摘要
玉勒肯哈腊苏中型斑岩型铜(钼)矿主要赋存在闪长玢岩中,有少量矿化产在北塔山组火山岩及似斑状黑云母石英二长岩中。矿化呈细脉状、细脉-浸染状和浸染状。围岩蚀变主要为钾化、硅化、绢云母化、石膏化、磁铁矿化、绿泥石化、绿帘石化。矿床的形成经历了斑岩期、剪切变形期和表生期,铜和钼矿化主要形成于斑岩期的硫化物-钾硅酸盐阶段和辉钼矿阶段。石英和方解石中的流体包裹体可划分为H2O-NaCl型和H2O-CO2(±CH4/N2)-NaCl型。硫化物-钾硅酸盐阶段的成矿温度为141~500℃,主要集中在200~340℃;流体的w(NaCleq)为2.96%~14.97%;流体的密度为0.60~0.98 g/cm3。碳酸盐阶段的流体以中-低温度(140~320℃)和低盐度〔w(NaCleq)为2.74%~10.61%〕为特征。硫化物的δ34S值集中于-4.5‰^-0.1‰,峰值为-3.5‰,表明硫来自深源岩浆。石英和方解石的δ18OSMOW值为9.1‰~13.2‰,δ18OH2O值为2.05‰~6.28‰,δD值为-120‰^-97‰,表明主成矿阶段的成矿流体主要是岩浆水,混合有大气降水;碳酸盐阶段的流体主要为大气降水,混合有岩浆水。成矿时代为中泥盆世〔(373.9±2.2 Ma)〕,成矿作用与闪长玢岩的侵入有关。温度和压力的降低导致流体沸腾,同时,水-岩交换反应、流体成分的改变等在铜钼成矿过程中起着主导作用。
The Yulekenhalasu medium-size porphyry copper-（molybdenum） deposit occurs in the diorite porphyry, with some mineralization also observed in the porphyroid biotite quartz monzonite and volcanic rocks of theBeitashan Formation. Mineralization occurs as veinlets, veinlet-disseminations and stockworks. Wall-rock altera tion is well developed, and mainly comprises K-feldspathization, biotitization, quartzification, sericitization, magnetitization, gypsification, chloritization, and epidotization. According to cutting relationships of the ore veins, mineral assemblages, paragenetic sequence and ore fabrics, the ore-forming process can be divided into three metailogenic periods： porphyry, shear deformation and supergene periods. The sulfides-K-silicate stage and the molybdenite stage in the porphyry period constituted the main stages for copper mineralization and molybdenum mineralization, respectively. Two types of fluid inclusions, namely H2O-NaCl and HaO-CO2 （ ＋ CH4/N2）-NaCltypes, have been recognized in quartz and calcite. Homogenization temperatures of fluid in- clusions in the sulfides-K-silicate stage vary from 141℃ to 500℃, concentrated from 200℃ to 340℃. Salinity w（NaCleq）ranges from 2.96% to 14.97%. Ore fluid densities range from 0.60 to 0.98 g/cm3. Fluids of the carbonate stage are characterized by medium-low temperatures （140℃ to 320℃ ） and low salinities （2.74 % to 10.61% ）. δ34S values of sulfides associated with mineralization range from - 4.5‰ to - 0.1‰, with the peak being - 3.5‰, indicating that sulfur was derived from deep-seated magma. δ18OsMow values of quartz and cal- cite range from 9.1‰ to 13.2‰, with the corresponding 318OH2o values between - 2.05‰ and 6.28‰, and 3D values of fluid inclusions vary between - 12‰ and - 97‰. The combined isotopic data imply that the ore- forming fluids of the sulfides-K-silicate stage in the Yulekenhalasu Cu-（Mo） deposit were mainly derived from magmatic fluids, with a minor part from the meteoric water, and the fluids of the carbonate stage were mainly derived from the meteoric water, with a minor part from magmatic fluids. Cu-（Mo） mineralization in Yuleken- halasu took place in Middle Devonian [（373.9 ± 2.2） Ma], related to the diorite porphyry. The decrease of temperature and pressure, the boiling of local ore-forming fluid, the water-rock exchange, and the compositional variation of ore fluids played important roles in ore-forming processes of the Cu-（Mo） ore bodies.
出处
《矿床地质》
CAS
CSCD
北大核心
2012年第5期965-982,共18页
Mineral Deposits
基金
国家自然科学基金项目(编号:40972069)
国家重点基础研究发展计划项目(编号:2007CB411302)联合资助
关键词
地球化学
斑岩铜(钼)矿床
流体包裹体
硫、氢、氧同位素
成矿作用
玉勒肯哈腊苏
准噶尔北缘
新疆
geochemistry, porphyry copper- （molybdenum） deposit, fluid inclusion, sulfur-oxygen-hydro- gen stable isotopes, metailogenesis, Yulekenhalasu, northern margin of Junggar, Xinjiang
