They are a form of sedimentary rocks, containing clasts of rock material or weathering products. Which are washed down steam the course of the river some of which are rounded in mineral forms such as clasts such as quads and feldspar, sandstone limestone and basalt.
Many of them are formed by strong water currents to produce rounded shapes. As most of the earth's sediments are distributed by the spreading stream sin most parts of the world.
Formed by chemical compaction deposition and sedimentation which binds the rocks back. Generally deposited at the bottom of stream channels.
