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西格马矿床由太古宙变质火山岩中的含金脉系组成,变质火山岩被不规则的斑状闪长岩体侵入,两者均受区域变形的影响,并被较年轻的未变形的长石斑岩墙所切割。含金碳脉切割所有岩石类型,主要由石英和电气石组成,并含少量碳酸盐、黄铁矿、绿泥石、白钨矿和自然金。脉就位于长石斑岩墙侵入之后的绿片岩相变质作用期间或其后,没有遭受任何后来变质或构造作用的实质性影响。矿山主要有两类脉;近垂直脉和近水平脉,它们是同源同时产物。近垂直脉产在陆倾斜东西向延伸的韧性剪切带内,沿韧性剪切带发生了逆向近垂直位移。在剪切带内,由于前进剪切运动,不平整,不规则叶理面和滑动面的递加,导致岩石产生裂开,脉就充填在这些裂开中。近水平脉充填韧性剪切带之间发育的张性破裂中,首先在更适宜的岩石中发生。岩这次脉形成于一次或多次对张开空间的充填。地质关系表明,矿化脉是在构造环境下,在韧性剪切带形成时或稍后逐渐就位的。构造分析显示,韧性剪切带和两类脉可能与下列方向的单一应变椭球体相关:Z-轴水平南北向延伸,Y-轴向西倾伏10°,x-向东倾伏80°。产在韧性剪切带的形变和脉就位,是区域变形后的晚期南北向压力作用的结果。
The Sigamae deposit is composed of gold-bearing vein facies in the Archean metamorphic volcanic rocks. The metamorphic volcanic rocks are intruded by irregular porphyritic diorite bodies, both of which are affected by the regional deformation and are replaced by the younger, undistorted feldspar Cut by the rock wall. Gold Cava cuts all types of rocks, mainly composed of quartz and tourmaline, with minor amounts of carbonate, pyrite, chlorite, scheelite and natural gold. The vein did not have any substantial subsequent metamorphism or tectonism during or after the metamorphism of the greenschist facies, which occurred just after the feldspar porphyry intrusion. There are two main types of mines; nearly vertical and horizontal veins, which are homologous products. The near-vertical pulse in the ductile shear zone extends eastward and westward along the slope of the slope, reversing the near-vertical displacement along the ductile shear zone. Within the shear zone, due to progressive shear movement, unevenness, irregular foliation and sliding surfaces, the rock cracks and the pulse fills in these cracks. Tensile fractures developed between nearly horizontal-filling pulse ductile shear zones first occur in more suitable rocks. This vein of veins forms in one or more fillings of open spaces. The geological relationship shows that the mineralization veins are in place during the formation of the ductile shear zone or later in the tectonic setting. Tectonic analyzes show that the ductile shear zones and two types of veins may be related to a single strain ellipsoid in the following directions: horizontal north-south extension of the Z-axis, 10 ° westward on the Y-axis and 80 ° eastward on the x-axis. Deformation in the ductile shear zone and pulse position, is the result of late-stage north-south pressure deformation after regional deformation.