【摘要】 北秦岭二郎坪群中存在与地层整合产出的层状重晶石岩和铜多金属矿床。重晶石岩贫Al2O3、TiO2组分含量;富集热液组分As、Sb、Ba、Ag和Hg;微量元素U/Th>1;低ΣREE(平均值27.78×10-6)、富集轻稀土(LREE)、亏损重稀土(HREE)、具明显Eu正异常、Ce负异常及与大西洋TAG热液区热液沉积物相似的球粒陨石标准化的稀土元素配分模式特征。这些特征揭示研究区重晶石岩是热水沉积成因型。热水沉积重晶石岩与铜多金属矿床的紧密联系说明,研究区铜金属矿床是海底热液喷流沉积成岩成矿作用的产物。更多还原

【Abstract】 There exist bedded baritic rocks and copper polymetallic deposits which are sandwiched conformably in the Erlangpin Group of northern Qinling Mountains.The baritic rocks contain Al2O3 and TiO2 in lower contents,with concentration of thermal fluid compositions such as As,Sb,Ba,Ag and Hg.The ratio of trace elements U and Th is more than 1.The total REE is low(averaging 27.78×10-6).The ΣREE patterns display ΣLREE-rich but ΣHREE-depletion,with positive Eu anomaly and negative Ce anomaly,which is similarly to REE distribution pattern of chondrite within normalized typical hydrothermal deposits in TAG region.The results show the baritic rocks belonging to type of hot-water deposit.The paragenetic relationship of hydrothermal sedimentogenic baritic rocks and copper polymetalic deposits manifest that the copper polymetalic deposits are formed by the submarine hydrothermal exhalative lithogenesis and mineralization.更多还原