Heggie, David T; Boreham, C J; Summons, Roger E (1992): Geochemistry of ODP Sites 123-765 and 123-766. PANGAEA, https://doi.org/10.1594/PANGAEA.760923, Supplement to: Heggie, DT et al. (1992): Biomarker and pyrolysis geochemistry of organic matter from Argo and Gascoyne Abyssal Plain sediments, northeastern Indian Ocean. In: Gradstein, FM; Ludden, JN; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 123, 215-224, https://doi.org/10.2973/odp.proc.sr.123.168.1992
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The sediments of the Argo and Gascoyne abyssal plains are generally lean in organic matter, are immature, and contain hydrocarbons trapped during sediment deposition rather than those generated during sediment catagenesis.
TOC concentrations in the Argo Abyssal Plain Cenozoic sediments are 0.5 wt%, and organic matter appears to be from mixed marine and reworked, degraded, organic matter sources, with the latter being contributed by turbidity flows from the nearby continental margin. TOC concentrations within the Cenozoic sediments of the Gascoyne Abyssal Plain are mostly undetectable (<0.1 wt%).
Biomarker distributions determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GCMS) indicate that organic matter extracted from the Lower Cretaceous sediments from both sites is predominantly marine with varying contributions from terrestrial organic matter. The specific marine biomarker, 24-n-propylcholestane is in relatively high abundance in all samples. In addition, the relatively high abundance of the 4-methylsteranes with the 23,24-dimethyl side chain (in all samples) indicates significant dinoflagellate contributions and marine organic matter.
The ratios of n-C27/n-C17 reflect relative contributions of marine vs. terrestrial organic matter. TOC, while generally low at Argo, is relatively high near the Barremian/Aptian boundary (one sample has a TOC of 5.1 wt%) and the Aptian/Albian boundary (up to 1.3 wt% TOC), and two samples from the Barremian and Aptian sections contain relatively high proportions of terrestrial organic carbon. TOC values in the Lower Cretaceous sediments from Gascoyne Abyssal Plain are low (<0.1 wt%) near the Aptian/Barremian boundary. TOC values are higher in older sediments, with maxima in the upper Barremian (1.02 wt%), the Barremian/Hauterivian (0.6 wt%), and Valanginian (1.8 wt%). Sediments from the upper Barremian contain higher amounts of terrestrial organic carbon than older sediments.
Median Latitude: -17.932022 * Median Longitude: 114.054212 * South-bound Latitude: -19.932000 * West-bound Longitude: 110.454100 * North-bound Latitude: -15.976000 * East-bound Longitude: 117.575200
Date/Time Start: 1988-09-07T00:00:00 * Date/Time End: 1988-10-26T00:00:00
123-765 * Latitude: -15.976000 * Longitude: 117.575200 * Date/Time Start: 1988-09-07T00:00:00 * Date/Time End: 1988-10-18T00:00:00 * Elevation: -5728.0 m * Penetration: 2564 m * Recovery: 732.7 m * Location: South Indian Ridge, South Indian Ocean * Campaign: Leg123 * Basis: Joides Resolution * Device: Composite Core (COMPCORE) * Comment: 134 cores; 1265.9 m cored; 0 m drilled; 57.9% recovery
123-765B * Latitude: -15.976000 * Longitude: 117.575200 * Date/Time Start: 1988-09-08T02:30:00 * Date/Time End: 1988-09-11T04:25:00 * Elevation: -5728.0 m * Penetration: 395.6 m * Recovery: 270.92 m * Location: South Indian Ridge, South Indian Ocean * Campaign: Leg123 * Basis: Joides Resolution * Device: Drilling/drill rig (DRILL) * Comment: 41 core; 395.6 m cored; 0 m drilled; 68.5 % recovery
123-765C * Latitude: -15.976000 * Longitude: 117.575200 * Date/Time Start: 1988-09-11T04:25:00 * Date/Time End: 1988-09-22T10:30:00 * Elevation: -5728.0 m * Penetration: 963.9 m * Recovery: 373.35 m * Location: South Indian Ridge, South Indian Ocean * Campaign: Leg123 * Basis: Joides Resolution * Device: Drilling/drill rig (DRILL) * Comment: 65 cores; 613.7 m cored; 0 m drilled; 60.8 % recovery
Datasets listed in this publication series
- Heggie, DT; Boreham, CJ; Summons, RE (1992): (Table 1) Organic geochemistry of ODP Leg 123 sites. https://doi.org/10.1594/PANGAEA.760916
- Heggie, DT; Boreham, CJ; Summons, RE (1992): (Table 2) Organic geochemistry of ODP Site 123-765. https://doi.org/10.1594/PANGAEA.760917
- Heggie, DT; Boreham, CJ; Summons, RE (1992): (Table 3) Organic geochemistry of ODP Hole 123-766A. https://doi.org/10.1594/PANGAEA.760918
- Heggie, DT; Boreham, CJ; Summons, RE (1992): (Table 4) Extractable organic matter and gas chromatography analsyes of ODP Leg 123 samples. https://doi.org/10.1594/PANGAEA.760919
- Heggie, DT; Boreham, CJ; Summons, RE (1992): (Table 5) Biomarkers in ODP Leg 123 samples. https://doi.org/10.1594/PANGAEA.760920
- Heggie, DT; Boreham, CJ; Summons, RE (1992): (Table 6) Maturation-dependent biomarkers in ODP Leg 123 samples. https://doi.org/10.1594/PANGAEA.760922