Ternary Feldspar Thermometry Research Articles

Ternary feldspar thermometry in granulites from the Oaxacan Complex, Mexico

Coexisting feldspars from across 2,000 km2 of the granulite facies Oaxacan Complex, southern Mexico exhibit variable amounts of solid solution from nearly binary (Ab-An and Ab-Or) to substantially ternary (Ab-An-Or). Reintegrated analyses of 21 coarsely exsolved perthite (AF)-plagioclase (PL) pairs yield AF=Or30–63 Ab30–56An2–15 and PL=Or1–2Ab70–84An11–28. These data have been used to test existing two feldspar geothermometers for this extended composition range.