Characteristics of tectonic evolution of Carboniferous-Permian coal measures in the north-central Qinshui basin

By restoring the paleo-tectonic and sedimentary environment of coal accumulation period, combining with the tectonic stress field and subsidence history, the formation process of Late Paleozoic coal measures in the North-central Qinshui basin and the influence of multi-stage tectonic movement on the occurrence of coal measures minerals were comprehensively analyzed. It is considered that during the C-P coal-accumulating period, the NE-trending sedimentary depression controlled the present tectonic framework of the basin. During Indosinian period, the basin underwent rapid subsidence and formed coal measures gas under the action of deep metamorphism. During Yanshanian period, the basin was destroyed by compression, the NE-trending main syncline formed, and the coal measures strata were uplifted. At the same time, due to magmatic heat, the degree of coalification increased, and the coal and coal measures gas on both sides of syncline were dissipated due to denudation. During Himalayan period, the basin was destroyed by the superimposition of tension. Large-scale rifts and a large number of normal faults developed in the northwest of the basin. Coal measures gas was partially evaporated and mainly enriched in the middle and eastern part of the study area.