Exudation−infiltration coupled mineralization model and prospecting direction of sandstone−type uranium deposit in Sifangtai Formation, Qian'an area, Songliao Basin

This paper is the result of mineral exploration engineering.

Objective The study of uranium metallogenic conditions and mineralization model of Sifangtai Formation, Qian’an area in the hinterland of Songliao basin is relatively weak. Comprehensively analyzing the mineralization conditions of the sandstone-type uranium deposits, evaluating their mineralization potential, and clarifying their exploration directions can develop new direction for uranium exploration in the Songliao Basin.

Methods Through comprehensive analysis of core, logging, seismic, trace element and other data, the tectonics, stratigraphy and transformation of Sifangtai Formation in Qian’an area has been sorted, and it is the first time to systematically summarize the uranium metallogenic elements of sandstone-type uranium deposits in the the hinterland of Songliao Basin.

Results Sifangtai Formation in Qian'an area has favorable metallogenic conditions such as structural window, deep and large faults, braided river delta channel sand belts, good uranium source conditions and epigenetic transformation. It is considered that Sifangtai Formation infiltrative and exudative uranium metallogenic conditions, and exudative metallogeny is dominant. Based on these facts, the exudation-infiltration coupled uranium metallogenic model of Sifangtai Formation, Qian'an area, Centrel Songliao Basin, has been constructed. Finally, it is proposed that the braided river to braided river plain channel sand in Rangzhi–Chaganhua Town has great uranium metallogenic potential, which has been predicted to be the most favorable object for further exploration.

Conclusions This study is the first to introduce exudative metallogeny into the systematic evaluation of uranium mineralization conditions in Sifangtai Formations of the Songliao Basin, changing the previous single approach of evaluating the target layer from the perspective of infiltration metallogeny. It can effectively expand the exploration thinking of the red variegated formations in the hinterland of the basin, thereby greatly expanding the prospecting range in the Songliao Basin.