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川西江浪穹隆在大地构造上位于松潘-甘孜造山带东南缘。环穹窿腰部分布着一系列产状、矿床特征相似的铜多金属矿床——里伍式铜矿床,包括里伍、中咀、笋叶林、柏香林、挖金钩、黑牛洞等矿床。这些矿床的矿体主要呈似层状产出于中元古代里伍群中,其成因模式目前尚不明确。本研究选择里伍和黑牛洞铜矿中的含矿石英-电气石脉作为重点研究对象,对其中的代表性电气石单矿物进行了电子探针分析及LA-MC-ICPMS原位硼同位素测试,据此制约矿床的成矿物质来源。背散射及显微图像特征揭示两矿床的含矿电气石具有单一的流体来源;电子探针分析结果表明这些电气石在类型上均属镁电气石;硼同位素测试结果显示两矿床的电气石δ11 B值分别为-15.47‰±0.83‰~-13.06‰±0.77‰(n=10)及-13.19‰±0.57‰~-5.91‰±0.67‰(n=16),与花岗岩的δ11B值区间非常一致,表明这两个矿床属(区内燕山期)岩浆期后热液矿床。通过对比研究,本文进一步提出在松潘-甘孜造山带内很可能存在一条NE-SW向的铜多金属成矿带,即松潘-甘孜铜多金属构造成矿带。本次研究不仅可以丰富层状型矿床成矿理论,而且对指导该造山带中其他穹窿体的找矿具有较为重要的实际意义。
The glacier dome in western Sichuan is located on the southeast margin of the Songpan-Garzê orogen in the tectonic setting. A series of copper polymetallic deposits of similar copper-polymetallic deposit - Liwu copper deposit, including Liwu, Zhongzui, Shibayanlin, BoXingLin, Dugou Hook, . The orebodies in these deposits are mostly lamellar and occur in the Middle Proterozoic Liwu formations. The genesis pattern of these deposits is not yet clear. In this study, the ore-bearing quartz-tourmaline veins in the Lvwu and Heiniuodong copper mines were selected as the main research objects. The electronic probe analysis of the representative tourmaline mono-mineral and the LA-MC-ICPMS in situ boron isotope Test, thus restricting the mineralization source of ore deposits. Backscattering and microscopic image features reveal that the ore-bearing tourmaline in the two deposits has a single source of fluid. The results of electron probe analysis indicate that these tourmalines are all magnesium tourmaline types. The boron isotope test results show that the tourmaline δ11 B values were -15.47 ‰ ± 0.83 ‰ ~ -13.06 ‰ ± 0.77 ‰ (n = 10) and -13.19 ‰ ± 0.57 ‰ ~ -5.91 ‰ ± 0.67 ‰ (n = 16), respectively, which were consistent with the δ11B value of granite , Indicating that these two deposits belong to the Late Paleohydrothermal deposits in the Yanshanian area. Through comparative study, this paper further proposed that there should be a NE-SW oriented copper polymetallic metallogenic belt in the Songpan-Garzê orogenic belt, ie the Songpan-Ganzi copper polymetallic metallogenic belt. This study not only enriches the stratiform deposit mineralization theory, but also has important practical significance for prospecting of other vaults in this orogenic belt.