10.1594/PANGAEA.743885
Stein, Ruediger
Ruediger
Stein
0000-0002-4453-9564
Rullkötter, Jürgen
Jürgen
Rullkötter
Littke, Ralf
Ralf
Littke
Schaefer, Rainer G
Rainer G
Schaefer
Welte, Dietrich Hugo
Dietrich Hugo
Welte
Organofacies reconstruction and lipid geochemistry of sediments from the Galicia margin
PANGAEA
1988
Drilling/drill rig
Leg103
Joides Resolution
Ocean Drilling Program (ODP)
1985-05-06T00:15:00/1985-06-15T13:30:00
en
Supplementary Publication Series of Datasets
10.2973/odp.proc.sr.103.158.1988
4 datasets
application/zip
Creative Commons Attribution 3.0 Unported
Samples of Lower to middle Cretaceous rocks from ODP Sites 638, 640, and 641, drilled on the Galicia continental margin in the northeast Atlantic, have been investigated by organic geochemical methods (i.e., organic carbon determination, Rock-Eval pyrolysis, kerogen microscopy, gas chromatography, and gas chromatography/mass spectrometry) to define the Organofacies types and the depositional environments of these sediments. The results of this study fit well into the general picture drawn for the depositional history of the organic matter in Cretaceous organic-carbon-rich sediments in the North Atlantic from previous DSDP investigations.
During the Valanginian to Albian, terrigenous organic carbon dominated the organic matter deposited on the Galicia continental margin. Cyclic changes in total organic carbon content were probably controlled by climatic-triggered changes in the supply of terrigenous organic matter from the nearby continent. A drastic change in depositional environment must have occurred near the Cenomanian/Turonian boundary. The preservation of large amounts of marine organic carbon in these sediments was probably caused by anoxic deep-water conditions during that time, rather than high productivity.
All of the primary organic matter of the sediment samples investigated is thermally immature, as indicated by very low vitrinite reflectance values.
Supplement to: Stein, Ruediger; Rullkötter, Jürgen; Littke, Ralf; Schaefer, Rainer G; Welte, Dietrich Hugo (1988): Organofacies reconstruction and lipid geochemistry of sediments from the Galicia margin, Northeast Atlantic (ODP Leg 103). In: Boillot, G; Winterer, EL; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 103, 567-585
-12.4633
-12.1817
42.0167
42.155
South Atlantic Ocean