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.

Dictionary of organic compounds; the constitution and physical and chemical properties of the principal carbon compounds and their derivatives, together with the relevant literature references.

Accompanied by "Supplement ... [to vol. 2-3]" (2 v.) Published: New York, Oxford University Press, 1943.

Dictionary of organic compounds; the constitution and physical and chemical properties of the principal carbon compounds and their derivatives, together with the relevant literature references.

Errata slips inserted.

The versenes, powerful organic chelating agents for the exacting chemical control of cations.

Mode of access: Internet.

Commercial organic analysis. A treatise on the properties, proximate analytical examination, and modes of assaying the various organic chemicals and products employed in the arts, manufactures, medicine, etc., with concise methods for the detection and determination of their impurities, adulterations, and products of decomposition.

v.I. Introduction. Alcohols, neutral alcoholic derivatives, sugars, starch and its isomers, vegetable acids, etc. 2d ed., rev. & enl.--v.II. Fixed oils, fats, waxes, glycerol, nitroglycerin and nitroglycerin explosives. Hydrocarbons, petroleum and coal-tar products, asphalt, phenols and creosotes. 2d ed., rev. & enl.--v. III, pt.I. Acid derivatives of phenols, aromatic acids, resins, and essential oils. Tannins, dyes, and colouring matters, writing inks. 2d ed., rev. & enl.--v. III, pt.II. Amines and ammonium bases, hydrarzines, bases from tar, vegetable alkaloids. 2d ed., rev. and enl. [1892] --v.III, pt.III. Vegetable alkaloids (concluded), non-basic vegetable bitter principles, animal bases, animal acids, cyanogen and its derivatives. 2d ed., rev. & enl. [1896]--v.IV. Proteids and albuminous principles, proteoïds or albuminoïds. 2d ed., rev. & enl. 1898.

Allen's commercial organic analysis; a treatise on the properties, modes of assaying, and proximate analytical examination of the various organic chemicals and products employed in the arts, manufactures, medicine, etc., with concise methods for the detection and estimation of their impurities, adulterations, and products of decomposition ...

Vols. 3-9 edited by W.A. Davis and Samuel S. Sadtler.

Organic compounds in surface sediments from the Pakistan continental margin

In order to assess whether the oxygen-minimum zone (OMZ) in the Arabian sea has an effect on the preservation and composition of organic matter in surface sediments we investigated samples from three different transects on the Pakistan continental margin across the OMZ. In addition to determining the total amount of organic carbon (TOC), we analyzed the extractable lipids by gas chromatography, combined gas chromatography/mass spectrometry, and compound-specific stable carbon isotope measurements. The extractable lipids are dominated by marine organic matter as indicated by the abundance of lipids typical of marine biota and by the bulk and molecular isotopic composition. Sediments from within the OMZ are enriched in organic carbon and in several extractable lipids (i.e. phytol, n-alcohols, total sterols, n-C35 alkane) relative to stations above and below this zone. Other lipid concentrations, such as those of total n-fatty acids and total n-alkanes fail to show any relation to the OMZ. Only a weak correlation of TOC with mineral surface area was found in sediments deposited within the OMZ. In contrast, sediments from outside the OMZ do not show any relationship between TOC and surface area. Among the extractable lipids, only the n-alkane concentration is highly correlated with surface area in sediments from the Hab and Makran transects. In sediments from outside the OMZ, the phytol and sterol concentrations are also weakly correlated with mineral surface area. The depositional environment of the Indus Fan offers the best conditions for an enhanced preservation of organic matter. The OMZ, together with the undisturbed sedimentation at moderate rates, seems to be mainly responsible for the high TOC values in this area. Overall, the type of organic matter and its lability toward oxic degradation, the mineral surface area, the mineral composition, and possibly the secondary productivity by (sedimentary) bacteria also appear to have an influence on organic matter accumulation and composition.

Formic acid mixing ratio (CIMS) and 3D wind data, plus SOSAA model runs -- Hyytiälä, Finland, Apr-Jun 2014

These are data of eddy covariance flux measurements of formic acid (HCOOH), performed by a chemical ionization mass spectrometer (CIMS) over a boreal forest canopy in Hyytiälä, Finland, in spring/summer 2014. Results from the 1-D chemical transport model runs using SOSAA (Simulate Organic vapours, Sulphuric Acid and Aerosols) are included as well. The data accompany a submission of a manuscript to Geophysical Research Letters for consideration for publication (Schobesberger et al.).