摘要
岩层初始含矿丰度包括易释出和难释出两部分矿质,这与现今岩样所测得现存丰度截然有别;特殊的(火山)沉积建造是判别矿源层的综合标志,含矿丰度只是其中一个重要标志,其对比标准以区域背景值更为现实可行。
The source bed usually refers to an original stratigraphic horizon from whichsecondary ore minerals were derived. It is mainly represented by a (metamor-phosed) sedimentary fromation with or without syngenetic volcanics. Throughlater actions of geological agents and subsursface hydrothermal fluids, theore substances are believed to be released from the bed and migrate to afavourable site to form relevant deposits. Therefore, the source bed has its limi-tation, i. e. it refers to one (or some) particular kind(s) of ore and has a definitevertical and lateral extent. The gold source bed is a branch of it. The primaryore substance abundace of a rock formation is utterly different from that meas-ured currently in the samples. The former comprises the readily reactive part andthe less reactive part. The readily reactive part tends to be first remobilized andreleaced out of the bed resulting in to a component part of ore through latermineralization. The content of ore substances of the current samples collected inor rear ore district are most probably the product undergone the same geologicaprocesses as the existing ore deposit. In most cases, the figure of major contentrepresents the less reactive part of ore substances. Thus, it is not advisable tomerely discuss the existence of the source bed and its relevant problems bymeans of the existing ore substance content. It is rather practicable for prospectingto integrate the content of ore substane of a bed with the whole special (volcanic)sedimentary formation as the regional background value.
出处
《地质论评》
CAS
CSCD
北大核心
1992年第4期311-315,共5页
Geological Review
关键词
金矿
金矿
矿源层
含矿丰度
gold deposit
source bed
ore substance abundace
