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Juneau金矿带中含金石英脉系形成于阿拉斯加海岸山脉的西部边缘、长160km、宽5~8km的地带。脉系与地形边界上中白垩纪逆断层附近的剪切带在空间上有成因联系。岩脉方向和剪应力大小、分布方向说明了最大主应力轴呈北东—南西走向,且近水平分布,而最小主应力轴近垂直分布。这种局部的应力排列方式与远源的始新世的板块排列方式相一致。岩脉形成的同位素年龄说明了流体循环发生在52.8~56.5Ma,这与早始新世板块运动方式的改变有成因上的联系。岩脉形成与金矿带中稍晚时期迅速的剥露作用以及大体积的深成作用是同步的。我们提出一个模型,在这种模型中,相关的构造事件使沿现在被剥露的剪切带容易发生断层阀运动和形成脉岩。
The gold-bearing quartz veins of the Juneau gold belt are formed on the western edge of the Alaskan Coastal Range, 160 km long and 5 to 8 km wide. The genesis of the shear zone near the Cretaceous reverse fault on the veins and terrain boundary is spatially related. The direction of dikes, the magnitude of shear stress and the direction of distribution indicate that the maximum principal stress axis is northeast-southwest and nearly horizontally distributed, while the minimum principal stress axis is nearly vertically distributed. This local arrangement of stresses is consistent with the remote Eocene plate arrangement. The isotopic age of dikes indicates that fluid circulation occurs at 52.8-56.5Ma, which is intrinsically linked to changes in the movement pattern of the Early Miocene plate. The formation of dikes is synchronized with the rapid delamination of the later period of the gold belt and the massive deep penetration. We present a model in which the associated structural events make fault-valve movement and formation of vein rocks prone to shear bands that are now exposed.