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Figure 138. (A) Uncompacted core from Rodriguez Key bank showing abundant sea grasses, an open burrow, and a mollusc shell near the bottom (from Shinn and Robbin, 1983). Circular grains are cross sections of the coralline alga Goniolithon. Flattened grains are Halimeda plates. The core was impregnated with resin before slicing. (B) Compacted core from Rodriguez Key bank; sediment was compressed under an extreme load (952 kg/cm², or 13,568 psi) for 34 days (from Shinn and Robbin, 1983). Note mashed wavy organic matter from sea grasses, obliteration of open burrows, complete absence of recognizable sea grasses, and closer packing of skeletal grains. Chemical compaction (organics dissolved under pressure) occurred in this core. psi = pounds per square inch.

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Coastal & Marine Geology Program > Center for Coastal & Watershed Studies > Professional Paper 1751