Quantitative Fault-System Architecture and Extensional Evolution. A case study of the Marib Sub-basin, Yemen

The objective of this study is to quantitatively analyze the fault-system architecture and extensional evolution of the Marib Sub-basin, Yemen. This was achieved by integrating subsurface 2D seismic reflection profiles and well-log correlations with direct surface geological mapping. A comprehensive dataset of 100 normal faults (21 exposed at the surface and 79 buried) was constructed to evaluate structural hierarchy and displacement partitioning. Results show that fault lengths range from 0.29 to 20.91 km, vertical throws from 10 to 3,804 m, horizontal heaves from 6 to 5,784 m, and net slips from 23 to 6,586 m. The frequency distributions exhibit a strong positive skew, indicating a mature extensional network where regional strain was predominantly absorbed by deeply rooted NW-SE master faults. Positive scaling trends on log-log graphs indicate progressive fault nucleation, lateral propagation, and ultimate linkage. We conclude that the basin evolved as an asymmetric, basement-controlled half-graben, strictly guided by inherited Precambrian fabrics. Unlike previous qualitative studies, this quantitative framework directly tracks displacement partitioning and structural inheritance, providing unprecedented additive knowledge and constraints for evaluating structural traps, fault seals, and reservoir compartmentalization for future hydrocarbon exploration in the Sab'atayn Basin.