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纳如松多铅锌矿床位于拉萨地块中部隆格尔-工布江达断隆带中段,以发育隐爆角砾岩型和矽卡岩型铅锌矿化为特征。西矿段与矽卡岩型铅锌矿化相关的岩体为粗斑和细斑两种石英正长斑岩,对其锆石进行的U-Pb定年、稀土元素、Lu-Hf同位素和锆石群型特征分析表明,粗斑石英正长斑岩侵位于(62.54±0.77)Ma,细斑石英正长斑岩侵位于(62.47±0.91)Ma;锆石稀土元素具有相似的左倾配分模式和Ce正异常、Eu负异常,在U/Yb-Y图解上均落于陆壳锆石范围;粗斑石英正长斑岩的176Hf/177Hf介于0.282577～0.282803,εHf(t)变化于-5.58～+2.21,反映岩浆来源于地壳物质的部分熔融,并有地幔物质的加入;锆石群型特征显示粗斑和细斑石英正长斑岩为地壳地幔混合岩浆成因的花岗岩。上述结果说明纳如松多铅锌矿床的岩浆侵入与成矿作用发生于印度-亚洲大陆碰撞造山的主碰撞期。由于印度陆壳随回转的新特提斯洋壳板片一起向拉萨地块之下陡俯冲,并产生异常热源,诱发了地幔物质上涌和上覆地壳部分熔融,形成的地幔地壳混合成因岩浆经结晶分异演化后上升侵位,形成矿区内粗斑和细斑两种石英正长斑岩及相关的铅锌矿化。
The Nadusson-lead-zinc deposit is located in the middle part of the Lungar-Gongbu-Jiangda uplift belt in the central Lhasa block, characterized by the development of cryptoexplosive breccia type and skarn-type lead-zinc mineralization. The rock bodies associated with skarn-type lead-zinc mineralization in the West Mine are coarse and fine speckles of quartz-type quartz porphyries. U-Pb dating, rare earth elements, Lu-Hf isotopes and zirconium The analysis of the petrogeographical characteristics shows that the orthorhombic porphyry of the plagioclase is located at (62.54 ± 0.77) Ma and the plagioclase positive plagioclase is (62.47 ± 0.91) Ma. The zircon REE has a similar left-diurnal distribution pattern and Ce positive anomalies and Eu negative anomalies all fall within the range of continental crust zircons on the U / Yb-Y plot. The 176Hf / 177Hf of the coarse plagioclase positive-porphyry range from 0.282577 to 0.282803 and the εHf (t) changes from -5.58 ~ + 2.21, reflecting the partial melting of magma originating from the crustal material and the addition of mantle materials. The zircon assemblages show that the coarse plagioclase and fine-grained quartz-bearing plagioclase are granites with mixed magmatic origin in the crust and mantle. The above results indicate that the magmatic intrusions and mineralization of the Natusson lead-zinc deposit occurred during the main collision of the Indian-Asian collision orogen. As the Indian continental crust steeply subducts beneath the Lhasa block with the turning of the new Tethys oceanic crust plates and generates abnormal heat sources, the upwelling of the mantle material and the partial melting of the overlying crust are induced, resulting in the mantle-mixed magmas of the mantle After the evolution of the crystallization differentiation evolved into emplacement, the formation of coarse and spot in the mining area of two kinds of quartz porphyrite and related Pb-Zn mineralization.