山东郯城金刚石砂矿区中生代以来构造环境演变对原生金刚石找矿的启示OA

By integrating existing geological data,field surveys,and the established tectonic framework of the Yi-Shu fault zone,this study elucidates the Mesozoic-Cenozoic tectono-environmental evolution of the study area.It analyzes the formation,distribution,and interrelationships of the principal diamond-bearing units—the Quaternary Xiaopuling,Yuquan,and Heituhu formations—and discusses the metallogenic geological conditions for primary diamond deposits from the pre-Mesozoic to the Cenozoic in northern Tancheng.Although located within the Tancheng depression of the central-southern Yi-Shu fault zone,the concealed strata show strong consistency with the pre-Mesozoic sedimentary sequences of the western Shandong region.The study area shares a similar tectonic setting and metallogenic conditions with the primary diamond-producing area in Mengyin,Shandong.Since the Mesozoic,driven by tectonic drivers such as the collision between the Yangtze and North China blocks,subduction of the Pacific Plate,and the subsequent destruction of the North China Craton,the area has experienced intense lithospheric thinning and magmatic activity.The associated magmatic rocks exhibit a well-defined mantle-derived evolutionary suite.The spatial distribution of placer deposits and the characteristics of diamond indicator minerals suggest the presence of proximal primary sources.It is recommended that future exploration follow the working rationale of"tracing material sources,evaluating structural controls,and identifying lithological targets",focusing on the Neoarchean uplift in the Dashao-Changlin-Fangzhuang area,the NE-trending major fault zones in Linghongbu-Xiaotang,and the multi-phase magmatic complexes in Chenbu-Jiangzhuang.