层控矿床初论

层控矿床是目前国际矿床学研究的重点课题之一,它有重要的理论和实际意义。 层控矿床的含义和分类,现今还缺乏统一的意见。我们认为,固体矿床可分为内生、外生和复生三大类。后者经历了多次不同的成矿作用。层控矿床应限于在复生矿床这一大类范围之内,是指那些成矿物质在同生沉积的基础上经后期地质作用的改造而形成的、受一定地层层位、岩性和层状构造所控制的矿床。在全局上,矿床成带状、层状,而在局部则既有层状、也有脉状和不规则状。它具有同生沉积的特点,也具有后期热液成矿的特征。这类矿床混淆了内生成矿和外生成矿的严格界线,所以长期对该类矿床的成因都是有争议的。有人把基本上未经改造的外生矿床和某些内生矿床都划为层控矿床,这样未免把范围过于扩大化了,使层控矿床无所不有、包罗万象。如此,势必使矿床分类造成混乱。

ON STRATABOUND DEPOSITS

Stratabound deposits are referred to those which are first formed by contemporaneous sedimentation and then reformed by geological processes of later period,and controlled by certain stratigraphical strata,lithology and stratiform tectonics.Based on the genetical classification,the stratabound deposits can be divided into the following types:1.Post-sedimentary deposits reformed by fossil underground hydrothermal solutions ;2.Metasedimentary and migmatizationary deposits;3.Post-sedimentary deposits overlapped by magmatic hydropneumatic process;4.Superficially reformed deposits; and5.Deposits of composite origin.In the present paper,the genetical mechanism,the controlling factors,the characteristics of China’s stratabound deposits and its possible applications to the finding of deposits are expounded and discussed.