Formation of porphyry Mo deposit in a deep fault zone, example from the Dabaoshan porphyry Mo deposit in northern Guangdong, South China
Formation of porphyry Mo deposit in a deep fault zone, example from the Dabaoshan porphyry Mo deposit in northern Guangdong, South China
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深断裂带斑岩型钼矿床的形成——以粤北大宝山斑岩型钼矿床为例
DOI：
10.1016/j.oregeorev.2016.07.013
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发表时间：
2017-03
影响因子：
3.3
通讯作者：
Zhang, Jian
中科院分区：
文献类型：
--
作者：
Liang, Hua-ying;Wu, Jing;Zou, Yin-qiao;Zhang, Jian
大宝山斑岩型钼存款矿床位于华南深断裂系统吴川-四会断裂带中。大宝山钼矿化以浸染状、细脉状产出于与川渡斑状二长花岗岩共生的大宝山斑岩和矽卡岩云英岩中。本文报道了上述斑岩的锆石LA-ICP-MS U-Pb年龄。本文还研究了大宝山斑岩的主、微量元素、全岩Sr-Nd和锆石Hf同位素组成。大宝山斑岩由弱-强过铝质二长花岗斑岩和花岗斑岩组成。它们的年龄分别为166.3 ± 2.0Ma（MSWD = 1.9）和166.2 ± 2.7Ma（MSWD = 2.7），略早于川渡斑状二长花岗岩的162.1 ± 1.6Ma（MSWD = 2.7）。这表明该地区存在两种不同的岩浆脉动。大宝山斑岩体SiO2含量为64.42%~ 75.41%，在Th与Co的关系图中显示出高钾钙碱性和钾玄石的亲和力。它们的[La/Yb]Nof为14.6-35.0，εNd（t）值范围为-8.2 ~-6.6。岩石的εNd（t）值比本区中侏罗世基性岩的εNd（t）值（εNd（t）=-2.7 ~+7.9）更负，但与华夏地块元古宙地壳的εNd（t）值（~ 165 Ma）相近。大宝山斑岩锆石的εHf（t）值为− 13.2 ~ − 7.5，两阶段Hf模式年龄（TDM 2）为1.7 ~ 2.0Ga，与华夏地块西部基底TDM 2（~ 1.7Ga）接近。大宝山斑岩的Th/U平均值为5.0，与华夏地块元古宙结晶基底的Th/U值（5.3-5.4）相近，但高于弧岩浆的Th/U值（1.5-3.0）。此外，斑岩的Nb/Ta比值（平均11.8）也与华夏元古代结晶基底的Nb/Ta比值（平均12.4）相似。这些地球化学特征表明，这些斑岩是华夏地块结晶基底高度部分熔融的产物。根据大宝山斑岩地球化学资料，结合吴川-四会深断裂带沿着分布的斑岩钼矿床地球化学资料，认为大宝山斑岩钼存款与侏罗纪时期古太平洋板块俯冲引起的吴川-四会深断裂活动有关。
The Dabaoshan porphyry Mo deposit is located in the Wuchuan-Sihui fault zone, a deep fault system in South China. The Dabaoshan Mo mineralization occurs as disseminations and veinlets in the Dabaoshan porphyries and skarn-greisen associated with the Chuandu porphyritic monzogranite. Here we report the zircon LA-ICP-MS U-Pb ages of the porphyries mentioned above. We also present the major and trace elements, whole-rock Sr-Nd and the zircon Hf isotopic compositions of the Dabaoshan porphyries. The Dabaoshan porphyries are composed of weakly to strongly peraluminous monzogranite porphyry and granite porphyry. They yield ages of 166.3 ± 2.0 Ma (MSWD = 1.9) and 166.2 ± 2.7 Ma (MSWD = 2.7), respectively, slightly older than the Chuandu porphyritic monzogranite pluton which crystallized at 162.1 ± 1.6 Ma (MSWD = 2.7). This is indicative of two distinct magmatic pulses in this region. The Dabaoshan porphyries have 64.42%–75.41% SiO2and show an affinity of high-K calc-alkaline and shoshonite in the plot of Th vs. Co. They have [La/Yb]Nof 14.6–35.0 and εNd(t) values ranging from − 8.2 to − 6.6. The εNd(t) values of the rocks are more negative than those for the Middle Jurassic mafic rocks (εNd(t) = − 2.7 to + 7.9) in the region, but similar to those for Proterozoic crust in the Cathaysia Block at ~ 165 Ma. Zircon from the Dabaoshan porphyries has εHf(t) values ranging from − 13.2 to − 7.5 and two-stages Hf model ages (TDM2) from 1.7 to 2.0 Ga, close to the TDM2(~ 1.7 Ga) of the basement in the western Cathaysia Block. The Dabaoshan porphyries have averaged Th/U of 5.0, similar to those for the Proterozoic crystalline basement (Th/U = 5.3–5.4) in the Cathaysia Block, but higher than those for arc magmas (Th/U = 1.5–3.0). Moreover, Nb/Ta ratios of the porphyries (average 11.8) are also similar to those of the Cathaysia Proterozoic crystalline basement (average 12.4). These geochemical features indicate that the porphyries were derived from high-degree partial melting of the crystalline basement in the Cathaysia Block. Based on the available geochemical data of the Dabaoshan porphyries, together with that of porphyry Mo deposits distributed along the Wuchuan-Sihui deep fault zone, it is concluded that the Dabaoshan porphyry Mo deposit is genetically related to the movements of the Wuchuan-Sihui deep fault induced by the subduction of the paleo-Pacific plate during the Jurassic.
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DOI：
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发表时间：
2000
期刊：
--
影响因子：
--
作者：
Chen Ying-jun
通讯作者：
Chen Ying-jun
影响因子：
3.5
作者：
Wei-dong Sun;Xiaoyong Yang;W. Fan;Fu-Yuan Wu
通讯作者：
Wei-dong Sun;Xiaoyong Yang;W. Fan;Fu-Yuan Wu
影响因子：
5.8
作者：
A. Draut;P. Clift
通讯作者：
A. Draut;P. Clift
DOI：
10.1360/03yd0042
发表时间：
2005-02
期刊：
Science in China Series D: Earth Sciences
影响因子：
--
作者：
T. Sun;Xinmin Zhou;Peirong Chen;Huimin Li;Hong-ying Zhou;Zhicheng Wang;W. Shen
通讯作者：
T. Sun;Xinmin Zhou;Peirong Chen;Huimin Li;Hong-ying Zhou;Zhicheng Wang;W. Shen
影响因子：
1.8
作者：
Chen Yanjing;Li Nuo
通讯作者：
Chen Yanjing;Li Nuo