Objective Deep−buried lithium−containing brine is an important type of lithium resources, and it is also one of the research hotspots of brine resources. This paper takes the underground lithium−containing brine in Zigong area of Sichuan as the research object, aiming to explore its mineralization and enrichment rules, and then guide the exploration practice.

Methods Through geological survey, geophysical (two−dimensional seismic, geophysical logging), mineral deposit research and analysis methods to carry out comprehensive research.

Results The lithium−containing brine in Zigong area occurs in the fifth member of Jialingjiang Formation (T₂j⁵) −the first member of Leikoupo Formation (T₂l¹) of Middle Triassic, and the spatial distribution is strictly controlled by the horizon. The development of Zigong salt basin constrains the initial collection of lithium−bearing brine, and the lithofaciespaleogeographic conditions and lithology determine the reservoir of lithium−bearing brine. The fracture development zone formed in the areas such as faults and fold turning ends is a favorable part for the enrichment of lithium−containing brine. The (secondary) faults in the brine storage structure promote the development of brine storage fractures, form a favorable solution pore−fracture type brine storage space, increase the storage capacity of lithium−containing brine, and provide good structural conditions for the migration, aggregation and enrichment of underground brine. It is an important control condition for lithium−containing brine enrichment.

Conclusions In general, the lithium−containing brine in Zigong area has the enrichment characteristics of ' salt basin−controlled area, structural fixed zone and pore−fracture brine storage, which is the result of the coupling of salt basin−lithology−structure. The lithium− containing brine layer also has geophysical characteristics of low resistivity, low density, low acoustic time difference and low wave impedance. Based on the metallogenic geological background, metallogenic process, enrichment characteristics and geophysical characteristics, the combination of anticline fold structure turning point and fault can be used as an effective structural marker for regional exploration of lithium−containing brine.