The break-up of the supercontinent Rodinia in the late Neoproterozoic led to the formation of the Nanhua rift basin within the South China Block. The Datangpo-type manganese deposit, which developed in the Nanhua rift basin, is one of the most important types of manganese deposits in South China. Although it is widely accepted that deep sedimentary structures significantly affect the manganese ore system, the relationship between the manganese deposits in South China and the Nanhua rifting process is still unclear. The origin of the manganese ore layer remains controversial. In this paper, we integrated the audio-frequency magnetotelluric (AMT) data, gravity data, and comprehensive geological and borehole data analysis to characterize the structure of the Datangpo-type manganese deposit in Songtao, Guizhou Province. The resistivity and density models produced an inclined layered structure, which correlated well with the coeval sediment strata of the Nanhua rift basin. A high-resistivity cap was observed from the surface to a depth of 800 m, corresponding to the Cambrian Loushanguan (${ϵ}_{3-4}\mathrm{ls}$) and Palang dolomite formation (${ϵ}_2\mathrm{p}$), which has helped the storage of the manganese ore. The most significant low-resistivity anomaly (25–40 Ω·m) resides at a depth of 1400 m in the Nantuo (Nh₃n) gravel sandstone and Datangpo (Nh₂d) silty and carbonaceous shale, corresponding to the ore-forming layer. This distinct low-resistivity layer was possibly produced by aqueous fluids and pyrite in the syn-sedimentary fault and alteration zone. The accumulations of sulfide minerals in the rock samples suggest a possible anoxic-euxinic deposition environment during the manganese mineralization and precipitation. The fault revealed in the resistivity models is perhaps a previous fault zone produced by extension in the Nanhua rifting process, which provided migration and upwelling channels for ore-forming minerals. Based on our resistivity models, density models, and geological survey, the manganese ore-forming model was derived, which can help to provide geophysical evidence for the origin of the Datangpo-type manganese deposit.

The Datangpo-type Mn ore deposits in northeastern Guizhou (southern China) are a relatively newly discovered type of sedimentary exhalative manganese ore deposit. Previous three-dimensional geological modeling has revealed an NW-trending trough-like depression that obliquely intersects the ENE-trending Nanhua Rift within the Nanhua System in this area. This depression likely represents a paleorift that was present before the metallogenetic period; its intersection with the Nanhua Rift corresponds precisely with the area in which a series of super-large and large new-type Mn ore deposits are located. Here, we used remote sensing image processing techniques, along with hierarchical spatial data fusion and mining methods adopted for exploration, to investigate this paleorift. Specifically, Bouguer gravity data were used to obtain middle–lower-crust structural information; aeromagnetic ΔT data were used to obtain middle–upper-crust structural information; and remote sensing and outcrop data coupled with regional geological survey, mineral exploration, and geochemical exploration data were used to obtain near-surface structural information. Combining these data, we determined the control that different deep tectonic frameworks exert on the formation and distribution of Mn ore deposits within the study area. This study proposes a new conceptual method and technical protocol permitting an improved understanding of the material source and mineralization pattern of Mn ore deposits within the study area, while verifying the existence of the NW-trending Tongren Paleorift.