Abstract:
This paper is the result of mineral exploration engineering.
Objective Jiaodong Peninsula is a famous gold metallogenic area in the world. The gold deposits are mainly controlled by fracture. Certainly, there are still many fractures in this area without ore. In the past, the deep form of the fracture and the distinction between the ore−bearing faults and the ore−free faults have not been thoroughly studied.
Methods In this paper, the gravity, magnetic and electric length profiles, wide area electromagnetic profiles and reflection seismic profiles that traverse the main gold deposits areas in Jiaoxibei area are used to reveal the deep characteristics of the fractures, providing important evidence for the identification of ore−bearing faults and ore free faults.
Results The geophysical detection shows that there are deep faults with steep dip angle, shovel faults with gentle dip angle and small faults with steep dip angle in Jiaoxibei area, among which the ore−controlling Sanshandao, Jiaojia and Zhaoping faults are shovel faults. Combined with the study on the gold deposits, it is found that the deposits mainly occur in the gentle dip faults, the ore bodies present the step−like mineralization pattern, while no obvious gold mineralization alteration has been found in the deep faults, and the maximum depth of the present gold deposits are about 5 km.
Conclusions Comprehensive analysis shows that the low−angle detachment faults and the large−angle small faults have better physical trap conditions, which are conducive to mineralization enrichment. However, the deep faults with flat and steep dip do not have the condition of physical trap, which are not conducive to mineralization. The prospecting direction of Jiaodong type gold deposits should be concentrated in the vicinity of the gentle dip shovel faults and its derived and associated small steep dip faults.
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