Milankovitch frequency peaks of ODP Site 113-693 (Table 3)
The first well logs collected below the Antarctic circle were obtained during Leg 113 at Site 693 on the Dronning Maud Land Margin (Antarctica) in the Weddell Sea. Gamma-ray, resistivity, and sonic logs were collected between 108.0 and 439.0 mbsf. The downhole logs show good agreement with the data...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.754301 2024-09-15T17:48:07+00:00 Milankovitch frequency peaks of ODP Site 113-693 (Table 3) Golovchenko, Xenia O'Connell, Suzanne B Jarrard, Richard D LATITUDE: -70.832000 * LONGITUDE: -14.573950 * DATE/TIME START: 1987-01-30T00:00:00 * DATE/TIME END: 1987-02-07T00:00:00 * MINIMUM DEPTH, sediment/rock: 127.5 m * MAXIMUM DEPTH, sediment/rock: 225.5 m 1990 text/tab-separated-values, 90 data points https://doi.pangaea.de/10.1594/PANGAEA.754301 https://doi.org/10.1594/PANGAEA.754301 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.754301 https://doi.org/10.1594/PANGAEA.754301 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess Supplement to: Golovchenko, Xenia; O'Connell, Suzanne B; Jarrard, Richard D (1990): Sedimentary response to paleoclimate from downhole logs at Site 693, Antarctic Continental Margin. In: Barker, PF; Kennett, JP; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 113, 239-251, https://doi.org/10.2973/odp.proc.sr.113.191.1990 113-693 COMPCORE Composite Core Depth bottom/max sediment/rock top/min Interval frequency Joides Resolution Leg113 Ocean Drilling Program ODP Sample comment Sedimentation rate Weddell Sea dataset 1990 ftpangaea https://doi.org/10.1594/PANGAEA.75430110.2973/odp.proc.sr.113.191.1990 2024-07-24T02:31:31Z The first well logs collected below the Antarctic circle were obtained during Leg 113 at Site 693 on the Dronning Maud Land Margin (Antarctica) in the Weddell Sea. Gamma-ray, resistivity, and sonic logs were collected between 108.0 and 439.0 mbsf. The downhole logs show good agreement with the data collected from cores and provide a continuous measurement of the sedimentary record. These continuous log records show that the rather uniform Tertiary lithology seen in cores is characterized by high-frequency variability in the log data. Several thin hard streaks are identified, the largest of which coincides with a major Miocene hiatus. Associated with this hiatus is a change to lower illite content (and correspondingly lower gamma-ray counts) and to a significant increase in diatom content. Spectral analysis of the logs was performed on the lower Pliocene through upper Oligocene interval (108.0-343.0 mbsf). Between 108.0 and 245.0 mbsf, average sedimentation rates (50 and 26 m/m.y.) are high enough to show that variance is present in the orbital eccentricity (~95 k.y.) and obliquity (~41 k.y.) bands. Between 253.0 and 343.0 mbsf, the sedimentation rate (8 m/m.y.) is too low to resolve high frequency variations. The Milankovitch frequencies are best developed in the resistivity logs. Resistivity is responding to changes in porosity, which in these sediments is controlled by the abundance of biosiliceous sediments, particularly diatoms. The orbital forcing suggested by the Milankovitch frequencies may be influencing diatom productivity by inducing oscillations in upwelling, ice coverage, pack ice, and/or polynya. Although variations in diatom abundance were observed in the cores, they were not attributed to a Milankovitch signal, and therefore in this environment, downhole logs are an important contribution to the detection and understanding of orbitally influenced changes in sedimentation. Dataset Antarc* Antarctic Antarctica Dronning Maud Land Weddell Sea PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(-14.573950,-14.573950,-70.832000,-70.832000) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
113-693 COMPCORE Composite Core Depth bottom/max sediment/rock top/min Interval frequency Joides Resolution Leg113 Ocean Drilling Program ODP Sample comment Sedimentation rate Weddell Sea |
spellingShingle |
113-693 COMPCORE Composite Core Depth bottom/max sediment/rock top/min Interval frequency Joides Resolution Leg113 Ocean Drilling Program ODP Sample comment Sedimentation rate Weddell Sea Golovchenko, Xenia O'Connell, Suzanne B Jarrard, Richard D Milankovitch frequency peaks of ODP Site 113-693 (Table 3) |
topic_facet |
113-693 COMPCORE Composite Core Depth bottom/max sediment/rock top/min Interval frequency Joides Resolution Leg113 Ocean Drilling Program ODP Sample comment Sedimentation rate Weddell Sea |
description |
The first well logs collected below the Antarctic circle were obtained during Leg 113 at Site 693 on the Dronning Maud Land Margin (Antarctica) in the Weddell Sea. Gamma-ray, resistivity, and sonic logs were collected between 108.0 and 439.0 mbsf. The downhole logs show good agreement with the data collected from cores and provide a continuous measurement of the sedimentary record. These continuous log records show that the rather uniform Tertiary lithology seen in cores is characterized by high-frequency variability in the log data. Several thin hard streaks are identified, the largest of which coincides with a major Miocene hiatus. Associated with this hiatus is a change to lower illite content (and correspondingly lower gamma-ray counts) and to a significant increase in diatom content. Spectral analysis of the logs was performed on the lower Pliocene through upper Oligocene interval (108.0-343.0 mbsf). Between 108.0 and 245.0 mbsf, average sedimentation rates (50 and 26 m/m.y.) are high enough to show that variance is present in the orbital eccentricity (~95 k.y.) and obliquity (~41 k.y.) bands. Between 253.0 and 343.0 mbsf, the sedimentation rate (8 m/m.y.) is too low to resolve high frequency variations. The Milankovitch frequencies are best developed in the resistivity logs. Resistivity is responding to changes in porosity, which in these sediments is controlled by the abundance of biosiliceous sediments, particularly diatoms. The orbital forcing suggested by the Milankovitch frequencies may be influencing diatom productivity by inducing oscillations in upwelling, ice coverage, pack ice, and/or polynya. Although variations in diatom abundance were observed in the cores, they were not attributed to a Milankovitch signal, and therefore in this environment, downhole logs are an important contribution to the detection and understanding of orbitally influenced changes in sedimentation. |
format |
Dataset |
author |
Golovchenko, Xenia O'Connell, Suzanne B Jarrard, Richard D |
author_facet |
Golovchenko, Xenia O'Connell, Suzanne B Jarrard, Richard D |
author_sort |
Golovchenko, Xenia |
title |
Milankovitch frequency peaks of ODP Site 113-693 (Table 3) |
title_short |
Milankovitch frequency peaks of ODP Site 113-693 (Table 3) |
title_full |
Milankovitch frequency peaks of ODP Site 113-693 (Table 3) |
title_fullStr |
Milankovitch frequency peaks of ODP Site 113-693 (Table 3) |
title_full_unstemmed |
Milankovitch frequency peaks of ODP Site 113-693 (Table 3) |
title_sort |
milankovitch frequency peaks of odp site 113-693 (table 3) |
publisher |
PANGAEA |
publishDate |
1990 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.754301 https://doi.org/10.1594/PANGAEA.754301 |
op_coverage |
LATITUDE: -70.832000 * LONGITUDE: -14.573950 * DATE/TIME START: 1987-01-30T00:00:00 * DATE/TIME END: 1987-02-07T00:00:00 * MINIMUM DEPTH, sediment/rock: 127.5 m * MAXIMUM DEPTH, sediment/rock: 225.5 m |
long_lat |
ENVELOPE(-14.573950,-14.573950,-70.832000,-70.832000) |
genre |
Antarc* Antarctic Antarctica Dronning Maud Land Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctica Dronning Maud Land Weddell Sea |
op_source |
Supplement to: Golovchenko, Xenia; O'Connell, Suzanne B; Jarrard, Richard D (1990): Sedimentary response to paleoclimate from downhole logs at Site 693, Antarctic Continental Margin. In: Barker, PF; Kennett, JP; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 113, 239-251, https://doi.org/10.2973/odp.proc.sr.113.191.1990 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.754301 https://doi.org/10.1594/PANGAEA.754301 |
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.75430110.2973/odp.proc.sr.113.191.1990 |
_version_ |
1810289238137110528 |