TY - JOUR
T1 - Middle to late Miocene planktonic foraminiferal datum levels and paleoceanography of the North and Southeastern Pacific Ocean
AU - Keller, Gerta
N1 - Funding Information:
I would like to thank John Barton for a critical review of this work and suggestions for improvements and Dick Poore, Jim Ingle, Yasumochi Matoba, and Jerry van Andel for helpful discussions. I am grateful to Dave Bukry for checking some nannoplankton zonations of Sites 319 and 310, to Lloyd Keigwin for providing isotope data of Site 310, and to Lloyd Burckle for making available unpublished diatom data on Sites 310 and 173. I gratefully acknowledge the United States Geological Survey at Menlo Park for the use of the Cambridge S-180 scanning electron microscope and thank Robert Oscar. son for operating the SEM. DSDP samples were made available by the National Science Foundation through the Deep Sea Drilling Project. This research was supported by NSF Grant OCE 76-82181 (CENOP).
PY - 1980
Y1 - 1980
N2 - Quantitative middle-late Miocene analysis of planktonic foraminifera of the North Pacific DSDP Sites 310, 173, 296, and 292 and the Southeast Pacific Site 319 reveal strikingly similar abundance distributions and foraminiferal datum levels permitting correlations between all sites. The following first (FA) and last (LA) appearances appear to be isochronous in tropical, subtropical, and temperate faunas: Globigerina nepenthes FA, G. druryi FA, Globorotalia mayeri LA, G. siakensis LA, Globoquadrina dehiscens LA, Globigerinoides kennetti FA and LA, and G. obliquus extremus FA. Isotope analysis is available for Site 310 and indicates a depletion in carbon at about 6.2 Ma following the extinction of G. kennetti and the first appearance of G. obliquus extremus. An increase in dissolution of calcium carbonate is apparent in the interval preceding the carbon shift at Site 310 and two further dissolution intervals are present lower in the section within paleomagnetic Epochs 7-8 (N16) and 12 (N14). Similar dissolution intervals have been observed in these same biostratigraphic intervals at DSDP Sites 296, 292, and 319. These dissolution intervals are often associated with a short hiatus and are marked by major faunal changes apparently due to climatic cooling.
AB - Quantitative middle-late Miocene analysis of planktonic foraminifera of the North Pacific DSDP Sites 310, 173, 296, and 292 and the Southeast Pacific Site 319 reveal strikingly similar abundance distributions and foraminiferal datum levels permitting correlations between all sites. The following first (FA) and last (LA) appearances appear to be isochronous in tropical, subtropical, and temperate faunas: Globigerina nepenthes FA, G. druryi FA, Globorotalia mayeri LA, G. siakensis LA, Globoquadrina dehiscens LA, Globigerinoides kennetti FA and LA, and G. obliquus extremus FA. Isotope analysis is available for Site 310 and indicates a depletion in carbon at about 6.2 Ma following the extinction of G. kennetti and the first appearance of G. obliquus extremus. An increase in dissolution of calcium carbonate is apparent in the interval preceding the carbon shift at Site 310 and two further dissolution intervals are present lower in the section within paleomagnetic Epochs 7-8 (N16) and 12 (N14). Similar dissolution intervals have been observed in these same biostratigraphic intervals at DSDP Sites 296, 292, and 319. These dissolution intervals are often associated with a short hiatus and are marked by major faunal changes apparently due to climatic cooling.
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U2 - 10.1016/0377-8398(80)90013-4
DO - 10.1016/0377-8398(80)90013-4
M3 - Article
AN - SCOPUS:0019145691
SN - 0377-8398
VL - 5
SP - 249
EP - 281
JO - Marine Micropaleontology
JF - Marine Micropaleontology
IS - C
ER -