As a river flows, it picks up sediment from the river bed, eroding banks, and debris on the water. The river mouth is where much of this gravel, sand, silt, and clay—called alluvium—is deposited. When large amounts of alluvium are deposited at the mouth of a river, a delta is formed.

A meander bend that gets cut off from the main channel becomes an oxbow lake. A stream with a single channel is called a braided stream. All of the possible answers are correct. A meander bend that gets cut off from the main channel becomes an oxbow lake.

Nile River delta, as seen from Earth orbit. The Nile is an example of a wave-dominated delta that has the classic Greek letter delta (Δ) shape after which river deltas were named.

Quartz, because it is stable under conditions present at the surface of the Earth, and because it is also a product of chemical weathering, is the most abundant mineral in sandstones and the second most abundant mineral in mudrocks.

Clay mineral

• Clay.
• Montmorillonite.
• Vermiculite.
• Sepiolite.
• Chlorite.
• Phyllosilicate.
• Kaolinite.
• Clay mineralogy.

Sedimentary rocks are formed from pre-existing rocks or pieces of once-living organisms. They form from deposits that accumulate on the Earth’s surface. Sedimentary rocks often have distinctive layering or bedding.

A rock is a naturally occurring solid. It is made of minerals (which are crystalline), or other mineral-like substances. The Earth’s outer solid layer, the lithosphere, is made of rock. That means the Earth’s crust is made of rock.

There are three kinds of rock: igneous, sedimentary, and metamorphic. Igneous rocks form when molten rock (magma or lava) cools and solidifies. Sedimentary rocks originate when particles settle out of water or air, or by precipitation of minerals from water.