Although there has been considerable interest in the consolidation of marine carbonate sediments, there has been little actual testing of carbonates. For our study, 34 sediment samples from the Gulf of Mexico, Florida Bay, and the Bahama Banks were tested in an Anteus back-pressure consolidometer to determine their consolidation characteristics. Eleven of the sediment samples were less than 50% calcium carbonate. Of the samples containing more than 70% carbonate, 12 samples were of Holocene age, deposited since Wisconsin glaciation, and 11 samples from the continental slope west of Florida were of Pleistocene-Pliocene age.

The samples were overconsolidated; that is, there was more structural strength than would be expected from the effect of the present overburden. There was a definite relation between the percentage of fine material present and the resulting consolidation.

In general, the results of consolidation tests were similar to those found by testing noncarbonate silty clay. The main differences observed were between the older carbonate sediments and the noncarbonate or partly carbonate sediments. Under a similar final load, the carbonate sediments did not compact to as low a porosity as the noncarbonates. This could be caused by differences in particle shape and strength of the individual particles. Age and incipient cementation must play a part because the Holocene carbonate sediments did not show this characteristic. This conclusion is supported by the results reported by several other workers--that the strength of carbonate sediments increases with age.

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