Oxygenation and organic-matter preservation in marine sediments: Direct experimental evidence from ancient organic carbon-rich deposits

被引:92
|
作者
Moodley, L
Middelburg, JJ
Herman, PMJ
Soetaert, K
de Lange, GJ
机构
[1] Netherlands Inst Ecol, NIOO, KNAW, NL-4401 NT Yerseke, Netherlands
[2] Univ Utrecht, Inst Earth Sci, NL-3584 CD Utrecht, Netherlands
关键词
organic carbon; preservation; remineralization; nitrogen isotopes; carbon isotopes; sapropel;
D O I
10.1130/G21731.1
中图分类号
P5 [地质学];
学科分类号
0709 ; 081803 ;
摘要
Clarification of the factors involved in the formation of unusual ancient organic carbon-rich deposits (like eastern Mediterranean sapropels) is central in understanding oceanic carbon cycling. The role of oxygenation remains a subject of controversy primarily due to two major uncertainties: (1) it is unknown if ancient organic-rich deposits reflect an accumulation of refractory organic matter (OM) or oxygenation-related aberrant sediment OM recycling, and (2) although marine OM degradation may be slower under anoxic conditions, its ultimate impact on organic carbon (C-org) preservation over geological time remains unclear. Here we provide direct experimental evidence that the Corg in eastern Mediterranean S1 sapropells (deposited > 5 ka) is still highly reactive and that a shutdown in labile organic matter degradation under anoxic conditions played a key role in the formation of these deposits.
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页码:889 / 892
页数:4
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