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本文通过年代学资料和其它地质依据建立了冀西北及邻区麻粒岩地体早前寒武纪主要地质事件的年代格架。早期的基性火山喷发事件发生在2868—2932Ma期间,形成本区的早期地壳。在2761Ma左右发生了大规模的TTG岩浆侵位事件,在2650Ma时发生了基性岩浆侵位,使地壳加厚。在2561—2503Ma期间,花岗闪长质岩浆在本区广泛侵入,使地壳进一步加厚。2477—2461Ma期间,紫苏花岗岩以岩株形式侵入,同时发生区域麻粒岩相变质,早期地壳受到改造。大约在2300Ma时发生第二阶段的麻粒岩相变质。此后,在2144—2087Ma期间红色花岗岩侵位,形成花岗岩带。
Based on chronological data and other geological evidences, this paper establishes the chronological framework of the early Precambrian major geological events in the granulite rock mass in the northwestern Hebei and its adjacent areas. Early basic volcanic eruptions occurred during 2868-2932 Ma, forming the early crust in this area. Large-scale TTG magmatic emplacement occurred around 2761Ma, and the basic magma emplacement occurred at 2650Ma, making the crust thicker. During 2561-2503 Ma, granodiorite magma invaded extensively in this area, further thickening the crust. During the period of 2477-2461Ma, perillae granite intruded in the form of rock and granulite facies metamorphism, and the early crust was transformed. The second phase of granulite facies metamorphism at about 2300 Ma. Since then, red granite emplaced during 2144-2087 Ma, forming a granite zone.