Chemistry of chlorite from the K-silicate-sericitic alteration in Elatsite porphyry Cu-Au deposit, Bulgaria

The K-silicate-sericitic alteration is one of the well-preserved hydrothermal alterations at the Elatsite porphyry-copper gold deposit (PCGD). It is observed in all lithological varieties, but shows asymmetric distribution of the secondary products. The alteration is genetically related with the occurrence of the K-silicate and Na-Ca-K-silicate alteration. The K-silicate-sericitic alteration has simple mineral content which includes mainly chlorite and sericite. The temperature of formation of the alteration is estimated between 250–268 °C.