Geochemistry and genesis of the Nadun Nb-enriched arc basalt in the Duolong mineral district, western Tibet: Indication of ridge subduction
Geochemistry and genesis of the Nadun Nb-enriched arc basalt in the Duolong mineral district, western Tibet: Indication of ridge subduction
复制标题
藏西多龙矿区纳敦富铌弧玄武岩地球化学及成因：山脊俯冲迹象
DOI：
10.1016/j.gsf.2021.101283
复制
发表时间：
2022
影响因子：
8.9
通讯作者：
Sun Weidong
中科院分区：
文献类型：
--
作者：
Zhang Tian-Yu;Deng Jianghong;Wang Ming;Li Cai;Zhang Lipeng;Sun Weidong
藏西多隆矿区是我国最大的斑岩型铜金存款矿田之一，具有重要的成矿潜力。与早白垩世铜金成矿有关的构造环境一直存在争议。本文报道了多隆矿区那墩地区新发现的玄武岩的全岩常量、微量元素和Sr-Nd-Hf-Pb同位素数据，以阐明其成因，进一步确定其形成的构造环境。纳顿火山岩段下部与玄武岩互层的同生流纹岩锆石LA-ICP-MS U-Pb年龄为122.5 ± 1.2Ma。玄武岩样品表现出高钾钙碱性/钾玄岩性质，并富含高场强元素，高TiO 2（1.43- 1.79wt.%）Nb（14.6- 19.5ppm），Nb/La比值高（0.4-0.6），与富Nb弧玄武岩（NEAB）的成分相当。的（87 Sr/86 Sr）i值为0.7052 ~ 0.7056，εNd（t）为负值（− 0.7至− 0.2）和εHf（t）值（+ 6.0至+ 6.5），高（206Pb/204Pb）i，（207Pb/204Pb）i，（208 Pb/204 Pb）离子比（18.522 ~ 18.561，15.641 ~ 15.645和38.679 ~ 38.730）表明，纳敦NEAB的丰度高于岛弧玄武岩。纳顿NEAB的放射性同位素略富集，表明俯冲沉积物在源区中起着重要作用。此外，它们的高Nb，Ti和Cu含量表明，源地幔楔的交代板片熔体。多隆矿区的纳敦NEAB等同时代岩浆岩包括埃达克岩、类OIB玄武岩、MORB型玄武岩、A型流纹岩和普通IAB等，是典型的洋脊俯冲岩石组合。推测多隆矿区是早白垩世洋脊俯冲作用的产物。
The Duolong mineral district in western Tibet is one of the largest porphyry Cu–Au deposit fields with significant metallogenic potential in China. Its tectonic environment relevant to Early Cretaceous Cu–Au mineralization remains controversial. Here we report new whole-rock major and trace element, and Sr-Nd-Hf-Pb isotopic data for the newly discovered basalt in the Nadun area, Duolong mineral district, to decipher their genesis and further constrain the tectonic environment. A contemporaneous rhyolite sample interbedded with the basalt in the lower part of the volcanic section in the Nadun area yields an LA-ICP-MS zircon U–Pb age of 122.5 ± 1.2 Ma. The basalt samples exhibit high-K calc-alkaline/shoshonite properties and are enriched in high field strength elements, e.g., high TiO2(1.43–1.79 wt.%) and Nb (14.6–19.5 ppm) contents, with high Nb/La ratios (0.4–0.6), which are compositionally comparable to those of Nb-enriched arc basalts (NEABs). The (87Sr/86Sr)iratios of 0.7052 to 0.7056, negativeεNd(t) (− 0.7 to − 0.2) andεHf(t) values (+ 6.0 to + 6.5), and high (206Pb/204Pb)i, (207Pb/204Pb)i, (208Pb/204Pb)iand ratios (18.522 to 18.561, 15.641 to 15.645 and 38.679 to 38.730, respectively) suggest that the Nadun NEABs are more enriched than those of the island arc basalts (IABs) in the area. The slightly enriched radiogenic isotopes for the Nadun NEABs indicate that the subducting sediments play an important role in the source. Furthermore, their high Nb, Ti, and Cu contents indicate that the source mantle wedge was metasomatized by slab melts. The Nadun NEAB and other coeval magmatic rocks in the Duolong mineral district, including adakite, OIB-like basalt, MORB-type basalt, A-type rhyolite, and common IAB, are typical rock assemblages of ridge subduction. We infer that the Duolong mineral district were formed by ridge subduction in the Early Cretaceous.
登录
查看更多内容
西藏羌塘南部中生代花岗岩体锆石U-Pb年龄和Hf同位素组成：对班公怒江特提斯洋俯冲的启示
影响因子：
6.1
作者：
Qishuai Huang;Xiaoran Zhang;Yahui Yue;Liyun Zhang
通讯作者：
Liyun Zhang
影响因子：
3
作者：
Pei‐yuan Hu;Cai Li;Ming Wang;Chao-Ming Xie;Yan-wang Wu
通讯作者：
Pei‐yuan Hu;Cai Li;Ming Wang;Chao-Ming Xie;Yan-wang Wu
影响因子：
3.7
作者：
Lu‐Lu Hao;Qiang Wang;D. Wyman;Quan Ou;Wei Dan;Zi-qi Jiang;Jin-Hui Yang;Jie Li;X. Long
通讯作者：
Lu‐Lu Hao;Qiang Wang;D. Wyman;Quan Ou;Wei Dan;Zi-qi Jiang;Jin-Hui Yang;Jie Li;X. Long
氧逸度与斑岩矿化：中国德兴斑岩铜矿床的锆石透视
影响因子：
5
作者：
Zhang Chan-chan;Sun Wei-dong;Wang Jin-tuan;Zhang Li-peng;Sun Sai-jun;Wu Kai
通讯作者：
Wu Kai
影响因子：
5.8
作者：
A. Draut;P. Clift
通讯作者：
A. Draut;P. Clift