Occurrence and isotopic composition (δ¹⁸O, δ¹³C) of benthic foraminifera in sediments from DSDP Leg 72
Changes in the vertical water mass structure of the Vema Channel during the Pliocene have been inferred from benthic foraminiferal assemblages and stable isotopic analyses from three sites of DSDP Leg 72 (South Atlantic). Faunal and isotopic results from Sites 516A and 518 suggest that a major chang...
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1985
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.718261 2023-05-15T13:42:09+02:00 Occurrence and isotopic composition (δ¹⁸O, δ¹³C) of benthic foraminifera in sediments from DSDP Leg 72 Hodell, David A Williams, Douglas F Kennett, James P MEDIAN LATITUDE: -30.257233 * MEDIAN LONGITUDE: -37.481056 * SOUTH-BOUND LATITUDE: -30.946800 * WEST-BOUND LONGITUDE: -38.135300 * NORTH-BOUND LATITUDE: -29.973700 * EAST-BOUND LONGITUDE: -35.285300 * DATE/TIME START: 1980-03-11T00:00:00 * DATE/TIME END: 1980-04-02T00:00:00 1985-06-11 application/zip, 9 datasets https://doi.pangaea.de/10.1594/PANGAEA.718261 https://doi.org/10.1594/PANGAEA.718261 en eng PANGAEA GSA data repository - Tables 1, 2 & 3 and appendix of DSDP sites (URI: ftp://rock.geosociety.org/pub/reposit/1985/8514.pdf) https://doi.pangaea.de/10.1594/PANGAEA.718261 https://doi.org/10.1594/PANGAEA.718261 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Hodell, David A; Williams, Douglas F; Kennett, James P (1985): Late Pliocene reorganization of deep vertical water-mass structure in the western South Atlantic: Faunal and isotopic evidence. Geological Society of America Bulletin, 96(4), 495-503, https://doi.org/10.1130/0016-7606(1985)96%3C495:LPRODV%3E2.0.CO;2 72-516A 72-517 72-518 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg72 South Atlantic/CONT RISE South Atlantic/FLANK Dataset 1985 ftpangaea https://doi.org/10.1594/PANGAEA.718261 https://doi.org/10.1130/0016-7606(1985)96%3C495:LPRODV%3E2.0.CO;2 2023-01-20T07:31:25Z Changes in the vertical water mass structure of the Vema Channel during the Pliocene have been inferred from benthic foraminiferal assemblages and stable isotopic analyses from three sites of DSDP Leg 72 (South Atlantic). Faunal and isotopic results from Sites 516A and 518 suggest that a major change occurred in deep-water circulation patterns in the late Pliocene near 3.2 Ma. Benthic oxygen isotopic records from Sites 516A and 518 show a characteristic increase in d18O values near 3.2 Ma. This has been documented in numerous Pliocene isotopic records. The magnitude of the oxygen isotopic enrichment near 3.2 Ma appears to increase with water depth from an average enrichment of 0.34 per mil in Site 516A (1313 m) to an average enrichment of 0.58 per mil in Site 518 (3944 m). We suggest that this enrichment resulted partly from a change in deep-water circulation patterns which included a decrease in bottom-water temperatures. Planktonic d18O values near 3.2 Ma show no evidence of an enrichment which would be indicative of an increase in global ice volume. On the contrary, d18O values in Sites 517 and 518 become more depleted near 3.2 Ma, indicating a surface-water warming perhaps due to a change in the strength and/or position of the Brazil Current. An increase in the relative abundance of the benthic foraminifer Nuttalides umbonifera, which is associated with Antarctic Bottom Water (AABW) in the modern ocean, coincides with the benthic 18O enrichment in Site 518. At 3.2 Ma, oxygen and carbon isotopic gradients between Sites 518 (3944 m) and 516A (1313 m) show a marked increase such that Site 518 becomes enriched in 18O and depleted in 13C relative to Site 516A. This enrichment in d18O is interpreted as partly representing a temperature decrease at Site 518; the depletion in d13C indicates a corrosive water mass which is high in metabolic CO2. We suggest that benthic foraminiferal and stable isotopic changes in Site 518 resulted from a pulse-like increase in the formation of AABW near 3.2 Ma. The cause of this ... Dataset Antarc* Antarctic PANGAEA - Data Publisher for Earth & Environmental Science Antarctic ENVELOPE(-38.135300,-35.285300,-29.973700,-30.946800) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
72-516A 72-517 72-518 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg72 South Atlantic/CONT RISE South Atlantic/FLANK |
spellingShingle |
72-516A 72-517 72-518 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg72 South Atlantic/CONT RISE South Atlantic/FLANK Hodell, David A Williams, Douglas F Kennett, James P Occurrence and isotopic composition (δ¹⁸O, δ¹³C) of benthic foraminifera in sediments from DSDP Leg 72 |
topic_facet |
72-516A 72-517 72-518 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg72 South Atlantic/CONT RISE South Atlantic/FLANK |
description |
Changes in the vertical water mass structure of the Vema Channel during the Pliocene have been inferred from benthic foraminiferal assemblages and stable isotopic analyses from three sites of DSDP Leg 72 (South Atlantic). Faunal and isotopic results from Sites 516A and 518 suggest that a major change occurred in deep-water circulation patterns in the late Pliocene near 3.2 Ma. Benthic oxygen isotopic records from Sites 516A and 518 show a characteristic increase in d18O values near 3.2 Ma. This has been documented in numerous Pliocene isotopic records. The magnitude of the oxygen isotopic enrichment near 3.2 Ma appears to increase with water depth from an average enrichment of 0.34 per mil in Site 516A (1313 m) to an average enrichment of 0.58 per mil in Site 518 (3944 m). We suggest that this enrichment resulted partly from a change in deep-water circulation patterns which included a decrease in bottom-water temperatures. Planktonic d18O values near 3.2 Ma show no evidence of an enrichment which would be indicative of an increase in global ice volume. On the contrary, d18O values in Sites 517 and 518 become more depleted near 3.2 Ma, indicating a surface-water warming perhaps due to a change in the strength and/or position of the Brazil Current. An increase in the relative abundance of the benthic foraminifer Nuttalides umbonifera, which is associated with Antarctic Bottom Water (AABW) in the modern ocean, coincides with the benthic 18O enrichment in Site 518. At 3.2 Ma, oxygen and carbon isotopic gradients between Sites 518 (3944 m) and 516A (1313 m) show a marked increase such that Site 518 becomes enriched in 18O and depleted in 13C relative to Site 516A. This enrichment in d18O is interpreted as partly representing a temperature decrease at Site 518; the depletion in d13C indicates a corrosive water mass which is high in metabolic CO2. We suggest that benthic foraminiferal and stable isotopic changes in Site 518 resulted from a pulse-like increase in the formation of AABW near 3.2 Ma. The cause of this ... |
format |
Dataset |
author |
Hodell, David A Williams, Douglas F Kennett, James P |
author_facet |
Hodell, David A Williams, Douglas F Kennett, James P |
author_sort |
Hodell, David A |
title |
Occurrence and isotopic composition (δ¹⁸O, δ¹³C) of benthic foraminifera in sediments from DSDP Leg 72 |
title_short |
Occurrence and isotopic composition (δ¹⁸O, δ¹³C) of benthic foraminifera in sediments from DSDP Leg 72 |
title_full |
Occurrence and isotopic composition (δ¹⁸O, δ¹³C) of benthic foraminifera in sediments from DSDP Leg 72 |
title_fullStr |
Occurrence and isotopic composition (δ¹⁸O, δ¹³C) of benthic foraminifera in sediments from DSDP Leg 72 |
title_full_unstemmed |
Occurrence and isotopic composition (δ¹⁸O, δ¹³C) of benthic foraminifera in sediments from DSDP Leg 72 |
title_sort |
occurrence and isotopic composition (δ¹⁸o, δ¹³c) of benthic foraminifera in sediments from dsdp leg 72 |
publisher |
PANGAEA |
publishDate |
1985 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.718261 https://doi.org/10.1594/PANGAEA.718261 |
op_coverage |
MEDIAN LATITUDE: -30.257233 * MEDIAN LONGITUDE: -37.481056 * SOUTH-BOUND LATITUDE: -30.946800 * WEST-BOUND LONGITUDE: -38.135300 * NORTH-BOUND LATITUDE: -29.973700 * EAST-BOUND LONGITUDE: -35.285300 * DATE/TIME START: 1980-03-11T00:00:00 * DATE/TIME END: 1980-04-02T00:00:00 |
long_lat |
ENVELOPE(-38.135300,-35.285300,-29.973700,-30.946800) |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Supplement to: Hodell, David A; Williams, Douglas F; Kennett, James P (1985): Late Pliocene reorganization of deep vertical water-mass structure in the western South Atlantic: Faunal and isotopic evidence. Geological Society of America Bulletin, 96(4), 495-503, https://doi.org/10.1130/0016-7606(1985)96%3C495:LPRODV%3E2.0.CO;2 |
op_relation |
GSA data repository - Tables 1, 2 & 3 and appendix of DSDP sites (URI: ftp://rock.geosociety.org/pub/reposit/1985/8514.pdf) https://doi.pangaea.de/10.1594/PANGAEA.718261 https://doi.org/10.1594/PANGAEA.718261 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.718261 https://doi.org/10.1130/0016-7606(1985)96%3C495:LPRODV%3E2.0.CO;2 |
_version_ |
1766163476333461504 |