Field geology, geochronology, and isotope geochemistry of the Luyuangou gold deposit, China: Implications for the gold mineralization in the eastern Qinling Orogen
Field geology, geochronology, and isotope geochemistry of the Luyuangou gold deposit, China: Implications for the gold mineralization in the eastern Qinling Orogen
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中国鹿源沟金矿床的野外地质、年代学和同位素地球化学：对东秦岭造山带金矿化的启示
DOI：
10.1002/gj.3064
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发表时间：
2018-03
影响因子：
1.8
通讯作者：
Tao Ni
中科院分区：
文献类型：
--
作者：
Lei Wanshan;Dai Jun;Zhao Taiping;Zhang Yanfei;Tao Ni
金矿床与增生作用密切相关。而中国东部的金成矿年龄一般大于100 Ma，并部分受伸展构造控制。芦园沟热液存款矿床受层间拆离断层控制，是典型的伸展构造下的成矿作用。通过对芦园沟矿脉和斑岩脉的矿物存款地质、构造地质、LA-ICP MS锆石U-Pb年龄和Sr-Nd-Hf同位素资料的研究，阐明了成矿作用。鹿源沟含金矿脉中锆石的形态特征和年龄与北秦岭地体秦岭群混合岩中深熔锆石相似，表明北秦岭地体可能是其物源之一。453 ± 13 Ma（MSWD = 3.3，N = 12）的主年龄峰不能确定成矿时代，但也暗示了芦园沟成矿作用与北秦岭地体之间的联系。矿后斑岩脉的加权平均年龄晚于芦园沟金矿化121.1 ± 1.5Ma（MSWD = 0.21，N = 14）。芦园沟含金矿脉及矿后斑岩脉的Sr-Nd-Hf同位素与太华群、熊耳群有显著差异，与秦岭群相似，表明秦岭群可能是芦园沟金存款的主要成矿物质来源。芦园沟金存款主成矿阶段的S-Pb同位素特征显示了明显的深部来源。综合分析认为，早中生代扬子-华北陆块大规模陆内碰撞是北秦岭地体向华北陆块下俯冲，导致陆内褶皱、逆冲、增厚，但未诱发大规模成矿作用或岩浆活动。晚中生代，太平洋板块俯冲导致增厚的大陆地壳不稳定，区域伸展构造发育，大规模壳幔岩浆活动，深部或幔源流体溶解沉积在层间拆离断层上的秦岭群物质。
Gold deposits are closely related to accretionary processes. Gold mineralization in eastern China, however, is usually > 100 Ma younger than associated collisional orogeny and partly controlled by extensional tectonics. Being controlled by interbedded detachment faults, the Luyuangou hydrothermal deposit is a typical mineralization under extensional tectonic. We present mineral deposit geology, tectonic geology, LA‐ICP MS zircon U–Pb age data, and Sr‐Nd‐Hf isotopic data for the Luyuangou ore vein and porphyritic dyke, with the aim of elucidating the metallogenesis. The morphological features and ages of zircons from the Luyuangou auriferous lode are similar to the anatectic zircons from migmatite within the Qinling Group (a metamorphic complex unit) of the North Qinling Terrane, indicating that the North Qinling Terrane may be one of the provenances. Although the major age peak of 453 ± 13 Ma (MSWD = 3.3, N = 12) cannot constrain the exact metallogenic timing, the data imply a possible link between the Luyuangou metallization and the North Qinling Terrane. Meanwhile, the weighted‐mean age of post‐ore porphyritic dyke postdates the Luyuangou gold mineralization at 121.1 ± 1.5 Ma (MSWD = 0.21, N = 14). The Sr‐Nd‐Hf isotopes of the Luyuangou auriferous lodes and post‐ore porphyritic dyke exhibit prominent differences from those of the Taihua Group and Xiong'er Group and are similar to those of the Qinling Group, implying that the Qinling Group is likely the main ore‐forming provenance of the Luyuangou gold deposit. The S‐Pb isotopes of the main mineralization stage of the Luyuangou gold deposit indicate a distinct deep‐seated source. According to comprehensive analysis, it is proposed that, during the early Mesozoic, the large‐scale continental collision between the Yangtze and the North China Craton involved the underthrusting of the North Qinling Terrane beneath the North China Craton that led to intracontinental folding, thrusting, and thickening without inducing extensive mineralization or magmatic activity. During the late Mesozoic, the subduction of the Pacific Plate induced the instability of the thickened continental crust and the development of the regional extensional structures, large‐scale crust–mantle magmatism as well as deep‐seated or mantle‐derived fluids dissolving materials from the Qinling Group that precipitated at the interbedded detachment faults.
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影响因子：
3.5
作者：
Hao Cheng;Chao Zhang;J. Vervoort;Xian‐Hua Li;Qiu-li Li;Y. Wu;Shu Zheng
通讯作者：
Hao Cheng;Chao Zhang;J. Vervoort;Xian‐Hua Li;Qiu-li Li;Y. Wu;Shu Zheng
影响因子：
2.9
作者：
R. Zartman;B. Doe
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R. Zartman;B. Doe
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1.8
作者：
Pirajno Key
通讯作者：
Pirajno Key
影响因子：
3.5
作者：
D. Rubatto;J. Hermann;A. Berger;M. Engi
通讯作者：
D. Rubatto;J. Hermann;A. Berger;M. Engi
影响因子：
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作者：
Tong Ying
通讯作者：
Tong Ying