贺兰山群层序及主变形期褶皱构造探讨

本文对贺兰山群由下到上划分为阿楞呼都格变粒岩组、柳树沟片麻岩组和秃鲁根钙硅酸粒岩－大理岩组。主变形期的构造事件为在南倾的北东东向倒转复式褶皱上发育着与其平行的区域性轴面面理、线理和逆冲型同变质韧性剪切带，其中又以塔什沟－柳树沟复背形和秃鲁根向形最具代表性。

THE DISCUSSION ON STRATIGRAPHIC SEQUENCEAND FOLD STRUCTURE DURING THE MAIN DEFORMATION PERION OF HELANSHAN GROUP

Under the guidance of structure-stratum method principle,this paper analyses the stratigraphic sequence andfold structure during the main deformation period of Helanshan group. It is believed that the Helanshan groupconsists of 3 lithological formations from the lower to upper part. They are:Alenghuduge leptynite formation,Liushugou gneiss formation and Tulugen calic-sillicate leptynite marble formation.The structure event duringmain deformation Period is characterised by thrusting. Synmetamorphic ductile shear zone and regional axialplane foliations and linedments paralleling to and developing on the southwards-tilting east and northeasttrending inverted multiple fold.The most representative characteristics of these are Tashigou-liushugou antiformand Tulugen Syncline. At the end of this paper protolith formation and sedimentary environment are discussed.