## 4 Tectonic Evolution and Sedimentary Filling of the Basin
### Basin Tectonic Evolution  
The Pan-African Movement (PAM) was a Precambrian-Cambrian tectonic movement across the African continent and Gondwana. This crustal movement was primarily characterized by tectonic-thermal events [59]. It resulted from the collision of a series of micro-plates, forming the stable Precambrian crystalline basement of the large \"Pan-Cratonic Basin\" in the Middle East-North Africa, which is clearly exposed in the Arabian Shield in the Middle East and the Hoggar Shield in southern Algeria in North Africa (Figure 3). The North African Craton Basin has a roughly similar tectonic evolution history. Overall, the tectonic evolution of the North African Craton Basin development area can be divided into three major tectonic evolution stages, namely, the Paleozoic Pan-Craton, the Mesozoic Depression, and the Cenozoic passive terrestrial basin [60] (Figure 4). The tectonic evolution process of the basin is discussed using the Triassic Basin, where the key research area (HBR block) is located, as an example. In the Triassic Basin, the tectonic evolution, which is similar to that of the Saharan Plateau Sedimentary Basin, mainly went through five tectonic stages, namely, Pan-African, Taconic, Caledonian, Hercynian, and Late Alpine, and the tectonic movements of the different folds in each tectonic stage exerteddifferent degrees of influence and modification on the basin, resulting in the basin's current tectonic appearance. Influenced by multiple tectonic cycles, the sedimentary basins in North Africa exhibit a three-layered superimposed geological structure [61]. During the Paleozoic Era, the Pan-craton basin had a wide sedimentary fill range. During the Mesozoic and Cenozoic Eras, the sedimentary range of the intracontinental depression basin continuously narrowed, and  
Figure 4: Tectonic–sedimentary filling evolution of the North African Basin. Figure 3: Paleoogeologic sketch of North Africa, the Middle East, and South China. (Modified from the Middle East and North Africa Basin Repository). the sedimentary center's position kept shifting, resulting in the basin showing a vertical migration and superposition characteristic (Figure 5). The typical characteristics of the basin include the following:  
During the Cambrian-Carboniferous crationic intracontinental depression basin phase, equivalent to the first structural layer, the sedimentary strata's thickness is relatively uniform. Two sets of hydrocarbon source rocks, the Silurian and Devonian, are developed. In the Triassic/Gueddames and Illizi Basins, a complete source-reservoir-seal combination is developed. After the Carboniferous, the Hercynian orogen caused differential uplift and subsidence, leading to significant erosion in uplifted areas such as the ancient Hassi Messaoud Uplift and Dirhemout Uplift. The earlier sedimentary strata are either incompletely preserved or have a limited distribution range. Above the Hercynian unconformity, the Triassic-Jurassic intracontinental sandstone and evaporite mudstone are deposited, belonging to the second structural layer of this region. Its distribution range is significantly smaller than the Paleozoic, mainly located in the central-western Triassic Basin. During the Cretaceous-Cenozoic period, the North African intracontinental depression basin deposited the third structural layer with the smallest distribution range, and the sedimentary center shifted. The central and upper Yangtze regions in South China are delineated by the Huaying Mountain, Qiyue Mountain, and Baojing-Cili Fault Zones. This demarcation gives rise to the Sichuan Basin, the Chongqing Eastern Barrier-style Fold Belt, and the Hunan-Hubei Western Trough-style Fold Belt. The central and upper Yangtze regions have a unified crystalline basement, and there must be a specific connection between their sedimentary and tectonic evolution characteristics and their shale gas reservoir conditions and enrichment patterns.