Climatic controls on alluvial-fan activity, Coastal Cordillera, northern Chile
Adrian J. Hartley, Anne E. Mather, Elizabeth Jolley, Peter Turner, 2005. "Climatic controls on alluvial-fan activity, Coastal Cordillera, northern Chile", Alluvial Fans: Geomorphology, Sedimentology, Dynamics, A. M. Harvey, A. E. Mather, M. Stokes
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A description of the distribution, drainage basin characteristics, surface morphology, depositional process and age of 64 alluvial fan systems from both flanks of the hyper-arid Coastal Cordillera of northern Chile between 22°15′S and 23°40′S is presented. The coastal fans on the western flank of the Coastal Cordillera are dominated by debris-flow deposits fed from steep catchments. Two drainage basin types are recognized: type A drainage basins are small (10–30 km2) and do not cut back beyond the main coastal watershed; and type B drainage basins are large (up to 400 km2) and cut inland beyond the coastal watershed. The western Central Depression fans on the eastern flank of the Coastal Cordillera are characterized by sheetflood deposition fed from relatively shallow catchments in small drainage basins (10–50 km2). The surface morphology, sedimentation rates, a luminescence date and regional cosmogenic radionucleide data suggest that these fans have been inactive for at least the last 230 000 years and probably for much of the Neogene.