This is subeconomic mineralization related to minor dyke swarms. 這是與小岩脈群有關的准經濟意義的礦化。
In addition, dyke exposures, the fault-collapsed karstic system and groundwater also caused some problems during the excavation of the tunnel. 加之,岩脈走向,斷層帶破裂面以及地下水的存在,在開挖過程中也導致了一些問題。