青海省石墨矿地质特征及可利用性评价

青海省位于青藏高原东北部，青北属秦祁昆造山系，青南属三江造山系，成矿带青北属秦祁昆成矿域，青南属特提斯成矿域，石墨矿较为丰富。省内石墨矿床主要分布于青北秦祁昆成矿域柴达木周缘地区，该区元古代变质老地层分布较为普遍，成矿地质条件优越，发现了众多的区域变质型晶质石墨矿床（点），找矿前景较好。对柴达木周缘地区成矿地质背景、石墨矿分布以及典型石墨矿床地质特征、成矿规律、成矿远景区、成矿地质条件、成矿时代、成矿温压条件、碳质来源、矿床成因、成矿模式进行了研究，并对区内石墨矿的可利用性进行了评价。研究表明：①柴达木周缘石墨矿的赋矿地层柴北缘主要为古元古代达肯大阪岩群，柴南缘主要为古元古代金水口岩群，富含有机质，碳同位素测定表明，碳质来源为地层沉积的有机质；②石墨矿沿元古代变质老地层及构造带分布，受岩浆活动影响，规模总体一般，但矿化规模较大，矿体规模一般，品位较高，矿石质量一般；③柴达木周缘主要可以划分为3个石墨成矿带、4个成矿亚带、6个成矿有利区段；④柴达木周缘晶质石墨矿的成矿阶段可以划分为沉积成岩阶段、区域变质作用阶段、构造-岩浆叠加改造作用阶段，具有区域变质+构造-岩浆改造的特征，成矿温压条件具备，成矿时代为加里东期，矿床成因属区域变质型石墨矿床；⑤大通沟南山、黄矿山北和巴勒木特尔等地区的晶质石墨矿床选矿回收率较高，有一批具有工业价值的区域变质型石墨矿床，可利用性良好。

Geological Characteristics and Availiability Evaluation of Graphite Deposit in Qinghai Province

Qinghai Province is located in the northeast of Qinghai-Xizang plateau，Northern Qinghai Province belongs to Qinqikun orogenic system，Southern Qinghai Province belongs to Sanjiang orogenic system，in terms of metallogenic belt，Northern Qinghai Province belongs to Qinqikun metallogenic domain，Southern Qinghai Province belongs to Tethys metallogenic domain，graphite deposit is relatively developed.The graphite deposits are mainly distributed in Qaidam peripheral region of Qinqikun metallogenic domain in Northern Qinghai Province，proterozoic metamorphic old strata is widely distributed in the area，the metallogenic geological conditions is favorable，many regional metamorphism type crystalline graphite deposits (points) are found，the prospecting prospect is good.Based on the newly geological investigation results and some related study results of Qaidam peripheral region，metallogenic geological background，distribution of graphite deposit are discussed，geological characteristics，metallogenic regularity，metallogenic prospect area，metallogenic geological conditions，metallogenic epoch，metallogenic temperature and pressure conditions，carbonaceous source，deposit genesis and metallogenic model of typical graphite deposits in the area are further summarized and studied，besides that，availiability of graphite deposit is evaluated.The study results show that:①in terms of the ore-bearing strata of graphite deposit in Qaidam peripheral region，Northern Qaidam is mainly for Ancient proterozoic Dakengdaban rock group，Southern Qaidam is mainly for Ancient proterozoic Jinshuikou rock group，which is rich for organic matter，carbon isotope test results indicated that carbonaceous source is the organic matter of stratigraphic deposit;②graphite deposits are distributed along proterozoic metamorphic old strata and tectonic belt，affected by magmatic activities，the distribution scale is general，but the mineralization scale is large，size of orebodies is general，ore grade is high，ore quality is general;③Qaidam periphery region can be divided into three graphite metallogenic belts，four metallogenic subbelts and six metallogenic favorable sections;④the metallogenic epoch of crystalline graphite deposit in Qaidam peripheral region can be divided into sedimentary diagenetic stage，regional metamorphism stage and tectonic-magmatic superposition transformation stage，the metallogenic temperature and pressure conditions are available，metallogenic epoch is Caledonian，deposit genesis belongs to regional metamorphism type graphite deposit;⑤recovery rate of the crystalline graphite deposits in Datonggounanshan，Northern Huangkuang Mountain and Balemuteer are higher than the ones of other areas，a number of industrial valuable regional metamorphic type graphite deposits are developed in the above three areas，the availability of graphite ores is good.