| Popis: |
The alluvial fan is a sediment storage in form of a prism by the mountain front, above a local base-level. Fans show in plan-view a triangular cone-shaped form, bridging in between highly erosive upland catchments and down-fan valleys. To form fans requires (a) an elevational difference and (b) a sharp change in the alluvial geometry when exiting the mountain front. Fan deltas are subaerial alluvial fans that prograde into a standing water body often as Gilbert-type fan deltas, recognizable by a tripartite internal geometry. Distinction should be made between mountain-front fans and tributary-junction fans. |
