Depth ranges of calcareous nannofossil datums from ODP Holes 113-689B and 113-690B
Magnetostratigraphic studies of Paleogene sediments piston-cored on Maud Rise, Weddell Sea (ODP Sites 689 and 690), are a cornerstone of Southern Ocean Paleogene and Neogene chronostratigraphy. However, parts of previous magnetostratigraphic interpretations have been called into question, and recent...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.718120 2024-09-15T17:42:18+00:00 Depth ranges of calcareous nannofossil datums from ODP Holes 113-689B and 113-690B Florindo, Fabio Roberts, Andrew P MEDIAN LATITUDE: -64.839000 * MEDIAN LONGITUDE: 2.152400 * SOUTH-BOUND LATITUDE: -65.161000 * WEST-BOUND LONGITUDE: 1.204900 * NORTH-BOUND LATITUDE: -64.517000 * EAST-BOUND LONGITUDE: 3.099900 * DATE/TIME START: 1987-01-16T08:00:00 * DATE/TIME END: 1987-01-21T07:00:00 2005 application/zip, 2 datasets https://doi.pangaea.de/10.1594/PANGAEA.718120 https://doi.org/10.1594/PANGAEA.718120 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.718120 https://doi.org/10.1594/PANGAEA.718120 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess Supplement to: Florindo, Fabio; Roberts, Andrew P (2005): Eocene-Oligocene magnetobiochronology of ODP Sites 689 and 690, Maud Rise, Weddell Sea, Antarctica. Geological Society of America Bulletin, 117(1-2), 46-66, https://doi.org/10.1130/B25541.1 113-689B 113-690B DRILL Drilling/drill rig Joides Resolution Leg113 Ocean Drilling Program ODP South Atlantic Ocean dataset publication series 2005 ftpangaea https://doi.org/10.1594/PANGAEA.71812010.1130/B25541.1 2024-07-24T02:31:20Z Magnetostratigraphic studies of Paleogene sediments piston-cored on Maud Rise, Weddell Sea (ODP Sites 689 and 690), are a cornerstone of Southern Ocean Paleogene and Neogene chronostratigraphy. However, parts of previous magnetostratigraphic interpretations have been called into question, and recent reinvestigation of the upper Paleocene-middle Eocene portion of Site 690 suggested that the records might be contaminated by spurious magnetizations, which raises doubts about the reliability of these important records. We undertook a high-resolution magnetostratigraphic study of Eocene-Oligocene u-channel samples from ODP Holes 689B, 689D, 690B, and 690C in order to address these concerns. A pervasive overprint appears to be present below the middle Eocene, which compromises magnetobiostratigraphic interpretations for the upper Cretaceous and lower Paleogene. Nevertheless, our new results provide a robust record of geomagnetic field behavior from 38.5 to 25 Ma and confirm the reliability of these sediments for calibration of biostratigraphic datum events during a crucial phase of earth history when major Antarctic ice sheets developed. Also, comparison of magnetozone thicknesses in multiple holes at the same site indicates that ~1.2-1.8 m of the stratigraphic record is missing at each core break, which corresponds to time breaks of 120-360 k.y. Lack of a continuous record within a single hole renders useless spectral analyses for investigating long geomagnetic and paleoclimatic time series. This observation reinforces the need for coring of multiple offset holes to obtain continuous paleoceanographic records. Sedimentary hiatuses have been identified only at the deeper of the two investigated sites (Site 690), which could mark a local response to the onset of the Antarctic Circumpolar Current. Other/Unknown Material Antarc* Antarctic South Atlantic Ocean Southern Ocean Weddell Sea PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(1.204900,3.099900,-64.517000,-65.161000) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
113-689B 113-690B DRILL Drilling/drill rig Joides Resolution Leg113 Ocean Drilling Program ODP South Atlantic Ocean |
spellingShingle |
113-689B 113-690B DRILL Drilling/drill rig Joides Resolution Leg113 Ocean Drilling Program ODP South Atlantic Ocean Florindo, Fabio Roberts, Andrew P Depth ranges of calcareous nannofossil datums from ODP Holes 113-689B and 113-690B |
topic_facet |
113-689B 113-690B DRILL Drilling/drill rig Joides Resolution Leg113 Ocean Drilling Program ODP South Atlantic Ocean |
description |
Magnetostratigraphic studies of Paleogene sediments piston-cored on Maud Rise, Weddell Sea (ODP Sites 689 and 690), are a cornerstone of Southern Ocean Paleogene and Neogene chronostratigraphy. However, parts of previous magnetostratigraphic interpretations have been called into question, and recent reinvestigation of the upper Paleocene-middle Eocene portion of Site 690 suggested that the records might be contaminated by spurious magnetizations, which raises doubts about the reliability of these important records. We undertook a high-resolution magnetostratigraphic study of Eocene-Oligocene u-channel samples from ODP Holes 689B, 689D, 690B, and 690C in order to address these concerns. A pervasive overprint appears to be present below the middle Eocene, which compromises magnetobiostratigraphic interpretations for the upper Cretaceous and lower Paleogene. Nevertheless, our new results provide a robust record of geomagnetic field behavior from 38.5 to 25 Ma and confirm the reliability of these sediments for calibration of biostratigraphic datum events during a crucial phase of earth history when major Antarctic ice sheets developed. Also, comparison of magnetozone thicknesses in multiple holes at the same site indicates that ~1.2-1.8 m of the stratigraphic record is missing at each core break, which corresponds to time breaks of 120-360 k.y. Lack of a continuous record within a single hole renders useless spectral analyses for investigating long geomagnetic and paleoclimatic time series. This observation reinforces the need for coring of multiple offset holes to obtain continuous paleoceanographic records. Sedimentary hiatuses have been identified only at the deeper of the two investigated sites (Site 690), which could mark a local response to the onset of the Antarctic Circumpolar Current. |
format |
Other/Unknown Material |
author |
Florindo, Fabio Roberts, Andrew P |
author_facet |
Florindo, Fabio Roberts, Andrew P |
author_sort |
Florindo, Fabio |
title |
Depth ranges of calcareous nannofossil datums from ODP Holes 113-689B and 113-690B |
title_short |
Depth ranges of calcareous nannofossil datums from ODP Holes 113-689B and 113-690B |
title_full |
Depth ranges of calcareous nannofossil datums from ODP Holes 113-689B and 113-690B |
title_fullStr |
Depth ranges of calcareous nannofossil datums from ODP Holes 113-689B and 113-690B |
title_full_unstemmed |
Depth ranges of calcareous nannofossil datums from ODP Holes 113-689B and 113-690B |
title_sort |
depth ranges of calcareous nannofossil datums from odp holes 113-689b and 113-690b |
publisher |
PANGAEA |
publishDate |
2005 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.718120 https://doi.org/10.1594/PANGAEA.718120 |
op_coverage |
MEDIAN LATITUDE: -64.839000 * MEDIAN LONGITUDE: 2.152400 * SOUTH-BOUND LATITUDE: -65.161000 * WEST-BOUND LONGITUDE: 1.204900 * NORTH-BOUND LATITUDE: -64.517000 * EAST-BOUND LONGITUDE: 3.099900 * DATE/TIME START: 1987-01-16T08:00:00 * DATE/TIME END: 1987-01-21T07:00:00 |
long_lat |
ENVELOPE(1.204900,3.099900,-64.517000,-65.161000) |
genre |
Antarc* Antarctic South Atlantic Ocean Southern Ocean Weddell Sea |
genre_facet |
Antarc* Antarctic South Atlantic Ocean Southern Ocean Weddell Sea |
op_source |
Supplement to: Florindo, Fabio; Roberts, Andrew P (2005): Eocene-Oligocene magnetobiochronology of ODP Sites 689 and 690, Maud Rise, Weddell Sea, Antarctica. Geological Society of America Bulletin, 117(1-2), 46-66, https://doi.org/10.1130/B25541.1 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.718120 https://doi.org/10.1594/PANGAEA.718120 |
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.71812010.1130/B25541.1 |
_version_ |
1810488814751186944 |