New insights into the crustal structures of the Arabian Plate and surrounding plates unveiled from the crustal thickness model and its implications for geodynamics

Abstract

Geodynamics of the Arabian Peninsula is less understood as crustal structures are not well delineated due to uneven distribution and lack of seismic measurements and ground based geophysical data in the Arabian interior. To address this, we delineated crustal structures in the Arabian Peninsula through the creation of a crustal thickness model from the inversion of GOCO60s gravity field model, which revealed details on the underlying crustal structures. Our model revealed strong crustal thickness variations in the Zagros fold belt that indicates high deformational history and crustal reworked, which also reflect directional collisional events between the Arabian and Eurasian Plates, similar to the Himalaya type as the result of mantle processes. The resolved crustal structures also reveal a relatively slow rifting process on the southern end of the Red Sea than at the northern end, which resulted in the bulging of crust in the southern part of Zagros Fold Mountains. Further, folding and bulging of crustal structures is more intense near the Arabian Platform and slower on the Eurasian side, which could indicate a relatively stable Eurasian plate compared to the geodynamically active Arabian Plate. Overall improvement in our high-resolution crustal thickness model yields an improved representation of crustal structures over previously derived models of the Arabian Peninsula and the Surrounding plates that indicates a variation in the Proterozoic crust in Arabian Plate, possibly indicating a secular variation in the crustal structure.