火焰山断裂带构造特征分析

Structure Features Analysis for Huo Yanshan Fracture Zone

火焰山断裂带的构造特征相当复杂,由于推覆体在向南推覆滑动过程中,存在推覆速率、阻力大小、岩性等不一致,使得火焰山构造带东西构造样式、断裂样式都存在巨大的差异。构造带中段主要发育"舌状断鼻",东西两段发育反转断坡背斜,北坡发育断鼻。虽然逆掩主断层(真正的火焰山断层)容易识别,但存在层间走滑断层,使构造更加复杂,构造特征也难以把握。构造滑脱面主要为西山窑、八道湾组的煤系地层和第三系的石膏层构成一个滑脱体系。该滑脱断层才是真正的火焰山断层,其与地表出露的火焰山次级断层在第三系的石膏层滑脱面之上形成一个夹块。

Structure characteristics of Huo Yanshan fracture zone are quite complicated. The difference of structure modality and fracture style is tremendous as a result of the diversity in nappe velocity, resistance, and lithology during the nappe slip to the southern. Tongue - like structures develop in the middle part of the fracture zone, and faulted slope overfolds develop in the west and east part, and faulted nose -like structures develop in the north slope. Although it is easy to identify the main overthrnst fault, the existing interlayer sliding faults cause structure characterisfics more complex, and made it more difficult to grasp structure characteristics. Slippage sections exist mainly in the middle and lower Jurassic coal seam and the Tertiary gypsum stratum. A slippage system is formed with them. That slippage fault is the real main Huo Yanshan thrust. Between the Huo Yansh sub - fault extending out of the earth＇s surface and the Slippage section in the Tertiary gypsum stratum, a fixture block is coming into being.