Extraction Of Geochemical Anomaly Information Of Pb And Its Related Elements And Its Metallogenic Prospect In Ala Teng Obo, Inner Mongolia

The Ala Teng obo region is located tectonically on the joint area of Sino-Korea plate, Tarim plate and Xing’an-Mongolian orogenic belt. Ala Teng obo, whose metallogenetic epoch was mainly Late Variscan to Indosinian, was considered as a key region for prospecting in recent years due to the fact that intensively and widespread magmatic activity, highly developed regional geochemical exploration abnormality.The research region is located on the midwest area of Alashan League, Inner Mongolia Province, where the basement rock exposed. 1:50,000 regional geological surveys were done on this region. The topography of the region is relatively flat and has well developed water system, most at an elevation less than 50 meters. It is difficult to achieve a complete control to the area if we take water samples according normal regulations. Depending upon program of major projects supported by National Science and Technology“demonstration research of copper, ferrum, lead and zinc metallogenic regularity and evaluation technology in Beishan-Langshan region”, this paper sampled from the first level stream sediment in the studied area and increased the sampling density in the key area, by which better results were achieved.Metallogenic element analysis of 15 elements including V、Cr、Ni、Cu、Zn、Pb、As、Sb、Bi、Hg、Mo、Sn、Ag、Co and Au by using cluster analysis and factor analysis suggests that Pb and Zn are highly correlated, and were formed by the similar Geological proces. Concentration contrast between stream sediment and background level of the rocks showed that Pb and Zn have no obvious enrichment or dispersion, indicating that contents of Pb and Zn in stream sediment are similar to the background values in the basement rocks.Take into account the fact that different anomaly threshold determination methods have their own merit and defect, conventional method, gridding method and geological unit dividing method were integratedly utilized and mainly the third method to determine the anomaly threshold value. The anomaly area was determined based on the anomaly threshold value in combination with the regional geology and mineral resource data. Detailed studies showed that it was necessary to sample more intensive in the key area during geochemical exploration, which could avoid leaving out some smaller anomalies. The geological unit dividing method could avoid the following situations such as larger area of anomaly determination in high background geological unit, or smaller area of anomaly determination in low background geological unit, in spite of large amount of calculation when determined the anomaly threshold using this method.Element abnormality of Pb and Zn mainly distributed in the second section of Hala Huo wart formation of Mesoproterozoic Bayan Obo Group (Jxh~2) and Suji volcanic rocks of Lower Permian (sv).