摘要
Abstract
Faulting structures with gentle angle are widely developed at the top and the bottom of Tongziyan For-mation of Middle Permian coal measures in Longyong coal field. This geological structure caused absence of stra-tum and has big influence on the occurrence of coal measures. In Fujian coal geological sector, it is called “de-tached fault”. The fault developed in certain layers, at several horizons along layers in cross section, parallel to each other, superimposed, occurred as group. From the old to the young horizons of the fault development, there are fault F0 between the limestone of Qixia Formation and underlying Devonian-Carboniferous, F0 between the lime-stone of Permian Qixia Formation and the coal measures of Tongziyan Formation, F01 between the first segment and the third segment of Tongziyan coal measures, F02 between Tongziyan coal measures and Upper Permian Cuipingshang Formation, F03 between Cuipingshan Formation and Lower Triassic Xikou Formation. The formation mechanism of the detached faults in Longyong coal field is as follows: in the Late Paleozoic, there were some big anticlines, and during Indosinian Period, the anticlines further uplifted, inducing instability of the gravity of the strata, there was a weak mechanical plan for the detachment of layers from the high place to the low place; the ex-terior trigging factors such as earthquake and volcano erruption made the rocks slide from the high place to the low place. Different horizons of the fault development had different influence on the coal measures. If developed in the bottom of the coal measures, the faults destroyed the coal measures, are unfavorable to coal searching based on ge-ology, if developed in the top of the coal measures, the faults protected the coal measures,and made the burial depth of coal measures shallower, favorable to deep coal searching.关键词
滑脱断层/控煤作用/成因机制/龙永煤田Key words
detached fault/control on coal/genetic mechanism/Longyong coal field分类
天文与地球科学
