Accumulation rates and composition of organic matter in sediments off Peru
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| Format: | Dataset Open Access |
| Sprache: | en |
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PANGAEA
1990
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| _version_ | 1867167664689905664 |
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| author | ten Haven, H Lo Littke, Ralf Rullkötter, Jürgen Stein, Ruediger Welte, Dietrich Hugo |
| author_facet | ten Haven, H Lo Littke, Ralf Rullkötter, Jürgen Stein, Ruediger Welte, Dietrich Hugo |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Deep-sea sediment samples from three Ocean Drilling Program (ODP) Leg 112 sites on the Peru continental margin were investigated, using a number of organic geochemical and organic petrographic techniques, for amounts and compositions of the organic matter preserved. Preliminary results include mass accumulation rates of organic carbon at Site 679 and characteristics of the organic facies for sediments from Sites 679, 681, and 684. Organic-carbon contents are high, with few exceptions. Particularly high values were determined in the Pliocene interval at Site 684 (4%-7.5%) and in the early Pliocene to Quaternary section of Hole 679D (2%-9%). Older sediments at this site have distinctively lower organic-carbon contents (0.2%-2.5%). Mass accumulation rates of organic matter at Site 679 are 0.02 to 0.07 g carbon/cm**2/k.y. for late Miocene to early Pliocene sediments and higher by a factor of 5 to 10 in the Quaternary sediments. The organic matter in all samples has a predominantly marine planktonic and bacterial origin, with minor terrigenous contribution. Organic particle sizes are strikingly small, so that only a minor portion is covered by visual maceral analysis. Molecular organic-geochemical data were obtained for nonaromatic hydrocarbons, aromatic hydrocarbons (including sulfur compounds), alcohols, ketones, esters, and carboxylic acids. Among the total extractable lipids, long-chain unsaturated ketones from Prymnesiophyte algae strongly predominate among the gas chromatography (GC) amenable components. Steroids are major constituents of the ketone and free- and bound-alcohol fractions. Perylene is the most abundant aromatic hydrocarbon, whereas in the nonaromatic hydrocarbon fractions, long-chain n-alkanes from higher land plants predominate, although the total terrigenous organic matter proportion in the sediments is small. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_753802 |
| institution | PANGAEA |
| language | en |
| publishDate | 1990 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Accumulation rates and composition of organic matter in sediments off Peru ten Haven, H Lo Littke, Ralf Rullkötter, Jürgen Stein, Ruediger Welte, Dietrich Hugo 112-679C; 112-679D; 112-681C; 112-684C; DRILL; Drilling/drill rig; Joides Resolution; Leg112; Ocean Drilling Program; ODP; South Pacific Ocean Deep-sea sediment samples from three Ocean Drilling Program (ODP) Leg 112 sites on the Peru continental margin were investigated, using a number of organic geochemical and organic petrographic techniques, for amounts and compositions of the organic matter preserved. Preliminary results include mass accumulation rates of organic carbon at Site 679 and characteristics of the organic facies for sediments from Sites 679, 681, and 684. Organic-carbon contents are high, with few exceptions. Particularly high values were determined in the Pliocene interval at Site 684 (4%-7.5%) and in the early Pliocene to Quaternary section of Hole 679D (2%-9%). Older sediments at this site have distinctively lower organic-carbon contents (0.2%-2.5%). Mass accumulation rates of organic matter at Site 679 are 0.02 to 0.07 g carbon/cm**2/k.y. for late Miocene to early Pliocene sediments and higher by a factor of 5 to 10 in the Quaternary sediments. The organic matter in all samples has a predominantly marine planktonic and bacterial origin, with minor terrigenous contribution. Organic particle sizes are strikingly small, so that only a minor portion is covered by visual maceral analysis. Molecular organic-geochemical data were obtained for nonaromatic hydrocarbons, aromatic hydrocarbons (including sulfur compounds), alcohols, ketones, esters, and carboxylic acids. Among the total extractable lipids, long-chain unsaturated ketones from Prymnesiophyte algae strongly predominate among the gas chromatography (GC) amenable components. Steroids are major constituents of the ketone and free- and bound-alcohol fractions. Perylene is the most abundant aromatic hydrocarbon, whereas in the nonaromatic hydrocarbon fractions, long-chain n-alkanes from higher land plants predominate, although the total terrigenous organic matter proportion in the sediments is small. |
| title | Accumulation rates and composition of organic matter in sediments off Peru |
| topic | 112-679C; 112-679D; 112-681C; 112-684C; DRILL; Drilling/drill rig; Joides Resolution; Leg112; Ocean Drilling Program; ODP; South Pacific Ocean |
| url | https://doi.org/10.1594/PANGAEA.753802 |