Thorium and uranium isotopes in upper Pleistocene sediments of the Baffin Bay ...

• Main Authors: Causse, Christiane, Vörösmarty, Charles J
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1989
• Subjects: Composite Core; Drilling/drill rig; Piston corer; Trigger corer; Leg105; Joides Resolution; Ocean Drilling Program ODP; Baffin Bay; Baffin; Greenland; Labrador Sea
• Online Access: https://dx.doi.org/10.1594/pangaea.744863; https://doi.pangaea.de/10.1594/PANGAEA.744863

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 ... : Supplement to: Causse, Christiane; Vörösmarty, Charles J (1989): Thorium and uranium isotopes in Upper Pleistocene sediments of ODP Sites 645 (Baffin Bay), 646, and 647 (Labrador Sea). In: Srivastava, SP; Arthur, M; Clement, B; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 105, 551-560 ...