Soil Geochemical Characteristics And Anomaly Evaluation In Toudaoqiao Area Of The Ewenki Autonomous Banner

The Toudaoqiao area is located in the northeast of Inner Mongolia autonomousregion, under the Hulunbeier city Ewenki autonomous banner, where the trafficconditions is poor. Within the lithostratigraphy is relatively complete, Strata exposedfrom old to new, include the Ordovician of lower Palaeozoic era Duobao mountainstrata; upper Palaeozoic, Devonian system Niqiu river strata and Damin mountaingroup strata, Carboniferous Hongshui Quan strata; Mesozoic Jurassic Baiyin gaolaogroup and Mani tu strata and Cenozoic quaternary strata etc.The purpose and task is toproceed the geochemical measurements for1378.56km2in Toudaoqiao area1:50000map, according to Mongolian autonomous region geological exploration projectbidding committee office in early2008, is sued by the overall goal of the taskassignment handout. Analysis Au, Ag, Cu, Pb, zinc, As, Sb, Bi, W, Sn, Mo, Mn, Fe₂O₃,Y, Nb and other15kinds of elements and compounds, abnormal delineatingmetallogenic elements and associated elements, using the comprehensive methodssuch As geological, geophysical and surface engineering to verify of1:50000geochemical anomalies, the prospecting prospect evaluation of anomalies.658soil samples we collected in Toudaoqiao area at the bottom of the B layer ofthe soil, in the hillside generally depth about30to50cm, weight500¹000g,Samples after natural drying, sieving interception of4²0mesh sample for150g,sample processing according to the rules of soil geochemical survey. The analysis ofthe sample through the national quality certification of the ministry of land andresources in Shenyang, mineral resources, supervision and inspection center （grade aqualification）, analysis item category for Au, Ag, Cu, Pb, zinc, As, Sb, Bi, W, Sn, Mo,Mn, Fe₂O₃, Y, Nb of15kinds of elements （oxide）. By monitoring sample tests, theanalysis methods and quality in accordance with relevant regulation and labeling.Each element analysis test data statistical results compared with eastern China crust element content has the following characteristics: the average copper content is18.53×10^-6, significantly lower than in eastern China crust element abundance value;the average content of lead is18.49×10^-6closed with the eastern China crust elementabundance value; Zinc in the average content of70.47×10^-6, slightly higher than ineastern China crust element abundance value; Molybdenum elements content of1.04×10^-6,significantly higher than in eastern China crust element abundance value;Average content of arsenic is17.45×10^-6, antimony elements in the average contentof1.35×10^-6,this two elements are significantly higher than in eastern China crustelement abundance value; Elements of niobium content15.42×10^-6, yttrium averagecontent of20.39×10^-6.The subregion median contrast filtering method defined as abnormal distribution:with12of Au element exception,7of Ag element exception,5of Cu elementexception,15of Pb element exception,12of Zn element exception,16of W elementexception,7of Sn element exception,9of Bi element exception,5of Mo elementexception,5of Mn element exception,3of As element exception,16of Sb elementexception,4of Nb element exception,8of Y element exception,3of Fe₂O₃exception;10of the lements of comprehensive contrast values anomalies.According to theToudaoqiao area geological situation, the element geochemical anomalycharacteristics, the research is divided into head west gold, polymetallicmetallogenic prospect areas （ⅠB） and forest farm niobium, yttrium metallogenicprospect areas （ⅡA） two metallogenic prospect areas, and on the basis ofmetallogenic prospective areas in each metallogenic prospect areas delineated a keyprospecting target areas, and provide the basis for the next exploration prospecting.