FIGURE 9.10 The percentage of opal rain rate that is preserved versus the opal rain rate. The dashed lines indicate the model opal preservation estimates of Broecker and Peng (1982). Their model suggests that the preservation is proportional to the opal rain rate, the dissolution rate of pure opal, and the burial rate of non-opal materials. The effects of different non-opal accumulation rates are shown (At = 1000, 2000, and 3000 µg/cm2/yr). For all of the model lines a pure opal dissolution rate of 3000 µg/cm2/yr was used.

THE RELATIONSHIP BETWEEN ALUMINOSILICATE AND BIOGENIC RAIN RATES

The aggregation of clays into larger, more rapidly settling particles is necessary to account for the discrete patterns of clay mineral distributions in deep ocean sediments. The direct relationship between the flux of organic carbon and aluminosilicate debris (Honjo, 1982; Deuser et al., 1983) indicates some biogenic aggregation mechanism. Indiscriminate filtering of zooplankton, which repackage fine-grained aluminosilicate debris into rapidly sinking fecal pellets, could account for the carbon-aluminosilicate relationship. Alternatively, organic-rich flocs or marine snow may incorporate fine, inorganic particles. Although correlation between aluminosilicate or alumi-

FIGURE 9.11 Organic carbon flux versus Al flux for site S samples. Only samples from the uppermost trap (700 m) deployed at this site were used. The different samples shown are the seasonal cups, which for S was only four samples.



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