冀东变质岩区太古代侵入体与表壳岩的变质

Metamorphism of Archean intrusion and supracrustal rocks in the area of metamorphic rock, Jidong

冀东变质岩区内太古代侵入体占变质岩分布区的大部分,太古代侵入体按其生成环境分为太古代浅成侵入体和太古代深成侵入体两种类型。本文指出了太古代侵入体不同的生成环境;论述了太古代侵入体基本特征及与表壳岩的区别。指出了野外太古代侵入体与表壳岩的鉴别特征;传统的混合岩如均质混合岩、混合花岗岩其实是太古代花岗质侵入体;同时太古代花岗质侵入体的侵入对冀东的表壳岩和变质铁矿产生了不同的破坏和改造;幔柱构造作用是引发大规模的区域变质作用的根源;产生大面积太古代岩石变质的岩浆活动可视为是由太古代幔柱构造作用引起的,可以说太古代深成侵入体岩浆的上侵作用就是或类似于地幔热柱上涌,同幔柱一样具有极大的能量,是表壳岩变质的热动力来源。识别太古代侵入体对区域地质填图、认识区域构造格架、地壳演化及变质铁矿勘查有重要意义。

Archean intrusion account for most of the metamorphic rock area in metamorphism area of Jidong. Archean intrusion are divided into the two types of Archean hypabyssal intrusion and Archean plutonic intrusion according to its forming environment. This paper points out the different forming environment of Archean intrusion, discusses the basic characteristic of Archean intrusion and the difference between Archean intrusion and Supracrustal rocks. There are the ifeld identiifcation features between Archean intrusion and supracrustal rocks in this paper. In fact the traditional migmatite such as homogeneous migmatite mixing granite is the Archean granitic intrusion. The invasion of the Archean granic intrusion produced different destruction and reconstruction for supracrustal rocks and metamorphic iron ore. Plume tectonics is the root of causing large-scale regional metamorphism. The igneous magma activity that caused large area metamorphism of Archean rocks may be caused by Archean mantle plume tectonics effect, it can be said that the intrusion effect of Archean plutonic intrusive magma is similar to the upwelling of mantle plume, which has a great energy as well as mantle plume and is the thermodynamic source of supracrustal rocks. Identifying the Archean intrusion has important guiding signiifcance on the reginonal geological mapping.the regional tectonic framework crustal evolution and metamorphic iron ore exploration.