CAJ | 학술논문

提位于西秦岭岷(县)-礼(县)成矿带西段的马坞金矿床,是近年发现的一个中型卡林型金矿床。矿体产出受NWW向断裂构造控制,其赋矿围岩为中泥盆统的千枚岩与灰岩。矿床流体包裹体研究表明,脉石矿物中主要发育CO2-H2O型和H2O溶液型包裹体；均一温度为135~389℃,盐度为4.4%~15.9%,为中-低温、中-低盐度流体；流体成矿压力为34.6~219.8 MPa,成矿深度为1.3~8.1 km。流体包裹体气相成分以H2O、N2为主,其次为CO2、O2,并含有少量CH4、CO等还原性气体；液相成分中阳离子以Ca2+、Na+为主,阴离子以Cl-和SO42-占主导地位,成矿流体为N2-H2O-Ca2+-Cl-体系。氢氧同位素测试结果表明,成矿流体的δ18O水为5.3‰~10.5‰,δD为-123‰~-93‰,成矿流体主要为热卤水。从流体性质及其演化来看,构造体制的转换使流体稳定体系发生改变与沸腾作用是造成金富集成矿的主要因素。
제위우서진령민(현)-례(현)성광대서단적마오금광상,시근년발현적일개중형잡림형금광상。광체산출수NWW향단렬구조공제,기부광위암위중니분통적천매암여회암。광상류체포과체연구표명,맥석광물중주요발육CO2-H2O형화H2O용액형포과체；균일온도위135~389℃,염도위4.4%~15.9%,위중-저온、중-저염도류체；류체성광압력위34.6~219.8 MPa,성광심도위1.3~8.1 km。류체포과체기상성분이H2O、N2위주,기차위CO2、O2,병함유소량CH4、CO등환원성기체；액상성분중양리자이Ca2+、Na+위주,음리자이Cl-화SO42-점주도지위,성광류체위N2-H2O-Ca2+-Cl-체계。경양동위소측시결과표명,성광류체적δ18O수위5.3‰~10.5‰,δD위-123‰~-93‰,성광류체주요위열서수。종류체성질급기연화래간,구조체제적전환사류체은정체계발생개변여비등작용시조성금부집성광적주요인소。
Located in the western part of the Min-Li metallogenic belt within the West Qinling Mountains, the Mawu gold deposit is a medium Carlin-type disseminated gold deposit discovered in recent years. The orebody is controlled by the NW-trending faults and hosted in the Devonian phyllite and limestone. Two main types of fluid inclusions, i.e., CO2-H2O inclusions and aqueous fluid inclusions, are trapped in the gangue minerals. The homogenization temperatures range from 135 ° C to 389 ° C, while the salinities range from 4.4%to 15.9%, indicating medium-low temperature and medium-low salinity. The trapping pressures are 34.6 MPa to 219.8 MPa. The gold mineralization occurred at the depths of 1.3 km to 8.1 km. Fluid inclusion analyses show that the gas phase is mainly composed of H2O and N2, with minor CO2 and O2, while the liquid phase is mainly composed of Ca2+, Na+, Cl-and SO42-. The ore-forming fluid belongs to the N2-H2O-Ca2+-Cl-system. The hydrogen and oxygen isotopic compositions of fluid inclusions show thatδ18OH2O values range from 5.3‰to 10.5‰, while δD values range from-123‰to-93‰. The ore-forming fluid came from the geothermal brine. An analysis of the fluid evolution shows that the variation of the stability of the fluid system caused by the structural transition and the boiling action played vital roles in the precipitation of gold.