贵州织金新华磷矿区风化磷块岩形成条件及风化淋滤富集机制初步研究

贵州织金新华磷矿是我国西南地区著名的超大型含稀土低品位磷矿床,矿床平均品位w(P_(2)O_(5))为17.22%,已探明磷矿石储量13.48亿t,稀土资源量350万t。近年研究发现,新华磷矿矿石品位的波动变化与风化淋滤富集作用关系密切。为了进一步阐明风化淋滤作用对磷矿元素地球化学的影响及磷矿的次生富集规律,以戈仲伍矿段为重点研究对象,对含磷岩系开展了野外观察描述,应用连续敲块法采集化学分析样品19件,运用光学显微镜进行岩矿鉴定样品16件,并对样品进行了岩石成分鉴定及综合研究工作。研究结果表明,风化磷矿中w(P_(2)O_(5))比原生磷矿提高了8%~18%,w(MgO)比原生磷矿降低了4%~7%,风化强度处于弱到成熟阶段。织金新华风化磷矿的形成受到岩性条件、地质构造、水文条件等因素控制。本研究可以为深入研究该矿床的次生风化成矿作用对磷矿石化学成分的影响及为新的矿产研究提供资料,为丰富我国风化淋积型磷矿床的成矿理论提供新认识,为该矿区风化磷矿资源的合理开发利用提供理论指导。

A new type of micro-disseminated gold deposits in association with diabase found in Yunnan and Guizhou provinces and Guangxi Zhuang Autonomous Region——Their geological characteristics and metallogenic conditions

With the continuous development of gold ore prospecting and exploration in recent years a new type of micro-disseminated gold deposits have been found in the regions of Southwest Guizhou Province and Northwest Guangxi Zhuang Autonomous Region,with the orebodies directly occurring in diabase or in the contact zone between diabase and strata.The orebodies are strictly controlled by fault structures.The discovery of this type of gold deposits has brought about new prospects for gold ore prospecting in the Yunnan-Guizhou-Guangxi Golden Triangle region.From the preliminary analysis of the geological characteristics of the Qiaoxiang gold deposit in Wangmo County,in combination with the results of research work in the adjacent areas in recent years,this paper roughly described the geological characteristics and metallogenic conditions of this type of gold ore deposits with an attempt to make more and more geologists pay enough attention to this type of gold ore deposits,so as to promote gold ore prospecting in Guizhou Province to develop toward a variety of types of gold deposits in all round way.