Identification of the geochemical anomalies using the catchment basin analysis: A case study of 1∶50000 geochemical survey of stream sediments in Wulasitai region, East Kunlun Orogenic Belt

Abstract

Geochemical survey of stream sediments is an effective technology for mineral prospecting. The extraction of geochemical anomalies in stream sediments based on catchment basins has always been one of the research hotspots.The catchment basin analysis method is proposed based on Sample Catchment Basin Analysis (SCBA)in this paper, and it is used to identify geochemical anomalies in the Wulasitai region, East Kunlun Orogenic Belt in Qinghai Province.Catchment basins are divided by a high-precision DEM, and the Au, Ag, and Pb factor loadings of 1∶50000 stream sediments are measured by the catchment basin analysis. During the extraction process, a variety of geomorphic parameters such as main stream slope, relief ratio, catchment basin area, are used as the sediment delivery ratios for residual correction calculation, and the geochemical background and anomalies are separated by the C-A fractal modeling. The anomaly extraction results show that the area of the catchment basin is the most suitable parameter as the sediment delivery ratio to participate in the downstream attenuation correction. The catchment basin method can effectively identify and extract geochemical anomaly information.Anomalies correspond well to the spatial location of ore deposits, and can provide beneficial information for the next step of mineral prospecting.

Keywords

• catchment basin
• stream sediment
• geochemical characteristics
• geochemical anomaly
• geochemical residual correction
• concentration-area fractal analysis
• east kunlun orogenic belt
• wulasitai region