地质通报
地質通報
지질통보
GEOLOGICAL BULLETIN OF CHINA
2014年
7期
1008-1014
,共7页
汪傲%赵元艺%许虹%卢伟%郭硕
汪傲%趙元藝%許虹%盧偉%郭碩
왕오%조원예%허홍%로위%곽석
40Ar-39Ar年龄%夕卡岩-斑岩型矿床%措勤-申扎岩浆弧%拉萨地块中北部
40Ar-39Ar年齡%夕卡巖-斑巖型礦床%措勤-申扎巖漿弧%拉薩地塊中北部
40Ar-39Ar년령%석잡암-반암형광상%조근-신찰암장호%랍살지괴중북부
40Ar/39Ar age%skarn-porphyry type deposit%Coqen-Xainza magmatic arc%mid-north Lhasa terrane
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。
西藏嘎拉勒夕卡巖型銅金礦床中銅的資源量達到中型規模,金的資源量達到大型規模。在繫統的野外地質調查基礎上,選取礦床夕卡巖中保存極好的白雲母,測得40Ar-39Ar年齡為91.48Ma±0.68Ma,代錶礦床成礦年齡,錶明礦床為燕山運動晚期的產物。結閤區域地質資料認為,在拉薩地塊中北部,成礦年齡約為90Ma的夕卡巖型-斑巖型礦床集中分佈在措勤-申扎巖漿弧上;在早白堊世班公湖-怒江洋盆閉閤後,獅泉河-永珠-納木錯-嘉黎蛇綠混雜帶(Slainajap帶)上的弧後盆地和弧間盆地縯化成瞭一繫列小洋盆,這些小洋盆的縯化與中拉薩地塊北部成礦年齡約為90Ma的夕卡巖-斑巖型礦床的形成有更直接的關繫。今後宜加大在措勤-申扎巖漿弧上尋找成礦年齡約為90Ma的夕卡巖-斑巖型礦床的力度。
서장알랍륵석잡암형동금광상중동적자원량체도중형규모,금적자원량체도대형규모。재계통적야외지질조사기출상,선취광상석잡암중보존겁호적백운모,측득40Ar-39Ar년령위91.48Ma±0.68Ma,대표광상성광년령,표명광상위연산운동만기적산물。결합구역지질자료인위,재랍살지괴중북부,성광년령약위90Ma적석잡암형-반암형광상집중분포재조근-신찰암장호상;재조백성세반공호-노강양분폐합후,사천하-영주-납목착-가려사록혼잡대(Slainajap대)상적호후분지화호간분지연화성료일계렬소양분,저사소양분적연화여중랍살지괴북부성광년령약위90Ma적석잡암-반암형광상적형성유경직접적관계。금후의가대재조근-신찰암장호상심조성광년령약위90Ma적석잡암-반암형광상적력도。
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.