Studies On Sulfide-metal Oxide Inclusions From Mesozoic Intrusions And Their Rock Xenoliths In Tongling, Anhui Province

The Tongling area in Anhui Province is located in the middle segment of the copper, iron and gold metallogenic belt in the Middle-lower Valley of Yangtze River. In this area are distributed a great number of intermediate to acidic intrusions of shoshonitic and high-K calc-alkaline series with various xenoliths, showing a feature of mixing material sources of mantle with crust.A set of sulfide and metal oxide inclusions have been observed in phenocrysts from the intrusions and minerals from the xenoliths, and a detailed study has been carried out on these inclusions, with a focus on their origin and evolution process.The following are major achievement obtained in this dissertation:1. Amphibole and pyroxene are defined as the major host minerals of sulfide inclusions, and sphene and apatite as secondary host minerals, which maybe reported for the first time in the world.2. The shape, distribution, mineral assemblage and variety of components of sulfide-oxide inclusions, especially their origin and its relation to the process for formation of the two series of magma rocks are preliminary found out, with temperature and pressure of"ovulation"of sulfide inclusions within amphibole and pyroxene being calculated;3. The derivation and composition of the basic end-member magma as a part of magma for the formation of meladiorite xenoliths are re-defined based on the characteristics of sulfide-metal oxide inclusions.4. The primary rock types of basement metamorphic rocks represented by the rock xenoliths of amphibole-plagioclase gneiss and plagioclase- amphibolite and their geochemical characteristics are preliminarily constrained.5. The relationship between contents of chromium, nickel and copper and types and quantities of sulfide and metal oxide inclusions is preliminarily demonstrated.These achievements result in widening of the extension of sulfide and oxide inclusions study.