Middle Eocene-lower Miocene calcareous nannofossil magnetobiochronology of ODP holes 699A and 703A in the subantarctic South Atlantic

Author(s): Wei, Wuchang
Author Affiliation(s): Primary:
Fla. State Univ., Dep. Geol., Tallahassee, FL, United States
Volume Title: Marine Micropaleontology
Source: Marine Micropaleontology, 18(1-2), p.143-165. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0377-8398 CODEN: MAMIDH
Note: In English. 50 refs.; illus. incl. strat. cols., sketch map
Summary: The distribution of calcareous nannofossils is documented for the middle Eocene through lowermost Miocene cores from Ocean Drilling Program Holes 699A and 703A in the subantarctic South Atlantic. The detailed nannofossil biostratigraphies established, in combination with published magnetostratigraphic data, have provided a fairly detailed age model for each hole. This study suggests that the middle Eocene through lowermost Miocene section from Hole 699A is virtually complete. A major hiatus has been identified in Hole 703A in the earliest Oligocene, coincident with an abrupt cooling in the southern ocean. Comparison of the nannofossil datum ages calibrated with magnetostratigraphy in the two holes with those from mid- and southern high latitudes demonstrates synchroneity or diachroneity for the following nannofossil datums which have last occurrence (LO) ages ranging from 26.8 Ma to 36.0 Ma and first occurrence (FO) ages ranging from 38.4 Ma to 39.0 Ma: LO Reticulofenestra bisecta, Chiasmolithus altus, R. umbilica, Isthmolithus recurvus, R. oamaruensis; FO R. oamaruensis, and I. recurvus. (Auth. mod.)
Year of Publication: 1991
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Algae; Atlantic Ocean; Biostratigraphy; Cenozoic; Eocene; Leg 114; Lower Miocene; Microfossils; Miocene; Nannofossils; Neogene; ODP Site 699; ODP Site 703; Ocean Drilling Program; Oligocene; Paleogene; Plantae; South Atlantic; Stratigraphy; Tertiary; Thallophytes
Coordinates: S513233 S513232 W0304037 W0304038
S470303 S470302 E0075341 E0075340
Record ID: 1992003684
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from the Antarctic Bibliography, United States