A SEM study of dissolution textures of detrital feldspars in Proterozoic sandstones, Sweden.

SEM examination of Proterozoic sandstones from Sweden reveals that diagenetic dissolution of detrital K-feldspar, microperthite, albite, and oligoclase has resulted in a variety of etching patterns. The results of this investigation indicate that there are variations in the intensity and, commonly, pattern of feldspar dissolution between the two rock units studied. These variations are principally related to the effect of the difference in T-P and hydrologic (based on porosity data) conditions. The lower diagenetic temperature (= or >150oC) and higher porosity of the Visingso Group compared to the Dala Sandstone (= or >200oC) have presumably resulted in maintenance of low ionic activity in pore solutions and thereby the relatively extensive dissolution of feldspar grains.-from Authors