中条山前寒武纪地壳演化

在中条山，古太古代—中太古代的涑水杂岩主要由ＴＴＧ岩套组成，另有一些表壳岩残体和基性岩墙群。以不整合覆于其上的新太古代绛县群由不成熟的浊积岩和双峰式火山岩组成，沉积于类似现代活动大陆边缘的构造环境，遭受了低绿片岩相至低角闪岩相的变质和强烈的变形。这些建造为原始大陆的组成部分。元古宙伊始，原始大陆破裂而形成原地台。在华北原地台的南缘，堆积了中条群等冒地斜建造，经受了早期从低绿片岩相到低角闪岩相的变质和以平卧褶皱为标志的强烈变形，指示收敛的古地热状态和陆壳的缩短，寓意华北原地台同扬子原地台曾经发生过焊接。中元古代开始，华北原地台南缘沿南北方向破裂，产生了以西阳河群大量安山岩喷发为标志的熊耳—汉高拗拉槽。距今１０００Ｍａ前，华北原地台逐渐同扬子原地台拼接，形成统一的大陆，接受中新元古代汝阳群、洛南群和震旦系等盖层沉积。

PRECAMBRIAN CRUSTAL EVOLUTION OF THE ZHONGTIAO MOUNTAINS

In the Zhongtiao Mountains, the Palaeo Mesoarchaean Sushui Complex is mainly composed of metamorphosed TTG Suite, some meta supracrustal relics and basic dyke swarms. The Neoarchaean Jiangxian Group is composed of immature turbidite and bimodal volcanics, and was accumulated unconformably in an environment analogous to that of the modern active continental margin, and underwent low greenschist to low amphibolite facies metamorphism and violent deformation. These Archaean formations made up a part of the primitive continent. From the beginning of Proterozoic, the primitive continent split into protoplatforms. In the southern margin of the north China protoplatform, a suite of miogeoclinal formation, the Zhongtiao Group and its counterpart, accumulated and underwent early phase regional metamorphism of low greenschist to low amphibolite facies and intense deformation characterized by recumbent folding. These mean that the convergent geothermal regime and crust shortening had operated, and imply that the north China protoplatform and the Yangtze protoplatform had been welded together once. At the beginning of Middle Proterozoic, the southern margin of north China protoplatform was broken along the NS direction, and the Xiong′er Hangao aulacogen emerged, which was an opened northern branch of a triple junction and was characterized by eruption of a mass of andisite, the Xiyanghe Group. 1000Ma ago, the North China protoplatform was gradually rewelded together with the Yangtze protoplatform to form an unified continental crust and to receive the cover formation, the Mid Late Proterozoic Ruyang Group, Luonan Group and the Sinian system.