摘要
富水杂岩体位于北秦岭商丹断裂带北侧,侵位于秦岭群中。岩体中的岩相类型呈同心环带状分布,边缘发育片麻状构造并与岩体边界平行,面状组构的发育型式及变形包体三维形态反映岩体的变形机制主体属压扁型,近岩体围岩中的先存面状构造适应岩体的几何形状。综合分析表明,杂岩体的侵位机制早期为岩墙扩展作用,晚期为斜向底辟-类气球状膨胀作用,经历了由被动侵位向主动侵位的转变,侵位机制受控于晚元古代以来大陆地壳的拉抻和随后的区域性大型左行地壳剪切作用及所诱导出的局部水平缩短作用,属整合的同构造深成杂岩体。
The Fushui complex lies to the north of the Shangnan -Danfeng Fault in the north Qiniing and intruded into the Qinling Group . The plutonic facies has a concentric zoning, and the genissic structure mainly developed at the border zone. It is parallel to the contact. The planar fabric pattern and the three-dimensional shape of the deformation inclusions show that the deformation mechanism of the pluton belongs to the flatten type. The preexisting planar structures in the wall rocks accommodate themselves to the pluton geomtry.
A synthetical analysis indicates that the emplacement mechanisms of the complex are dike propagation in the early stage and oblique diapirism is of balloon-like shape in the late stage. The complex was undergoing the transition from passive emplacement to the active one . The emplacement mechanisms are controlled by the continental crustal extension, the following regional great cruatal shearing and the local horizontal shortening . The complex belongs to a syntectonic concordant pluton.
关键词
富水杂岩体
变形构造
北秦岭
Fushui complex, Deformation ctructure, Emplacement mechanism, The North Qinloing