冀北双井子穹状火山与银铅(锌)矿化的关系

通过区域地质调查，认为丰宁满族自治县双井子南西一带的晚侏罗世张家口期火山-侵入活动、同熔型岩浆作用、火山通道及火山断裂与银、铅(锌)矿化关系密切。在整体的火山-侵入活动过程中，先期的火山活动可使成矿物质初步富集，后期的岩浆侵入作用封闭性好，热量充足，可使成矿物质进一步叠加富集成矿。同熔型岩浆作用形成的石英正长斑岩是成矿物质的主要提供者，岩石中Ag、Pb、Zn等成矿元素的丰度值普遍较高，约为世界同类岩石平均值的4～10倍，呈强富集状态。火山通道深达上地幔，有利于岩浆向上运移及深部含矿热液的上升环流，是良好的导岩导矿构造。火山周边断裂规模相对较大，其内多形成构造角砾岩带，是成矿物质沉淀、富集的理想场所和最有利的容矿构造。放射状断裂是沟通火山通道和火山周边断裂并使含矿热液从火山通道向火山周边断裂运移的重要渠道，起到配矿构造的作用。

On the Relation Between the Domelike Volcanics and Au-Pb-(Zn) Mineralization in Shuangjingzi, Northern Hebei Province

In this paper, it is suggested that there is a close relationship between the domelike volcanics and Au-Pb-Zn deposits in Shuangjingzi1, Fengning County, Northern Hebei Province through the geological investigation. During the intruding activity, the early volcanic activity could make the ore-forming materials enrich initially. The late magma intrusion with closely sealing off and sufficient heat might have them pile up or deposit ores. The quartz syenite from the contemporary-melting type magma activity provided with the main ore-forming materials. The abundance of the ore-forming elements such as Ag, Pb, Zn in this kind of rock is about as 4 ~ 10 times as the average in the world. The volcanic pipe deep to the upper mantle is the structure as a passageway for rock and ore. The fractures around the volcanic dome are rich in structural breccia belt, which is good place for the ore depositing, and became the host structure. The fractures radiating from the volcanic crater are the ore-distributing passageways, which let the ore-forming material move into the host structures and the deposit.