CHRONOSTRATIGRAPHIC FRAMEWORK FOR UPPER CAMPANIAN-MAASTRICHTIAN SEDIMENTS ON THE BLAKE NOSE (SUBTROPICAL NORTH ATLANTIC)
A new chronostratigraphic framework is presented for upper Campanian-Maastrichtian pelagic sediments cored at DSDP/ODP Sites 390A/1049, 1050, and 1052, which were drilled across a 1300-m depth transect on the Blake Nose (subtropical western Atlantic Ocean). The planktonic fora-miniferal zonation is...
| Main Authors: | , , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.545.4957 http://si-pddr.si.edu/dspace/bitstream/10088/7430/1/paleo_Huber_et_al_JFR_2008.pdf |
| Summary: | A new chronostratigraphic framework is presented for upper Campanian-Maastrichtian pelagic sediments cored at DSDP/ODP Sites 390A/1049, 1050, and 1052, which were drilled across a 1300-m depth transect on the Blake Nose (subtropical western Atlantic Ocean). The planktonic fora-miniferal zonation is based on standard global biozones for this interval, but rare and sporadic occurrence of two zonal biomarkers, Ganssevina ganssevi and Globotruncana aegyp-tiaca, precludes reliable identification of the nominate zones for those species. The Pseudoguembelina palpebva Partial-range Zone is defined as a means of subdividing this upper Campanian biostratigraphic interval. Planktonic foraminif-eral, calcareous nannofossil and paleomagnetic datums are integrated to construct reliable age-depth curves for each of the Blake Nose drill sites. These age models are largely confirmed by Sr-isotopic data and suggest significant unconformities at various positions within the sections. Compilation of stable isotope datasets for this time interval from the Blake Nose sites reveals no significant shifts in 5'^0 and 6"C at the time of the inoceramid bivalve extinction (now dated as 68.5-68.7 Ma in the Blake Nose sections) and no correlation with proposed Campanian-Maastrichtian glacial intervals. However, benthic warming associated with Deccan volcanism during the late Maastrichtian is supported. |
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