Neogene and Quaternary paleoenvironmental history at DSDP Leg 71 Holes
The Neogene and Quaternary sedimentary record of Leg 71 and previously drilled sequences from the Southern Ocean reveal evidence of a major late Miocene change of oceanic and glacial conditions in the southern high latitudes during paleomagnetic Chron 9. The characteristics of late Miocene sedimenta...
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PANGAEA
1983
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Online Access: | https://doi.pangaea.de/10.1594/PANGAEA.815095 https://doi.org/10.1594/PANGAEA.815095 |
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.815095 2023-05-15T13:42:11+02:00 Neogene and Quaternary paleoenvironmental history at DSDP Leg 71 Holes Ciesielski, Paul F Weaver, Fred M MEDIAN LATITUDE: -49.888129 * MEDIAN LONGITUDE: -58.366233 * SOUTH-BOUND LATITUDE: -68.996800 * WEST-BOUND LONGITUDE: 104.488300 * NORTH-BOUND LATITUDE: -46.046200 * EAST-BOUND LONGITUDE: -24.640000 * DATE/TIME START: 1973-01-06T00:00:00 * DATE/TIME END: 1980-02-08T00:00:00 1983-06-03 application/zip, 3 datasets https://doi.pangaea.de/10.1594/PANGAEA.815095 https://doi.org/10.1594/PANGAEA.815095 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.815095 https://doi.org/10.1594/PANGAEA.815095 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Ciesielski, Paul F; Weaver, Fred M (1983): Neogene and Quaternary paleoenvironmental history of Deep Sea Drilling Project Leg 71 sediments, Southwest Atlantic Ocean. In: Ludwig, WJ; Krasheninnikov, VA; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 71, 461-477, https://doi.org/10.2973/dsdp.proc.71.120.1983 28-267A 28-268 28-269 28-274 29-278 35-322 35-323 35-325 36-328B 36-329 71-513 71-513A 71-514 Antarctic Ocean/BASIN Antarctic Ocean/CONT RISE Antarctic Ocean/PLAIN Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg28 Leg29 Leg35 Leg36 Leg71 South Atlantic South Atlantic/BANK South Atlantic/BASIN South Atlantic/FLANK Dataset 1983 ftpangaea https://doi.org/10.1594/PANGAEA.815095 https://doi.org/10.2973/dsdp.proc.71.120.1983 2023-01-20T07:33:01Z The Neogene and Quaternary sedimentary record of Leg 71 and previously drilled sequences from the Southern Ocean reveal evidence of a major late Miocene change of oceanic and glacial conditions in the southern high latitudes during paleomagnetic Chron 9. The characteristics of late Miocene sedimentation and in particular the study of erosional patterns and ice-rafted debris suggest the following conclusions. 1) In the late Miocene, the Polar Front first migrated to the northern latitudes of the Southern Ocean and surface water temperatures became similar to those of today. 2) Extensive ice shelves or ice tongues were not present along the Antarctic margin until late Chron 9 (about 9.0 Ma). 3) Before Chron 9, West Antarctica was occupied by an archipelago and the West Antarctic Sea. 4) Extensive ice shelves formed in the West Antarctic region, eventually coalescing and thickening to form the grounded West Antarctic ice sheet by Chron 9. 5) The newly formed West Antarctic ice sheet was probably unstable and frequently became an ungrounded ice shelf, thus accounting for the scarcity of late Miocene ice-rafted debris. 6) Extensive erosion or nondeposition of sediment was probably the result of increased Antarctic Bottom Water (AABW) formation in the West Antarctic region during the initial formation of extensive West Antarctic ice shelves and during periods when the West Antarctic ice sheet was ungrounded. 7) In the Southwest Atlantic, AABW velocity waned during the latest Miocene. During the late Gilbert Chron a major and permanent change occurred in the pattern of ice-rafting to the South Atlantic, and after 4.35 Ma the increased IRD accumulation rate and frequency of major episodes of IRD accumulation suggest increased stability of the West Antarctic ice sheet. In addition, radiolarian faunas of Hole 514 record at least eight migrations of the Polar Front to the north of the site during the past 4.07 m.y. An apparent increase in the frequency of Polar Front migrations occurred about 2.7-2.6 Ma, possibly in ... Dataset Antarc* Antarctic Antarctic Ocean Antarctica Ice Sheet Ice Shelf Ice Shelves Southern Ocean West Antarctica PANGAEA - Data Publisher for Earth & Environmental Science Antarctic Southern Ocean The Antarctic West Antarctica West Antarctic Ice Sheet Antarctic Ocean ENVELOPE(104.488300,-24.640000,-46.046200,-68.996800) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
28-267A 28-268 28-269 28-274 29-278 35-322 35-323 35-325 36-328B 36-329 71-513 71-513A 71-514 Antarctic Ocean/BASIN Antarctic Ocean/CONT RISE Antarctic Ocean/PLAIN Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg28 Leg29 Leg35 Leg36 Leg71 South Atlantic South Atlantic/BANK South Atlantic/BASIN South Atlantic/FLANK |
spellingShingle |
28-267A 28-268 28-269 28-274 29-278 35-322 35-323 35-325 36-328B 36-329 71-513 71-513A 71-514 Antarctic Ocean/BASIN Antarctic Ocean/CONT RISE Antarctic Ocean/PLAIN Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg28 Leg29 Leg35 Leg36 Leg71 South Atlantic South Atlantic/BANK South Atlantic/BASIN South Atlantic/FLANK Ciesielski, Paul F Weaver, Fred M Neogene and Quaternary paleoenvironmental history at DSDP Leg 71 Holes |
topic_facet |
28-267A 28-268 28-269 28-274 29-278 35-322 35-323 35-325 36-328B 36-329 71-513 71-513A 71-514 Antarctic Ocean/BASIN Antarctic Ocean/CONT RISE Antarctic Ocean/PLAIN Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg28 Leg29 Leg35 Leg36 Leg71 South Atlantic South Atlantic/BANK South Atlantic/BASIN South Atlantic/FLANK |
description |
The Neogene and Quaternary sedimentary record of Leg 71 and previously drilled sequences from the Southern Ocean reveal evidence of a major late Miocene change of oceanic and glacial conditions in the southern high latitudes during paleomagnetic Chron 9. The characteristics of late Miocene sedimentation and in particular the study of erosional patterns and ice-rafted debris suggest the following conclusions. 1) In the late Miocene, the Polar Front first migrated to the northern latitudes of the Southern Ocean and surface water temperatures became similar to those of today. 2) Extensive ice shelves or ice tongues were not present along the Antarctic margin until late Chron 9 (about 9.0 Ma). 3) Before Chron 9, West Antarctica was occupied by an archipelago and the West Antarctic Sea. 4) Extensive ice shelves formed in the West Antarctic region, eventually coalescing and thickening to form the grounded West Antarctic ice sheet by Chron 9. 5) The newly formed West Antarctic ice sheet was probably unstable and frequently became an ungrounded ice shelf, thus accounting for the scarcity of late Miocene ice-rafted debris. 6) Extensive erosion or nondeposition of sediment was probably the result of increased Antarctic Bottom Water (AABW) formation in the West Antarctic region during the initial formation of extensive West Antarctic ice shelves and during periods when the West Antarctic ice sheet was ungrounded. 7) In the Southwest Atlantic, AABW velocity waned during the latest Miocene. During the late Gilbert Chron a major and permanent change occurred in the pattern of ice-rafting to the South Atlantic, and after 4.35 Ma the increased IRD accumulation rate and frequency of major episodes of IRD accumulation suggest increased stability of the West Antarctic ice sheet. In addition, radiolarian faunas of Hole 514 record at least eight migrations of the Polar Front to the north of the site during the past 4.07 m.y. An apparent increase in the frequency of Polar Front migrations occurred about 2.7-2.6 Ma, possibly in ... |
format |
Dataset |
author |
Ciesielski, Paul F Weaver, Fred M |
author_facet |
Ciesielski, Paul F Weaver, Fred M |
author_sort |
Ciesielski, Paul F |
title |
Neogene and Quaternary paleoenvironmental history at DSDP Leg 71 Holes |
title_short |
Neogene and Quaternary paleoenvironmental history at DSDP Leg 71 Holes |
title_full |
Neogene and Quaternary paleoenvironmental history at DSDP Leg 71 Holes |
title_fullStr |
Neogene and Quaternary paleoenvironmental history at DSDP Leg 71 Holes |
title_full_unstemmed |
Neogene and Quaternary paleoenvironmental history at DSDP Leg 71 Holes |
title_sort |
neogene and quaternary paleoenvironmental history at dsdp leg 71 holes |
publisher |
PANGAEA |
publishDate |
1983 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.815095 https://doi.org/10.1594/PANGAEA.815095 |
op_coverage |
MEDIAN LATITUDE: -49.888129 * MEDIAN LONGITUDE: -58.366233 * SOUTH-BOUND LATITUDE: -68.996800 * WEST-BOUND LONGITUDE: 104.488300 * NORTH-BOUND LATITUDE: -46.046200 * EAST-BOUND LONGITUDE: -24.640000 * DATE/TIME START: 1973-01-06T00:00:00 * DATE/TIME END: 1980-02-08T00:00:00 |
long_lat |
ENVELOPE(104.488300,-24.640000,-46.046200,-68.996800) |
geographic |
Antarctic Southern Ocean The Antarctic West Antarctica West Antarctic Ice Sheet Antarctic Ocean |
geographic_facet |
Antarctic Southern Ocean The Antarctic West Antarctica West Antarctic Ice Sheet Antarctic Ocean |
genre |
Antarc* Antarctic Antarctic Ocean Antarctica Ice Sheet Ice Shelf Ice Shelves Southern Ocean West Antarctica |
genre_facet |
Antarc* Antarctic Antarctic Ocean Antarctica Ice Sheet Ice Shelf Ice Shelves Southern Ocean West Antarctica |
op_source |
Supplement to: Ciesielski, Paul F; Weaver, Fred M (1983): Neogene and Quaternary paleoenvironmental history of Deep Sea Drilling Project Leg 71 sediments, Southwest Atlantic Ocean. In: Ludwig, WJ; Krasheninnikov, VA; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 71, 461-477, https://doi.org/10.2973/dsdp.proc.71.120.1983 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.815095 https://doi.org/10.1594/PANGAEA.815095 |
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.815095 https://doi.org/10.2973/dsdp.proc.71.120.1983 |
_version_ |
1766164489221177344 |