Alkali-rich igneous rocks and related Au and Cu large and superlarge deposits in China

【Abstract】 The alkali-rich igneous rocks in China occur as fifteen linear distributed belts of each extending several hundreds to several thousands kilometers in length. These include most types of alkali-rich igneous rock categories discovered worldwide. The related Au, Cu large and superlarge deposits or metallogenic focus-areas include Dongping, Guilaizhuang, Yulong, etc. Direct and indirect genetic links have been found between alkali-rich igneous rocks and Au, Cu mineralization. The petrogenesis and metallogenesis of the alkali-rich igneous rocks are mainly controlled by (1) mantle enrichment, (2) strong interaction between mantle and crust, (3) lower contens of sulfur, high 2Ofand high contents of volatiles, (4) the significant turn of regional tectonic framework from compress to extension and (5) the strong change of regional lithosphere structure.更多还原