GENERAL GEOLOGY

Detailed explanation-1: -As the river rushed into the wide valley, the sediment fanned out across a triangle-shaped area, creating an alluvial fan. An alluvial fan is a triangle-shaped deposit of gravel, sand, and even smaller pieces of sediment, such as silt. This sediment is called alluvium.

Detailed explanation-2: -Deltas are wetlands that form as rivers empty their water and sediment into another body of water, such as an ocean, lake, or another river. Although very uncommon, deltas can also empty into land. A river moves more slowly as it nears its mouth, or end.

Detailed explanation-3: -Fan-deltas are gravel-rich deltas formed where an alluvial fan is deposited directly into a standing body of water from an adjacent highland. They occupy a space between the highland (usually a fault-bounded margin) and the standing body of water.

Detailed explanation-4: -Arcuate Delta: It is fan-shaped Delta. A bowed or curved Delta with the convex margin facing the body of water. Relatively coarse sediments are formed in this type of Delta. The river activity is balanced with the wind.

Detailed explanation-5: -Deposition also occurs when a stream or river empties into a large body of still water. In this case, a delta forms.