ATLANTIC

Deep sea benthic foraminiferal faunas were studied from three DSDP sites in the equa-torial Pacific (Leg 85, depth about 4.5 kin), and two DSDP sites in the North Atlantic (Leg 94, depth 3.5 and 2.5 km), for the interval between 25 and 0 Ma. The number of first appearances (FA's) and last appea...

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Bibliographic Details
Main Author: E. Thomas
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 1984
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.587.7135
http://ethomas.web.wesleyan.edu/ThomasP386.pdf
Description
Summary:Deep sea benthic foraminiferal faunas were studied from three DSDP sites in the equa-torial Pacific (Leg 85, depth about 4.5 kin), and two DSDP sites in the North Atlantic (Leg 94, depth 3.5 and 2.5 km), for the interval between 25 and 0 Ma. The number of first appearances (FA's) and last appearances (LA's) of taxa in the early to middle Miocene was similar at all sites, despite differences in location and depth. Specific events, however, were rarely coeval at several sites, even within the Pacific. Changes in faunal composition began earlier (at about 18 Ma) in the equatorial Pacific than in the North Atlantic (about 15.5 Ma); these changes affected between about 20 and 30 % of the total fauna. There is no simple, globally valid correlation between the changes in composition of the benthic foraminiferal faunas and events in oxygen and carbon isotopic records. The FA of Cibici-doides wuellerstorfi, however, appears to be coeval with the increase in oxygen isotopic ratios in the early middle Miocene.