Ice-rafted debris in sites of ODP Leg 114
All holes drilled during Leg 114 contained ice-rafted debris. Analysis of samples from Hole 699A, Site 701, and Hole 704A yielded a nearly complete history of ice-rafting episodes. The first influx of ice-rafted debris at Site 699, on the northeastern slope of the Northeast Georgia Rise, occurred at...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.735005 2024-09-15T17:45:26+00:00 Ice-rafted debris in sites of ODP Leg 114 Allen, Carl P Warnke, Detlef A MEDIAN LATITUDE: -50.218667 * MEDIAN LONGITUDE: -15.489450 * SOUTH-BOUND LATITUDE: -52.985000 * WEST-BOUND LONGITUDE: -30.677000 * NORTH-BOUND LATITUDE: -46.879000 * EAST-BOUND LONGITUDE: 7.420800 * DATE/TIME START: 1987-03-20T10:45:00 * DATE/TIME END: 1987-04-26T06:54:00 1991 application/zip, 6 datasets https://doi.pangaea.de/10.1594/PANGAEA.735005 https://doi.org/10.1594/PANGAEA.735005 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.735005 https://doi.org/10.1594/PANGAEA.735005 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess Supplement to: Allen, Carl P; Warnke, Detlef A (1991): History of ice rafting at leg 114 sites, Subantarctic/South Atlantic. In: Ciesielski, PF; Kristoffersen, Y; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 114, 599-607, https://doi.org/10.2973/odp.proc.sr.114.118.1991 114-699A 114-701A 114-701B 114-701C 114-704A DRILL Drilling/drill rig Joides Resolution Leg114 Ocean Drilling Program ODP South Atlantic Ocean dataset publication series 1991 ftpangaea https://doi.org/10.1594/PANGAEA.73500510.2973/odp.proc.sr.114.118.1991 2024-07-24T02:31:20Z All holes drilled during Leg 114 contained ice-rafted debris. Analysis of samples from Hole 699A, Site 701, and Hole 704A yielded a nearly complete history of ice-rafting episodes. The first influx of ice-rafted debris at Site 699, on the northeastern slope of the Northeast Georgia Rise, occurred at a depth of 69.94 m below seafloor (mbsf) in sediments of early Miocene age (23.54 Ma). This material is of the same type as later ice-rafted debris, but represents only a small percentage of the coarse fraction. Significant ice-rafting episodes occurred during Chron 5. Minor amounts of ice-rafted debris first reached Site 701, on the western flank of the Mid-Atlantic Ridge (8.78 Ma at 200.92 mbsf), and more arrived in the late Miocene (5.88 Ma). The first significant quantity of sand and gravel appeared at a depth of 107.76 mbsf (4.42 Ma). Site 704, on the southern part of the Meteor Rise, received very little or no ice-rafted debris prior to 2.46 Ma. At this time, however, the greatest influx of ice-rafted debris occurred at this site. This time of maximum ice rafting correlates reasonably well with influxes of ice-rafted debris at Sites 701 (2.24 Ma) and 699 (2.38 Ma), in consideration of sample spacing at these two sites. These peaks of ice rafting may be Sirius till equivalents, if the proposed Pliocene age of Sirius tills can be confirmed. After about 1.67 Ma, the apparent mass-accumulation rate of the sediments at Site 704 declined, but with major fluctuations. This decline may be the result of a decrease in the rate of delivery of detritus from Antarctica due to reduced erosive power of the glaciers or a northward shift in the Polar Front Zone, a change in the path taken by the icebergs, or any combination of these factors. Other/Unknown Material Antarc* Antarctica South Atlantic Ocean PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(-30.677000,7.420800,-46.879000,-52.985000) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
114-699A 114-701A 114-701B 114-701C 114-704A DRILL Drilling/drill rig Joides Resolution Leg114 Ocean Drilling Program ODP South Atlantic Ocean |
spellingShingle |
114-699A 114-701A 114-701B 114-701C 114-704A DRILL Drilling/drill rig Joides Resolution Leg114 Ocean Drilling Program ODP South Atlantic Ocean Allen, Carl P Warnke, Detlef A Ice-rafted debris in sites of ODP Leg 114 |
topic_facet |
114-699A 114-701A 114-701B 114-701C 114-704A DRILL Drilling/drill rig Joides Resolution Leg114 Ocean Drilling Program ODP South Atlantic Ocean |
description |
All holes drilled during Leg 114 contained ice-rafted debris. Analysis of samples from Hole 699A, Site 701, and Hole 704A yielded a nearly complete history of ice-rafting episodes. The first influx of ice-rafted debris at Site 699, on the northeastern slope of the Northeast Georgia Rise, occurred at a depth of 69.94 m below seafloor (mbsf) in sediments of early Miocene age (23.54 Ma). This material is of the same type as later ice-rafted debris, but represents only a small percentage of the coarse fraction. Significant ice-rafting episodes occurred during Chron 5. Minor amounts of ice-rafted debris first reached Site 701, on the western flank of the Mid-Atlantic Ridge (8.78 Ma at 200.92 mbsf), and more arrived in the late Miocene (5.88 Ma). The first significant quantity of sand and gravel appeared at a depth of 107.76 mbsf (4.42 Ma). Site 704, on the southern part of the Meteor Rise, received very little or no ice-rafted debris prior to 2.46 Ma. At this time, however, the greatest influx of ice-rafted debris occurred at this site. This time of maximum ice rafting correlates reasonably well with influxes of ice-rafted debris at Sites 701 (2.24 Ma) and 699 (2.38 Ma), in consideration of sample spacing at these two sites. These peaks of ice rafting may be Sirius till equivalents, if the proposed Pliocene age of Sirius tills can be confirmed. After about 1.67 Ma, the apparent mass-accumulation rate of the sediments at Site 704 declined, but with major fluctuations. This decline may be the result of a decrease in the rate of delivery of detritus from Antarctica due to reduced erosive power of the glaciers or a northward shift in the Polar Front Zone, a change in the path taken by the icebergs, or any combination of these factors. |
format |
Other/Unknown Material |
author |
Allen, Carl P Warnke, Detlef A |
author_facet |
Allen, Carl P Warnke, Detlef A |
author_sort |
Allen, Carl P |
title |
Ice-rafted debris in sites of ODP Leg 114 |
title_short |
Ice-rafted debris in sites of ODP Leg 114 |
title_full |
Ice-rafted debris in sites of ODP Leg 114 |
title_fullStr |
Ice-rafted debris in sites of ODP Leg 114 |
title_full_unstemmed |
Ice-rafted debris in sites of ODP Leg 114 |
title_sort |
ice-rafted debris in sites of odp leg 114 |
publisher |
PANGAEA |
publishDate |
1991 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.735005 https://doi.org/10.1594/PANGAEA.735005 |
op_coverage |
MEDIAN LATITUDE: -50.218667 * MEDIAN LONGITUDE: -15.489450 * SOUTH-BOUND LATITUDE: -52.985000 * WEST-BOUND LONGITUDE: -30.677000 * NORTH-BOUND LATITUDE: -46.879000 * EAST-BOUND LONGITUDE: 7.420800 * DATE/TIME START: 1987-03-20T10:45:00 * DATE/TIME END: 1987-04-26T06:54:00 |
long_lat |
ENVELOPE(-30.677000,7.420800,-46.879000,-52.985000) |
genre |
Antarc* Antarctica South Atlantic Ocean |
genre_facet |
Antarc* Antarctica South Atlantic Ocean |
op_source |
Supplement to: Allen, Carl P; Warnke, Detlef A (1991): History of ice rafting at leg 114 sites, Subantarctic/South Atlantic. In: Ciesielski, PF; Kristoffersen, Y; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 114, 599-607, https://doi.org/10.2973/odp.proc.sr.114.118.1991 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.735005 https://doi.org/10.1594/PANGAEA.735005 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1594/PANGAEA.73500510.2973/odp.proc.sr.114.118.1991 |
_version_ |
1810493262103838720 |