Carbonate oozes

The matrices and sources of the sediments listed in Table 4.2 are sometimes unclear. Those that are known are highly weighted toward clastic (quartz- and aluminosilicate-rich) marine sediments from coastal environments. Some of these reference materials, such as MESS-3 (NRC-Canada), MAG-1 (USGS) and the Arabian Sea and Pacific Ocean samples (IAEA 315, and 368), could provide excellent examples of clastic marine sediment representing the main repositories of organic matter in the ocean (Hedges and Keil, 1995). The listed materials fail to include both open-ocean opal and carbonate oozes, as well as pelagic red clays. 

In contrast to the total sedimentary carbonate mass, oceanic carbonate oozes have a decay constant of 0.02 ma 1, about 10 times that of the global carbonate mass. The pelagic oozes compose about 8% of the global sedimentary carbonate mass but presently account for about 60% of carbonate deposition. 

At the outer edge of the shelf and in the upper part of the continental slope, silty and clayey coquina and lowly-carbonate oozes are mostly developed. The sediments of the continental slope (as well as those of the major part of the deep-water basin of the Black Sea) are represented by clayey-calcareous (coc-colith) oozes. 

Droxler A. W., Schlager W., and Wallon C. C. (1983) Quaternary aragonite cycles and oxygen-isotopic records in Bahamian carbonate ooze. Geology 11, 235-239. 

Seawater Pore water Siliceous oozes Carbonate oozes Pelagic days Clastic sediments Altered basalts Fresh basalts Layer-3 gabbros Continental sediments Sandstones Limestones Shales... 

Lind.I.L. 1993.DjoOcean Drilling Program, Scientific Results.Vol 30. p673-686. 

Figure 1 Carbonate oozes in the deep sea are dominated by the skeletal remains of (A) planktonic foraminifera x 50 magnification) and (B) coccolithophorids x 6000 magnification). Specimens shown here were isolated from a Caribbean sediment core.

With time and burial, carbonate oozes undergo a progressive sequence of diagenesis and are transformed first to chalk and then to limestone through a combination of gravitational compaction,... 

Collectively, all of these sediments are enriched in 0 decreasing from siliceous oozes with the highest 3 0 values (>35 permil), carbonate oozes withintermediate 3 0 values ( 30 per mil), and clays ( 20 per mil depending on their provenance). Because deposition rates for pelagic sediments are very slow, millimeters per thousand years, the high 0 sedimentary layer is relatively thin (less than a few hundred meters). 

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