摘要
吐拉苏火山盆地金矿成矿构造系统由2种类型的成矿构造组成,一种是火山机构中的高角度塌陷式断裂;另一种是爆发-沉积相中的低角度水压式断裂.阿希金矿受控于弧形塌陷式断裂,其北东段坍塌强度大于南东段,最大张裂空间控制的矿体群向NE侧伏.阿希火山机构东侧的阿恰勒河组下可能隐伏着与西侧对应的高角度弧形塌陷式成矿断裂.爆发-沉积相中硅化岩型金矿受控于水压式断裂,不透水凝灰岩层圈闭富水粗火山碎屑岩层,组成压力仓构造并发生水力压裂作用.由水力压裂作用形成的层控水压式成矿断裂出现的几率,远大于后期由非成矿断裂切割抬升它们出现的几率.构造解析表明吐拉苏火山盆地2类成矿构造控制的金矿具有巨大的地质找矿潜力.
Two kinds of metallotectonics compose the metallotectonics system of the gold deposits in Tulasi volcanic basin, one is high-angle collapse fractures in the volcanic apparatus and the another is low-angle hydrofracturing fractures in the explosive-sedimentary fades. Studies show that A'xi gold deposit is controlled by arcuate collapse fractures in which the collapse extent of northeastern section is stronger than that of its southeastern section. The orebody group, controlled by the biggest pullapart spaces, laterally plunge to the northeast. Based on the formation mechanism of arcuate collapse fractures, we put forward that there are a possible mineralizing fracture under the Aqialeihhe formation in the eastern side of A'xi volcanic apparatus like the high-angle arcuate collapse fractures in its western side. In the explosive-sedimentary facies, the silicified-rock-type gold deposits are controlled by hydrofractures. The hydrofractures were formed in the compartment structures that are composed of water-rich coarse pyroclastic rock layers confined by nonpermeable tuff layers. It is also considered that there is much more possibility that the formation of layered hydrofractures is controlled by hydrofracturing than by the cut and lift of late nonmineralizing fracture. Tectonic analysis indicated that the exploration prospect of gold deposits controlled by the two kinds of metallostructures above in Tulasi volcanic basin is affirmative.
出处
《新疆地质》
CAS
CSCD
2003年第4期383-386,共4页
Xinjiang Geology
基金
国家973项目(2001CB409805)资助
关键词
火山盆地
水压式断裂:塌陷式断裂
成矿构造系统
金矿
Metallotectonic system, Collapse fracture, Hydrofracturing fracture, Volcanic basin, Tulasi in west Tianshan
