Abstract:
In recent years, great progress has been made in the deep prospecting in the Sanshandao area and the northern sea area, Jiaodong, and it has become a typical case of deep prospecting in China.The three-dimensional visualization analysis of it is of great practical significance to the guidance of deep prospecting.In this paper, the three-dimensional geological model of Sanshandao super giant gold deposit is established based on 311 borehole data.The three-dimensional spatial characteristics of the gold deposit are analyzed, and the key ore-prospecting sections along the ore-controlling faults are pointed out.The three-dimensional visualization analysis shows that the main orebodies of several gold deposits, which were previously considered to be independent, are connected to each other to the deep, and constitute a super-giant gold deposit with more than 1000 tons of resources.The Sanshandao fault, which is endowed with ore, has obvious fluctuation of occurrence, with steep dip angle in the shallow part and gradual slow dip angle in the deep part, showing a shovel step shape.The coupling relationship between the thickness and grade of the main orebody and the dip angle of the fracture surface shows that the grade and thickness of ore body change alternately along strike and dip, and they are positively correlated.The gold orebody mainly occurs in the section where the fracture surface with relatively low slope.In the northern sea area, the Sanshandao fault has two significant steps with low-angle dip in 2000 m depth range, which occurrence the shallow and deep gold ore body respectively.In the shallow step of the fracture, which located at -20~-600 m elevation, the average slope of the surface is 48.21°while it is 44.72°at the orebody occurrence section.In the deep step of the fracture, which located at -940~-1760 m elevation, the average slope of the surface is 44.56°while it is 42.75°at the orebody occurrence section.Comprehensive analysis shows that the gentle dip angle section of the fault is the key area for deep ore prospecting.