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2008年5月12日在青藏高原东缘龙门山地区发生了毁灭性的汶川地震(Ms 8.0),并沿映秀—北川断裂和灌县—安县断裂分别产生约270 km和80 km长、并具不同运动性质的地表破裂带。大地震后的断裂带科学钻探是研究地震机制的有效方法,为更好地了解汶川地震过程中的断裂机制、岩石的物理、化学变化和特征,2008年11月4日(汶川地震后的178 d)快速实施了汶川地震断裂带科学钻探项目(WFSD),该项目在这两条断裂带的上盘布置深浅不一的五口群钻(500～3000 m深)。笔者以汶川科钻一号孔(WFSD-1)岩心为主要研究对象,通过对岩心的岩石学研究和构造分析,识别出映秀—北川断裂带中的不同断裂岩分布和组合,以及确定了汶川地震主滑移带位置,为进一步研究汶川地震断裂机制提供了基础。
On May 12, 2008, a devastating Wenchuan earthquake (Ms 8.0) occurred in the Longmenshan area on the eastern margin of the Qinghai-Tibetan Plateau and resulted in about 270 km and 80 km long along Ying-Ying-Beichuan fault and Guanxian-An County fault, respectively Surface rupture zone with different sports properties. Scientific drilling of the fault zone after the Great Earthquake is an effective method to study the earthquake mechanism. To better understand the fracture mechanism during the Wenchuan earthquake, the physical and chemical changes and characteristics of the rock, d) Rapid implementation of the Wenchuan Earthquake Fracture Zone Scientific Drilling Project (WFSD), which arranged five different group drill holes (500-3000 m deep) on the upper and lower plates of the two fault zones. Based on the core of the WFSD-1 core, the authors have identified the distribution and assemblage of different fracture rocks in the Yingxiu-Beichuan fault zone by studying the core petrology and tectonics. The location of the main slip band of the earthquake provides the basis for further study on the fault mechanism of the Wenchuan earthquake.