Carbon chemistry of ODP Leg 105 sites ...

• Main Authors: Stein, Ruediger, Littke, Ralf, Stax, Rainer, Welte, Dietrich Hugo
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1989
• Subjects: Drilling/drill rig; Composite Core; Leg105; Joides Resolution; Ocean Drilling Program ODP; Baffin Bay; Baffin; Labrador Sea
• Online Access: https://dx.doi.org/10.1594/pangaea.744883; https://doi.pangaea.de/10.1594/PANGAEA.744883

The quantity and quality of organic carbon of Eocene to Holocene sediments from ODP Sites 645, 646, and 647 were investigated to reconstruct depositional environments. Results were based on organic-carbon and nitrogen determinations, Rock-Eval pyrolysis, and kerogen microscopy.The sediments at Site 645 in Baffin Bay are characterized by relatively high organic-carbon values, most of which range from 0.5% to almost 3%, with maximum values in the middle Miocene. Distinct maxima of organic-carbon accumulation rates occur between 18 and 12.5 Ma and between 3.4 and 0 Ma. At Sites 646 and 647 in the Labrador Sea, organic-carbon contents vary between 0.1% and 0.75%. Cyclic 'Milankovitch-type' changes in organic-carbon deposition imply climate-controlled mechanisms that cause these fluctuations.The composition of organic matter at Site 645 is dominated by terrigenous components throughout the entire sediment sequence. An increased content of marine organic carbon was recorded only in the late-middle Miocene. At ... : Supplement to: Stein, Ruediger; Littke, Ralf; Stax, Rainer; Welte, Dietrich Hugo (1989): Quantity, provenance, and maturity of organic matter at ODP Sites 645, 646, and 647: implications for reconstruction of paleoenvironments in Baffin Bay and Labrador Sea during Tertiary and Quaternary time. 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, 185-208 ...