A Study On Uranium Metallogenic Conditions In Lujiapu Area

Lujiapu area has good prospect of exploration due to the widely distributed abnormalities.According to the sequence stratigraphy,the key interfaces and landmarks of the uranium-bearing rock series in Lujiapu area are identified through the comprehensive interpretation of logging,logging and core information,The compilation of comparative stratigraphy of network stratigraphy in the whole region has established the isochronal stratigraphic framework of uranium formation in Lujiapu area,and has divided into four stratigraphic units,namely the Yaojia Formation,Nenjiang Formation,Sifangtai Formation and Mingshui formation.The western region does not have mingshui formation.Through tracing and contrasting of the key sections of the network,an isochronal stratigraphic framework containing uranium series in Lujiapu area was established.The strata of this area are generally thin in the west and south,and the thickness of the strata in the Ludong area is obviously larger than that in the Luxi area.From the characteristics of uranium reservoir distribution in each horizon,the sand body of Yaojia Formation and Sifangtai Formation are well developed,and the provenance comes from the northwest direction,from Yaojia Formation to Sifangtai Formation in Ludong area.There is a gradual shift from southwest to northeast.The distribution of red sandstone in the target horizon is NW-SE,indicating the direction of interlayer oxidation,which is consistent with the direction of provenance.Taking the contour of the red sand body thickness 10 as the front line of the interlayer oxidation zone,the zonal characteristics of interlayer oxidation were preliminarily determined.On this basis,the spatial distribution of provenances in Lujiapu area and the developmental characteristics of uranium reservoirs' sedimentary facies and oxidation zones are studied.Combined with the situation of uranium source in the eroded area,Metallogenic conditions were analyzed.It is considered that the anomalous distribution of uranium in this area is restricted by the size of the uranium reservoir and the oxidation band between the layers.Uranium anomalies tend to occur when the uranium reservoir thickness is between 20-50 m and the sand content is between 30% and 60%.Uranium anomalies are mainly distributed in the interlayer oxidation zone near the forward line.