(1. 中南大學有色金屬成礦預測與地質環(huán)境監(jiān)測教育部重點實驗室，長沙 410083；
2. 中南大學地球科學與信息物理學院，長沙 410083)
摘 要: 果洛龍洼金礦位于東昆侖造山帶東段，華力西-印支期是最重要的成礦期。礦體受近東西向斷裂控制，地層為礦源層和隔擋層，對礦質進行圈閉，變質熱液及巖漿提供熱源和物質。成礦作用分為變質熱液期和巖漿熱液期，前者包括乳白色石英脈階段(A)和含金石英黃鐵礦階段(B)，為主成礦期，后者對應石英硫化物再富集階段(C)，起疊加改造作用。綜合穩(wěn)定同位素及包裹體的特征，從多因復成的角度探討其成礦作用。穩(wěn)定同位素反映成礦物質及流體為多來源。包裹體研究表明：B、C階段發(fā)育3種包裹體：I型水溶液包裹體、II型水溶液-CO2包裹體、III型純CO2包裹體。B階段發(fā)育的3種包裹體溫度集中于260~360℃，I型、II型包裹體鹽度分別為10.70％~22.69%和3.52%~12.42%，流體可能來源于變質熱液，屬變質熱液期。C階段發(fā)育I型包裹體及少量II型包裹體，溫度集中于160~320℃，I型、II型包裹體鹽度分別為15.90％~23.32％和10.62%~13.57%，成礦熱液可能主要來源于巖漿熱液，為巖漿熱液期。礦床在變質熱液期成礦，后期受到巖漿熱液疊加改造，礦質進行再富集。因此，礦床具多大地構造階段、多控礦因素、多成礦物質來源、多成礦作用及多成因類型，屬多因復成礦床。
關鍵字: 成礦作用；多因復成；果洛龍洼金礦
（1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,
Ministry of Education, Central South University, Changsha 410083, China;
2. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China）
Abstract:TheGuoluolongwa gold deposit is located at the eastern part of east Kunlun orogenic belt. The Variscan- Indosinian period is the most important mineralization period in this region. EW trending faults take a significant control of the ore bodies, the formation is the ore source, and acts as a barrier to trap the ore-forming minerals, besides, metamorphic hydrothermal and magmatic activity play a role in providing materials and heat for mineralization. Mineralization can be classified into metamorphic hydrothermal episode and magmatic hydrothermal episode. The former is the main mineralization episode, which consists of milky quartz vein stage (A) and gold-bearing quartz pyrite stage (B), and the latter corresponds to quartz sulfide enrichment stage (C). Polygenesis of the deposit was discussed according to study of S—Pb isotope, fluid inclusion microthermometry and H—O isotope. S—Pb isotope and H—O isotope analysis show multiple origins of ore-forming materials and fluids. Based on fluid inclusion petrography, three types of fluid inclusions are identified in B and C stages: aqueous inclusion (type I), CO2-aqueous inclusion (type II) and pure CO2 inclusion (type III). All three types of inclusions are present in stage B, having homogenization temperatures at 260- 360 ℃, and salinities ranging from 10.70% to 22.69% for type I and 3.52%-12.42% for type II, showing that ore-forming fluid maybe derived from metamorphic fluids and this stage belongs to metamorphic hydrothermal episode. Type I and a small amount of type II inclusions are developed in stage C, with homogenization temperatures concentrating from 160 ℃ to 320 ℃, and salinities ranging from 15.90%-23.32% for type I and 10.62%-13.57% for type II, indicating that mineralization fluid maybe magmatic hydrothermal and this stage belongs to magmatic hydrothermal episode. Gold mineralization mainly occurs in metamorphic hydrothermal episode, and superposition of magmatic hydrothermal in the late leads to re-enrichment of ore-forming minerals. To sum up, the deposit has a long evolution history, sources for ore-forming materials and fluids are multiple, and there exists a variety of ore-controlling factors, as well as various genetic types, illustrating that the deposit belongs to polygenetic compound deposit.
Key words: metallogenesis; polygenetic compound; Guoluolongwa gold deposit
