摘要
前言 我国某地区砂岩铜矿床曾由地质、冶金部门的地质队、昆明工学院、地质科学研究院等单位进行过研究,对矿床所作的规律性总结,在地质勘探工作中起了积极的作用,但在矿床成因问题上仍存在分歧意见。主要观点有二:其一,认为矿床为同生沉积期产物,环境属古代湖泊,矿床及与之密切相关的岩石红—灰色调的形成受湖泊微地貌控制;其二,矿床系沉积-改造产物,部分人认为矿床的形成与热液作用有关。
While studying the mode of occurrence of the copper deposits in Red Beds of Cretaceous age in a certain district of China,both in the field and laboratory,the writer paid much attention to the origin of the coloration,lithofacies,and controlling factors of the country rocks,mainly red sandstones.Based on mineralogical,petrochemical and sedimentation investigations,it is considered that the gray color of the country rocks is due to decoloration at the diagenetic-anagenetic stage,while the gasliquid phase of organic matter also played an important role in its formation.The ore-bearing sedimentary rocks are of fluviatile origin.Their characteristics are:presence of more or less marked cyclothems(showing graded bedding),lenticular and tabular sand bodies,scour-fill structure,large-scale cross-bedding,regular grainsize distribution due to river drainage,and so on.The conclusion is thus reached that the ancient L river was a braided river,and that the ancient W river was a low-sinuosity river.The metallogenetic stage of the copper deposits is considered anadiagenetic because of the following reasons:distinct close relationship between the mineralization and the gray coloration of the rocks,the ore bodies obliquely intersecting the bedding planes,no genetic relation between mineralization and primary sedimentation,no genetic relation between the clastic constituents and rocks of the near-by old land,the metallic minerals occurring mainly as replacement,dissemination and veinlets,and finally the anadiagenetic zonal distribution of metallic minerals.The author believes the ore-forming solution may be halogenic hot ground water.In the present paper,all the following factors,such as the old land,folding and faulting,color of rocks,bedded reduction and bedded concentration,lithofacies,rock characters,organic matter,temperature,pressure,Eh and pH,and the role of the solution,effected to the concentration are discussed.Emphasis is laid on the old land(source of material),structure(folding and faulting),gaseous phase of organic matter,the color and permeability of the rocks,Eh and pit.
出处
《地质学报》
1975年第1期28-44,共17页
Acta Geologica Sinica
