include several breakage, and (3) an upper yellowish-brown silty clay. species of Ovulidae (Dolin and Dolin, 1983), a These strata contain a thanatocoenosis comprised of family which is presently a symbiot of the allochthonous elements of heterogenous origins and alcyonarian and gorgonian corals, the echinoid autochthonous elements of the fossil community. predators Cassidaria and Semicassis. the Notable proofs of an indigenous origin within the fossil fragile Tudicla. and the curious Austropharpa? community include the suspension-feeding endobion­ (Pseudoscapha} . Least in abundance are the tic annelids (in situ) of the "Oiptrupa" subgranulosa larger gastropods Amaurellina (Pachycrom­ group (20 em to 30 em in length). the presence of all mium). Tibia (Ampogladius). Vicetia. Clavilithes. ontogenic development stages of the gastropods, and others. Ttiese mollusks by their biomass articulated shells of the epibiontic bivalves Chlamys indicate the high productivity of the biotope. rouaulti. Spondylus ogormani. Spondylus paucispinosus The high population density and specific diversity of (as figured by Cossmann. 1923, pl. 2. fig. 25). and the pteropods at "Tuilerie" suggest the long term presence endobiontic bivalves Pinna pyrenaica (ibid .. text figs. 2- of vertical currents (upwellings) rich in nutrients (fide 4). Cardium ( Trachycardium) gigas (ibid .. text fig. 1). Baldi, 1973). These currents are important to benthic as Crassatella ogormani (ibid .. pl. 2. fig. 5) . the articulated well as planktic organisms. crabs. and corroborating evidence of predation such as "Tuilerie" fossil assemblages are related to the silty

MISSISSIPPI GEOLOGY 6 Plate 1. Apical (A) and apertural (B) views of Gisortia gigantea (Munster, 1828) from "Tuilerie", Gan, France. Length 177.4 mm, width 107.4 mm. Apical view shows breakage due to fish or cephalopod predation.

7 JUNE 1985 or muddy detrital sand assemblage group of Peres (middle Eocene) of California. Also. the Triviacea­ (1982). Of the many fossil assemblages that might be Cypraeacea of the "Tuilerie" malacofauna are more included in this assemblage group (over 100, fide Peres, evolutionarily advanced and strictly different from 1982), the "Tuilerie" assemblages seem to have the those of the Cuisian s.s. of the (NP 12. fide closest relationship with the Alveinus-Corbula and Aubry, 1983). This fauna is more closely related to the Nucula-Hipponix-solitary coral assemblages of Elder and early fauna of San Giovanni llarione, Italy, and Hansen (1981) from the Moodys Branch Formation Chaumont-en-Vexln (NP 14 fide Aubry, 1983) and (upper Eocene) in Mississippi and Louisiana. The Parnes, France. Moodys Branch fauna, as described in part by Dockery (1977, 1980) and paleoecologically reviewed by OLIGOCENE OF : Shiebout et al. (1982). shows many convergences with PALEOCLIMATIC SETTING the "Tuilerie" fauna at the generic level (i.e. Fusimitra). The "Tuilerie" fossil assemblages also display affinities The European Oligocene is divided into two stages: with deeper infralittoral and circalittoral communities the Stampian (= upperTongrian and ) and the and particularly with the Pitar beyrichi and Flabellipec­ upper Oligocene ( ). Cavelier (1979) placed the ten-Odoncyathus communities of Baldi (1973), which Eocene-Oligocene boundary between P 17 and P 18 lived in depths ranging from 30 to 120 meters. and between NP 21 and NP 22 at the base of the Stalked crinoids, which presently live in deep water Stampian. According to Cavalier and Pomerol (1976) environments. permit reliable estimates for bathymetric and Pomerol (1978), the lower Oligocene or Stamplan ranges of respective paleobiotopes. Roux and Plaziat is P 18 toP 20/ N 1 and NP 22- NP 23, and the upper (1978) discussed and gave an "actualistic" interpre­ Oligocene or Chattian (s.l.) is P 20/N 1 toP 22/N 3 and tation of stalked crinoids from some lower NP 24 to NP 25. Pyrenean outcrops without including Acot and Paleontologists have recognized for many years the "Tuilerie". The "Tuilerie" locality contains a significant existence of two provinces in the Tertiary of Europe: number of columnar pieces of Conocrinus species. a "northern" or "boreal" province and a "mesogean" indicating a calm neritic platform environment ranging or "Mediterranean" province. Hall (1964) demonstrated between 100 and 150 meters in depth (fide Roux and the present-day relationship of molluscan provinces Plaziat). However, Roux and Montenat (1977) observed and shallow water marine climates. This work provides that Conocrinus and related crinoids have the propen­ a basis for analyzing European Oligocene molluscan sity In active tectonic zones (such as was the case for faunas to distinguish marine climate zones during this the "Tuilerie" deposits, which were contemporaneous period. Thus, in the lower Oligocene of the Aquitaine with the rising of the ) to inhabit shallower Basin (along with other basins in Italy, Yugoslavia, waters. The stalked crinoid Conocrinus at "Tuilerie" Rumania, and Armenia) there are very rich mesogean was probably at the uppermost limit of its range in a faunas (Gaveller, 1979) containing Turbo (including tectonic zone. various subgenera), Cerithium ( Gourmya), Campanile, Cypraeidae, Globularia, Strombus, Oostrombus, Cy­ of the Acot and 'Tuilerie" Outcrops mathium, Cassis, Melongena, Harpa, Vasum , Chlamys arcuatus, Crassatella, Discors, Nemocardium, and The "Cuisian" of Gan consists of a 800-meter thick others. This fauna Is Identical with the Indian Oligocene sequence of sandy or silty clays that are nonfossilifer­ fauna described by Vredenburg (1925, 1928) and char­ ous in the greater part. Schaub (1981) in a study of acterizes the inner tropical zone. During the same benthic foraminifers placed the entire section in the period, most of these genera are unknown or very rare planulatus or Alveolina oblonga zone in the Paris Basin and Mainz Basin (Germany) and (P 8) of the lower Cuisian (upper ) and placed are totally unknown in the Belgian Basin, which the Acot outcrop as older than that at "Tuilerie". Siesser represents the fauna of the North Sea Basin. and Dockery (1985) placed samples from "Tuilerie" as The molluscan faunas of the Paris and Mainz basins NP 14 (= P 9 in part) based on the occurrence of are indicative of the outer tropical zone. while the Rhabdosphaera inflata. This placement gives a younger fauna of the lower Rupelian of Belgium (Sables de age (later upper Ypresian to lower Lutetlan) than that Berg) indicates a warm temperate climate. The assigned by Schaub and classical European authors, presence of many genera in the lower Oligocene and confirms the writers' conclusions derived from a (Stampian) of the Paris Basin such as Jujubinus, study of the Ovulidae (Dolin and Dolin, 1983). In this Omalogyra, Rissoa. Bittium, Potamides. Aporrhais. study, some of the "Tuilerie" Ovulidae were found to be Glycymeris, Corbula (Varicorbula). and Lentidium. conspecific with species from the Meganos Formation which are very common in the Lusitanian (Mediter-

MISSISSIPPI GEOLOGY 8 ranean) Province, along with paleosynecologic analysis littoral environment. Laterally at Espibos, they grade (Gitton et al., in press) indicate that the modern into a blue with pieces of lignitized and a Mediterranean Province began in the early Oligocene. brackish water fauna. The upper Oligocene (Chattian) mollusks of the Overlying the branched coral at Lagouarde is North Sea Basin as revised by Janssen (1978, 1979) and the famous Oostrombus auriculatus layer, which yields of the Paratethys (Central Europe, Egerian) contain the major part of fossils from Gaas. The thickness of certain tropical genera such as Orbitestella, Protoma, this layer is 70 em at Lagouarde and 40 em at Espibos. Ficus, Morum, Lyria, Oliva, Perrona, and others, which It is a sandy, yellowish or steel-blue marl containing are indicative of the outer tropical zone. At the same many worn. current-rolled shells. This layer contains period typical Oligocene tropical species appear in the an accumulation of mollusks, bryozoans, and corals upper Egerian of Hungary (upper Oligocene according from different biocoenoses indicating current transport. to Baldi, 1973) including Trisidos schafarzcki, Cras­ However, the most common forms are well preserved satella carcarensis, Globularia ( Cernina) compressa, and were derived from coral environments near the Tibia dentata, Tibia neuvillei, Melongena basilica, shoreline. Euthriofusus burdigalensis, and Athleta rarispina. The The uppermost unit contains an abundance of the distribution of these taxa shows a broad expansion foraminifer Nummulites intermedius. At Lagouarde, of the tropical mesogean (Mediterranean) province this unit consists of sandy marls, which are locally before the close of the Oligocene Epoch. This ex­ indurated. These marls grade into sandy pansion is a precursor to an extension of the province at Espibos. into the Paratethys domain in the Epoch. The molluscan assemblage of the Gaas strata is The previously mentioned Tertiary climatic zones of typical of the lower Oligocene (Stampian) with Europe are supported by several lines of biological characteristic species associated with the tropical evidence. Data provided by reef corals indicate that the European mesogean province including Oostrombus northern limit at which coral reefs were prolific during auriculatus, Strombus radix, Ampullinopsis crassatina, the lower Oligocene (Cavelier, 1979) and probably also and Campanile charpentieri. A small part of the Gaas during the upper Oligocene was approximately at the fauna invaded the Paris Basin in the upper Stampian present day 45° N latitude (north of the Aquitaine (Sables of Pierrefitte). It is possible that the tropical Basin). This limit is almost identical with the northern fauna of Gaas corresponds to the "hot phase" of the limit of the molluscan inner tropical zone. upper Stampian of the Paris Basin. In a study of the Hammatocythere, Ducasse and Rousselle (1979) Lower Oligocene (Stampian) of Adour Basin distinguished four ostracod biozones in the Stampian of the Aqu itaine Basin. The Gaas strata at Lagouarde The world-famous Gaas marls are well known for and Espibos are situated in the uppermost biozone. their abundant and excellently preserved marine fauna. As a matter of fact, this faunal assemblage is the richest Upper Oligocene (Chattian) of the Adour Basin and best preserved assemblage of the European mesogean lower Oligocene. Several studies have been The lower - upper Oligocene boundary coincides made on the Gaas fauna including the benthic foramin­ reasonably well with an important lowstand in the ifers (Poignant, 1967), corals (Chevalier, 1956), and eustatic sea-level curve of Vail et al. (1977). In France, mollusks (Verg neau-Saubade, 1967). the upper Stamp ian was a period of regression with the At the Lagouarde locality, the series begins with sea retreating from the Paris and Armorican basins and marls that contain the branched corals Stylophora, from the northern part of the Aquitaine Basin. In the Acropora, Dictyarea, and others. some small coral Adour Basin (southern part of the Aquitaine Basin), patches, and various mollusks including the bivalves Kiener (1 973) recognized an important erosional phase Lima, Corbula (Caryocorbula), and Cardium, and the during the Stampian in which the Paleo­ gastropods Lucapinella, Co/Ionia, Homalopoma, Orbit­ canyon was downcut. This paleocanyon was invaded estella, Deshayesia, and Bullidae. Intercalated wi~h the by the sea in the late Oligocene due to both coral-rich marls are beds containing abundant gastro­ and eustatic sea-level rise and contains the only marine pods of the family Globulariidae including Ampullinop­ upper Oligocene deposits known in France. Presently sis crassatina, Crommium angustatum, and Deshayesia the Saubrigues Paleocanyon is filled with a few hundred parisiensis. The species Lucapinella clypeata of the meters of upper Oligocene and lower Miocene subfamily Diodoriinae is also present. These sediments, (, Burdigalian) sediments. The remains of which probably reach a thickness of about 10 meters, this canyon form the present day "le Gout de Capbre­ were deposited in very tranquil conditions within the ton" (Capbreton Canyon, Gascogna Gulf).

9 JUNE1985 The discovery of upper Oligocene marine strata Outcrops in the parish of Saint-Paul-les-Dax contain within the Saubrigues Paleocanyon is attributed to fringe reef coral facies, which are 2 to 3 meters thick at Raulin (1890). The position of the "Faluns bleus" of Abbesses and only 20 centimeters thick at Estoti. The Raulin (blue shelly marls) has been a subject of dis­ molluscan assemblages also differ between these two cussion for many years. These deposits begin with the localities in that they are not exactly contemporaneous sandy marls of La Peyrere near , which but close together. At Estoti the basal section consists contain the beautiful lepidocycllnlds (Cahuzac, 1980) of sandy with reef corals and a molluscan Miogypsinoides ubaghsi and Miogypsinoides com­ fauna of Tibia dentata, Cassis aquensis, Keepingia planatus, 30 species of corals (Chevalier, 1963), and praecedens (all three species are unknown at Abbesses), about 400 species of mollusks. According to Chevalier. an abundance of the family Eulimidae (parasitic on this community lived in the sublittoral zone between 50 holothurians), species of Alvania and Cerithiopsidae meters and 100 meters in depth and corresponds to the (which live in association with sponges), and well muddy detrital assemblage of Peres (1982). Strata of preserved specimens of Patella n. sp. (unknown at the same age near La Peyrere (Tauziede and Haulon) Abbesses) and Siphonaria (which indicate the proximity have yielded planktic foraminifers and calcareous of the mediolittoral zone). This coral facies is overlain nannoplankton of the N 3 - N 4 (part) Zone and NP 25 by a sandy limestone that is locally indurated and Zone. contains small abraded (rolled) fossils including Farther west, the blue-gray marls of St.-Etienne fragments of Donax. The thanatocoenosis of this facies d'Orthe are also upper Oligocene in age but are indicates sedimentation on the lower beach environ­ younger than the La Peyrere deposits. These marls were ment. deposited probably in a bathyal environmant on the The basal strata at Abbesses contain two easily upper part of the continental slope and contain a distinguishable coral horizons that vary laterally. In fossil community similar to the Hungarian upper the first horizon, the corals are in situ and constitute Oligocene (Egerian) Hinia-Cadulus community of coral patches. Lateral spaces between the coral patches Baldi (1973). Mollusks of the St.-Etienne d'Orthe contain a fauna dominated by benthic foraminifers but community consist of suspension feeders Corbu/a also containing the browsing gastropodsA/aba, Tricolia, (Varicorbula), predators of the families Volutidae. and Rissoina (genera that are rare or unknown at Turridae. Ringiculidae, and Dentaliidae, scavengers Estoti), and a small species of the sessile bivalve Pteria. Hlnia, deposit-feeders Nuculidae, Tibia neuvillei and This assemblage indicates the presence of a well the characteristic endemic aporrhaid species Triacon­ developed flora of metaphytes. In the second coral tium mirandus, and the parasitic family Pyramidellidae. horizon, many fossils are abraded (rolled), and the Other mollusks include the deep-water archeogastro­ positions of corals and bivalves (convex face up) and pod family Seguenziidae, the Rissoidae species the presence of pebbles indicate a different hydrody­ Profundialvania peyreirensis, and the epibiontic bivalve namic regime of moderate to high energy. Amussium (Propeamussium) duodecimlamellatum. Overlying the second coral horizon is a sandy lime­ Fossiliferous marine upper Oligocene strata in the stone devoid of corals. This bed was deposited in more coastal region of the Adour Basin occur at Escornebeou, tranquil conditions than that of the previous environ­ Saint-Paul-les-Dax (Abbesses and Estoti localities), ments and contains bivalves with both valves present. and Pontonx (Mineur locality). The St.-Geours de Weathering of this bed below its overburden Maremne (Escornebeou) locality is a series of old marl has leached much of its fossil content. On the whole, pits 15 kilometers southwest of Dax. The mollusks of the molluscan assemblage of Abbesses is characterized this locality are known only by the Pectinidae, which by: Alaba, Tricolia, Rissoina (several subgenera), Erato, Dollfus ( 1917) concluded were of upper Oligocene age. Globularia (Cernina), Athleta rarispina, and Melongena A study of the calcareous nannoplankton by Muller (in basilica. These mollusks are rare or unknown at Estoti. G.F.R. N., 1974) placed the Escornebeou deposits in According to Saubade and Cahuzac (1978), the the Spherolithus ciperoensis Zone (NP 25). The mollusks of Abbesses-Estoti indicate an upper Oligo­ biotope at Escornebeou was characterized by poorly cene age. Mollusks of this fauna that are typical of the oxygenated water above a muddy substrate. upper Oligocene of the European mesogean province Upper Oligocene fossils in the vicinity of Dax were include Trisidos (upper Oligocene in Italy and Hungary), first studied by Grateloup in 1820. In 1847, Grateloup Globularia (Cernina) compressa, Sphaerocypraea published his monograph "Conchyliologie fossile des oligovata, Melongena basilica, and Volutilithes subele­ terrains tertiaires du bassin de I'Adour," which included gans. The Me/ongena lineage is a good example of 48 plates of gastropods. morphological evolution during the upper Oligocene

MISSISSIPPI GEOLOGY 10 and lower Miocene in western Europe and probably specimens of the typical mediolittoral-supralittoral also in eastern America where similar species are tropical genus Tectarius. The disappearance of known: pebbles in the marls above the Strom bus sublatissimus Molluscan species which are otherwise regarded by bed indicates a change to more tranquil conditions. the writers as typically Miocene also occur at Estoti A preliminary comparison of the Pontonx (Mineur) and Abbesses, including Ficus burdigafensis, Trona and Estoti-Abbesses faunas shows that Miocene feporina, Tibia dentata, Homafocantha pauli, "Tudicla" species are less important at Pontonx while typical rusticufa, Euthriofusus burdigalensis, and Subufa Stampian species such as Ampullinopsis crassatina plicaria. Likewise some typical lower Oligocene increase. These data agree with a study of Miogypsi­ (Stampian) taxa are present including Rhinoc/avis noides by Cahuzac (1980) that placed the Pontonx strata submelanoides, Ataxocerithium pellati, Globularia. as upper Oligocene but slightly older than at Estoti­ and Keepingia. The Abbesses-Estoti molluscan fauna Abbesses. Muller and Pujol (1979) studied the planktic contains a notably larger number of Miocene forms than foraminifers and calcareous nannoplankton at Pontonx do other upper Oligocene strata in the Adour Basin. in strata below that discussed in this paper and placed Therefore it probably represents the upper part of the the strata (sample GA 29777) as NP 25. Adour Basin upper Oligocene. The same results were deduced from a study of Miogypsinoides by Drooger Lower Miocene of the Ad our Basin (Moulin de Carreau) and Freudenthal (1964) . According to Cahuzac (1980), It may be concluded that the strata of Abbesses-Estoti The lower part of the outcrop at Moulin de Carreau is correspond to the upper part of the Globigerina a limestone that contains a fresh water fauna with some ciperoensis Zone and the lower part of the N 4 Zone brackish water influence. Above and lateral to this lime­ (after the time scale of Hardenbol and Berggren, 1978, stone is a 2-meter thick succession of steel blue marls p. 218). The age of this sequence according to the time with thin layers of limestone. The most abundant scale of Pomerol (1978) can be estimated at 22-24 MA. species in this interval are the gastropods Tympano­ At Pontonx (Mineur) the paleoecological succession tonos tournoueri and Granu/olabium pficatum. Living in the upper part of the sequence can be briefly sum­ representatives of these taxa are quite common in marized as follows. The base of the outcrop is a sandy, and mud-flats at the mediolittoral position in gray to yellow marl with fossiliferous lenses. This unit West (Tympanotonos) and Australia (Granufo­ contains the bivalves Lucinidae, Donax, and Lentidium fabium). Thus these marls were probably deposited in a n. sp. along with other shells, often abraded (rolled), shallow with a maximum depth of 1 meter. from different biotopes including Nerita and the family Overlying these sediments is a 10-meter thick sequence Auriculidae. This assemblage corresponds to the of very fossiliferous (shelly), coarse sand with cross­ present-day biocoenosis of the upper clean sand bedding and shell lenses that indicate the presence of assemblages of Peres (1982), which may be observed tidal currents. The rich fauna of this sequence is indica­ on the lower beaches of shores worldwide. Overlying tive of the lower beach environment in a tropical sea the first bed at an interval from 40 em to 50 em from and includes bivalves of the families Mactridae, the base of the outcrop is a black clay containing Arcidae, Ludinidae, Veneridae, and others, the numerous lsognomon, , Teredo tubes, Calyptraea, gastropod families Trochidae, Rissoidae, Cerithiidae, Terebralia, and many pieces of lignitized wood, some Naticidae, Cypraeidae, Muricidae, Melongeniidae, and of which have barnacles attached. These fossils sug­ others, and fragments of corals. This fauna is followed gest the presence of mangrove swamps. Above this by a reinstatement of lagoonal communities (marls clay are sandy blue marls with a progressive develop­ with Mefongena faine1). ment of pebbles upward within the unit. This Formerly thought to be lower Miocene (Aquitanian), unit indicates the formation of a lagoon and a return to a study of Miogypsinoides at Moulin de Carreau by a moderate to high energy flow regime. Principal Drooger (1958) indicated a lower Burdigalian age. mollusks of this unit include the brackish water species Nevertheless, molluscan data (Degrange-Touzin, 1912) Ampuflinopsis crassatina and Neritina picta, the rocky­ suggest that this fauna is slightly older than the classic substrate species Tectarius elegans (mediolittoral), Burdigalian of the northern Aquitaine Basin. Odin Anomia, and Thericium calculosum. The top of this (1982, p. 703) dated the Aquitanian-Burdigalian horizon contains a 25 em thick Strombus (Tricornis) boundary at in the southern part of the sublatissimus bed rich in pebbles and coral fragments Aquitaine Basin at 20.5 ± 1 MA. The biostratigraphic and also containing the mollusks Hipponyx, Astraea, position of the glauc.:>nite sample dated by Odin is Tectarius, Nassarius and others. The proximity of the probably situated at about the same level as the Moulin shore line is indicated by abundant and well preserved de Carreau strata.

11 JUNE 1985 Stampian (lower Oligocene) of the Paris Basin (Morigny) , v. 90, p. 375-410. Chevalier, J.P., 1963, Les madreporairesdei'Aquitanien The Morigny-Jeurre Formation (7 meters in thick­ inferieur de Peyrere pres Peyrehorade (): ness) comprises the upper part of the lower Stampian Ann. A.R.E.R.S .. I. fasc. 2, p. 3-15. (NP 23, Aubry, 1983) in the Paris Basin. In the basal Cossmann, M., in O'Gorman, G., and Cossmann, M., part, the sands of Morigny are characterized by an 1923, Le gisement Cuisien de Gan (Basses abundance of the bivalve Glycymeris obovata. This Pyrenees), Pau: XXVII + 188 p .. 5 fig., 12 pl., 1 tabl. Glycymeris layer predominantly contains suspension Degrange-Tauzin, A. . 1912, Contribution a l'etude de feeding bivalves including Glycymeris obovata, Laevi­ I'Aquitanien dans Ia vallee de Ia Douze (Landes): cardium tenuisulcatum, and Parvicardium scobinulum. Act. Soc. Linn. , v. 66, p. 5-39. but also contains gastropods including the suspension Dockery, D.T .. Ill, 1977, MolluscaoftheMoodysBranch feeders Calyptraea striatella, the predators Polinices Formation. Mississippi: Mississippi Geological and Typhis, and the scavenger Keepingia gossardi. Survey, Bull. 120. 212 p., 28 pl. This community corresponds exactly with the infralit­ Dockery, D.T., Ill, 1980, The invertebrate macropaleon­ toral climax biocoenosis of the fine well-sorted sand tology of the Clarke County, Mississippi, area: assemblage (Gitton et al., in press). These assemblages Mississippi Bureau of Geology, Bull. 122, 387 p., live below the lower li mit of the upper clean sands 82 pl. assemblage to a depth of about 20 meters on hard, Dolin, C., and Dolin, L., 1983, Revision des Triviacea et terrigenous. well-sorted. fine sand (Peres, 1982, p. Cypraeacea (. Prosobranchiata) 434). recoltes dans les localites de Gan (Tuilerie et The Glycymeris-layer community passes upward Acot) et Bosdarros (Pyrenees Atlantiques, into an assemblage containing the bivalve Divaricella France): Meded. Werkgr. Tert. Kwart. Geol.. (Paralucinella) and the crustacean Callianassa. This (Leiden). v. 20 (1 ), p. 5-48, 31 fig. same community presently lives in the upper infralit­ Dollfus. G.F.. 1917, L'Oiigocene superieur marin dans toral to mediolittoral zone, thus indicating a retreat of le bassin de I'Adour: Bull. Soc. Geol. France, v. 4, the lower Stampian Sea. Disconformably overlying the no. 17, p. 89-102. Morigny-Jeurre Formation is the Vauroux-Saint­ Drooger, C.W., 1958, Foraminiferes importants pour Antoine Formation of the upper Stampian. According les subdivisions et limites du Miocene inferieur et to the time scale of Curry and Odin (1982, p. 629, in moyen: C.r. Congr. Soc. Sav. Paris et Dep., Odin. ed.), the age of the Morigny-Jeurre Formation Colloque Miocene, Paris (Gauthiers-Villars). can be estimated at 32 MA. p. 171-179. Drooger, C.W. , and Freudenthal, T. , 1964, Associations REFERENCES CITED of Miogypsina and Lepidocyclina at some Euro­ pean localities: Eclogae Geologicae Helvetiae, v. Aubry. M.P., 1983, Biostratigraphie du Paleogene 57, p. 509-528. epicontinental de !'Europe du Nord-Ouest: Etude Ducasse, 0 .. and Rousselle, L., 1979, Les Hammatocy­ fondee sur les nannofossiles calcaires: Docum. there (Ostracodes) de !'Oligocene Aquitain: Bull. Lab. de Geol. Lyon, no. 89, 317 p. 38 fig., 7 tabl., lnst. Geol. Bassin d'Aquitaine (Bordeaux), v. 25, 8 pl. p. 221-255. Baldi, T.. 1973, Mollusc fauna of the Hungarian Upper Elder, S.R., and Hansen, T.A., 1981, Macrofossil as­ Oligocene/Egerian: Budapest (Akademiai Kiado). semblages of the Moodys Branch Formation 511 p., 55 fig. , 51 pl. (upper Eocene), Louisiana and Mississippi: Cahuzac, B., 1980, L'Oiigo-Miocene de Ia region de Mississippi Geology, v. 2, no. 1, p. 6-11 . Dax (Landes, France): Unpublished thesis. Gitton, J.L., Lozouet, P., and Maestrati, P., (in press), Bordeaux, 602 p., 79 fig., 17 pl. Analyse biostratigraphique et paleoecologique Cavelier, C., 1979, La limite Eocene/Oligocene en des gisements types du Stampien de Ia region Europe Occidentale: Mem. Sciences Geol. Stras­ d'Etampes: Geologie de Ia France, B.R.G.M. bourg, no. 54, 280 p. G.F.R.N .. 1974, Etude biostratigraphique des gisements Cavalier, C .. and Pomerol, C .. 1976, Proposition d'une d'Escornebeou: Docum. Labor. Geol. Fac. Sc. echelle stratigraphique standard pour le Paleo­ Lyon. v. 59, 86 p., 33 pl. gene: Newsletters on Stratigraphy, v. 6, no. 1. Grateloup, S., 1847, Conchyliologie fossile des terrains p. 56-66. tertiaires du bassin de I'Adour: Bordeaux, Atlas, Chevalier, J.P., 1956, Les polypiers Anthozoaires du 48 pl. Stampien de Gaas (Landes): Bull. Soc. Hist. Nat. Hall, C.A., 1964. Shallow water marine climates and

MISSISSIPPI GEOLOGY 12 molluscan provinces: Ecology, v. 45, no. 2, p. v. 3. no. 19, p. 8-13. 226-233. Roux, M., and Montenat, C., 1977, Site a cnnoides Hardenbol, J., and Berggren, W.A., 1978, A new Paleo­ pedoncules et bathymetrie des bassins messiniens gene numerical time scale: Amer. Assoc. Pet. dans les cordlllieres betiques orientales (Espagne Geol., Studies In Geology, no. 6, p. 213-234. meridionale): Bull. Soc. Geol. France, 7, v. 19, no.2. Hartman, 0 ., 1963, Submarine canyons of Southern p. 405-416. California. Part II, Biology, Allan Hancock Pac. Roux, M., and Plaziat, J.C., 1978, lnventaire des Exp., 27: Unlv. Southern California Press, Los crinoides et Interpretation paleobathymetrlque de Angeles, 424 p. gisements du Paleogene pyreneen franco­ Houbrlck, R.S., 1980, Review of the deep-sea genus espagnol: Bull. Soc. Geol. France, 7, v. 20, no. 3, Argyropeza (: Prosobranchia: Ceri­ p. 299-308. thiidae): Smithsonian Contributions to Zoology. Saubade, A.M., and Cahuzac, B., 1978, Le g1sement v. 321 . 30 p . 12 fig. d'Estoti a Saint-Paul-les-Dax (Landes). Etude de Janssen, R., 1978, Die molluskan der Oberoligozans Ia malacofaune fossile: Bull. Soc. Borda (Dax), v. (Chattium) im Nordsee Becken: Arch. Moll., v. 103, p 103-118, 2 pl. 109 (1/3), p. 137-227, (4/6), p. 277-376. Schaub, H., 1981, Nummulites et Assilines de Ia Tethys Janssen, R., 1979, Revision de des Obero­ Paleogene, Taxlnomie, Phylogenese et Biostrati­ llgozans (Chattium, Kasseler Meeressand): Geol. graphie: Mem. Sulsses de Paleontol., v. 14, pt. I, Abh. Hessen., v. 78, 181 p. 72 p. Kiener, M .. 1973. Evolution de I'Aquitalne au cours du Schiebout, J A., and van den Bold, W .. principal investi­ Tertiaire: B.S.G.F. . 7, v. 15. no 1.. p. 4D-50. gators, 1982, Paleontological investigation in the Muller, C., and Pujol, C., 1979, Etudedu nannoplancton vicinity of Montgomery Landing, Red River calcaire et des foraminiferes planctoniques dans Waterway: Dept. of the Army, Corps of Engineers, I'Ollgocene et le Miocene en Aqultalne (France): New Orleans District, project no. DACW29-79- Geologie Mediterraneenne, v. 6, no 2, p. 357-368. C082, 431 p. Odin, G.S.. ed., 1982, Numerical dating in stratigraphy: Siesser, W.G., and Dockery. D.T .. Ill, 1985, Calcareous Wiley lnterscience Publ., John Wiley and Sons. nannoplankton biostratigraphy of selected Ter­ Chichester, New York, v. 2, 1040 p. tiary localities in the Paris, Adour, and Beam Peres, J.M., 1982, Major benthic assemblages, in basins of France and their correlation with the Marine Ecology, v. 5, part 1, Ocean Management, North American Gulf Coast Tertiary sequence: p. 373-522: John Wiley and Sons, New York. Mississippi Geology, v. 5, no. 3, p. 9-19. Poignant, A., 1967, L'OIIgo-Miocene d'Aquitalne Vail, P.R., Mitchum, A.M., and Thompson. S., 1977, meridionale: Unpublished thesis, Paris, 385 p. Seismic stratigraphy and global changes of sea Pomerol. C., 1973. Ere Cenozoique, Stratigraphie et level, Part 4: Global cycles of relative changes of Paleogeographie: Dom, Paris, 269 p. sea level, in Payton, C.E., ed., Seism1c stratigraphy­ Pomerol, C., 1978, Critical review of isotopic dates in applications to hydrocarbon exploration: Amer relation to Paleogene stratotypes: Amer. Assoc. Assoc. Pet. Gaol .• Memoir 26, p. 83-97. Pet. Geol., Studies in Geology, no 6, p. 235-245. Vergneau-Saubade, A.M., 1967, Les gisements de Pomerol, C., 1982, The Cenozoic Era. Tertiary and I'Oilgocene marin en Aquitaine: Bull. lnst. Gaol. Quaternary: Ellis Horwood Series In Geology, Bassin d'Aquitaine (Bordeaux), v 4, p. 196-210. John Wiley and Sons, New York, 272 p. (English Vredenburg, E.W , 1925, 1928, Description of Mollusca translation of Pomerol, 1973) from the post-Eocene Tertiary formations of Raulin, V., 1890, Sur quelques faluns bleus Ineon nus du North-Western India: Mem. Geol. Surv. India. departement des Landes: Bull. Soc. Geol. France, v. 50, pt. 1' p. 1-325, pt. 2, p. 351-462.

13 JUNE1985 molluscan provinces: Ecology, v. 45, no. 2, p. v. 3, no. 19, p. 8-1 3. 226-233. Roux, M., and Montenat, C., 1977, Site a crinoides Hardenbol, J., and Berggren, W.A. , 1978, A new Paleo­ pedoncules et bathymetrie des bassins messiniens gene numerical time scale: Amer. Assoc. Pet. dansles cordillieres betiques orientales (Espagne Geol., Studies In Geology, no. 6, p. 213-234. meridionale): Bull. Soc. Geol. France, 7, v. 19, no. 2, Hartman, 0 ., 1963, Submarine canyons of Southern p. 405-416. California. Part II , Biology, Allan Hancock Pac. Roux, M., and Plaziat, J.C., 1978, lnventaire des Exp., 27: Univ. Southern California Press, Los crinoides et interpretation paleobathymetrique de Angeles, 424 p. gisements du Paleogene pyreneen franco­ Houbrick, R.S., 1980, Review of the deep-sea genus espagnol: Bull. Soc. Geol. France, 7, v. 20, no. 3, Argyropeza (Gastropoda: Prosobranchia: Ceri­ p. 299-308. thiidae): Smithsonian Contributions to Zoology, Saubade, A.M., and Cahuzac, B., 1978, Le gisement v. 321 , 30 p., 12 fig. d'Estoti a Saint-Paul-les-Dax (Landes). Etude de Janssen, R., 1978, Die molluskan der Oberoligozans Ia malacofaune fossile: Bull. Soc. Borda (Dax), v. (Chattium) im Nordsee Becken: Arch. Moll .. v. 103, p. 103-118, 2 pl. 109 (1/3), p. 137-227, (4/6), p. 277-376. Schaub, H., 1981 , Nummulites et Assilines de Ia Tethys Janssen, R., 1979, Revision de Bivalvia des Obero­ Paleogene, Taxinomie, Phylogenese et Biostrati­ ligozans (Chattium, Kasseler Meeressand): Geol. graphie: Mem. Suisses de Paleontol., v. 14, pt. I, Abh. Hessen., v. 78, 181 p. 72 p. Kiener, M., 1973, Evolution de I'Aquitaine au cours du Schiebout, J.A., and van den Bold, W., principal investi­ Tertiaire: B.S.G.F., 7, v. 15, no. 1., p. ~50 . gators, 1982, Paleontological investigation in the Muller, C., and Pujol, C., 1979, Etudedu nannoplancton vicinity of Montgomery Landing, Red River calcaire et des foraminiferes planctoniques dans Waterway: Dept. of the Army, Corps of Engineers, !'Oligocene et le Miocene en Aquitaine (France): New Orleans District, project no. DACW29-79- Geologie Mediterraneenne, v. 6, no. 2, p. 357-368. C082, 431 p. Odin, G.S., ed., 1982, Numerical dating in stratigraphy: Siesser, W.G .. and Dockery, D.T., Ill, 1985, Calcareous Wiley lnterscience Publ., John Wiley and Sons, nannoplankton biostratigraphy of selected Ter­ Chichester, New York, v. 2, 1040 p. tiary localities in the Paris, Adour. and Bearn Peres, J.M., 1982, Major benthic assemblages, in basins of France and their correlation with the Marine Ecology, v. 5, part 1, Ocean Management, North American Gulf Coast Tertiary sequence: p. 373-522: John Wiley and Sons, New York. Mississippi Geology, v. 5, no. 3, p. 9-19. Poignant, A , 1967, L'Oiigo-Miocene d'Aquitaine Vail, P.R., Mitchum, A.M., and Thompson, S., 1977, meridionale: Unpublished thesis, Paris, 385 p. Seismic stratigraphy and global changes of sea Pomerol. C., 1973, Ere Cenozoique, Stratigraphie et level, Part 4: Global cycles of relative changes of Paleogeographie: Doin, Paris, 269 p. sea level, in Payton, C.E., ed., Seismic stratigraphy­ Pomerol, C., 1978, Critical review of Isotopic dates in applications to hydrocarbon exploration: Amer. relation to Paleogene stratotypes: Amer. Assoc. Assoc. Pet. Geol., Memoir 26, p. 83-97. Pet. Geol., Studies in Geology, no. 6, p. 235-245. Vergneau-Saubade, A.M., 1967, Les gisements de Pomerol, C., 1982, The Cenozoic Era. Tertiary and !'Oligocene marin en Aquitaine: Bull. lnst. Geol. Quaternary: Ellis Horwood Series in Geology, Bassin d'Aquitaine (Bordeaux), v. 4, p. 196-210. John Wiley and Sons, New York, 272 p. (English Vredenburg, E.W., 1925, 1928, Description of Mollusca translation of Pomerol, 1973). from the post-Eocene Tertiary formations of Raulin, V., 1890, Sur quelques faluns bleus inconnus du North-Westem India: Mem. Geol. Surv. India, departement des Landes: Bull. Soc. Geol. France, v. so. pt. 1, p. 1-325, pt. 2, p. 351-462.

13 JUNE 1985 NEW BUREAU OF GEOLOGY PUBLICATION:

MINERAL PRODUCERS DIRECTORY, 1985

The Bureau of Geology announces the publication Information Series 85-2 may be purchased from the of Information Series 85-2, "Mineral Producers Direc­ Bureau of Geology at 2525 North West Street for $1 .00 tory, 1985" by S. Cragin Knox. The publication is 20 per copy. Mail orders will be accepted when accom­ pages in length and contains 3 illustrations. panied by payment ($1 .00, plus $.90 postage and "Mineral Producers Directory, 1985" contains infor­ handling). Address mail orders to: mation on the major mineral producers in Mississippi, with emphasis placed on the clay, sand and gravel, and Bureau of Geology stone industries. Only those operators who actually P.O. Box 5348 mine for the purpose of sale are listed. Information on Jackson, MS 39216 oil and gas producers is not included.

NEW BUREAU OF GEOLOGY PUBLICATION

ELECTRICAL LOGS OF WATER WELLS AND TEST HOLES ON FI LE AT THE BUREAU OF GEOLOGY -SUPPLEMENT

The Bureau of Geology announces the publication recorded the log, location, log interval, and date is also of Information Series 85-3, "Electrical Logs of Water included in the tabulations. Wells and Test Holes on File at the Bureau of Geology­ Information Series 85-3 may be purchased from the Supplement," by James J. Sims, Jr. Bureau of Geology, 2525 North West Street, Jackson, The publication consists of 225 pages of which 208 Mississippi, for $5.00 per copy. Mail orders will be are locations and tabulations of electrical logs in accepted when accompanied by payment ($5.00, plus Mississippi that were recorded between January 1, $1 .25 postage and handling). Address mail orders to: 1979, and December 31 , 1984. The logs are located and tabulated by individual county and listed numeri­ Bureau of Geology cally and alphabetically by Bureau file number. Other P.O. Box 5348 pertinent information such as ownership, agency that Jackson, MS 39216

15 JUNE 1985 MISSISSIPPI GEOLOGY Department of Natural Resources Bureau of Geology Post Office Box 5348 Jackson, Mississippi 39216

Mississippi Geology is published quarterly in March, June, September, and December by the Mississippi Department of Natural Resources, Bureau of Geology. Contents include research articles pertaining to Mississippi geology, news items, reviews, and listings of recent geologic literature. Readers are urged to submit letters to the editor and research articles to be considered for publication; format specifications will be forwarded on request. For a free subscription or to submit an article, write to:

Editor, Mississippi Geology Bureau of Geology P. 0. Box 5348 Editors: Michael B. E. Bograd and David Dockery Jackson, Mississippi 39216