Structure and sand body characteristics of Lower Cretaceous Saihan Formation in Aqituwula area
The study area is located in the north-west part of Tengger Depression,where uranium mineraliza-tion occurs mainly in the paleochannel sand bodies developed in the upper section of Saihan Formation of Lower Cretaceous.Thus,it is helpful to advance the prospecting and enhance the prospecting effect of urani-um deposit that the structure of interest bed(Saihan Formation)for prospecting made be cleared,especially development characteristics of sand body.Based on the controlled source audio magnetotelluric(CSAMT)data completed in the study area,combined with rock resistivity and borehole data,the structure of Saihan Formation of Lower Cretaceous and the development characteristics of sand bodies are studied in this paper.The result shows that the roof of Saihan Formation of Lower Cretaceous is about 150 m deep and at inclina-tion from the rise to the central sag.The maximum thickness of Durimu sag is about 550 m,which is com-posed of mud and sand and mud.The thickness of upper mudstone is 80～100 m.Braided river and deltaic sand bodies(mainly in Durimu sag)are developed in the middle layer,which are continuously stable in transverse direction,about 8-13 km wide,thickness increase to 220 m from NW to SE.The thickness of mudstone in the bottom layer is 100-280 m.The above-mentioned development characteristics of target strata provides the geological and geophysical information for uranium resources evaluation in the area.
Aqituwula areaupper section of Saihan FormationCSAMTgeoelectric structuresand body
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NSTL
万方数据
