锡铁山铅锌矿床含矿岩系主褶皱的初步厘定

PRELIMINARY RECOGNIZATION OF THE MAIN PHASE FOLD WITHIN ORE BEARING LITHOLOGICAL SERIES IN THE XITIESHAN LEAD ZINC DEPOSIT,QINGHAI PROVINCE

锡铁山铅锌矿床含矿岩系主褶皱是一个由绿片岩片理（Ｓ０＋Ｓ１）褶皱而成的斜卧褶皱。主褶皱枢纽沿走向波状起伏，转折端较开阔，两翼向深部紧闭。研究表明：矿体主要赋存于主褶皱转折端大理岩与绿片岩间的构造虚脱空间内，明显地受主褶皱空间展布、形态及完整性的影响和控制。主褶皱的初步厘定及相关构造特征研究，对重新认识该矿床的构造控矿形式，确定找矿方向具有指导意义。

It is found that the main phase fold developed within the ore bearing metamorphic rock series in the Xitieshan lead zinc deposit is an oblique fold of schistosities (S 0+S 1) green schists.The fold is a gentle hinge zone with sag and swell from place to place. Its turning end is open, and both limbs are tightly closed toward depth.It is revealed that the orebodies are mainly formed within the saddle like spaces between marbles and green schists in the hinge zone of the fold, and that the orebodies are clearly controlled and/or affected by the spatial distribution patterns and its completeness of the fold.The recognization of the main phase fold and the study of its features are significant for understanding the way how structures control the mineralization,and for effective prospecting.