Structural Ordering of Feldspars as an Indicator of the Temperature of Mineral-Forming Processes
摘要
Abstract
The processes of albite ordering were experimentally studied in the temperature range of 500–150°C at a pressure of 0.5–1 kbar in alkaline solutions of sodium hydroxide with excess silica. Our original experimental and literature data on the ordering of albite and sodic plagioclase were used to derive dependences for evaluating the temperature based on the degree of feldspar structural ordering. Temperatures were determined for plagioclase-bearing mineral assemblages of rocks from various greenschist-facies metamorphic complexes.