滇西保山核桃坪铅锌矿床稀土元素地球化学特征及其成因意义

核桃坪铅锌矿床产于滇西保山古生代地块内，是近年来在西南“三江”地区勘查发现的大型铅锌(铜银)多金属矿床，也是该区为数不多的以断控脉状矽卡岩赋矿为特征的矿床。详细研究了区内铅锌矿体的各种赋矿围岩、蚀变(脉)体及矿石的稀土元素地球化学特征，结果表明：围岩的稀土元素主要富集在粘土矿物中，上侵的矽卡岩流体萃取了围岩中的稀土元素，并使自身稀土元素组成发生改变；当前揭露浅部矽卡岩的成岩流体为中-低温、酸-弱酸性流体，其酸度随流体演化而不断增加。认为核桃坪铅锌矿床可能是一个远端矽卡岩型矿床，矽卡岩及伴生铅锌(铜银)的成岩成矿作用均受控制于隐伏的岩浆-热液系统。

REE Geochemical Characteristics of Hetaoping Pb-Zn Deposit,Baoshan County,Western Yunnan Province and Its Genetic Implications

The Hetaoping Pb-Zn deposit of Baoshan County is located in western Yunnan Province. It is one of large-scale lead-zinc(copper-silver)polymetallic deposits characterized of vein skarn-type ore-bearing deposits and controlled by fractures in Three River area of Yunnan Province, southwestern China. The authors systematically studied rare earth element (REE) geochemical characteristics of the surrounding rocks, Pb-Zn ores and hydrothermal veins of Hetaoping Pb-Zn ore fields. The results show that REE in the surrounding rocks is mainly enriched in clay minerals. The skarn fluids extract the REE in the surrounding rocks and change their REE chondrite-normalized patterns. For now, exploration revealed shallow skarn diagenetic fluid is in medium-low temperature and acid-weak acid fluid, with the fluid evolutionary, the acidity of the fluid increases. Combined with the previous researching results, it is considered that the Hetaoping Pb-Zn deposit is a distal skarn-type Pb-Zn deposit and the rock-and ore-formations of the skarm and lead-zine (copper-silver) controlled by magmatic hydrothermal.