Skip to main content

Research Repository

Advanced Search

Diagenesis in salt dome roof strata: barite - calcite assemblage in Jebel Madar, Oman

Vandeginste, Veerle; Stehle, Manuela C.; Jourdan, Anne-Lise; Bradbury, Harold J.; Manning, Christina; Cosgrove, John W.

Diagenesis in salt dome roof strata: barite - calcite assemblage in Jebel Madar, Oman Thumbnail


Manuela C. Stehle

Anne-Lise Jourdan

Harold J. Bradbury

Christina Manning

John W. Cosgrove


Halokinesis causes a dynamic structural evolution with the development of faults and fractures, which can act as either preferential fluid pathways or barriers. Reconstructing reactive fluid flow in salt dome settings remains a challenge. This contribution presents for the first time a spatial distribution map of diagenetic phases in a salt dome in northern Oman. Our study establishes a clear link between structural evolution and fluid flow leading to the formation of diagenetic products (barite and calcite) in the salt dome roof strata. Extensive formation of diagenetic products occurs along NNE-SSW to NE-SW faults and fractures, which initiated during the Santonian (Late Cretaceous) and were reactivated in the Miocene, but not along the E-W fault, which was generated during Early Paleocene time. We propose that the diagenetic products formed by mixing of a warm (100 °C) saline (17 wt% NaCl eq.) 87Sr enriched (87Sr/86Sr: 0.71023) fluid with colder (35 °C) meteoric fluid during Miocene to Pleistocene. The stable sulphur and strontium isotope composition and fluid inclusion data indicate that a saline fluid, with sulfate source derived from the Ara Group evaporite and Haima Supergroup layers, is the source for barite formation at about 100 °C, predominantly at fault conjunctions and minor faults away from the main graben structure in the dome. In the Miocene, the saline fluid probably ascended along a halokinesis-related fault due to fluid overpressure (due to the rising salt and impermeable layers in the overlying stratigraphic sequence), and triggered the formation of barite due mixing with barium-rich fluids, accompanied by a drop in temperature. Subsequently, evolving salt doming with associated fault activity and erosion of the Jebel allows progressively more input of colder meteoric fluids, which mix with the saline warmer fluid, as derived from stable isotope data measured in the progressively younger barite-associated calcite, fault zone calcite and macro-columnar calcite. The reconstructed mixing model indicates a 50/50 to 90/10 meteoric/saline fluid mixing ratio for the formation of fault zone calcite, and a 10 times higher concentration of carbon in the saline fluid end member compared to the meteoric fluid end member. The presented mixing model of salt-derived fluids with meteoric fluids is suggested to be a general model applicable to structural diagenetic evolution of salt domes world wide.


Vandeginste, V., Stehle, M. C., Jourdan, A., Bradbury, H. J., Manning, C., & Cosgrove, J. W. (2017). Diagenesis in salt dome roof strata: barite - calcite assemblage in Jebel Madar, Oman. Marine and Petroleum Geology, 86, 408-425.

Journal Article Type Article
Acceptance Date Jun 6, 2017
Online Publication Date Jun 8, 2017
Publication Date Sep 30, 2017
Deposit Date Jun 8, 2017
Publicly Available Date Jun 9, 2018
Journal Marine and Petroleum Geology
Print ISSN 0264-8172
Electronic ISSN 1873-4073
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 86
Pages 408-425
Keywords Diagenesis; Halokinesis; Salt; Barite; Isotopes; Mixing
Public URL
Publisher URL


You might also like

Downloadable Citations