Dioctahedral corrensite from Permian Red Beds, Lisbon Valley, Utah.

Abstract

Corrensite occurs as grain coatings in marine and aeolian sandstones of the Permian Cutler formation in Utah. It is suggested that smectite was a precursor of the corrensite. Three stages of mineral precipitation have been recognized: quartz precipitated early as grain overgrowths, followed by the formation of authigenic clay minerals, and later calcite cementation which destroyed much of the original rock fabric. The corrensite + illite/smectite in the sandstones were probably formed by rising hydrothermal fluids interacting with smectite and an Al-bearing phase in conditions of T approx 100oC, low pH, and low dissolved silica.-R.E.S.