Clay and smectite analysis of sediment core CRP-2A

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Auteur principal: Ehrmann, Werner
Format: Dataset Open Access
Langue:en
Publié: PANGAEA 2000
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author Ehrmann, Werner
author_facet Ehrmann, Werner
collection Datos científicos de ciencias marinas y ambientales
contents Sediments of the CRP-2/2A drill core from the continental shelf of McMurdo Sound in Ross Sea, Pacific sector of the Southern Ocean, have been investigated for their clay mineral assemblages, especially for the smectite contents and smectite crystallinities. Highest smectite amounts and best crystallinities occur in three intervals below 485 mbsf in CRP-2/2A. They indicate deposition of sediments during a time when chemical weathering was active on large ice-free areas on the nearby Antarctic continent. In he upper part of the core, smectite contents are much lower and crystallinities are worse. This clay mineral composition indicates deposition of sediments during a time when physical weathering prevailed on an ice-covered continent. At deep-sea sites around Antarctica the shift from smectite-dominated to smectite-poor and illite-rich assemblages is well dated as earliest Oligocene, 33.9-33.1 Ma, and documents the onset of continental glaciation in East Antarctica. At CIROS-1 a corresponding shift in the clay mineralogy was observed at a depth of 425-445 mbsf.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_56138
institution PANGAEA
language en
publishDate 2000
publisher PANGAEA
record_format pangaea
spellingShingle Clay and smectite analysis of sediment core CRP-2A
Ehrmann, Werner
14.2 km at 096° true from Cape Roberts; Cape Roberts Project; Core wireline system; CRP; CRP-2__Campaign; CRP-2A; CWS; DEPTH, sediment/rock; Grain size, sieving/settling tube; off Cape Roberts, Ross Sea, Antarctica; Sampling/drilling from ice; Size fraction < 0.002 mm, clay; Smectite, integral width; Smectite/standard ratio; X-ray diffraction TEXTUR, clay fraction
Sediments of the CRP-2/2A drill core from the continental shelf of McMurdo Sound in Ross Sea, Pacific sector of the Southern Ocean, have been investigated for their clay mineral assemblages, especially for the smectite contents and smectite crystallinities. Highest smectite amounts and best crystallinities occur in three intervals below 485 mbsf in CRP-2/2A. They indicate deposition of sediments during a time when chemical weathering was active on large ice-free areas on the nearby Antarctic continent. In he upper part of the core, smectite contents are much lower and crystallinities are worse. This clay mineral composition indicates deposition of sediments during a time when physical weathering prevailed on an ice-covered continent. At deep-sea sites around Antarctica the shift from smectite-dominated to smectite-poor and illite-rich assemblages is well dated as earliest Oligocene, 33.9-33.1 Ma, and documents the onset of continental glaciation in East Antarctica. At CIROS-1 a corresponding shift in the clay mineralogy was observed at a depth of 425-445 mbsf.
title Clay and smectite analysis of sediment core CRP-2A
topic 14.2 km at 096° true from Cape Roberts; Cape Roberts Project; Core wireline system; CRP; CRP-2__Campaign; CRP-2A; CWS; DEPTH, sediment/rock; Grain size, sieving/settling tube; off Cape Roberts, Ross Sea, Antarctica; Sampling/drilling from ice; Size fraction < 0.002 mm, clay; Smectite, integral width; Smectite/standard ratio; X-ray diffraction TEXTUR, clay fraction
url https://doi.org/10.1594/PANGAEA.56138