Alluvial fans are delta shaped deposits of sediment that form at the base of a hill or mountain.
(Alluvial fans; are; delta shaped deposits of sediment that form at the base of a hill or mountain) (delta shaped deposits of sediment; form; L:at the base of a hill or mountain)
Alluvial fans delta shaped deposits of sediment
are form
delta shaped deposits of sediment that form at the base of a hill or mountain
L:at the base of a hill or mountain