Precipitation patterns formed by self-organizing processes in porous media

摘要

We compare laboratory and field examples of self-organized mineral precipitates in porous media. Laboratoryntests of silver chromate precipitation in glass beads and glass bead ⁄ gel mixtures produce structures such as peri-nodic banding and mm-size spherules. These are morphologically similar to the varied forms of iron oxide precipi-ntates in the Jurassic Navajo Sandstone, Utah USA, that preserve records of former fluid redox boundaries in anporous and permeable sandstone. Experimental studies of periodic precipitates in porous media can providenvaluable insight for understanding the diagenetic history of similar precipitates in natural environments.