A Nd Isotopic Study of Southern Sourced Waters and Indonesian Throughflow at Intermediate Depths in the Cenozoic Indian Ocean
We present Nd isotopic data for fossil fish teeth recovered from the past 40 m.y. at ODP Site 757, currentlylocated at 1650m water depth on the Ninetyeast Ridge in the Indian Ocean. Although Site 757 sits in a regionstrongly influenced by weathering inputs from the Himalayas and volcanic inputs from...
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ftunivsouthcar:oai:scholarcommons.sc.edu:geol_facpub-1038 2024-05-19T07:49:01+00:00 A Nd Isotopic Study of Southern Sourced Waters and Indonesian Throughflow at Intermediate Depths in the Cenozoic Indian Ocean Martin, Ellen E Scher, Howie 2006-09-27T07:00:00Z application/pdf https://scholarcommons.sc.edu/geol_facpub/39 https://scholarcommons.sc.edu/context/geol_facpub/article/1038/viewcontent/scher_gcubed.pdf unknown Scholar Commons https://scholarcommons.sc.edu/geol_facpub/39 https://scholarcommons.sc.edu/context/geol_facpub/article/1038/viewcontent/scher_gcubed.pdf Martin, E. E. & Scher, H. (2006). A Nd isotopic study of southern sourced waters andIndonesian Throughflow at intermediate depths in the Cenozoic Indian Ocean. Geochemistry, Geophysics, Geosystems, 7 (9), 1-14. © Geochemistry, Geophysics, Geosystems 2006, American Geophysical Union Faculty Publications Nd isotopes Indonesian Throughflow paleocirculation Indian Ocean Cenozoic ODP Site 757 Earth Sciences text 2006 ftunivsouthcar 2024-04-30T23:59:54Z We present Nd isotopic data for fossil fish teeth recovered from the past 40 m.y. at ODP Site 757, currentlylocated at 1650m water depth on the Ninetyeast Ridge in the Indian Ocean. Although Site 757 sits in a regionstrongly influenced by weathering inputs from the Himalayas and volcanic inputs from the Indonesian arc, the pattern of Nd isotopic variations does not appear to respond to these potential sources of Nd. Instead, secular variations correlate to changes in the composition of intermediate to deep water masses bathing thesite and circulation patterns in the Indian Ocean. From ~40 to 10 Ma, eNd values and the pattern of change at Site 757 closely match those of ODP Site 1090, a deep water site in the Atlantic sector of the Southern Ocean. Comparison to data from several Fe-Mn crusts in the Indian Ocean suggests that intermediate to deep waterflow paths were similar to the modern distribution of Circumpolar DeepWater. At approximately 10 Ma, Ndisotopic values increase in a step function by 2 eNd units, suggesting that plate motions had carried Site 757into a region influenced by Indonesian Throughflow. Estimates of the vertical and horizontal position of thissite at 10 Ma imply that Indonesian Throughflow extended as far south as ~20S and to a depth of ~1500 m. From 10 to 0 Ma, Nd isotopic variations at Site 757 appear to record variations in Indonesian Throughflow. From 10 to 5.5 Ma, values at Site 757 overlap with those from crusts located in the southwest Pacific,indicating extensive flow through the Indonesian Seaway. From 5.5 to 3.4 Ma, eNd values become lessradiogenic at Site 757 and more radiogenic in the southwest Pacific, suggesting increasing closure of theseaway and concomitant rerouting of equatorial Pacific waters. Beginning at 3.4 Ma, eNd values becomemore radiogenic again at Site 757, which may be attributed to enhanced opening of the seaway or to a changein the source of Throughflow waters from a southern to a northern Pacific region. Text Southern Ocean University of South Carolina Libraries: Scholar Commons |
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Open Polar |
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University of South Carolina Libraries: Scholar Commons |
op_collection_id |
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topic |
Nd isotopes Indonesian Throughflow paleocirculation Indian Ocean Cenozoic ODP Site 757 Earth Sciences |
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Nd isotopes Indonesian Throughflow paleocirculation Indian Ocean Cenozoic ODP Site 757 Earth Sciences Martin, Ellen E Scher, Howie A Nd Isotopic Study of Southern Sourced Waters and Indonesian Throughflow at Intermediate Depths in the Cenozoic Indian Ocean |
topic_facet |
Nd isotopes Indonesian Throughflow paleocirculation Indian Ocean Cenozoic ODP Site 757 Earth Sciences |
description |
We present Nd isotopic data for fossil fish teeth recovered from the past 40 m.y. at ODP Site 757, currentlylocated at 1650m water depth on the Ninetyeast Ridge in the Indian Ocean. Although Site 757 sits in a regionstrongly influenced by weathering inputs from the Himalayas and volcanic inputs from the Indonesian arc, the pattern of Nd isotopic variations does not appear to respond to these potential sources of Nd. Instead, secular variations correlate to changes in the composition of intermediate to deep water masses bathing thesite and circulation patterns in the Indian Ocean. From ~40 to 10 Ma, eNd values and the pattern of change at Site 757 closely match those of ODP Site 1090, a deep water site in the Atlantic sector of the Southern Ocean. Comparison to data from several Fe-Mn crusts in the Indian Ocean suggests that intermediate to deep waterflow paths were similar to the modern distribution of Circumpolar DeepWater. At approximately 10 Ma, Ndisotopic values increase in a step function by 2 eNd units, suggesting that plate motions had carried Site 757into a region influenced by Indonesian Throughflow. Estimates of the vertical and horizontal position of thissite at 10 Ma imply that Indonesian Throughflow extended as far south as ~20S and to a depth of ~1500 m. From 10 to 0 Ma, Nd isotopic variations at Site 757 appear to record variations in Indonesian Throughflow. From 10 to 5.5 Ma, values at Site 757 overlap with those from crusts located in the southwest Pacific,indicating extensive flow through the Indonesian Seaway. From 5.5 to 3.4 Ma, eNd values become lessradiogenic at Site 757 and more radiogenic in the southwest Pacific, suggesting increasing closure of theseaway and concomitant rerouting of equatorial Pacific waters. Beginning at 3.4 Ma, eNd values becomemore radiogenic again at Site 757, which may be attributed to enhanced opening of the seaway or to a changein the source of Throughflow waters from a southern to a northern Pacific region. |
format |
Text |
author |
Martin, Ellen E Scher, Howie |
author_facet |
Martin, Ellen E Scher, Howie |
author_sort |
Martin, Ellen E |
title |
A Nd Isotopic Study of Southern Sourced Waters and Indonesian Throughflow at Intermediate Depths in the Cenozoic Indian Ocean |
title_short |
A Nd Isotopic Study of Southern Sourced Waters and Indonesian Throughflow at Intermediate Depths in the Cenozoic Indian Ocean |
title_full |
A Nd Isotopic Study of Southern Sourced Waters and Indonesian Throughflow at Intermediate Depths in the Cenozoic Indian Ocean |
title_fullStr |
A Nd Isotopic Study of Southern Sourced Waters and Indonesian Throughflow at Intermediate Depths in the Cenozoic Indian Ocean |
title_full_unstemmed |
A Nd Isotopic Study of Southern Sourced Waters and Indonesian Throughflow at Intermediate Depths in the Cenozoic Indian Ocean |
title_sort |
nd isotopic study of southern sourced waters and indonesian throughflow at intermediate depths in the cenozoic indian ocean |
publisher |
Scholar Commons |
publishDate |
2006 |
url |
https://scholarcommons.sc.edu/geol_facpub/39 https://scholarcommons.sc.edu/context/geol_facpub/article/1038/viewcontent/scher_gcubed.pdf |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Faculty Publications |
op_relation |
https://scholarcommons.sc.edu/geol_facpub/39 https://scholarcommons.sc.edu/context/geol_facpub/article/1038/viewcontent/scher_gcubed.pdf |
op_rights |
Martin, E. E. & Scher, H. (2006). A Nd isotopic study of southern sourced waters andIndonesian Throughflow at intermediate depths in the Cenozoic Indian Ocean. Geochemistry, Geophysics, Geosystems, 7 (9), 1-14. © Geochemistry, Geophysics, Geosystems 2006, American Geophysical Union |
_version_ |
1799467429454151680 |