Comment on "Lack of enhanced preservation of organic matter in sediments under the oxygen minimum on the Oman Margin" by T.F. Pedersen, G.B. Shimmield, and N.B. Price

Abstract

A comment on the study on the lack of enhanced preservation of organic matter in sediments under the oxygen minimum on the Oman Margin is given. As such a negative correspondence between productivity and organic enrichment was pointed out which rules out the possibility of settling flux of organic carbon being the principal control on the accumulation of organic matter in the marine sediments. Observations indicated the effectiveness of oxygen minimum zone stress and vital role of anoxia in the enrichment and preservation of organic matter. No correlation between the abundance of organic matter and the bottom water oxygen concentration merits a discursion. It was felt that the observed C/N ratio could be the effect of denitrification under anoxic conditions and under such conditions it is difficult to determine the empirical relationship between C/N and dissolved oxygen. It was proposed that the inter play of various factors, such as texture of sediments rate of sedimentation, productivity, bottom currents, shelf width, slope gradient, in an exclusively anoxic milieu, play a decisive role in the preservation and spatially variable concentration of organic carbon