Accumulation rates and composition of organic matter in sediments off Peru

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.

Peru: a commercial and industrial handbook,

Mode of access: Internet.

An an[n]otated bibliography of rural development, urbanization, and levels of living in Peru /

"December 1979."

Frankfort Harbor maintenance dredging, revision of disposal plan to incorporate changes in the nearshore and slternative deepwater placement of dredged materials, evaluation and EA B1; FONSI : environmental impact statement.

Mode of access: Internet.

Peru, agricultural cooperative federations development : project paper : proposal and recommendations for the review of the Development Loan Committee /

"Unclassified."

The cabildo in Peru under the Hapsburgs : a study in the origins and powers of the town council in the Viceroyalty of Peru, 1530-1700.

Bibliography: p. 285-298.

National survey of hazardous waste generators and treatment, storage, and disposal facilities regulated under RCRA in 1981.

Mode of access: Internet.

Handbook, septage treatment and disposal.

"EPA-625/6-84-009."

Environmental regulations and technology : use and disposal of municipal wastewater sludge /

At head of title: Technology transfer, EPA 625/10-84-003.

Handling and disposal of sludges from combined sewer overflow treatment : phase 1, characterization /

Mode of access: Internet.

Handling and disposal of sludges from combined sewer overflow treatment : phase II, impact assessment /

Mode of access: Internet.

1978 Atlantic 3800-meter radioactive waste disposal site survey : sedimentary, micromorphologic and geophysical analyses /

"Prepared June 1979."