摘要
西华—龙门场推覆构造,主要表现为麻源群变质岩作为外来系统被推覆到原地系统的二叠系地层之上,麻源群变质岩分布于山腰以上部位,二叠系地层分布于洼地处。它自西南至东北可分为根带、中段、前锋三个部分,推覆面波状起伏,总体向南西西倾,据推覆面附近的滑脱褶皱分析,推覆方向为南西西向北东东。据其所影响的地层可知,推覆时代为印支期,推覆距离大于10公里。该推覆构造的发现与确定,不仅查明了该区麻源群变质岩之下掩埋有近40平方公里的二叠系地层,扩大了煤矿勘探远景,而且对该区基底地层的研究无疑也具有重大意义。
The major manifestations of Xihua-Longmenchang nappe structure are:(1)the metamorphic rocksof Mayuan Group being treated as external system have been pushed onto the top of Permian stratawhich belongs to sedentary system,and (2) the metamorphic rocks of Mayuan Group are mainly dis-tributed over hillside while Permian strata down in depressive area.The structure can be divided intothree parts form southwest to northeast (i.e.the root,the middle part and the front) with a wavy nap-ping plane and a plunge direction of SWW.According to those strata influenced by the structure andthe analysis of decollement fold near the nappe structure plane,the napping,existing during Indo-Sini-an movement,possesses an extension stretching from SWW toward NEE and a displacement of 10km.The discovery and determination of this nappe structure have played an important role in proving theexistance of Permian strata with an area of 40 square kilometers covered by Mayuan Group metamor-phic rocks,highlighting the future of coal exploration,as well as researching basement strata in thearea.
出处
《福建地质》
1990年第4期312-316,共5页
Geology of Fujian
