Ehrmann, Werner (2000): Clay and smectite analysis of sediment core CRP-2A [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.56138, Supplement to: Ehrmann, W (2000): Smectite content and crystallinity in sediments from CRP-2/2A, Victoria Land Basin, Antarctica. Terra Antartica, 7(4), 575-580, hdl:10013/epic.28291.d001
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Abstract:
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.
Project(s):
Cape Roberts Project (CRP)
Coverage:
Latitude: -77.005980 * Longitude: 163.719450
Date/Time Start: 1998-10-16T07:30:00 * Date/Time End: 1998-11-25T14:20:00
Minimum DEPTH, sediment/rock: 7.11 m * Maximum DEPTH, sediment/rock: 623.81 m
Event(s):
CRP-2A (14.2 km at 096° true from Cape Roberts) * Latitude: -77.005980 * Longitude: 163.719450 * Date/Time Start: 1998-10-16T07:30:00 * Date/Time End: 1998-11-25T14:20:00 * Elevation: -177.9 m * Recovery: 624 m * Location: off Cape Roberts, Ross Sea, Antarctica * Campaign: CRP-2 * Basis: Sampling/drilling from ice * Method/Device: Core wireline system (CWS) * Comment: 921 m at 284° from CRP-1. Sea-ice thickness: 2.0 m (1 Oct) to 2.2 m (23 Nov). Sea riser embedded to 13.03 mbsf. Lateral ice movement: 9.87 m to east from 17 Oct to 23 Nov. HQ core to 199.31 mbsf. NQ core to 624.15 mbsf. 13.03 to 45.97 mbsf, 11.29 m (34%) partially following CRP-2. 45.07 to 624.15 mbsf, 548.67 m (95%) new hole. Deepest core-lithology: hard sandy siltstone. Deepest core-age: earliest Oligocene (ca. 33 Ma on diatoms, nannofossils and dinoflagellates)
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | DEPTH, sediment/rock | Depth sed | m | Geocode | ||
| 2 | Size fraction < 0.002 mm, clay | <2 µm | % | Ehrmann, Werner | Grain size, sieving/settling tube | |
| 3 | Smectite/standard ratio | Smec/std | Ehrmann, Werner | X-ray diffraction TEXTUR, clay fraction | ||
| 4 | Smectite, integral width | Smec IW | d2Theta | Ehrmann, Werner | X-ray diffraction TEXTUR, clay fraction |
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
222 data points