Mineralogy of graphite-bearing schists and calculation of graphitization temperature in the Band-e-Cherk district, Anarak metallogenic zone

The Band-e-Cherk exploration area is located in the structural zone of central Iran, northeast of the city of Ardestan, and the Anarak metallogenic zone. The outcropping rock units in this area include Kuh-e-Dom metamorphic schist complex and recrystallized limestone, Cretaceous limestone sediments, Paleocene conglomerate, Eocene volcanic rocks composed of andesite, andesite-basalt, trachyte, as well as tuff and diorite intrusions. The Kuh-e-Dom metamorphic complex is of lower Paleozoic age, and includes muscovite schist to graphite-muscovite schist, epidote-hornblende-calc schist, muscovite-chlorite schist, calc schist, crystalline limestone and marble. Graphite mineralization is concentrated along the schistose surfaces of graphite-muscovite schist units, and quartz, kaolinite, illite, muscovite (sericite), orthoclase and dickite minerals are other minerals. Comparison of the temperature range for the formation of high-quality flake graphite, which is formed at temperatures above 450°C, mainly between 470 and 560°C (in the amphibolite facies), with the temperature obtained by interpreting the results of Raman spectroscopy on high-quality graphite-bearing samples from the Band-e-Cherk area, shows that graphitization in the Band-e-Cherk area is of an amorphous type and at a temperature lower than 450°C (436°C). Therefore, it was formed under the temperature conditions associated with the greenschist metamorphic facies.