云南省富乐分散元素多金属矿床地质特征——一个分散元素超常富集的铅锌矿床

Geological Characteristics of the Fule Polymetallic Deposit in Yunnan Province: A Pb-Zn Deposit with Dispersed Elements and Unusual Enrichment

云南富乐分散元素多金属矿床位于扬子地台西南缘,川滇黔铅锌多金属成矿域东南部,是一个中型的铅锌矿床,伴生Cd、Ge、Se、Ga四种具有工业价值的分散元素,其中Cd、Ge、Se储量达到大型矿床规模。矿体赋存于二叠系茅口组二段白云岩中的层间破碎带内,形态呈透镜状、似层状、脉状,矿体一般长100～1000m,宽50～500m,厚0.5～25m。矿石发育粗粒结构,角砾状构造。矿石矿物主要为闪锌矿、方铅矿,脉石矿物主要为白云石、方解石,分散元素主要呈类质同像形式赋存于闪锌矿中。分散元素富集的原因是含有机质的古油田卤水对矿源层——石炭、二叠纪地层中Pb、Zn、Cd、Ge、Se、Ga的强烈萃取,分散元素主要富集在闪锌矿中。

The Fule Pb-Zn-Cd-Ge-Se-Ga polymetallic deposit is located on the southwestern margin of the Yangtze block, southeast of the Sichuan- Yunnan-Guizhou lead-zinc polymetallic region. It is a medium-sized lead-zinc deposit and contains associated dispersed minerals of Cd, Ge, Se, Ga with commercial values. The reserves of Cd, Ge, and Se reach the standard of a large-scale deposit. The orebodies occur in the interlayer fracture zones of the Permian Maokou Fm. dolomite, with lenticular, layering-like and veined shape. The orebodies are generally 100 - 1000m long, 50 - 500m wide and 0.5 25m thick. The ores are of coarse-grained texture and brecciated structure. The ore minerals are dominated by sphalerite and galena with major gangue minerals of dolomite and calcite. The dispersed elements are present in the sphalerite ores. The strong extraction of the ore-originated horizons-Carbona-ceous and Permian strata through paleo-brine is responsible for the enrichment of the dispersed elements in this deposit.