DISCUSSION ON DEEP ORE PROSPECTING IN THE MIDDLE AND LOWER REACHES OF YANGTZE RIVER MINERALIZATION BELT

The proven mineral resources above elevation of-500~-2000m at the ore belt of middle and lower Yangtze river have almost been exhausted and is urgent the ore prospecting to depth in the belt.Comprehensive study on geological exploration and mining for more than latest half century shows that the ore control factors are as follows: lithosphere thinning that is the prerequisite of mineralization;strong Yanshanian(J3-K2-3) tectonic-magmatic activities that are the key to regional mineralization;surfacial fractural pattern that is expression of the deep structural activity;sedimentary formations in foreland basin that is favorable host rocks of ore deposit;various wall rock alteration patterns of Fe,Cu ore deposits of which adakite is the indirect mark for Cu ore prospecting.Four philosophical ideas for further prospecting target depth are pointed out:(1) to depth beneath of volcanic basins,(2) to depth of the target strata,(3) to depth of the complex ore deposits,(4) to depth of the multi-stepped contact zones.