摘要
广西中生代岩溶作用有两期:地洼初动和激烈期。这两期岩溶作用形成的地下洞穴,分别为T_3-J_2、K-E的洞穴堆积物——岩溶沉积岩充填或成为目前已不被现代地下水循环所利用的化石岩溶-古岩溶沉积体。地洼初动期岩溶作用,与Cu、zn、Mo、Ag、Sb、Au、U等成矿关系密切,形成古岩溶矿床。成矿物质来源于先成的矿源层、体或矿化、经表生风化浸出,由地表水带入古地下洞穴中,在细菌作用下富集成矿。这种类型矿床,在广西找矿潜力很大。找矿模式可归纳为:先成的矿源→地洼→古叠置型岩溶洼地→地洼初动期岩溶沉积体→亲硫元素和放射性等异常→沿古岩溶方向沉积体中下部→矿体。
Two palaeo-karstification periods, the preliminary mobilization period and the climax-mobilization period of diwa development have been recognized.The subsurface caverns formed in these two periods were separately filled with T_3-J_3,K-E accumulation materials and karst Palaeokarst sedimentary rock subsequently transformed into the fossil karst-palaeo-karst sedimentary bodies which are not currently carried by modern ground water circulation. During the preliminary mobilization period of diwa development, karstification was intimately associated with Cu, Zn, Mo, Ag, Sb,Au and U mineralizations, thus resulting in the formation of palaeo-karst deposit.It is supposed that ore materials were derived from the perexisting ore source stratum, bodies or mineralizations.They were suffered from epigenetic weathering and leaching, were transported into ancient underground caves and were concentrated to form deposits by bacterial action. This type of the deposit possesses great potential in prospecting.The genetic model can be briefly summarized as follows: the pre-existing ore source→the diwa→superimposed palaeo-karst depression→the karst sedimentary bodies of the preliminary-mobilization period of diwa development→ the anomalies of sulphophile element and radioactivity→the middle to bottom part of palaeo-karst sedimentary body along the direction of palaeo-karst→ore bodies.
出处
《铀矿地质》
CSCD
北大核心
1989年第6期321-329,共9页
Uranium Geology
关键词
地诖
岩溶
成矿
初动期
广西
Diwa
Preliminary mobilization period
Karst
Metallogenes is
