内蒙狼山-渣尔泰山中元古代拉张型过渡壳的形成、形变及成矿

FORMATION, DEFORMATION AND MINERALIATION OF THE MID-PROTEROZOIC ERA TENSILE TRANSITIONAL CRUST IN LANG SHAN-CHAERTAI AREA, NEIMONGGU

Within split geotectogene of the northern margin of the North China plateform, the ore source beds formed in tensile transitional crust formation of Mid-Proterozoic Era of Langshan-chaertai, associated with the sedimentation of land-source clasts, which are from both volcanic activities and erosions. Duing the process of fold backevolution at the end of Changchen period, the Chaertai Group was deeply reconstructed by such structues as bedding slip, fold superposition and thrust nappe. In Dongshengmao-Tanyiaokou regions, the intensive thrust and nappe structures resulted in hydrothermal alteration and migmatization, making ore-forming elements migrate toward fissured and easy-altered dolomite-marbleand enrich to economic deposits. The intensive superposed fold in the northwestern part of Langshan and Chaertai made original ore beds more enriched and thicker at the hing zone of the folds. Both fault ore-forming model and fold ore-forming model have been established in this paper on the basis of the facts menitoned above.