Abstract Many intraplate volcanic chains are explained as hotspot trails formed by plate motion over mantle plumes, yet some deviate from this model. The Rodrigues Ridge, a volcanic lineament extending eastward from the Réunion hotspot track toward the Central Indian Ridge (CIR), is one such case. To assess its origin, we integrated field studies with zircon U‐Pb and (U‐Th)/He geo‐/thermochronology, groundmass K‐Ar dating, and major and trace element analyses of volcanic rocks from Rodrigues Island. Our results reveal that Rodrigues Island experienced a prolonged subaerial volcanic history from 4.1 to 1.1 Ma, 2.7 million years longer than previously thought. This history shows two episodes of volcanic construction: (a) a circular ‐volcano construction between 4.1 and 2.5 Ma, followed by erosion, subsidence, and coral reef development and (b) fissural volcanism from 2.3 to 1.1 Ma, which shaped the island's elongated morphology. Subaerial lavas are more alkalic and enriched in incompatible elements than older submarine ridge lavas. This geochemical evolution suggests an eastward migration of partial melting degree, with oceanic accretion driving magmatism along the Rodrigues Ridge. Combined with magnetic anomalies of the oceanic lithosphere, the chronology points to at least two propagation episodes toward the CIR (≥9.9–7.9 Ma and 4.1–0.4 Ma). We conclude that the Rodrigues Ridge originated as a fracture in the oceanic lithosphere, driven by plume‐related buoyancy forces and asthenospheric flow beneath the CIR, without any direct contribution from the Réunion plume to the partial melting degree. These findings emphasize the role of lithospheric stresses and oceanic accretion in shaping off‐axis volcanic chains.
Seghi et al. (Wed,) studied this question.