The two-phase source rocks deposited during the Lower Cretaceous in the Persian Gulf Basin play a pivotal role in the regional hydrocarbon system. However, previous studies have lacked a macroscopic perspective constrained by the Tethyan Ocean context, which has limited a deeper understanding of their developmental patterns and hydrocarbon control mechanisms. To address this issue, this study aims to clarify the spatiotemporal evolution of the two-phase source rocks and their hydrocarbon control effects, with a particular emphasis on the critical impact of terrestrial input on the quality improvement of source rocks. Unlike previous studies that relied on a single research method, this study employed a comprehensive approach, including time series analysis, sequence stratigraphy, lithofacies, well logging, well correlation, seismic data, and geochemical analysis, to systematically compare and analyze the depositional periods, distribution, and characteristics of the two-phase source rocks under different sedimentary facies in the region. The goal was to reveal the intrinsic relationship between the Neo-Tethyan Ocean context and regional sedimentary responses. The results indicate the following: (1) the late Tithonian–Berriasian and Aptian–Albian source rocks in the Northern Persian Gulf were deposited during periods of extensive marine transgression, closely aligning with the global Weissert and OAE1d anoxic events, reflecting the profound impact of global environmental changes on regional sedimentary processes; (2) in the early stages of the Neo-Tethyan Ocean, controlled by residual topography, the Late Tithonian–Berriasian source rocks exhibited a shelf–intrashelf basin facies association, with the intrashelf basin showing higher TOC, lower HI, and higher Ro values compared to the deep shelf facies, indicating more favorable conditions for organic matter enrichment; (3) with the opening and deepening of the Neo-Tethyan Ocean, the Aptian–Albian source rocks at the end of the Lower Cretaceous transitioned to a shelf–basin facies association, with the basin facies showing superior organic matter characteristics compared to the shelf facies; (4) the organic matter content, type, and thermal maturity of the two-phase source rocks are primarily controlled by sedimentary facies and terrestrial input, with the Aptian–Albian source rocks in areas with terrestrial input showing significantly better quality than those without, confirming the decisive role of terrestrial input in improving source rock quality. In summary, this study not only reveals the differences in the depositional environments and hydrocarbon control mechanisms of the two-phase source rocks, but also highlights the core role of terrestrial input in enhancing source rock quality. The findings provide a basis for facies selection in deep natural gas exploration in the Zagros Belt and shale oil exploration in the western Rub’ al-Khali Basin, offering systematic theoretical guidance and practical insights for hydrocarbon exploration in the Persian Gulf and broader tectonic domains.

In the northern Persian Gulf Basin, a carbonate succession developed during the Berriasian–Valanginian of the Early Cretaceous, constituting an important reservoir in the Middle East. The genetic types of this succession are highly variable and controlled by sequence evolution. However, the sequence construction processes and sedimentary model evolution remain poorly understood. To analyze sedimentary models and sequence-controlling factors, this study examines sequence stratigraphic characteristics. The analysis is based on core thin sections, well logs, seismic data, and global sea-level records. The results indicate that: (1) During the Berriasian to Valanginian, one retrogradational sequence (SQ1) and three progradational sequences (SQ2–SQ4) were identified, arranged from bottom to top. The three sequences (SQ2 to SQ4) exhibit a vertically stacked progradational pattern towards the northeast. (2) SQ1 is dominated by shelf facies, while SQ2 to SQ4 are characterized by platform facies. Within each sequence (SQ2 to SQ4), the depositional environments transition from basin to slope, platform margin, and finally restricted platform facies. Specifically, during the SQ2 period, the platform margin had a low dip angle (<1.0°), indicating a gently sloping platform. In contrast, during the SQ3 to SQ4 sequences, the platform margin exhibited a steeper dip angle (1.2–1.5°), suggesting a rimmed platform. (3) SQ1 is governed by the global marine transgression during the Early Cretaceous, representing a global sea-level sequence. SQ2 to SQ4 are influenced by the combined effects of tectonic activities and sea-level changes, constituting tectonic/global sea-level change sequences. The transgressive sequences have developed high-quality source rocks, while the regressive sequences have formed extensive reservoirs, together creating favorable hydrocarbon source–reservoir assemblages. The reef and shoal distribution model developed in this study offers valuable insights for reservoir prediction. Additionally, the interpreted transgressive sequences may have global correlation potential.