Molecular evidence for degradation and preservation of organic matter in the anoxic Black Sea Basin

Journal Article · Mon Aug 01 04:00:00 EDT 1994 · Geochimica et Cosmochimica Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(94)90094-9· OSTI ID:6854351

Sun, Ming-Yu; Wakeham, S G ^[1]

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1. Skidaway Institute of Oceanography, Savannah, GA (United States)

Lipids were measured in a short core covering the past 150 years in the Black Sea, in order to examine the biogeochemical factors involved in the degradation and preservation of organic matter in anoxic sediments. Most of the degradation of labile compounds occurs in the upper 20 mm of the sediment, although for some compounds there appeared to be insignificant loss with increasing depth. A diagenetic model consisting of two pools of organic matter, labile and refractory, was used to calculate first-order degradation rate constants. From the rate constants, an order of relative reactivity was constructed for selected lipids in Black Sea sediment: fatty acids > neutral lipids; unsaturated and branched fatty acids > saturated fatty acids; isoprenoid alkenes > sterols and n-alkanols > n-alkanes, long-chain alkenones, long-chain alkyldiols, and long-chain alkylketols. Degradation rate constants were also used to estimate rain rates describing delivery of lipids to the sediment and accumulation rates are discussed in terms of their molecular structures, autochthonous vs. allochthonous sources, and rates of delivery to the sediment.

• OSTI ID: 6854351
• Journal Information: Geochimica et Cosmochimica Acta; (United States), Journal Name: Geochimica et Cosmochimica Acta; (United States) Vol. 58:16; ISSN GCACAK; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540320* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
ALCOHOLS
ANAEROBIC CONDITIONS
BLACK SEA
CARBON CYCLE
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
HYDROXY COMPOUNDS
LIPIDS
MATTER
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC MATTER
PRESERVATION
SEAS
SURFACE WATERS