Genisis Studies Of Typical Crystalline Graphite Deposits,in The North China

North China craton (the North) is the world’s oldest (-3.8 Ga) Craton, one of a series of major geological events in their crustal evolution, including the land of nuclear development, the formation of the crystalline basement, craton lysis, aggregation, collage, seal development, sedimentary-metamorphic and magmatic activities; and major geological events had massive graphite mineralization, forming a rich resource of graphite. In 2004, the discovery of graphene, graphite mineral prominent strategic position, set off a new round of international exploration and prospecting boom graphite; North’s unique graphite mineralization geological conditions, should be the key areas of domestic ore, but because in the past in North China Graphite deposits in the lower level, only individual deposit done some research in geological characteristics and mineralization genesis deposit, not only restrict the conduct of graphite prospecting work, and to some extent limit the country its specific strategic planning.Through systematic research on the geological setting and the North has a graphite deposit geological data, divided into Shandong, North China northern margin of the Qinling, Liaoji four graphite mineralization belt and Lacey-roughness, Zhuyang Off-willow Springs shop Asia and other 12 metallogenic belt. Select metallogenic belt in a typical graphite deposit, mineralization geological features of its analysis, the deposit Fu seam bits deep metamorphic rocks, with the typical characteristics khondalite system; ore-rich rock types containing mainly aluminum sheet Regional metamorphism of graphite; ore bodies controlled by folds, wrinkles have needed to restore a closed environment metamorphic mineralization, the graphite in this accumulation, storage; gneiss, schist, leptite, diopside rocks and marble They are closely related, the higher the rank, the greater the graphite crystals; migmatization late, on the one hand to promote the further enrichment of graphite growth, on the other hand causing local ore relatively depleted. Rock samples were collected chemical processing and analysis, major elements feature shows siliceous shale SiO2 content of the sample is about 80%, carbonate content of more than 30% SiO2, granite SiO2 content between 50% to 70% with alkali-rich and land-based sources and other features, reflecting the original sedimentary environment of shallow shelf or continental rift environment, rich set of original rock mainly carbon, aluminum-rich pelitic rocks, mafic volcanic rocks and folders Carbonate; trace element characteristics indicate enrichment Rb, U, La, Nd, Sm, loss of Sr, Ba, Th, Nb law, Rb/Sr and Sr/Ba ratio reflects the deterioration of the original rock is mainly terrigenous features, Th/U, V/V+Ni and V/Cr ratios reflect hypoxia metamorphosed sedimentary environment:rare earth elements show LREE enrichment, HREE is depletion, was rightist curve,δCe values are about 1,8Eu value is less than 1, REE graph shows a weak negative Eu anomaly and no Ce anomaly, reflecting the original sedimentary environment of shelf late Archean sedimentary characteristics. Graphite samples were collected SHRIMP U-Pb zircon dating shows that the graphite mineralization in Shandong laixi nanshu metallogenic belt era 1.82 Ga～1.86Ga, the Late Paleoproterozoic; North northern marginal mineralization belt Xing kiln loess The first deposit of graphite mineralization metamorphic age 1.97Ga, the Late Paleoproterozoic; Qinling belt small chagou first metamorphic graphite deposit mineralization age 2.08Ga, Paleoproterozoic mid Liaoji metallogenic belt Chang Fort graphite deposit first metamorphic mineralization age 2.36Ga, ancient yuan early antiquity, the first of the age of four typical deposits metamorphic mineralization and metamorphic ages are consistent with the location of layers, while graphite deposits are characterized by the superposition of metamorphism match. Carbon isotope δ13C numerous graphite deposits in North test analysis,δ13C ‰ value in the range of -6.72‰～-28.93‰ (the vast majority of between -18‰～-28.93‰), with the modern organic, geological each era organisms and δ13C ‰ value comparison carbonates, results showed graphite carbon mainly from organic carbon (regional metamorphism), a few from the inorganic carbon (migmatization form).Geochemical study of the special characteristics of mineralization’s geological characteristics typical of graphite deposit, and 13C isotopic characteristics, the results showed that the main causes of graphite deposit type of mixed rock type. Comprehensive migmatized type graphite deposits in ore controlling conditions and prospecting mark established Prospecting prediction model; prediction model based Prospecting, choose a favorable prospecting targets, first of all to carry out exploration and prospecting work, and in Inner Mongolia black lake, Liaoning Du village and Zhang Jiabao made significant prospecting results, so that scientific metallogenic model and prospecting model has been well validated, indicate Prospecting prediction model graphite ore zone has important guidance and migmatized graphite deposit is still the focus of future prospecting zone type.