陕西汉南碑坝地区野猪塘金矿床的发现及找矿前景

汉南碑坝地区位于米仓山的南部,是扬子板块北缘残存的古老陆块之一,区域上属汉南-米仓山推覆构造体系中的米仓山推覆隆起带。野猪塘金矿床是陕西省汉南杂岩内近期新发现的构造蚀变岩型金矿床。野猪塘金矿床的形成与米仓山隆起带南缘基底与盖层间的层间滑动带密切相关,金矿体严格受控于基底隆起带南侧印支-燕山期形成的近东西向断裂带,与地层关系不甚密切。矿体主要呈不规则脉状,长220~740m,厚3.13~7.17m,品位3.55~9.15g/t。矿石结构为隐晶质结构、自形粒状结构等。矿石构造有条带状构造、蜂窝状构造、块状构造、角砾状构造及浸染状构造等。围岩蚀变主要有硅化、黄铁矿化、白云母化及电气石化等。找矿标志为构造蚀变带内的条带状蜂窝状硅化块状褐铁矿石和发育五角十二面体及立方体黄铁矿化的断层碎裂岩、花岗质碎裂岩。文章通过总结野猪塘金矿床成矿规律和找矿标志,评价了区内金矿床成矿潜力,扩大了找矿远景,对于该区获求更多的金资源量具有实际意义,以期对碑坝地区实现找金突破,为汉南-米仓山地区进一步找金提供找矿思路。

Discovery and ore-search prospect of the Yezhutang gold deposit in the Hannan Beiba area

The Hannan Beiba area is located in south of the Micang Mountains, which is one of the remnants of ancient continental blocks in the northern margin of the Yangtze plate, belonging to the Micang Mountain nappe belt of the Hannan-Micang Mountains nappe system. The Yezhutang gold deposit is of structural altered rock type that was recently found in the Hannan complex of Shanxi Province, of which the formation is closely related to the interlayer sliding belt between the southern margin of the Micang Mountains nappe belt and cover. Its ore bodies are strictly controlled by a EW trending fault zone of the Indosinian-Yanshan period on the south side of the basement uplift zone, while without close relation to strata. They are dominated by irregular veins, 220m~740m long, 3.13m~7.17m thick, with grades 3.55g/t~9.15g/t. The ore structures are euhedral granular and cryptocrystalline features. The ore bodies show various shapes such as massive, disseminated, banded, honeycomb and agglomerate structures. The main country rock alterations are pyritization, silicification, muscovite, greisenization and tourmalinization. The prospecting marks include the ribbon cellular silicification brown iron ore , fault cataclastic rock and granitic cataclastic rock of pentagonal dodecahedron and cubic. In this paper, the metallogenic potential and gold-search potential of the Yezhutang gold deposit in the area are evaluated by summarizing the metallogenic regularity and prospecting criteria. It is of practical significance for the region to find more gold resources. It also expects a breakthrough of gold prospecting in the Beiba area and provides a new line of thought for gold prospecting in the Hannan-Micang Mountains area.