Benthic foraminifers, isotopes and varimax factors at DSDP Holes 72-517 and 72-518
Pliocene changes in the vertical water mass structure of the western South Atlantic are inferred from changes in benthic foraminiferal assemblages and stable isotopes from DSDP Holes 516A, 517, and 518. Factor analysis of 34 samples from Site 518 reveals three distinct benthic foraminiferal assembla...
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1983
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.814013 2023-05-15T13:42:11+02:00 Benthic foraminifers, isotopes and varimax factors at DSDP Holes 72-517 and 72-518 Hodell, David A Kennett, James P Leonard, Kathleen A MEDIAN LATITUDE: -30.168320 * MEDIAN LONGITUDE: -38.116480 * SOUTH-BOUND LATITUDE: -30.946800 * WEST-BOUND LONGITUDE: -38.135300 * NORTH-BOUND LATITUDE: -29.973700 * EAST-BOUND LONGITUDE: -38.041200 * DATE/TIME START: 1980-03-30T00:00:00 * DATE/TIME END: 1980-04-02T00:00:00 1983-05-30 application/zip, 6 datasets https://doi.pangaea.de/10.1594/PANGAEA.814013 https://doi.org/10.1594/PANGAEA.814013 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.814013 https://doi.org/10.1594/PANGAEA.814013 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; Kennett, James P; Leonard, Kathleen A (1983): Climatically induced changes in vertical water mass structure of the Vema Channel during the Pliocene: evidence from Deep Sea Drilling Project Holes 516A, 517, and 518. In: Barker, PF; Carlson, RL; Johnson, DA; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 72, 907-919, https://doi.org/10.2973/dsdp.proc.72.146.1983 72-517 72-518 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg72 South Atlantic/CONT RISE South Atlantic/FLANK Dataset 1983 ftpangaea https://doi.org/10.1594/PANGAEA.814013 https://doi.org/10.2973/dsdp.proc.72.146.1983 2023-01-20T07:33:01Z Pliocene changes in the vertical water mass structure of the western South Atlantic are inferred from changes in benthic foraminiferal assemblages and stable isotopes from DSDP Holes 516A, 517, and 518. Factor analysis of 34 samples from Site 518 reveals three distinct benthic foraminiferal assemblages that have been associated with specific subsurface water masses in the modern ocean. These include a Nuttalides umbonifera assemblage (Factor 1) associated with Antarctic Bottom Water (AABW), a Globocassidulina subglobosa-Uvigerina peregrina assemblage (Factor 2) associated with Circumpolar Deep Water (CPDW), and an Oridorsalis umbonatus-Epistominella exigua assemblage associated with North Atlantic Deep Water (NADW). Bathymetric gradients in d13C between Holes 516A (1313 m), 517 (2963 m), and 518 (3944 m) are calculated whenever possible to monitor the degree of similarity and/or difference in the apparent oxygen utilization (AOU) of water masses located at these depths during the Pliocene. Changes in bathymetric d13C gradients coupled with benthic foraminiferal assemblages record fundamental changes in the vertical water mass structure of the Vema Channel during the Pliocene from 4.1 to 2.7 Ma. At Site 518, the interval from 4.1 to 3.6 Ma is dominated by the N. umbonifera (Factor 1) and O. umbonatus-E. exigua (Factor 3) assemblages. The d13C gradient between Holes 518 (3944 m) and 516A (1313 m) undergoes rapid oscillations during this interval though no permanent increase in the gradient is observed. However, d13C values at Site 518 are clearly lighter during this interval. These conditions may be related to increased bottom water activity associated with the re-establishment of the West Antarctic Ice Sheet in the late Gilbert Chron (-4.2 to 3.6 Ma) (Osborn et al., 1982). The interval from 3.6 to 3.2 Ma is marked by a dominance of the G. subglobosa-U. peregrina (Factor 2) assemblage and lack of a strong d13C gradient between Holes 518 (3944 m) and 516A (1313 m). We suggest that shallow circumpolar waters ... Dataset Antarc* Antarctic Ice Sheet NADW North Atlantic Deep Water North Atlantic PANGAEA - Data Publisher for Earth & Environmental Science Antarctic West Antarctic Ice Sheet Osborn ENVELOPE(-120.378,-120.378,56.604,56.604) ENVELOPE(-38.135300,-38.041200,-29.973700,-30.946800) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
72-517 72-518 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg72 South Atlantic/CONT RISE South Atlantic/FLANK |
spellingShingle |
72-517 72-518 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg72 South Atlantic/CONT RISE South Atlantic/FLANK Hodell, David A Kennett, James P Leonard, Kathleen A Benthic foraminifers, isotopes and varimax factors at DSDP Holes 72-517 and 72-518 |
topic_facet |
72-517 72-518 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg72 South Atlantic/CONT RISE South Atlantic/FLANK |
description |
Pliocene changes in the vertical water mass structure of the western South Atlantic are inferred from changes in benthic foraminiferal assemblages and stable isotopes from DSDP Holes 516A, 517, and 518. Factor analysis of 34 samples from Site 518 reveals three distinct benthic foraminiferal assemblages that have been associated with specific subsurface water masses in the modern ocean. These include a Nuttalides umbonifera assemblage (Factor 1) associated with Antarctic Bottom Water (AABW), a Globocassidulina subglobosa-Uvigerina peregrina assemblage (Factor 2) associated with Circumpolar Deep Water (CPDW), and an Oridorsalis umbonatus-Epistominella exigua assemblage associated with North Atlantic Deep Water (NADW). Bathymetric gradients in d13C between Holes 516A (1313 m), 517 (2963 m), and 518 (3944 m) are calculated whenever possible to monitor the degree of similarity and/or difference in the apparent oxygen utilization (AOU) of water masses located at these depths during the Pliocene. Changes in bathymetric d13C gradients coupled with benthic foraminiferal assemblages record fundamental changes in the vertical water mass structure of the Vema Channel during the Pliocene from 4.1 to 2.7 Ma. At Site 518, the interval from 4.1 to 3.6 Ma is dominated by the N. umbonifera (Factor 1) and O. umbonatus-E. exigua (Factor 3) assemblages. The d13C gradient between Holes 518 (3944 m) and 516A (1313 m) undergoes rapid oscillations during this interval though no permanent increase in the gradient is observed. However, d13C values at Site 518 are clearly lighter during this interval. These conditions may be related to increased bottom water activity associated with the re-establishment of the West Antarctic Ice Sheet in the late Gilbert Chron (-4.2 to 3.6 Ma) (Osborn et al., 1982). The interval from 3.6 to 3.2 Ma is marked by a dominance of the G. subglobosa-U. peregrina (Factor 2) assemblage and lack of a strong d13C gradient between Holes 518 (3944 m) and 516A (1313 m). We suggest that shallow circumpolar waters ... |
format |
Dataset |
author |
Hodell, David A Kennett, James P Leonard, Kathleen A |
author_facet |
Hodell, David A Kennett, James P Leonard, Kathleen A |
author_sort |
Hodell, David A |
title |
Benthic foraminifers, isotopes and varimax factors at DSDP Holes 72-517 and 72-518 |
title_short |
Benthic foraminifers, isotopes and varimax factors at DSDP Holes 72-517 and 72-518 |
title_full |
Benthic foraminifers, isotopes and varimax factors at DSDP Holes 72-517 and 72-518 |
title_fullStr |
Benthic foraminifers, isotopes and varimax factors at DSDP Holes 72-517 and 72-518 |
title_full_unstemmed |
Benthic foraminifers, isotopes and varimax factors at DSDP Holes 72-517 and 72-518 |
title_sort |
benthic foraminifers, isotopes and varimax factors at dsdp holes 72-517 and 72-518 |
publisher |
PANGAEA |
publishDate |
1983 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.814013 https://doi.org/10.1594/PANGAEA.814013 |
op_coverage |
MEDIAN LATITUDE: -30.168320 * MEDIAN LONGITUDE: -38.116480 * SOUTH-BOUND LATITUDE: -30.946800 * WEST-BOUND LONGITUDE: -38.135300 * NORTH-BOUND LATITUDE: -29.973700 * EAST-BOUND LONGITUDE: -38.041200 * DATE/TIME START: 1980-03-30T00:00:00 * DATE/TIME END: 1980-04-02T00:00:00 |
long_lat |
ENVELOPE(-120.378,-120.378,56.604,56.604) ENVELOPE(-38.135300,-38.041200,-29.973700,-30.946800) |
geographic |
Antarctic West Antarctic Ice Sheet Osborn |
geographic_facet |
Antarctic West Antarctic Ice Sheet Osborn |
genre |
Antarc* Antarctic Ice Sheet NADW North Atlantic Deep Water North Atlantic |
genre_facet |
Antarc* Antarctic Ice Sheet NADW North Atlantic Deep Water North Atlantic |
op_source |
Supplement to: Hodell, David A; Kennett, James P; Leonard, Kathleen A (1983): Climatically induced changes in vertical water mass structure of the Vema Channel during the Pliocene: evidence from Deep Sea Drilling Project Holes 516A, 517, and 518. In: Barker, PF; Carlson, RL; Johnson, DA; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 72, 907-919, https://doi.org/10.2973/dsdp.proc.72.146.1983 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.814013 https://doi.org/10.1594/PANGAEA.814013 |
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.814013 https://doi.org/10.2973/dsdp.proc.72.146.1983 |
_version_ |
1766164487089422336 |