The genetic relationship between Habo alkaline intrusion and its surrounding deposits, Yunnan Province, China: geological and S–Pb isotopic evidences

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• 作者：Zhongneng Meng ; Qian Zhang ; Lin Ye ; Yupin Liu ; Jiangbo Lan ; Dapeng Wang
• 关键词：The Habo Au and Pb–(Zn) deposits ; Alkaline intrusion ; Ore genesis ; S–Pb isotope analyses ; Source materials
• 刊名：Chinese Journal of Geochemistry
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：35
• 期：4
• 页码：391-407
• 全文大小：3,527 KB
• 刊物主题：Geochemistry;
• 出版者：SP Science Press
• ISSN：1993-0364
• 卷排序：35

文摘

The Habo alkaline intrusion, which is located in the south of the Sanjiang area, Yunnan Province, China, is a typical Cenozoic alkaline intrusion. There are a series of small to medium-sized Au and Pb–(Zn) deposits around this intrusion. Those deposits are spatially associated with the Habo alkaline intrusion. (1) The δ34S values of sulfides from Au deposits range from −1.91 ‰ to 2.69 ‰, which are similar to those of Pb–(Zn) deposits (−3.82 ‰ to −0.05 ‰) and both indicate a much greater contribution from magma. (2) The Habo alkaline intrusion has relatively homogeneous Pb isotopic compositions with 206Pb/204Pb ranging from 18.608 to 18.761, 207Pb/204Pb from 15.572 to 15.722 and 208Pb/204Pb from 38.599 to 39.110. These Pb isotope ratios are similar to those of Au deposits, whose 206Pb/204Pb range from 18.564 to 18.734, 207Pb/204Pb from 15.582 to 15.738 and 208Pb/204Pb from 38.592 to 39.319. Pb ratios in both the intrusion and Au deposits suggest that Pb mainly derived from the depth, probably represents a mixture of mantle and crust. Pb–(Zn) deposits, however, show a decentralized trait, and most of them are similar to that of the alkaline intrusion with 206Pb/204Pb ranging from 18.523 to 18.648, 207Pb/204Pb from 15.599 to 15.802, and 208Pb/204Pb from 38.659 to 39.206. (3) In the plumbotectonic diagram 207Pb/204Pb versus 206Pb/204Pb, almost all of Au and Pb–(Zn) deposits have the same projection area with the Habo alkaline intrusion, which indicates that those deposits almost share the same source with the alkaline intrusion. (4) Isotopic age of the Habo alkaline intrusion is 36–33 Ma, which is similar to that of Beiya, whose ore-related alkaline porphyries age is 38–31 Ma and molybdenite Re–Os age is 36.9 Ma. Therefore, along with S–Pb isotope traits, we suggest that the Habo Au and Pb–(Zn) deposits should be typically Ailaoshan-Red RiverCenozoicalkaline-related deposits and ore-forming ages of these deposits should be later than that of the Habo alkaline intrusion.