镇旬盆地金矿地质特征及找矿方向

镇-旬盆地金鸡岭向斜南北两翼是秦岭板块内重要的成金区域。区内金矿类型有三种：金龙山细碎屑岩-碳酸盐岩型、二台子钠长石角砾岩型、牛家沟石英脉-蚀变岩型。主要载金矿物为黄铁矿、含砷黄铁矿、黄铜矿、毒砂、石英、方解石等。金以自然金为主，次有含银自然金。本区含矿地层主要为中泥盆统古道岭组（D2g）、上泥盆统南羊山组（D3n）、星红铺组（D3x）和下石碳统袁家沟组（C1y）。近东西向的剪切破碎带直接控制矿体的分布。蚀变以黄铁矿化、黄铜矿化、毒砂矿化、汞锑矿化、硅化、方解石化等为主。Au，As，Sb，Hg元素组合直接指示金矿床的存在。分析镇-旬盆地金鸡岭复式向斜南北两翼成矿条件．得出在北带金龙山-丘岭金矿带东延的西坡岭-丁家山背斜带；中带的泗峡口-二天门带；南带的仁河口-公馆-回龙复背斜汞锑矿带；是成金的有利区域。

Characteristics of gold deposits in Zhen''''an-Xunyang Basin and gold resources targeting

Both northern and southern flanks of the Jinjiling Syncline in the Zhen'an-Xunyang Basin belong to an important gold veining belt. To date within the belt, three type gold deposits are recognized as the clastic-carbonate rock-hosted disseminated (Jinlongshan), albite breccia (Ertaizi) and quartz vein-altered rocks (Niujiagou). The auriferous minerals mainly comprised pyrite, arsenic pyrite, chalcopyrite, arsenopyrite and calcite. Gold was dominated by the natural Au element and less frequently it also contained certain silver. Three Devonian formations, namely Middle Devonian Gudaoling (D_2g), Upper Devonian Nanyangshan (D_3n) and Xinghongpu (D_3x), acted as the major hosting sequences of gold deposits in the study area, and some gold deposits were also hosted by the Yuanjiagou Formation (C_1y) of Lower Carboniferous age. Nearly EW-orientated shearing zones controlled the distribution of ore bodies, and the main alteration was identified by pyritization, chalcopyritization, arsenopyritization, mercury and antimony mineralization, silicification and calcitization. The Au, As, Sb and Hg association hence was indicative of gold deposits. On the basis of the geological setting of the northern and southern flanks of the Jinjiling Synclinorium and synthetic analyses of gold metallogeny, the Xilingpo-Dingjiashan Anticline (north zone) as the east extension of the Jinlongshan-Qiuling Gold Belt, Sixiakou-Ertianmen (middle zone) and the Renhekou-Gongguan-Huilong Hg- and Sb-bearing Synclinorium (south zone) were proposed as important targets for locating gold resources.