摘要
蒙古国乌兰铅锌矿与查夫、甲乌拉、查干不拉根铅锌矿共同构成了中蒙克鲁伦—满洲里成矿带铅锌矿矿集区。本文从含矿地层、控矿构造、赋矿岩脉、围岩蚀变特征、矿体特征等方面对该矿床地质特征展开阐述。样品岩石地球化学特征研究结果表明:乌兰铅锌矿容矿围岩为一套中-高硅、中铝、高钾钙碱性火山岩;样品稀土元素总量(∑REE)为412.25×10^(-6)~999.06×10^(-6),轻重稀土元素分馏明显((La/Yb)_N=4.41~43.10),呈现轻稀土(LREE)富集的右倾趋势,负Eu异常明显(δEu=0.56~0.88);普遍富集大离子亲石元素(LILE)Ba、Rb、Ce,高场强元素Nb、Ta、Th及Zr,明显亏损Li、Sr、Y等元素。锆石LA-ICP-MS U-Pb同位素分析结果表明,围岩成岩时代为晚侏罗世((150.8±4.4)Ma^(164.7±3.1)Ma)。初步限定乌兰铅锌矿形成于140~155 Ma期间外贝加尔一大兴安岭转换挤压弧形成之后的裂谷环境,成因类型为受爆破角砾岩控制的浅成热液脉型铅锌矿床。
The Ullan lead-zinc deposit in Mongolia, together with Tsav, Jiawula, Chaganbulagen lead-zinc deposits, forms a lead-zinc ore concentration area in the Kerulen-Manchuria metallogenic belt. Geological characteristics of the Ullan deposit were described in the aspects of ore-bearing strata, ore-controlling structure, ore-bearing dike, wall rock alteration and orebody characteristics. Rock geochemical studies show that ore-bearing rocks are calc-alkaline volcanic rocks with medium-high Si, medium-Al and high K. The rocks are enriched in large-ion lithophile elements （Ba, Rb, Ce）, high field-strength elements （Nb, Ta, Th）, Zr and depleted in Li, Sr, Y, with the data∑REE=412.25 ＆#215; 10-6-999.06 ＆#215; 10-6,（La/Yb）N=4.41-43.10 and strong Eu anomalies （δ Eu=0.56-0.88）. Zircon LA-ICPMS U-Pb isotope ages indicate that wall rocks formed in Late Jurassic （from（150.8±4.4）Ma to （164.7 ± 3.1） Ma）. The authors also determined that Ullan lead-zinc deposit was formed in a rift setting after the formation of Transbaikal-Da Hinggan Mountains transpressional arc in the period of 140-155 Ma and hence belongs to the hypabyssal hydrothermal vein-type deposit controlled by explosion breccia.
出处
《中国地质》
CAS
CSCD
北大核心
2014年第4期1124-1135,共12页
Geology in China
基金
中国地质调查局项目(1212011120328)资助
