西藏嘎拉勒夕卡岩型铜金矿床中铜的资源量达到中型规模，金的资源量达到大型规模。在系统的野外地质调查基础上，选取矿床夕卡岩中保存极好的白云母，测得40Ar-39Ar年龄为91.48Ma±0.68Ma，代表矿床成矿年龄，表明矿床为燕山运动晚期的产物。结合区域地质资料认为，在拉萨地块中北部，成矿年龄约为90Ma的夕卡岩型-斑岩型矿床集中分布在措勤-申扎岩浆弧上；在早白垩世班公湖-怒江洋盆闭合后，狮泉河-永珠-纳木错-嘉黎蛇绿混杂带（Slainajap带）上的弧后盆地和弧间盆地演化成了一系列小洋盆，这些小洋盆的演化与中拉萨地块北部成矿年龄约为90Ma的夕卡岩-斑岩型矿床的形成有更直接的关系。今后宜加大在措勤-申扎岩浆弧上寻找成矿年龄约为90Ma的夕卡岩-斑岩型矿床的力度。%Located in Gegya County of Ngari Prefecture, Tibet, and lying in the mid-north Lhasa terrane, the Galale skarn-type cop-per-gold deposit contains medium-size copper resources and large-size gold resources. Based on a systematic field geological survey, the authors obtained a 91.48Ma ± 0.68Ma 40Ar-39Ar age of muscovite from skarn in this deposit, which presents its metallogenic age and suggests a late Yanshanian product. Combined with regional geological data, the authors have concluded that skarn-porphyry type deposits in mid-north Lhasa terrane, whose metallogenic age is about 90Ma, are mainly concentrated in the Coqen-Xainza mag-matic arc. After the closure of Bangong-Nujiang Ocean in the Early Cretaceous, these back-arc basins and inter-arc basins, repre-sented now by the Slainajap belt, evolved into some small oceans, and the evolution of these small oceans seemed to be the main fac-tor for the formation of these 90Ma deposits. The authors hold that more work should be done on the exploration of 90Ma skarn-porphyry type deposits along Coqen-Xainza magmatic arc.
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