Petrographical, geochemical characteristics and ironmineralization of mafic massif at Tan Hoa area of Tan Chau, Tay Ninh

Abstract

The mafic massif at Tan Hoa area, Tan Chau, Tay Ninh (Hill 95) was detected in 1986 and was classified as Tay Ninh complex (K1tn, Nguyen Ngoc Hoa et al, 1995). Petrographical composition of this complex was clarified through the bores in 2013. It included gabbrodiorite, gabbronorite, gabbro, gabbropyroxenite and pyroxenite. The main mineral components were plagioclase, clinopyroxene, orthopyroxene and green hornblende. The secondary mineral was biotite. The accessory minerals are apatite, sphene, magnetite, pyrrhotite. Tay Ninh complex was in high content of titanium, rich in elements of Fe, Ti, V but low content of Rb, Sr, Y, Cs, Ba, Sm, Eu, Nd. The rare and trace elements standardized with primitive mantle and chondrite showed that their origin was from the deep, clear mantle and classified in rift on active continental margin pattern. Tay Ninh complex was characterized by its high anomalies in geophysics. The results of chemical and spectroscopic analysis, grinding and ore selection offered prospect of iron and titanium mineralization for complex.