Convective fluid flow and diagenetic patterns in domed sheets.

Analytical solutions have been obtained for the fluid flow and temperature fields for the case of a folded porous layer embedded in an impermeable medium heated from below and held at a constant temperature above. This corresponds to a layered sequence of rocks in which a permeable sand is bounded above and below by impermeable shales. The present results are limited to gently folded strata (small dip angles) but are quite general with regard to the actual layer geometry. The solutions depend on the fact that the temperature field can be uncoupled from the fluid flow when convection is weak. This results in a purely conductive temperature field which drives the fluid motion through buoyancy effects. It is shown that the dynamics of the system are most strongly influenced by the geometry of the porous layer and the ratio of thermal conductivities of the rocks. -from Authors