Transfer zones in continental domains connect rift segments characterized by different extensional styles. We performed three sets of analogue models to investigate how transfer zones depend upon the initial configuration of the rift segments, the geometry of decollement levels and differential rates of extension along the rift axis. We used dry quartz sand to simulate the brittle behaviour of the upper crust and silicone putty for the ductile behaviour of decollement levels. Analogue models have reproduced en-echelon rift segments linked by transfer zones. The transfer zones are bordered by faults with a predominant normal motion, whose arcuate shape in map view is connected to the local perturbation of the direction of the maximum extension. Strike-slip faults are present inside the transfer zone, providing the angle alpha (between the extension direction and the major axis of the transfer zone) is less than 45 degrees : this value represents an upper boundary for the development of strain partitioning processes in transfer zones. The presence of decollement layers inhibits the development of strike-slip faults within the transfer zones, which are characterized by relay ramps. Our experimental results are compared with transfer zones from narrow rifts worldwide (East African Rift System, Rio Grande Rift, Rhinegraben), where an overall similar geometrical and kinematical pattern is observed.

You do not currently have access to this article.