@article {719,
	title = {Sedimentary organic matter preservation: A test for selective degradation under oxic conditions},
	journal = {American Journal of Science},
	volume = {299},
	year = {1999},
	note = {263rmTimes Cited:194Cited References Count:104},
	month = {Sep-Nov},
	pages = {529-555},
	abstract = {We report here a test of the hypothesis that the extent of organic matter preservation in continental margin sediments is controlled by the average period accumulating particles reside in oxic porewater immediately beneath the water/sediment interface. Oxygen penetration depths, organic element compositions, and mineral surface areas were determined for 16 sediment cores collected along an offshore transect across the Washington continental shelf, slope, and adjacent Cascadia Basin. Individual amino acid, sugar, and pollen distributions were analyzed for a 11 to 12 cm horizon from each core, and (14)C-based sediment accumulation rates and stable carbon isotope compositions were determined from depth profiles within a subset of six cores from representative sites. Sediment accumulation rates decreased, and dissolved O(2) penetration depths increased offshore along the sampling transect. As a result, oxygen exposure times (OET) increased seaward from decades (mid-shelf and upper slope) to more than a thousand years (outer Cascadia Basin). Organic contents and compositions were essentially constant within individual sediment cores but varied consistently with location. In particular, organic carbon/surface area ratios decreased progressively offshore and with increasing OET. Three independent compositional parameters demonstrated that the remnant organic matter in farther offshore sediments is more degraded. Both concentration and compositional patterns indicated that sedimentary organic matter exhibits a distinct and reproducible "oxic effect" OET helps integrate and explain organic matter preservation in accumulating continental margin sediments and hence provides a useful tool for assessing transfer of organic matter from the biosphere to the geosphere.},
	issn = {0002-9599},
	doi = {10.2475/ajs.299.7-9.529},
	author = {Hedges, J. I. and Hu, F. S. and Devol, A. H. and Hartnett, H. E. and Tsamakis, E. and Keil, R. G.}
}
@article {761,
	title = {Influence of oxygen exposure time on organic carbon preservation in continental margin sediments},
	journal = {Nature},
	volume = {391},
	year = {1998},
	note = {Yv594Times Cited:355Cited References Count:27},
	month = {Feb 5},
	pages = {572-574},
	abstract = {Today, over 90\% of all organic carbon burial in the ocean occurs in continental margin sediments(1). This burial is intrinsically linked to the cycling of biogeochemically important elements (such as N, P, S, Fe and Mn) and, on geological timescales, largely controls the oxygen content of the atmosphere(2-4). Currently there is a volatile debate over which processes govern sedimentary organic carbon preservation(5-8). In spite of numerous studies demonstrating empirical relationships between organic carbon burial and such factors as primary productivity(9), the flux of organic carbon through the water column(10), sedimentation rate(11,12), organic carbon degradation rate(13), and bottom-water oxygen concentration(8,14), the mechanisms directly controlling sedimentary organic carbon preservation remain unclear. Furthermore, as organic carbon burial is the process that, along with pyrite burial(15), balances O-2 concentrations in the atmosphere, it is desirable that any mechanism proposed to control organic carbon preservation include a feedback buffering atmospheric oxygen concentrations over geological time. Here we compare analyses of sediments underlying two regions of the eastern North Pacific Ocean, one which has oxygen-depleted bottom waters and one with typical oxygen distributions. Organic carbon burial efficiency is strongly correlated with the length of time accumulating particles are exposed to molecular oxygen in sediment pore waters. Oxygen exposure time effectively incorporates other proposed environmental variables(8-14), and may exert a direct control on sedimentary organic carbon preservation and atmospheric oxygen concentrations.},
	issn = {0028-0836},
	doi = {10.1038/35351},
	author = {Hartnett, H. E. and Keil, R. G. and Hedges, J. I. and Devol, A. H.}
}
