河南省原生金刚石矿找矿潜力分析
Analysis on Potentiality of Diamond Mine Prospecting in Henan Province
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摘要: 近年来,我国重新启动了金刚石地质找矿工作。河南省金刚石找矿工作中专家们积累了大量历史资料,但尚未取得找矿的突破性进展。河南省的大地构造位置横跨华北板块、扬子板块和奏岭-大别造山带具有太古界陆壳基底,境内有金伯利岩等深源岩浆活动,具有形成金刚石的地质条件。理论研究和找矿实践表明,原生金刚石矿的成因模式包括金伯利岩和钾镁煌斑岩型,超镁铁质岩型和超高压变质型。鹤壁地区有金伯利岩出露,有金刚石出土且指示矿物齐全,发育深大断裂及次级断裂系统,具备形成金伯利岩型金刚石矿的地质条件。理论分析表明,超高压变质作用过程中有可能形成宝石级金刚石。在桐柏地区榴辉岩中,有可能存在超高压变质岩型宝石级金刚石。对于河南省的金刚石找矿工作,需加强鹤壁地区金伯利岩含矿性评价的基础理论研究,可尝试在桐柏地区寻找超高压变质型金刚石。Abstract: In recent years, our country restarted the work of geological exploration for diamond mine, Despite that a lot of diamond mine prospecting materials have been accumulated,until now autogenetic diamond has not been found yet in Henan Province. Henan Province is located at North China Plate, Yangzi Plate and the Qinling-Dabie mountain belts in the viewpoint of plate tectonics. There are archean continental basements in the North China Plate and Yangzi Plate. There are some kimberlite outcrops in Hebi region, and this geological background may form autogenetic diamond, Theory analysis and exporation practice show that natural diamond is found in kimberlite and lamproite rocks, ultramafic igneous, and ultrahigh press metamorphic rocks. Hebi region in Henan Province existed some kimberlites,and some micro-diamonds were found in soil accompanied with indicator minerals abnormity here, which is located adjacent to a big fault system. All these geological information gives clues of diamond mine potentiality. Theoretic analysis shows that the eclogite-facies ultrahigh pressure metamorphism may grow gem quality diamond, So it is feasible to find gem quality diamond in the ecologites from Tongbo region, Basic research is necessary for the ore potentiality assessment on the kimberlites in Hebi region. Attempts to explore the ecologites in Tongbo region are expected in the future.