Range, velocity, and material flux of compaction flow in growing sedimentary sequences

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ABSTRACT

In growing sedimentary sequences range and velocity of vertically ascending pore water (advection) can be determined quantitatively by using a simple graphical method. During continuing deposition and maintenance of compaction equilibrium, the pore water from deeper layers cannot reach the sediment-water interface. Range and velocity of advective flow decrease from top to bottom of a sequence and depend on the thickness affected by compaction. The velocity of pore water flow as well as the transport of solutes by advective flux are proportional to the sedimentation rate. Compaction flow can also result from under-con-solidation and diagenetic reduction of pore space. At the sediment-water interface, a direct contact between the ascending pore water and the overlying water body is feasible only under special conditions (interrupted sedimentation over under-consolidated material, erosion). These results are demonstrated on geometric models of sedimentary sequences, on experimentally deposited clay, and on selected examples of the Deep Sea Drilling Project.

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