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

• Main Author: Wei, Wuchang
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1991
• Subjects: Drilling/drill rig; Leg114; Joides Resolution; Ocean Drilling Program ODP; Southern Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.687607; https://doi.pangaea.de/10.1594/PANGAEA.687607

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 n 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: (1) The last occurrence (LO) of Reticulofenestra bisecta is a consistent and reliable biostratigraphic marker for the Oligocene/Miocene boundary from mid- to high latitudes but not in ... : Supplement to: Wei, Wuchang (1991): Middle Eocene-lower Miocene calcareous nannofossil magnetobiochronology of ODP Holes 699A and 703A in the subantarctic South Atlantic. Marine Micropaleontology, 18(1-2), 143-165 ...