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多龙是西藏班—怒成矿带中最大的斑岩Cu(Au)矿集区,其区域动力学演化历史一直是研究的热点。矿集区内尕尔勤地区侏罗系海相沉积地层中发现了枕状玄武岩块,对其成岩时代和岩石地球化学的研究,将有助于了解班公湖—怒江洋盆的演化历史。岩石地球化学分析显示,枕状玄武岩稀土元素总量较低(∑REE为38.01×10~(–6)~63.56×10~(–6)),轻重稀土分异不明显,标准化配分曲线属于平坦型,表现出E-MORB的特征。离子探针分析(SHRIMP)获得其锆石U-Pb年龄为(298±11)Ma,与区域晚石炭—早二叠地层中基性岩脉和玄武岩时代一致,可能是早二叠世班怒洋初始裂解时期大规模火山活动的产物。
Duolong is the largest porphyry Cu (Au) porphyry in the Tibet Class-Anger metallogenetic belt. The history of regional dynamics evolution has been a hot topic. Pillow-like basalt blocks are found in the Jurassic marine sedimentary strata in the Gaerqin area in the ore-gathering area. The study of diagenetic age and petrogeochemistry will help to understand the evolution history of the Banbo-kwu-Nujiang oceanic basins. The lithogeochemical analysis shows that the total amount of rare earth elements in pillow-shaped basalt is relatively low (ΣREE is 38.01 × 10 -6 ~ 63.56 × 10 -6), and there is no significant difference between light and heavy rare earth elements. The normalized distribution curve is flat Type, showing the characteristics of E-MORB. The zircon U-Pb dating obtained by SHRIMP was (298 ± 11) Ma, consistent with the age of basaltic dykes and basalts in the Late Carboniferous-Early Permian of the area, possibly due to the Early Permian Class Fury The product of massive volcanic activity during the initial pyrolysis in the ocean.