赣西浒坑钨矿床成矿岩体的磷灰石和锆石微量元素特征及其对成岩成矿的指示

赣西地区浒坑钨矿是我国华南钨、锡、铜多金属成矿区与中生代岩浆活动密切相关的典型矿床之一。对浒坑钨矿床中与成矿有关的白云母花岗岩开展了锆石U-Pb定年、磷灰石和锆石原位微量元素研究，结果表明：赋矿白云母花岗岩的成岩时代为（152.3±1.73）Ma；磷灰石具有特殊的“M”型REE球粒陨石标准化配分模式，富F和Mn，贫Cl和Mg；锆石具有高Th/U比值，REE球粒陨石标准化配分模式亏损LREE、富集HREE。锆石微量元素（Ce、U和Ti）温度计和氧逸度计结果表明，锆石形成于岩浆早期高温（800 ℃）和低氧逸度条件下。研究认为，浒坑赋矿花岗岩在演化初期经历了强烈的矿物结晶分异，矿床的形成可能与还原性高分异岩浆演化相关。

Trace Element Characteristics of Zircon and Apatite Metallogenic in Rocks of Hukeng Tungsten Deposit in Western Jiangxi Province：Implications for Petrogenesis and Mineralization

The South China Block is an important polymetallic metallogenic area mainly related to the W，Sn，Cu and other metals，most of that mineralization is closely related to the Mesozoic magmatism.Based on the analysis of zircon U-Pb dating and trace element of apatite and zircon of the muscovite granite related to mineralization in the Hukeng tungsten deposit，the age，magmatic properties and evolution characteristics of the metallogenic rock was constraint in this study.The results show that the muscovite granite was formed at （152.3±1.73）Ma，which is consistent with the peak period of polymetallic mineralization in South China（170~150 Ma）.In addition，trace element of apatite shows that it has a M-shaped REE chondrite normalized pattern，with features of enrich in F［w（F） is 3.52%~4.09%）］and Mn（5 081×10^-6~13 948×10^-6），and depleted in Cl［w（Cl）<0.012%］ and Mg（5.91×10^-6~24.08×10^-6），which are consistent with that in the high fractionated S-type granite.Besides，trace element of zircon shows that it has high Th/U ratio，LREE-depleted and HREE-enriched REE chondrite normalized pattern.Furthermore，the oxidized state and temperature of the rock were constraint by Ce，U and Ti content in zircon，which shows that zircon was crystallized at the conditions of high temperature（800 ℃） and low oxygen fugacity in the early period of magma.Combined with previous studies，it is concluded that the Hukeng granite experienced strong early fractional crystallization and the formation of the Hukeng deposit may be related to the evolution of reductive highly fractionated magmas.