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多不杂矿床是班公湖-怒江缝合带上发现的第一处大型斑岩铜矿床。该矿床位于班公湖-怒江缝合带的北侧,羌塘地块的南缘。含矿斑岩体属花岗闪长斑岩,其SiO2含量为61.37%～67.73%,平均为65.16%;稀土元素总量为(41.4～94)×10-6,LREE>HREE,属轻稀土元素富集型;微量元素特征表现为富集大离子不相容元素Rb、K、Th、Ba、La、Ce、Sr,亏损高场强元素Nb、Ta、P、Ti。含矿斑岩的稀土元素和微量元素特点反映出岛弧带的岩浆作用特征。含矿斑岩中锆石的U-PbSHRIMP测年获得(120.9±2.4)Ma(MSWD=4.3)谐和年龄,代表了含矿斑岩的形成时代。6个辉钼矿样品的Re-Os模式年龄范围非常一致,其变化范围为(117.6±1.3)～(118.5±1.4)Ma,等时线年龄为(118.0±1.5)Ma(MSWD=0.30),代表了该矿床的成矿年龄。该矿床的形成时代对应于班公湖-怒江早白垩世期间的多岛弧-盆系演化时期,其形成环境类似于东南亚的多岛弧-盆系统。
Many non-mineral deposits are the first large-scale porphyry copper deposit discovered in the Bangong-Nujiang suture zone. The deposit is located in the northern side of Bangong Lake - Nujiang suture zone, southern Qiangtang block. The ore-bearing porphyries are granodiorite porphyries with SiO2 contents of 61.37% -67.73% and an average of 65.16%. The total amount of rare earth elements is (41.4-94) × 10-6, LREE> HREE, Elemental enrichment. The trace element characteristics are enriched in Rb, K, Th, Ba, La, Ce, Sr and depleted high field strength elements Nb, Ta, P and Ti. The characteristics of rare earth elements and trace elements in porphyry porphyry reflect the magmatic characteristics of island arc zone. The U-Pb SHRIMP dating of ore-bearing porphyries yields a (120.9 ± 2.4) Ma (MSWD = 4.3) harmonic age dating for the age of the ore-bearing porphyries. The Re-Os model age range of the six molybdenite samples is very consistent with the range of (117.6 ± 1.3) ~ (118.5 ± 1.4) Ma and the isochron age of (118.0 ± 1.5) Ma (MSWD = 0.30) Represents the metallogenic age of this deposit. The age of this deposit corresponds to the multi-island arc-basin evolution during the Early Bangla-Nujiang Early Cretaceous and its formation environment is similar to the multi-island arc-basin system in Southeast Asia.