Amphibole mineral chemistry of amphibolites from the Makran accretionary complex (southeast of Iran)

Amphibolites are a major component of the northern Makran ophiolite belts. They include both foliated and massive types. They are diverse in mineralogy and include amphibolite, garnet-pyroxene amphibolite, and epidote-garnet amphibolite. In addition to plagioclase and amphibole, which are the main constituent phases, other minerals such as zircon, sphene and quartz are also found in amphibolites. According to mineral chemistry, the amphiboles in these rocks are calcic type, and compositionally range from magnesian to ferrohornblende. Geothermobarometry of the amphiboles indicates a pressure ≤ 7 kbar (4-6 kbar) and a temperature range of 750-800°C. Thus, geothermobarometry of amphiboles shows that the Makran amphibolites were metamorphosed at high-temperature and low to medium pressure metamorphic facies (Abukuma-type metamorphism).