Metamorphic characteristics and carbon origin of Guokuishan graphite deposit

The Guokuishan graphite deposit in Heilongjiang Province is a large newly-discovered sedimentary metamorphic graphite deposit, and the study on the metamorphic characteristics and processes of the deposit and its carbon source is still a blank. The protolith of mining metamorphic rocks was reinstated through methods of petrology, petrochemistry and carbon isotope composition, and the stigma of degeneracy and ore genesis were also discussed in this paper. The results show that the metamorphism degree of the metamorphic rocks in this area was high amphibolite facies, and the silica was formed in the melt crystallization after the isothermal decompression degeneration. The original rock is a shallow sea-coastal phase carbon silica with characteristics of khondalite series and two kinds of information about Archean ancient continent and Proterozoic stable sediments. The source of metallogenic material is organic carbon, belonging to the organic origin. This research has certain guiding significance in the search of the same type of deposit in this area.