Control of Alluvial Sedimentation at Foreland-Basin Active Margins: A Case Study from the Northeastern Ebro Basin (Southeastern Pyrenees, Spain)

摘要

Alluvial fans are the main geomorphological and depositional features at active margins of nonmarine foreland basins. The characteristics of these fans have already been extensively studied in relation to mountain-emergent thrust fronts. However, how an entire mountain front (from emergent to blind thrusts) controls the depositional environment, organization, and evolution of a foreland fan system is not yet well explored. These controls are discussed here through a case study of the Berga Formation, deposited in the late Eocene–early Oligocene in the eastern Ebro foreland basin, south of the Pyrenean chain.