Microtextures in recent and fossil caliche

Microtextures of calcite in recent caliche are similar to those of authigenic calcite in Upper Carboniferous, Permian and Lower Triassic continental sandstones and mudstones in the South-Central Pyrenees, Spain. Except for one profile in the Permian, no complete caliche profiles containing calcrete occur in the ancient deposits. It is suggested that the fossil authigenic calcite crystallized in early stages of diagenesis under climatic conditions favourable to the development of caliche.