Citation:

epic.28292.d001

Always quote citation above when using data! You can download the citation in several formats below.

RIS Citation BibTeX Citation Text Citation Facebook TwitterShow Map Google Earth

Abstract:

In this paper the relationship between whole-core compressional wave velocities and gamma-ray attenuation porosities of sediments cored at CRP-2/2A is examined, and compared with results from CRP-1, CRP-2/2A core-plug samples, and global models for velocity/porosity relationships of marine sediments. The high degree of data scatter observed in the velocity/porosity relationship of CRP-1 core is even larger in CRP-2/2A core. The general pattern of the velocity/porosity relationship is similar in CRP-2/2A whole core and core plug measurements. Despite scatter, all data indicate a strong primary dependence of velocity on porosity. This relationship appears to be independent of lithology except for sections with zero porosity and porosity >0.6, which are attributed to large lonestones and lapillistones, respectively. Core velocity/porosity patterns of CRP-1 and CRP-2/2A are very similar for sediments from the same age interval (19-23 Ma), both characterized by relatively low velocities (mostly between 2 and 3 km s-1) compared to porosity (0.1 - 0.4). Within this range of porosity, core velocities increase significantly up to more than 4 km s-1 below ca 440 mbsf. The change in the velocity/porosity relationship as a function of core depth is attributed to down-core increase in intergrain coupling enhanced by carbonate cementation. This is confirmed by a positive correlation of carbonate content with velocities higher or lower than empirically predicted from porosity. After removing first-order compaction control from the whole-core porosity record, no significant control by clay content can be identified (R = 0.3). This is different to the results for core from CRP-1 (R = 0.6) which is not cemented.

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: 12.250 m * Maximum DEPTH, sediment/rock: 624.140 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: * 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	Porosity	Poros	% vol	Niessen, Frank	Multi-Sensor Core Logger 17, GEOTEK
3	Density, wet bulk	WBD	g/cm³	Niessen, Frank	Multi-Sensor Core Logger 17, GEOTEK
4	Velocity, compressional wave	Vp	m/s	Niessen, Frank	Multi-Sensor Core Logger 17, GEOTEK
5	Susceptibility	Suscept	sensor values	Niessen, Frank	Multi-Sensor Core Logger 17, GEOTEK	loop corrected raw data (10**-5 SI units)
6	Susceptibility	Suscept	sensor values	Niessen, Frank	Multi-Sensor Core Logger 17, GEOTEK	raw data (10**-5 SI units)

License:

Creative Commons Attribution 3.0 Unported (CC-BY-3.0)

Size:

126049 data points

Download Data

Download dataset as tab-delimited text — use the following character encoding:

View dataset as HTML (shows only first 2000 rows)