Paleoceanography of the eastern equatorial Pacific during the Neogene: Synthesis of Leg 138 drilling results
The primary objective of Leg 138 was to provide detailed information about the ocean's response to global climate change during the Neogene. Two north-south transects were drilled (95° and 110°W) within the region of equatorial divergence-driven upwelling (and thus high accumulation rates and r...
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1995
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ftuninhampshire:oai:scholars.unh.edu:ccom_affil-1014 2023-05-15T17:13:55+02:00 Paleoceanography of the eastern equatorial Pacific during the Neogene: Synthesis of Leg 138 drilling results Pisias, Nicklas G. Mayer, Larry A. Mix, Alan C. 1995-01-01T08:00:00Z application/pdf https://scholars.unh.edu/ccom_affil/15 https://scholars.unh.edu/cgi/viewcontent.cgi?article=1014&context=ccom_affil unknown University of New Hampshire Scholars' Repository https://scholars.unh.edu/ccom_affil/15 https://scholars.unh.edu/cgi/viewcontent.cgi?article=1014&context=ccom_affil Affiliate Scholarship Geology Oceanography and Atmospheric Sciences and Meteorology text 1995 ftuninhampshire 2023-01-30T21:32:01Z The primary objective of Leg 138 was to provide detailed information about the ocean's response to global climate change during the Neogene. Two north-south transects were drilled (95° and 110°W) within the region of equatorial divergence-driven upwelling (and thus high accumulation rates and resolution) and spanning the major equatorial ocean current boundaries (and thus recording a high-amplitude signal of the response of the sediment to climatically and/or tectonically driven changes in ocean circulation). The Neogene is marked by a number of well-known climatic and tectonic events (the closing of the Isthmus of Panama, the onset of North Atlantic Deep Water (NADW), the rapid uplift of the Himalayas, the major intensification of Northern Hemisphere glaciation), and the response of the ocean before and after these events was a key focus of Leg 138 drilling. To address these objectives at the highest resolution possible, the Leg 138 scientific staff developed a number of new shipboard strategies and analytical procedures. These included the real-time analysis of the near-continuous gamma ray attenuation porosity evaluator (GRAPE) and susceptibility profiles produced by the multisensor track (MST) on unsplit cores to monitor core recovery and, if necessary, to modify the drilling strategy to ensure proper offset of coring gaps; the collection of near-continuous color reflectance data on split cores; the logging of the first hole drilled at each site to optimize drilling and sampling strategies for subsequent holes; and the use of multiple continuous records to unambiguously construct complete composite sections for each site. The complete, continuous records provided by the GRAPE (with a temporal resolution of often yr), in conjunction with an excellent microfossil stratigraphy and often excellent magnetostratigraphy, allowed for astronomical tuning of the stratigraphic record and resulted in a set of internally consistent, high-resolution age models that provide a secure, absolute time scale for the past 6 m.y. ... Text NADW North Atlantic Deep Water North Atlantic University of New Hampshire: Scholars Repository Pacific |
institution |
Open Polar |
collection |
University of New Hampshire: Scholars Repository |
op_collection_id |
ftuninhampshire |
language |
unknown |
topic |
Geology Oceanography and Atmospheric Sciences and Meteorology |
spellingShingle |
Geology Oceanography and Atmospheric Sciences and Meteorology Pisias, Nicklas G. Mayer, Larry A. Mix, Alan C. Paleoceanography of the eastern equatorial Pacific during the Neogene: Synthesis of Leg 138 drilling results |
topic_facet |
Geology Oceanography and Atmospheric Sciences and Meteorology |
description |
The primary objective of Leg 138 was to provide detailed information about the ocean's response to global climate change during the Neogene. Two north-south transects were drilled (95° and 110°W) within the region of equatorial divergence-driven upwelling (and thus high accumulation rates and resolution) and spanning the major equatorial ocean current boundaries (and thus recording a high-amplitude signal of the response of the sediment to climatically and/or tectonically driven changes in ocean circulation). The Neogene is marked by a number of well-known climatic and tectonic events (the closing of the Isthmus of Panama, the onset of North Atlantic Deep Water (NADW), the rapid uplift of the Himalayas, the major intensification of Northern Hemisphere glaciation), and the response of the ocean before and after these events was a key focus of Leg 138 drilling. To address these objectives at the highest resolution possible, the Leg 138 scientific staff developed a number of new shipboard strategies and analytical procedures. These included the real-time analysis of the near-continuous gamma ray attenuation porosity evaluator (GRAPE) and susceptibility profiles produced by the multisensor track (MST) on unsplit cores to monitor core recovery and, if necessary, to modify the drilling strategy to ensure proper offset of coring gaps; the collection of near-continuous color reflectance data on split cores; the logging of the first hole drilled at each site to optimize drilling and sampling strategies for subsequent holes; and the use of multiple continuous records to unambiguously construct complete composite sections for each site. The complete, continuous records provided by the GRAPE (with a temporal resolution of often yr), in conjunction with an excellent microfossil stratigraphy and often excellent magnetostratigraphy, allowed for astronomical tuning of the stratigraphic record and resulted in a set of internally consistent, high-resolution age models that provide a secure, absolute time scale for the past 6 m.y. ... |
format |
Text |
author |
Pisias, Nicklas G. Mayer, Larry A. Mix, Alan C. |
author_facet |
Pisias, Nicklas G. Mayer, Larry A. Mix, Alan C. |
author_sort |
Pisias, Nicklas G. |
title |
Paleoceanography of the eastern equatorial Pacific during the Neogene: Synthesis of Leg 138 drilling results |
title_short |
Paleoceanography of the eastern equatorial Pacific during the Neogene: Synthesis of Leg 138 drilling results |
title_full |
Paleoceanography of the eastern equatorial Pacific during the Neogene: Synthesis of Leg 138 drilling results |
title_fullStr |
Paleoceanography of the eastern equatorial Pacific during the Neogene: Synthesis of Leg 138 drilling results |
title_full_unstemmed |
Paleoceanography of the eastern equatorial Pacific during the Neogene: Synthesis of Leg 138 drilling results |
title_sort |
paleoceanography of the eastern equatorial pacific during the neogene: synthesis of leg 138 drilling results |
publisher |
University of New Hampshire Scholars' Repository |
publishDate |
1995 |
url |
https://scholars.unh.edu/ccom_affil/15 https://scholars.unh.edu/cgi/viewcontent.cgi?article=1014&context=ccom_affil |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
NADW North Atlantic Deep Water North Atlantic |
genre_facet |
NADW North Atlantic Deep Water North Atlantic |
op_source |
Affiliate Scholarship |
op_relation |
https://scholars.unh.edu/ccom_affil/15 https://scholars.unh.edu/cgi/viewcontent.cgi?article=1014&context=ccom_affil |
_version_ |
1766071111747895296 |