Evolution of a Pliocene fan-delta: links between the Sorbas and Carboneras Basins, southeast Spain

The connection between a partially enclosed, fluvially dominated, tectonically elevated sedimentary basin (Sorbas Basin) and a less elevated basin with marine connections (Carboneras Basin) is examined. The two basins are separated by faulted, and differentially uplifted, basement across which a connection was maintained throughout the basin evolution but which became increasingly restricted as a result of continued tectonism. In the Pliocene the connection between the two basins had been reduced to a shallow valley through which the fluvial system of the Sorbas basin exited, to form part of a small fan-delta complex in the northern part of the Carboneras Basin. This complex was also fed by a more proximal source area located in the uplifted basement of the Sierra Alhamilla. As a result of its proximity to the fan-delta complex, sediment from this latter source area reached the fan delta fairly rapidly and dominated its early history. Initially high sediment yield from the Sorbas Basin was able to keep pace with contemporaneous deformation between the two basins. With continued uplift and regression, however, incision of the fan-delta complex and overlying fluvial deposits ensued. -from Author