Experimental Study Of Geochemical Exploration Method In The African Tropical Grassland Landscape

The Pala area is the most important mining area of alluvial gold in Mayo Kebbi Region,Chad.This paper is based on the geochemical exploration of gold mine in Pala which tries to discuss the geochemical exploration method in African tropical grassland landscape.The understandings and conclusions achieved by this paper are as follows:1.Preliminary experiment results show that stream sediments survey can delineate the prospecting target areas in relatively flat terrain of African tropical grassland landscape.Only 312 samples can find the prospecting targets quickly and confirm the key exploration areas in the 700km2 of mineral rights area.2.We inspect the stream sediments anomalies and find the primary gold mineralization by the soil geochemical survey in Ganboke north,Ganboke south,Ganboke southwest and Pala north which indicates that soil geochemical survey canplay a role in the anomaly inspection of this landscape.3.We find out the character of Au' value in the soil gravel layer containing gold which above the primary gold mineralization by studying the distribution of Au in the vertical soil profiles.The result of different size fractions samples indicates that Au is enriching in the soil gravel layer and Au is obviously enrich in the-10?+60 mesh samples.4.According to the distribution of Au in the stream sediments,soil and rock,the geology character of primary gold mineralization,the regional geological evolution history,climate,and topography landscape conditions,we conclude the dispersion pattern under the condition of hypergenesis.This pattern can explain why we can not find any big gold ore body in the study area where have very high stream sediments Au anomalies,high soil anomalies and a big range of soil gravel layer containing gold.5.More and more domestic companies and individuals invest in mining in foreign countries under the "going out" strategy of mineral exploration.To reduce the risk,we must do some necessary work by combining the local conditions.We should never copy the domestic experience and do blind adventure because we may be confused by the superficial phenomenon.