## 1 Introduction  
In recent years, the exploration and study of marine shale gas have become a key research direction in the field of oil and gas [1, 2]. The formation and distribution of hydrocarbon source rocks are central to petroleum geology research [3, 4, 5, 6]. Against this backdrop, this study aims to explore the genesis and distribution patterns of widely distributed graphtolite shale hydrocarbon source rocks in Paleozoic Silurian shelf facies in the North Africa-Middle East-South China region. The primary issues of this study revolve around clarifying the genesis and distribution characteristics of Silurian hot shale hydrocarbon source rocks [7, 8]. Based on the data of the North African basins, the achievements of the \"Twelfth Five-Year Plan\", and previous research findings, analyses are conducted using core, well-logging, seismic, and laboratory analytical data. Through a comprehensive analysis of the characteristics of the Silurian hydrocarbon source rocks in the \"North Africa-Middle East-South China Plate\" region, this research focuses on key geological issues, such as the tectonic-sedimentary infill evolution of significant basins in the Paleo-Tethys Ocean and the formation and evolution patterns of hydrocarbon source rocks. These regions, located at the northern part of the continent Gondwana and the southern margin of the Paleo-Tethys Ocean during the Silurian period, provide a unique geological background for studying the formation and distribution of hydrocarbon source rocks [9, 10, 11]. Under nearly identical tectonic movements, these regions have positively impacted the mobility of hydrocarbon source rocks [12, 13]. Through a systematic analysis of these key geological processes, this study reveals their impact on the development and characteristics of oil and gas reservoirs, providing a theoretical basis and geological model for oil and gas exploration. Through the analysis of the tectonic positions of North Africa, the Middle East, and South China, and in conjunction with a comparative analysis of global sea level changes and Silurian characteristics [14], this study aims to both reveal how these regions, under a similar ancient plate tectonic backdrop, experienced comparable sea level changes and explore how these changes influenced the sedimentary infill characteristics of the basins [15; 16]. Furthermore, we will also conduct a detailed analysis of the organic matter type, gamma-ray characteristics, and total organic carbon (TOC) content of the Silurian hydrocarbon source rocks in North Africa, the Middle East, and South China to assess the similarity of their depositional origins [17]. The black shale of the shelf facies, which is rich in fossils, such as graptolites, and formed in a deep-water shelf-anoxic environment [18], is widely distributed in the Paleozoic \"Pan-craton basin\" in North Africa and the Middle East. In North Africa, apart from the coastal-delta facies that developed in the peripheral areas north of the Eglab-Hoggar Shield, the shallow marine shelf facies are widespread across vast regions of the Tindouf, Timimoun, Triassic/Ghadames, Murzuq, and Sirt Basins located in the central and western parts of the Sahara Platform [19; 20]. In the Middle East's Arabian Platform [21], aside from coastal-delta facies that developed on the eastern periphery of the Arabian Shield, shallow marine shelf facies are prevalent across vast areas of the Western Arabian, Central Arabian, and Rub' al Khali basins. In the western part of the Yangtze Platform in South China, delta-coastal facies have developed around the Sichuan Uplift and the Guizhou Uplift [22]. However, in the eastern regions of Sichuan, Hubei, Hunan, and Jiangxi, a vast area exhibits the development of shallow marine shelf facies. Moreover, the developed deep-water shelf environments often manifest as shelf depressions (or basins) with stagnant water conditions [23]. The weak hydrodynamic energy and anoxic conditions in these stagnant waters ensure the excellent preservation of deposited organic matter [24].