“二十大”矿务局开采矿脉的中央矿段,矿床形态变化极大,多数是沿走向延伸的层状矿体和急倾斜柱状矿体。由于矿体多处变厚、出现分支现象,因而变得复杂。另外,经常发现矿体尖灭,有的矿体沿走向或深度方向汇合。矿体厚度变化很大,从10到30米,因而生产探矿网度为:沿倾斜35～40米,沿走向25～ The “Twentieth Big” Mining Bureau exploits the central ore section of the veins. The deposits vary greatly in shape, mostly stratified and steeply inclined columnar ore bodies extending along the strike. Due to multiple thickening of the ore body, branching phenomenon, which becomes complicated. In addition, it is often found that the ore bodies are sharply annihilated and that some ore bodies converge in the direction of depth or depth. The thickness of the ore body varies greatly from 10 to 30 meters, so the prospecting degree of the ore body is as follows: 35 to 40 meters along the slope and 25 ~