(1. 青海省第三地質(zhì)勘查院，西寧 810029；
2. 中國地質(zhì)大學(xué)(北京) 地球科學(xué)與資源學(xué)院，北京 100083；
3. 吉林大學(xué) 地球科學(xué)學(xué)院，長春 130061)
摘 要: 庫德爾特金多金屬礦床位于東昆侖西段卡爾卻卡礦田內(nèi)，具有獨特的金礦成礦特點。基于礦床特征分析、成礦階段劃分、金礦主成礦期的流體包裹體及氫、氧、硫同位素研究，探討礦床形成機制和礦床成因，這不僅對區(qū)域金礦成礦規(guī)律研究具有科學(xué)價值，而且對于促進(jìn)東昆侖區(qū)域金礦勘查具有重要的實際意義。通過工作，取得以下認(rèn)識和成果：①金礦石中流體包裹體主要是富液相兩相水溶液包裹體(Ⅰ型)，少量為含CO2三相水溶液包裹體(Ⅱ型)。②金礦成礦流體具有中低溫(160.7~259.9 ℃)、中低鹽度(3.5%~ 12.9%NaCleqv)的特點。③成分測定顯示，成礦流體主要是NaCl-H2O體系，其次為NaCl-CO2-H2O體系。④氫、氧同位素組成分別為δD=-37‰~-72‰，平均為-56‰，δ18OWater=-3.3‰~-0.3‰，平均為-2.08‰，說明金礦成礦流體主要為巖漿建造水和大氣降水的混合；硫同位素組成為δ34S=10.5‰~10.8‰，反映礦石中的硫來源單一，硫主要來自巖漿熱液。⑤綜合分析認(rèn)為，庫德爾特金多金屬礦床屬于接觸交代-中低溫?zé)嵋盒偷V床，成礦與花崗閃長巖密切相關(guān)，多金屬礦形成于接觸交代作用；金礦形成于石英硫化物晚期，是花崗閃長巖巖漿期后熱液活動的結(jié)果；金礦石具有細(xì)脈浸染型特點(廣義斑巖型)，該類型金礦在東昆侖西段具有優(yōu)越的成礦背景，找礦前景巨大。
關(guān)鍵字: 礦床成因；接觸交代-中低溫?zé)嵋盒停粠斓聽柼亟鸲嘟饘俚V；東昆侖西段；青海
（1. The Third Geological Exploration Institute of Qinghai Province, Xining 810029, China;
2. School of Earth Sciences and Resources, China University of Geosciences(Beijing), Beijing 100083, China;
3. College of Earth Sciences, Jilin University, Changchun 130061, China）
Abstract:Kuderte gold-polymetallic deposit located in the Kaerqueka ore-field in the western part of East Kunlun, which has unique characteristics of gold mineralization. Based on the analysis of deposit characteristics, the classification of metallogenic stages, and the study on the fluid inclusion in the main gold metallogenic period and the H-O-S isotopes, metallogenic mechanism and origin of ore deposit have been discussed. The study is not only scientific valuable for regional gold metallogenic regularity, but also it is important practical significance for promoting gold ore exploration in East Kunlun. The following knowledge and achievements were achieved: ①Fluid inclusions in the gold-ore is mainly rich liquid two-phase aqueous inclusions(I-type), small amount of aqueous solution containing CO2 three-phase inclusions(Ⅱ); ②The ore-forming fluids has the characteristics of middle-low temperature(160.7-259.9 ℃) and middle-low salinity(3.5%-12.9%NaCleqv); ③Fluid inclusion composition testing shows that the ore-forming fluid is mainly NaCl-H2O system, followed is NaCl-CO2-H2O system; ④The δDV-SMOW ratios are -37‰－-72‰, with an average of -56‰ and the δ18Owarter(V-SMOW) ratios are -3.3‰－-0.3‰, with an average of -2.08‰. The results of hydrogen and oxygen isotopes indicate that the gold ore-forming fluid is mainly mixture of magmatic water and atmospheric precipitation. The δ34S ratios are 10.5‰-10.8‰, reflecting the sulfur in the ore is single source, mainly from magmatic hydrothermal; ⑤According to the comprehensive analysis, the genesis of Kudeerte gold-polymetallic deposit belongs to the contact metasomatism-medium and low temperature hydrothermal type. Metallogenesis is closely related to granodiorite. The polymetallic ore was formed by contact metasomatism and the gold ore was formed in the late quartz sulfide period, which was the result of hydrothermal activity after the magmatic period of granodiorite. The gold ore has the characteristic of veins-disseminated type (Generalized porphyry type). This type gold deposit has the superior metallogenic background and huge prospecting foreground in western part of East Kunlun.
Key words: deposit genesis; contact metasomatism-medium and low temperature hydrothermal type; Kudeerte Gold-polymetallic deposit; western part of East Kunlun; Qinghai Province
