Citation:

odp.proc.sr.105.155.1989

Name: Thorium and uranium isotopes in upper Pleistocene sediments of the Baffin Bay
Published: 1989
License: https://creativecommons.org/licenses/by/3.0/

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:

Concentrations and activity ratios of uranium and thorium isotopes (234U/238U, 230Th/232Th) were determined at about 5-m intervals through the composite top 22-m sequence of Ocean Drilling Program (ODP) Hole 645 in Baffin Bay and, in the Labrador Sea, at 1-m intervals through the top 11 m of Core 84-030-003 (TWC and P) collected by the Hudson during a preliminary survey of Site 647, and also at about 2-m intervals through the composite top 22-m sequence of Hole 646. In the Labrador Sea, surficial sediments show unsupported 230Th having a 230Th/234U activity ratio of about 3. At Site 647, a regular decrease in the 230Th/232Th activity ratio was observed downcore from about 1.2 (at 1 mbsf) to about 0.4 (at ~8 mbsf), through a sequence spanning over 18O stages 2 through 8. The correlative thorium/uranium chronology and 18O stratigraphy indicate relatively constant sedimentation rates throughout the sequence. At Site 646, down Greenland slope, and at Site 645, in Baffin Bay, highly variable uranium and thorium concentrations and isotopic ratios were observed in relation to highly variable sedimentation rates. As a whole, the lower-excess observed in Baffin Bay records is indicative of very high absolute sedimentation rates in comparison with those of the Labrador Sea. These rates are confirmed by the 18O-stratigraphy and a few AMS 14C controls on handpicked foraminifers. At both Labrador Sea sites, a clear indication of an initial 230Th-excess (over the 230Th-rain from the water column) was found.

Project(s):

Ocean Drilling Program (ODP)

Coverage:

Median Latitude: 64.333287 * Median Longitude: -56.483250 * South-bound Latitude: 58.209300 * West-bound Longitude: -64.654800 * North-bound Latitude: 70.457550 * East-bound Longitude: -48.369100

Date/Time Start: 1985-09-03T00:00:00 * Date/Time End: 1985-10-13T21:01:00

Event(s):

105-645 * Latitude: 70.457550 * Longitude: -64.654800 * Date/Time Start: 1985-09-03T00:00:00 * Date/Time End: 1985-09-28T00:00:00 * Elevation: -2018.1 m * Penetration: 1980 m * Recovery: 850.8 m * Location: Baffin Bay * Campaign: * Basis: Joides Resolution * Method/Device: Composite Core (COMPCORE) * Comment: 139 cores; 1276.8 m cored; 0 m drilled; 66.6% recovery

105-646B * Latitude: 58.209300 * Longitude: -48.369100 * Date/Time Start: 1985-10-04T08:45:00 * Date/Time End: 1985-10-13T21:01:00 * Elevation: -3459.0 m * Penetration: 766.7 m * Recovery: 404.25 m * Location: Labrador Sea * Campaign: * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 80 cores; 766.2 m cored; 0 m drilled; 52.8 % recovery

HUD85-027-16 * Latitude: 70.457000 * Longitude: -64.540000 * Elevation: -2091.0 m * Location: Labrador Sea * Method/Device: Piston corer (PC)

License:

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

Size:

4 datasets

Download Data

Download ZIP file containing all datasets as tab-delimited text — use the following character encoding:

Datasets listed in this publication series

Causse, C; Vörösmarty, CJ (1989): (Table 4) Thorium and uranium concentrations and isotope activity ratios at ODP Site 105-645. https://doi.org/10.1594/PANGAEA.744862
Causse, C; Vörösmarty, CJ (1989): (Table 3) Initial 230Th/232Th values in sediments of ODP Site 105-646B. https://doi.org/10.1594/PANGAEA.744861
Causse, C; Vörösmarty, CJ (1989): (Table 2) Thorium and uranium concentrations and isotope activity ratios at ODP Site 105-646B. https://doi.org/10.1594/PANGAEA.744859
Causse, C; Vörösmarty, CJ (1989): (Table 1) Thorium and uranium concentrations and isotope activity ratios in sediment profile HUD85-027-16. https://doi.org/10.1594/PANGAEA.744858