Eocene calcareous nannofossil biostratigraphy and community structure from Exmouth Plateau, eastern Indian Ocean (ODP Site 762)

Author(s): Shamrock, Jamie L.; Watkins, David K.
Author Affiliation(s): Primary:
University of Nebraska-Lincoln, Department of Geosciences, Lincoln, NE, United States
Volume Title: Stratigraphy
Source: Stratigraphy, 9(1), p.1-54. Publisher: Micropaleontology Press, New York, NY, United States. ISSN: 1547-139X
Note: In English. 103 refs.; illus., incl. 10 plates, 7 tables, geol. sketch map
Summary: A relatively complete section of Eocene (∼33.9-55.8 Ma) pelagic chalk from offshore northwestern Australia was used to analyze range and abundance data of ∼250 Eocene species to test the efficacy of the existing CP (Okada and Bukry 1980) and NP (Martini 1971) biostratigraphic zonation schemes. Changes in nannofossil diversity, abundance, and community structure were monitored through several Eocene paleoenvironmental events, as identified by changes in δ13C and δ18O data, to examine variations in surface water conditions. Major changes in nannofossil assemblages, as indicated by dominance crossovers, correspond to paleoenvironmental shifts such as the PETM (Paleocene-Eocene thermal maximum) and the EECO (Early Eocene climatic optimum). This research also provides systematic paleontology and range data for one new genus (Hexadelus) and eight new species or variants (Calcidiscus ellipticus, Cruciplacolithus nebulosus, Cruciplacolithus opacus, Cyclicargolithus parvus, Hexadelus archus, Hayella situliformis var. ovata, Markalius latus, Pedinocyclus annulus) and addresses several taxonomic issues in other Eocene species.
Year of Publication: 2012
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Algae; Assemblages; Biostratigraphy; Biozones; C-13/C-12; Calcidiscus ellipticus; Carbon; Cenozoic; Chemostratigraphy; Communities; Cruciplacolithus; Cyclicargolithus parvus; Eocene; Exmouth Plateau; Hayella situliformis ovata; Hexadelus archus; Indian Ocean; Isotope ratios; Isotopes; Leg 122; Marine environment; Markalius latus; Microfossils; Morphology; Nannofossils; New taxa; O-18/O-16; ODP Site 762; Ocean Drilling Program; Oxygen; Paleo-oceanography; Paleocene-Eocene Thermal Maximum; Paleoclimatology; Paleoecology; Paleoenvironment; Paleogene; Pedinocyclus annulus; Plantae; Stable isotopes; Taxonomy; Tertiary
Coordinates: S195315 S195314 E1121515 E1121514
Record ID: 2013020742
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute.