This land deposit you speak of is called a delta.
Land formed at the mouth of a river by deposited silt is known as a delta. It typically forms when the river's velocity decreases as it meets the ocean, causing sediment carried by the river to be deposited, building up land over time.
lake
The Delta
delta
A delta
The answer is delta
The land formed by deposited soil at the mouth of a river is called a delta (named for the Greek letter, which is similarly triangular in shape).
The land area that includes soil carried downstream by a river and deposited at the rivers mouth is called a delta. The delta is also where the river enters the ocean or lake.
The land area that includes soil carried downstream by a river and deposited at the rivers mouth is called a delta. The delta is also where the river enters the ocean or lake.
Delta
Delta
Delta