S-PB ISOTOPIC CHARACTERISTICS OF JINCHANGHE IRON-COPPER-LEAD-ZINC POLYMETALLIC DEPOSIT IN BAOSHAN CITY, YUNNAN PROVINCE
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摘要: 滇西金厂河铁铜铅锌多金属矿床位于云南省保山地块北部、NS向保山—施甸复背斜与NNW向澜沧江断裂的锐角交汇部位的南部。文章在以往工作的基础上,研究金厂河铁铜铅锌多金属矿床的S-Pb同位素特征,这对分析该矿床成矿物质来源及探究成矿过程具有十分重要的意义。采样及测试结果显示,该矿床硫化物的δ34S值为+2.5‰~+11.1‰,平均+5.65‰,说明矿床硫化物硫的来源为深部幔源岩浆硫和混合硫(复杂硫);共生含硫矿物中富集δ34S的均值为:黄铜矿(+5.65‰)>闪锌矿(+5.38‰)>方铅矿(+3.45‰),表明矿床硫同位素分馏未达到平衡。207Pb/204Pb—206Pb/204Pb、208Pb/204Pb—206Pb/204Pb铅同位素模式图中样品点分布位置及朱炳泉Δβ—Δγ变化范围图解结果表明,该矿床铅同位素主要来源于上地壳,此外和深部岩浆的侵入活动相关。Abstract: The Jinchanghe iron-copper-lead-zinc polymetallic deposit in western Yunnan Province is located in the north of Baoshan block and the south of the sharp intersection of NS-trending Baoshan-Shidian abdominal anticline and NNW-trending Lancang River fault. On the basis of previous work, the S-Pb isotope characteristics of Jinchanghe iron-copper-lead-zinc polymetallic deposit are studied, which is of great significance for analyzing the source of ore-forming materials and exploring the metallogenic process of the deposit. Sampling and testing results show that the sulfide value δ34S of the deposit is +2.5‰~+11.1‰, with an average of +5.65‰, indicating that the sulfide source of the deposit is deep mantle-derived magmatic sulfur and mixed sulfur (complex sulfur); the average value of enriched Delta 34S in symbiotic sulfur-bearing minerals is chalcopyrite (+5.65‰) > sphalerite (+5.38‰) > galena (+3.45‰), indicating that the sulfur isotope fractionation of the deposit is not up to balance. The distribution of sample points in 207Pb/204Pb~206Pb/204Pb, 208Pb/204Pb~206Pb/204Pb lead isotope pattern and the variation range of Zhu Bingquan Δβ-Δγ show that the lead isotopes of the deposit mainly originate from the upper crust and are related to the intrusion of deep magma.
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Key words:
- S-Pb isotope /
- source of metallogenic material /
- Jinchanghe deposit
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