Differential Hydrocarbon Enrichment Patterns in the Eastern Tethys: Insights from Supercontinent Breakup and Assembly

The Tethyan tectonic domain ranks among the world's most prolific hydrocarbon provinces. However, its eastern segment exhibits comparatively lower petroleum potential, significantly contrasting with the Middle East, with substantial variations in petroleum geological conditions across different basins. However, the fundamental geodynamic controls underlying this disparity remain poorly constrained. Through systematic analysis of the tectonic evolution of the eastern Tethys (including collision, rifting, drift, and accretion of major Gondwana-derived blocks) alongside the developmental characteristics and petroleum geology of associated basins, this study reveals that the nature, morphology, and scale of the underlying continental blocks exert fundamental controls on the formation and preservation of hydrocarbon-rich basins. These blocks are categorized into three types: large cratons, ribbon terranes, and microcontinental blocks. Large cratonic blocks (e.g., India, South China, North China, Tarim) possess high deformation resistance, with major tectonic deformation predominantly confined to their margins. Consequently, they typically preserve multiphase superimposed basins even related to pre-Gondwana rifting, developing multiple petroleum systems with substantial resource potential. In contrast, ribbon terranes (e.g., Lhasa, Qiangtang, Sibumasu) exhibit weak basements and commonly undergo pervasive modification by subsequent collisional and subduction-related tectonism. Only basins formed during the latest tectonic stage are effectively preserved, with locally favorable petroleum geological conditions. Similarly, microcontinental blocks in eastern Indonesia primarily preserve hydrocarbon-rich basins from the latest tectonic phase. However, Australian-affiliated blocks within this group, remaining in the relatively early stages of collision, can additionally retain continental margin deposits from the northern Australian block. The nature of the basement fundamentally dictates the development and modification of overlying petroliferous basins. This study provides a novel perspective for understanding differential hydrocarbon enrichment patterns across macroscopic regions.