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许多前寒武纪地区的太古宙—元古宙地壳,都由两个特征截然不同的构造单元组成,即由花岗—绿岩地体构成的太古宙克拉通地块和太古宙—早元古代活动带、褶皱带或造山带组成。后者把克拉通分割开并环绕克拉通改变方位和发生流动。克拉通是相对硬的地块,具有韧性和脆性的变形历史。环绕克拉通的活动带既可以是高应变带和高级变质带,也可以是褶皱的盆地。因之,较韧性的活动带包围着相对硬的克拉通。可以推断,虽然相邻的多角形的硅铝质单个大陆微板块在地幔及主欧拉极控制下曾发生过相对运动,而且由于相互推挤使它们间的共同边界发生了递进变形,但太古宙克拉通最初是彼此分离的。变了形的边界就是现在环绕克拉通的韧性和高应变活动带,它代表了地壳持续性的缺陷;克拉通代表低应变较硬的核和残斑,它们在太古宙以后一直处于稳定的状态。克拉通与活动带之间巨型尺度上的关系(如东非)可以与在眼球状片麻岩及糜棱岩中观察到的规模很小的显径—小型尺度上残斑—基质结构相对比。这些构造关系虽然数量级差别很大(10~8),但因它们之间存在着连续的各种不同的中间尺度构造,所以,是完全可以比较的。几何学上的相似性,表明它们具有共同的力学—流变学成因机制。
Many Archean-Proterozoic crustal rocks in the Precambrian are composed of two distinct structural units, the Archean Craton and the Archean-Early Proterozoic Activities, fold belt or orbital composition. The latter split the craton and moved around the craton to change its direction and flow. Cratons are relatively hard plots with ductile and brittle deformation histories. Activities around the craton can be both high-strain and high-grade metamorphic belt, can also be a fold basin. As a result, the tougher activity zone surrounds the relatively hard carat. It can be inferred that although the neighboring polygonal Si-Al single continental plates have undergone relative motion under the control of the mantle and the main Euler pole, and due to the mutual push, the common boundary between them undergoes progressive deformation, Archean cratons were originally separated from each other. The deformed boundary is now the zone of ductile and high-strain activity that now surrounds cratons, which represents the continuity of the earth’s crust; cratons represent harder nuclei and peridotites that are stable after Archaean . The mega-scale relationship between the craton and the active zone (eg, East Africa) can be compared with that of the small-scale shoot-matrix structure observed on the eye-gneiss and mylonites. Although these structural relationships vary greatly in magnitude (10 to 8), they are completely comparable because of the various intermediate scale structures that are continuous between them. Geometrical similarities suggest that they share a common mechanistic-rheological mechanism of genesis.