Effect of geological mapping in shallow overburden area of East Junggar, Xinjiang Province: A case of bedrock geological mapping in the Dure shallow overburden area

How to "peel off " the cover to obtain the underlying bedrock geology (strata, magmatic rock and structure)and mineralization information is an important research content of geological mapping in shallow overburden area of metallogenic belt.Combined with the characteristics of regional geology and geophysical field, the problems related to the mapping area and bedrock geological mapping were sorted out.Based on the physical property analysis of the mapping area, through the processing and analysis of 1:50000 gravity, magnetic and IP measurement data, the multi-parameter mutual constraint interpretation technique and drilling verification were used to peel off the overburden, and then the underlying bedrock geological map of the Dure overburden area was obtained.Meanwhile, a comprehensive investigation technology guided by "penetrating" geophysical technology (gravity, magnetism, and electricity), integrating geology, geochemistry and shallow drilling was proposed.In this paper, 43 concealed plutons and 22 faults in the mapping area were recognized, including 18 intermediate-acid plutons, 21 medium-basic plutons and 4 basic-ultrabasic plutons.Three 3-order geological tectonic zones were divided, namely Aermantai-Zhahaba ophilitic melange belt, Sawur-Ertai Paleozoic composite island arc belt in the north, and Xiemistai-Kulankazigan Paleozoic composite island arc belt in the south.The Aoyidage-Jilekumu Cu-Au-Co-Fe prospect was determined, in which 4 ore prospects were delineated.Among ore prospects, the Yutasi Cu-Au-Co target area in the west of Aermantai-Zhahaba ophilitic melange belts exhibits agreeable prospecting potential.Through geophysical interpretation and drilling verification, it was successfully predicted and confirmed that the Aermantai-Zhahaba ophilitic melange belt on the basin-mountain junction belt in the northern margin of Jungar extends to the shallow coverage area in the west.The geological mapping of batholith in the Dure shallow coverage area can provide the important basic geological and mineralized alteration information for the regional tectonic environment, metallogenic geological backgrounds and predictions of ore prospects.