Structural Characteristics and Formation Mechanism of the Northwestern Geologic Structure of the Madre de Dios Basin in Peru

The Andean fold-thrust belt in the northwest of the Madre de Dios Basin in Peru is a geologic structure where multidirectional tectonic stresses converge, and its structural complexity is higher than that of other areas of the basin. The Permian gas reservoirs in the basin are controlled by this fold-thrust belt, and the distribution of gas reservoirs varies greatly in different tectonic belts. By investigating the structural characteristics of the fold-thrust belt and the characteristics of faults in the fold-thrust belt and the distribution of the fold-thrust belt, this paper identifies the mode of tectonic evolution of the fold-thrust belt and summarizes the formation mechanism of the fold-thrust belt. The results of this study shows that three thrust belts have formed in the north, middle and south under compressional stresses in the southwest and south directions. Due to differences in the directions and magnitudes of tectonic stresses acting on the three belts, these belts trend NW-SE in the north, nearly E-W in the middle, and E-W in the south. The traps discovered in the study area exhibit a trend of increase in both number and area from south to north. This understanding provides valuable guidance on the optimal selection of favorable exploration targets and the search for the subsequent exploration direction.