【摘要】 波龙、多不杂斑岩铜金矿床是青藏高原中部发现的两个大型斑岩铜金矿床。对波龙、多不杂斑岩铜金矿床含矿花岗闪长斑岩和不含矿花岗闪长斑岩的锆石Ce4+/Ce3+比值以及氧逸度等特征进行研究,并且通过计算得到了3个含矿花岗闪长斑岩的锆石Ce4+/Ce3+比值分别为536.03,492.18,454.02;1个不含矿的花岗闪长斑岩的锆石Ce4+/Ce3+比值为0.67。说明波龙、多不杂斑岩矿床中与成矿相关的岩体具有相对更高的氧化状态。对比西藏冈底斯成矿带中的斑岩矿床、云南中甸岛弧成矿带中的烂泥塘斑岩铜矿床、金沙江-红河成矿带中的马厂箐、铜厂铜钼矿以及玉龙成矿带铜钼矿床岩体的锆石Ce4+/Ce3+比值,发现含矿岩体锆石Ce4+/Ce3+比值一般>250。结合波龙、多不杂矿床的锆石Ce4+/Ce3+的计算结果发现Ce4+/Ce3+基本>300,因此将锆石Ce4+/Ce3+>300作为波龙、多不杂矿床斑岩成矿的一个地球化学标志。此外,通过（Ce/Ce*）D锆石氧逸度计和(XCe4+melt/XCe3+melt)锆石氧逸度计计算得到的波龙、多不杂矿床含矿花岗闪长斑岩体的氧逸度(log(fO2))分别位于MH（磁铁矿-赤铁矿）缓冲带和FMQ（铁橄榄石-磁铁矿-石英）缓冲带之上,平均值为ΔMH+3.24和ΔFMQ+1.78,前人研究发现多不杂含矿石英斑岩的氧化状态较高,平均ΔNNO+2.4,含矿斑岩体的形成具有较高的氧逸度条件,说明高氧逸度更有利于多龙矿集区斑岩型铜矿成矿。更多还原

【Abstract】 Study of zircon Ce4+/Ce3+ ratios and oxygen fugacity of ore-bearing granite diorite porphyry and barren granite diorite porphyry of Bolong and Duobuza porphyry Cu-Au deposits in the central Tibetan Plateau shows that the zircon Ce4+/Ce3+ ratios of three ore-bearing granodiorite porphyry samples are 536.03,482.18 and 454.02,while the zircon Ce4+/Ce3+ ratios of no ore-bearing granodiorite porphyry sample is 0.64.The oxidation state of ore-bearing intrusions is relatively higher than that of no ore-bearing intrusions.Comparison of Ce4+/Ce3+ ratios of ore-bearing intrusions and no ore-bearing intrusions in the Gangdese metallogenic belt with those of Lannitang porohyry copper deposit in Zhongdian island arc in Yunnan,of Machangqing and Tongchang porphyry Cu-Mo deposit in Jinshajiang-Red River metallogenic belt,of Cu-Mo deposit in Yulong metallogenic belt indicates that the Ce4+/Ce3+ ratios of ore-bearing intrusions are usually greater than 250,while the no ore-bearing intrusions usually less than 250.It is found that the Ce4+/Ce3+ ratio of the Bolong and Duobuza deposit are basically over 300,which can be used as the geochemical indicators for Bolong and Duobuza porphyry Cu-Au deposit.Calculation value of oxygen fugacity of ore-bearing granite diorite porphyry by（Ce/Ce*）D oxy-barometers is basically located on the MH buffer with average of ΔMH+3.24,and the oxygen fugacity by(XCe4+melt/XCe3+melt) oxy-barometers is all located on the FMQ buffer with average of ΔFMQ+1.78.Previous research revealed that the mineralized Duobuza quartz diorite porphyry has a high oxidation state（average ΔNNO+2.4）,and therefore,high oxygen fugidity is a favorable condition for the porphyry copper mineralization in Duolong.更多还原