Mukhopadhyay Prasanta K Rullkötter Jürgen j.rullkoetter@icbm.de Schaefer Rainer G R.G.Schaefer@fz-juelich.de Welte Dietrich Hugo d.h.welte@fz-juelich.de 1986 Facies and diagenesis of organic matter in sediments at DSDP Leg 87 dataset publication series https://doi.org/10.1594/PANGAEA.802076 Mukhopadhyay Prasanta K Rullkötter Jürgen j.rullkoetter@icbm.de Schaefer Rainer G R.G.Schaefer@fz-juelich.de Welte Dietrich Hugo d.h.welte@fz-juelich.de 1986 Facies and diagenesis of organic matter in Nankai Trough sediments, Deep Sea Drilling Project Leg 87A book chapter In: Kagami, H; Karig, DE; Coulbourn, WT; et al. (eds.), Initial Reports of the Deep Sea Drilling Project, Washington (U.S. Govt. Printing Office) 87 https://doi.org/10.2973/dsdp.proc.87.134.1986 877-889 A series of upper Pliocene to Pleistocene sediment samples from DSDP Sites 582 and 583 (Nankai Trough, active margin off Japan) were investigated by organic geochemical methods including organic carbon determination, Rock- Eval pyrolysis, gas chromatography of extractable hydrocarbons, and kerogen microscopy. The organic carbon content is fairly uniform and moderately low (0.35 to 0.77%) at both sites, although accompanied by high sedimentation rates. The low organic matter concentrations are the result of the combined effect of several factors: low bioproductivity, oxic depositional environment, and dilution with lithogenic material. Organic petrography revealed a mixture of three maceral types: (1) fresh, green fluorescent alginites of aquatic origin probably transported by turbidites from the shelf edge, (2) gelified huminites and paniculate liptinites derived from the erosion of unconsolidated peat, and (3) highly reflecting inertinites derived from continental erosion. By a combination of organic petrography and Rock-Eval pyrolysis results, the organic matter is characterized as mainly type III kerogen with a slight tendency to a mixed type II-III. During Rock-Eval pyrolysis, a mineral matrix effect on the generated hydrocarbons was observed. The organic matter in all sediments has a low level of maturity (below 0.45% Rm) and has not yet reached the onset of thermal hydrocarbon generation according to several geochemical maturation parameters. This low maturity is in contrast to anomalously high extract yields at both sites and large hydrocarbon proportions in the extracts at Site 583. This contrast may be due to early generation of polar compounds and perhaps redistribution of hydrocarbons caused by subduction tectonics. Carbon isotope data of the interstitial hydrocarbon gases indicate their origin from bacterial degradation of organic matter, although only very few bacterially degraded maceral components were detected. 133.8543 133.9138 31.775 31.835 133.88335757142855 31.805601142857142 1982-06-28T00:00:00 1982-07-08T00:00:00 DSDP Deep Sea Drilling Project https://www.deepseadrilling.org/ Deep Sea Drilling Project DSDP 4 CC-BY-3.0 Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/ Sample code/label | Sample label | DSDP/ODP/IODP sample designation | Sample comment | Area/locality | Area | Period | Lithology/composition/facies | Lithology | Carbon, organic, total | TOC | Element analyser CS, LECO | Comment | Rock eval pyrolysis (Espitalié et al. 1977) | Hydrogen index, mass HC, per unit mass total organic carbon | HI, HC/TOC | Oxygen index, mass CO2, per unit mass total organic carbon | OI, CO2/TOC | Production index, S1/(S1+S2) | PI | Pyrolysis temperature maximum | Tmax | Rock eval pyrolysis (Behar et al., 2001) | Huminite reflection | Humi refl | Huminite reflection, standard deviation | Humi refl std dev | Of sclerotinite or semifusinite grain | Reflection, minimum | Refl min | Huminite/vitrinite ratio | Huminite/vitrinite | Flow-blending extraction technique (Radke et al., 1978) | Inertinite | Amporphous | Humic compounds | Hum comp | Particulate liptinite B (sporinite-cutinite-suberinite-resinite). #11 - mainly resinite & cutinite; #16 - mainly resinite; #18 - including 3% resinite | Liptinite | Particulate liptinite A (phytoclasts and zooclasts) | Alginite | Amorphous liptinite (sapropelinite I and II) | Solid | Bitumen | Bitum | 25-31 | Carbon Preference Index | CPI | Peak area integration using a Kratos-Instem Datachrom II system | 29 | 27-29 | Pristane/n-heptadecane ratio | Pr/C17 | Pristane/n-octadecane | Pr/C18 | Pristane/Phytane ratio | Pr/Phy | Extract | of Corg | C15+ of Corg | Hydrocarbons | HC | Gas chromatography | C15+ saturated; of extract | C15+ aromatic; of extract | Including residue; of extract | NSO-fraction (fraction of polar compounds) | NSO fraction | Liquid chromatography supplement citable method19 method33 method5059 method6328 method6640 method7791 method7905 method7906 param103488 param120648 param121283 param121284 param121285 param121295 param14933 param15373 param1570 param18011 param21498 param24423 param24424 param2834 param45193 param5010 param5029 param5032 param5225 param53101 param67 param68 param752 param790 param808 param8402 param92437 param97819 pi24441 author10237 author10263 author20090 author24441 geocode1599 geocode1600 geocode1601 inst41 license101 project4 ref37843