机构地区: 中国地质大学地球科学学院
出 处: 《地学前缘》 2004年第1期161-167,共7页
摘 要: 微板块拼合之后 ,板内盖层部分常因强烈变形而重新形成为若干次级地质单元 ,后者多发育不规则的边界形态和特殊的构造组合。为认识其形成机理 ,进一步了解板内变形的某些特殊现象乃至普适规律 ,对铜陵矿集区进行了以景观重塑为目的的变形模拟。结果发现 ,即使原本相对规则和均一的构造单元 ,在周围地区的夹持和围限下 ,也有可能因经历复杂的“挤压—剪切—旋转—拖带”式递进变形 ,而在两个对峙的角顶部位发育一种特殊的“拖带”凹陷 ,并最终形成不规则的地质边界。前者可视作板内变形特有的区域尺度流变构造 。 Almost all intraplate caprocks had experienced strong deformation during the convergence of microplates, and then disintegrated into secondary geologic units with irregular boundaries and particular structural assemblages. In order to understand the formation mechanism of these special phenomenon, a rheological experiment of structural scenery in Tongling has been carried out. The result shows that the originally regular and uniform boundary of Tongling block became irregular caused by the enclosing and confinement of surrounding units within the “compression-shear-rotation-drag” process. Simultaneously, two specific “drag depressions” developed at the opposite corners of the block. The former phenomenon can be regarded as the characteristic regional-scale rheological effect of intraplate deformation and the latter may represent the necessary outcome of intraplate deformation.