Structural Evolution and Characteristics Analysis of Carboniferous in Zhundong Area

In this paper, the tectonic evolution and characteristics of the Carboniferous in the eastern Junggar Basin (Zhundong area) are studied in detail, aiming to reveal the tectonic evolution history of the area and provide geological basis for deep oil and gas exploration. The study area is located in the eastern Junggar Basin. It has undergone multiple tectonic evolutions and formed a complex fault system and a chessboard distribution pattern. Due to the strong tectonic movement and denudation, the Paleozoic geological information is seriously lost and the drilling data is scarce, which restricts the resource evaluation and exploration decision-making. The results show that the tectonic evolution from Carboniferous to Cenozoic in Zhundong area has the characteristics of multi-cycle and multi-stage. In the early Carboniferous, the regional extension led to the formation of rift basins, and the shallow sea-coastal clastic rocks in the upper part of the Songkalsu Formation (C₁sb) were deposited. In the middle Carboniferous, intense volcanic activity formed the volcanic rocks and pyroclastic rocks of the Batamayineishan Formation (C₂b). In the late Carboniferous, the tectonic stress field was adjusted, and the sea-land alternating strata of the Shiqiantan Formation (C₂sh) were deposited. During the Permian period, the basin experienced lacustrine deposition and compressional tectonic events, forming high-quality source rocks and structural traps. From Triassic to Jurassic, the basin entered a relatively stable depression sedimentary stage, and local structural changes affected oil and gas migration and preservation. Influenced by the India-Eurasia plate collision in the Cenozoic, the tectonic activity was strong, and the thrust faults and closed folds readjusted the oil and gas distribution pattern. Through seismic profile interpretation and stratigraphic analysis, this paper reveals the tectonic evolution history from Carboniferous to Cenozoic in Zhundong area, and clarifies the influence of tectonic events in different periods on the geological structure and hydrocarbon accumulation conditions of the basin. The research results provide an important geological basis for deep oil and gas exploration in the eastern Junggar Basin.