镇远-贵阳断裂带活动历史及其对黔中隆起演化的制约

Activities History of Zhenyuan-Guiyang Fault Belts and Constraint on the Evolution of Centre Guizhou Uplift

对镇远-贵阳断裂带两侧沉积地层、岩浆建造、宏观构造、微观构造及流体包裹体测温的研究表明,该断裂带在早古生代以前就已存在,在中奥陶世的都匀运动期间表现为南南东向的正滑,在志留纪末泥盆纪初的广西运动期间表现为右行的剪切和局部的拉张;中晚二叠世的东吴运动使断裂带再次拉张,并伴有钾镁煌斑岩[锆石U-Pb法年龄(261.3±8)Ma]侵入;断裂带还经历了侏罗纪—早白垩世早燕山期右行压剪、晚白垩世-渐新世的晚燕山期强烈挤压、左行剪切和中新世至今喜山期的挤压等多期复合的演化历程。断裂带在古生代的多期活动直接控制了黔中隆起南缘的演化。

By a comprehensive research of the contrast sedimentary , magma activities, the characteristics analysis of macrostructure and microstructure and the temperature measured by fluid of both sides of the Zhenyuan-Guiyang Faults Belts leads to the conclusion that the faults had existed before the early Paleozoic. It is normal-slip to SSE in the Duyun movement at the end of the Middle Ordovician, and shear clockwise and normal-slip in the Guangxi movement at the turn of the end of the Silurian and the beginning of the Devonian. The dating of lamproite near Zhenyuan area, （261.3±8） Ma, shows the faults extension a- gain in Dongwu movement between the Guadalupian and the Lopingian of Permian. The faults also underwent comprehensive evolution process in the Mesozoic and Cenozoic, including several times of dextral shear in the early Yanshanian from the early Jurassic to the early Cretaceous, anticlockwise shear and intensively squeeze in the late Yanshanian from the late Cretaceous to the Oligocene, and the squeezing in the Himalayan period since Miocene. Several activities of the faults belts were also found in early Paleozoic constraint on the evolution of the southeast margin of the Centre Guizhou Uplift directly.