Annika Sanfilippo

Late Paleocene-Early Eocene sedimentary history in western Cuba: Implications for the LPTM and for regional tectonic history

The San Agustine and San Francisco de Paula sections constitute two complementary, albeit incomplete, records of late Paleocene-early Eocene history of western Cuba (Bahia Honda tectonic unit). The San Agustine section is of exceptional value because it is the only definitive known record of the Late Paleocene Thermal Maximum (LPTM) in the Caribbean. This extends the geographic distribution of the LPTM calcareous nannofossil assemblage from the western Indian Ocean to the Caribbean through the Tethys and North Atlantic Ocean. The fact that this assemblage has not yet been documented outside this area may reflect provincialism or, alternatively, broadly distributed unconformities. The San Francisco de Paula section, sampled with the hope that would constitute a suitable reference section for the Paleocene/Eocene boundary, yields a valuable record of successive latest Paleocene-earliest Eocene erosional events, that may reflect regional tectonic in the Caribbean or may be part of a global pattern of sedimentary history.

Radiolarians, diatoms, silicoflagellates and calcareous nannofossils in the Mediterranean Neogene

Radiolarian fauna described (one new genus, four new species), diatom, silicoflagellate and nannofossil assemblages related to radiolarians, zonations correlated, Miocene, Pliocene, Majorca, Italy

Upper Paleocene-Lower Eocene Radiolarian Biostratigraphy of the San Francisco de Paula Section, Western Cuba: Regional and Global Comparisons

In response to a growing need to define the Paleocene/Eocene boundary and record the events which immediately preceded and followed it within a 5 my span, the San Francisco de Paula section of western Cuba was evaluated for its potential as a boundary stratotype. Radiolarians, reported in previous studies by Cuban geologists as a major component of the faunal assemblages in this section, have been recollected and reanalyzed to determine their stratigraphic utility for recognition of the Paleocene/Eocene boundary in Cuba. On the basis of this and other recent microfossil studies of the San Francisco de Paula section, it is now known that the Paleocene/Eocene boundary in this succession is within an unconformity. Its placement herein is based on the highest occurrence of the planktonic foraminifera Morozovella velascoensis (Fernandez-Rodrguez et al. 1999, this volume). Radiolarians are present throughout the San Francisco de Paula succession with the exception of a barren interval in the middle of the section and two thin barren intervals near the top and the base. The most diverse radiolarian assemblages are from the shaley mudstones, which contain poorly preserved radiolarians that range from abundant to very rare. Other lithologies contain sparse, poorly preserved assemblages that appear strongly affected by dissolution. Thirty-five lowest and highest occurrences are noted within the section; however, because of poor preservation, several of these datums are higher or lower than expected when compared with the known global ranges of these species. The radiolarians from this study of the San Francisco de Paula section can be assigned to the stratigraphic interval from the upper Paleocene Bekoma campechensis to the lower Eocene Buryella clinata Zones. Species typical of the B. campechensis Zone include Bekoma campechensis, B. demissa, Bekoma spp., Buryella pentadica, B. tetradica, B. foremanae and Lamptonium pennatum. Faunas of the Bekoma bidartensis Zone contain Buryella tetradica, Giraffospyris lata, Phormocyrtis turgida, Podocyrtis (Podocyrtis) papalis, Pterocodon tenellus, Theocorys phyzella, Theocotyle nigriniae, Theocotylissa alpha, T auctor and Thyrsocyrtis (Thyrsocyrtis) hirsuta. The radiolarian assemblage representing the lower part of the Buryella clinata Zone is similar to that of the Bekoma bidartensis Zone, and also includes the marker species Buryella clinata. Assignment of the upper part of the San Francisco de Paula section to the Buryella clinata Zone is tentative, because of poor preservation. In the San Francisco de Paula section, the precise location of the Paleocene/Eocene boundary cannot be determined on the basis of radiolarians. However, taken together, radiolarian and calcareous nannofossil evidence indicate that the Paleocene/Eocene boundary is within an unconformity between samples SFP-22 and SFP-21 at the highest local occurrence of Morozovella velascoensis, equivalent o the top of planktonic foraminiferal Zone P5. In addition to tabulating the stratigraphic ranges of radiolarian species in western Cuba, this study presents a preliminary correlation between the lower Paleogene standard radiolarian low latitude zonation and other zonal schemes presented for the Caribbean region and mid to high latitudes. Although the San Francisco de Paula section does possess some of the characteristics desirable in a stratotype for the Paleocene/Eocene boundary, its usefulness in terms of biostratigraphy is limited. INTRODUCTION Programme Project #308 was initiated to study Paleocene/EoThe Paleocene/Eocene boundary interval is an interesting pecene boundary sections worldwide, including potential sections riod in Earth history, characterized by warm high latitudes previously documented in western Cuba (e.g., Bronnimann and (Stott and Kennett 1990; Kennett and Stott 1991) and changes Rigassi 1963). in oceanic circulation associated with deep water production at low latitudes (Miller et al. 1987; Kennett and Stott 1991; In contrast to calcareous microfossil groups for which a considThomas 1990a, 1990b, 1993). Consequently, definition of the erable amount of lower Paleogene biostratigraphic information Paleocene/Eocene boundary takes on increasing significance as is available from land-based sequences in the Caribbean region it becomes necessary to place these climatic and as well as from Deep Sea Drilling Project (DSDP)/Ocean paleoceanographic events in their correct chronological succesDrilling Program (ODP) cores, most biostratigraphic informasion. To meet this need. International Geological Correlation tion on Cenozoic radiolarians in the Caribbean region is from micropaleontology, volume 45, supplement 2, pp. 57-82, text-figures 1-3, plates 1-2, table 1, 1999 57 A. Sanfilippo and D.M. Hull: Upper Paleocene Lower Eocene radiolarian biostratigraphy of the San Francisco de Paula Section, western Cuba deep-sea drilling cores alone. Radiolarians from Cretaceous and lower Paleogene formations in western Cuba have been reported by Flores Albin (1983) and Flores Albin and Femaindez-Rodriguez (1985), and a small amount of additional information on Cenozoic radiolarians from Cuba, Barbados and Trinidad is summarized in Riedel and Sanfilippo (1971), and Sanfilippo and Riedel (1976). Maurrasse (1973, 1976, 1979) reported mainly on the paleoecologic and paleobiogeographic implications of radiolarian facies in Caribbean mid-Paleogene deep-sea sediments. DSDP Leg 4 collected useful Caribbean middle Eocene sequences with radiolarians at Site 29 (Riedel and Sanfilippo 1970). Leg 10 in the Gulf of Mexico sampled a similar sequence (Foreman 1973; Sanfilippo and Riedel 1973) and Leg 15 provided Caribbean equivalents of the sediment sequences in the Gulf of Mexico (Riedel and Sanfilippo 1973) which permitted correlation with calcareous microfossils. Subsequent DSDP/ODP Legs (76-78, 96, 100-102 and 110) in the Caribbean region recovered only younger than middle Eocene radiolarian-bearing sediments. Although more numerous Paleocene and lower Eocene samples have been obtained from different parts of the world ocean, the recovery is still intermittent and radiolarian preservation commonly not adequate for detailed biostratigraphic work (Sanfilippo and Nigrini 1998a). For these reasons it was anticipated that the discovery of a new land-based locality, south of the village of San Francisco de Paula in western Cuba (text-figure 1), would contain a suitable Paleocene/Eocene boundary section that would resolve at least some of the stratigraphic problems around the boundary and at the same time allow correlation between the calcareous and siliceous microfossil groups with the results from paleomagnetic and isotope investigations (M.-P. Aubry, person. communs., 1996, 1997; Femaindez-Rodriguez t al. 1999, this volume). LOCATION AND LITHOSTRATIGRAPHY The San Francisco de Paula section is located in western Cuba near the city of Habana (text-figure 1). It is 56m thick and consists of the Apolo Formation (Paleocene and lowermost Eocene) and the lower part of the overlying Capdevila Formation (also known locally as the Alcava Formation; lower Eocene, for further explanation see FemaJndez-Rodriguez et al. 1999, this volume). The lower 40m of the section (text-figure 2), which includes the Paleocene/Eocene boundary interval, is composed of marly mudstones and soft shales which are weathered and, in places, largely covered by vegetation. The base of the section is more massively bedded with coarser-grained rocks and conglomeratic limestones. Forty-three meters above the base of the San Francisco de Paula section, the rock sequence is marked by a distinctive lithologic boundary. The rocks above this boundary are much coarser-grained and are well indurated with distinctive graded bedding, suggesting storm or turbidite deposition. White marly clasts appear in linear bands just above the lithologic boundary. Fossils present in the San Francisco de Paula succession include planktonic and benthic foraminifera, large foraminifera, radiolarians, calcareous nannofossils, ostracodes, bryozoans, calcareous algae and mollusk fragments (Flores Albin and Fernandez-Rodriguez 1985; Fernmandez-Rodrfguez et al. 1999, this volume). Unfortunately, all fossil groups show varying degrees of preservation, and none occur continuously throughout the sequence. Fernmandez-Rodrfguez et al. (1999, this volume), in their analysis of the planktonic foraminifera, suggest the presence of four unconformities in the sequence. Recognition of these unconformities is based in part on abrupt changes in abundance, diversity, and preservation of the foraminiferal faunas. They relate these unconformities to the 58 to 54 Ma time span of active local tectonics which has been noted by other authors (Bralower and Ituralde-Vinent 1997; Lewis and Draper 1990). METHODS AND MATERIALS Initial discovery and collection of material from the San Francisco de Paula section was made by E. Flores Albin, G. Femrnandez-Rodriguez and other Cuban colleagues shortly after this section was cut along a new road. Consequently, the original samples are relatively unweathered. The Cuban geologists measured the section, collected samples, described lithofacies, and analyzed the material principally for foraminifera and radiolarians (Flores Albin, Appendix 1; Femrnandez-Rodriguez et al. 1999, this volume). In 1993, a group of scientists from the U.S., including A. Sanfilippo and D. Hull, joined the Cuban geologists to revisit the San Francisco de Paula section as well as other potential Paleocene/Eocene boundary sections in western Cuba on behalf of IGCP Project #308. The section was re-measured, described, and 54 samples were collected for studies of planktonic and benthonic foraminifera, radiolarians, and calcareous nannofossils; portions of these same samples were also set aside for carbon/oxygen isotope determinations. The selection of procedures used to measure and sample the section during the 199

An evaluated list of Cenozic-Recent radiolarian species names (Polycystinea), based on those used in the DSDP, ODP and IODP deep-sea drilling programs

A first reasonably comprehensive evaluated list of radiolarian names in current use is presented, covering Cenozoic fossil to Recent species of the primary fossilising subgroup Polycystinea. It is based on those species names that have appeared in the literature of the Deep Sea Drilling Project and its successor programs, the Ocean Drilling Program and Integrated Ocean Drilling Program, plus additional information from the published literature, and several unpublished taxonomic database projects. 1192 names are recognised as valid, and several hundred additional names including synonyms and mispellings are given as well. A brief list of valid names is provided in the main paper, while the full list, with synonyms, author, year of publication, family assignment, geologic age interval and notes is provided as a SOM spreadsheet table.

Pliocene Radiolaria from Bianco, Calabria, Italy

A diverse radiolarian assemblage is described from the Pliocene of Bianco in southern Italy. Previously, radiolarians have not been described from the Pliocene of continental southern Italy, and the section contains a fairly continuous record of both calcareous and siliceous microfossils, the latter of which occur very sporadically in other time-equivalent Italian sections. Comparison with assemblages from tropical and subtropical oceans reveals that the fauna belongs to the late Spongaster pentas or the early Pterocaniumprismatium Zone. Strong paleoenvironmental signals are reflected in the fluctuations ofabundances of several of the 30 taxa studied, but no definite trend or consistent co-variation of any group of species was found through the section.

The upper Paleocene-lower Eocene San Francisco de Paula section: Biostratigraphic synthesis

The San Francisco de Paula section is one of the few that permit direct correlations between siliceous and calcareous microfossil zonal schemes near the Paleocene/Eocene boundary. We discuss these correlations, delineate unconformities in the section and discuss the location of the Paleocene/Eocene boundary.