The Discovery of Gold Occurrences in Early Triassic Metatrachyandesıtes and Their Enclaves in Nnw Konya/Turkey

Abstract

Early Triassic trachyandesitic metavolcanic is located in Afyon zone, NW Konya. It includes relatively abundant enclaves, which are angular to spheroidal/ellipsoidal in shape, with host rock contact varying from straight/sharp to undulated/transitional. The enclaves with gold mineralizations are greenish to yellowish in color whereas gold-free enclaves have blackish to grayish colors. They contain both relict igneous (plagioclase, sanidine, clinopyroxene, hornblende and biotite) and overprinting metamorphic mineral assemblages (white mica, chlorite, Na-amphibole, epidote, sphene, and opaque oxides) in a hypocrystalline porphyritic texture. The enclaves exhibit similarity to its host for its petrographical and petrological characteristics, with similar patterns in spider diagrams. Both metavolcanic and its enclave are predominantly metatrachyandesite in composition with alkaline affinity, exhibiting strong enrichment of LILE (e.g. 1.31-6.69 wt. % K2O) and LREEs, and depletion of HFSE and HREEs, with negative Eu, Sr, Nb, Ta and Ti anomalies. It was found out that the samples host gold, up to 1633 ppb in enclaves, Pb and Cu mineralizations. The values determined could indicate existence of an economic gold mining in the region in relation with Triassic volcanism and magma mixing/mingling, and need further exploration studies.