摘要
在世界上太古宙陆核地体共有三类,其中产出包括金在内的多种矿产,金矿类型虽共有四种,但“石英脉型”金矿床分布最广,在我国更具有重要意义。对该类型矿床的研究己经建立了多种形成模式,唯独高级变质组合地体中该类矿床的形成模式尚无成型的报导。陕西潼峪金矿属同生构造型金矿床,空间上严格受区域复背形控制,产于太华群上部层位中。成矿作用完成于区域地质构造发展演化过程中:初期,原地槽的裂谷槽内堆积初始矿源层;早期,粘性变形一变质作用,物质活化迁移;中期,塑性变形—变质作用,矿床形成;晚期,脆性变形—叠加成矿,矿床出露。潼峪金矿床的控矿因素分为三级:一级(区域主体复背形)控制矿田(带),二级(脆—韧性剪滑断裂),控制矿床,三级(石英脉体的破碎扩容带)控制矿体。矿床形成中物质的热—动力分异及其控矿作用具主导意义。依据实际资料建立了“变形—变质—成矿”的三段式矿床形成模式。该矿床形成模式稍加扩展,可运用于小秦岭其它“石英脉型”金矿床。
There are three types of terrain in Archean era on which many kinds of deposits including gold exist. Although four types of gold deposit have been recognized, the 'quartz vein' type has the widest distribution and is of important significance in China. So far, many kinds of pattern for this type of deposit have been established except those in Archean terrain. Tongyn gold deoosit, completely controlled by regional antiform, occurs in the upper bed of Taihua Group. The deposit was formed during the late deformation and evolution of Taihua Group: the primary source-bed formed in the rift of primary geosyncline; the early Viscose plastic deformation-metamorphism making the ore-forming material remobilizated and starting migration; plastie deformation—metamorphism making the deposit formed; brittle deformation making the orebody deformed, denuded and superposed. The tectonic controlling factors of the ore deposits in Tongyu area can be divided into three orders: the first order—regional antiform; the second order—shear-slide fracture; the third order—the fracture in quartz veins. The thermal dynamical-differentiation process was important in ore-forming control. The pattern of deformation-metamorphism-ore-forming could be worked out on this basis. This pattern could be used to other gold deposits of quartz vein type in Xiaoqinling ore belt with some needed informations.
