cathywilliam wrote:fan-shaped bedrock surface at the foot of a mountain, often where a stream flows out onto a piedmont slope. It is often covered with a thin veneer of alluvium and may be confused with an alluvial fan. Rock fans are usually quite steep (20° to 26° slope). It has been suggested that they represent the early stage of pediment development.
It's funny I have agued how to express geology relevant to fan. I prefer to say, alluvial fan, but the guy I have agued with says: fan deposit.
Are we all right?