The Brazos River is a major river in Texas. In many parts of the Cross Timbers and Prairies ecoregion, the river has formed tall, steep cliffs in the rock along its banks through the process(es) of

Weather and erosion.

Explanation:

In Geography, weathering is the process of breaking down of rocks, minerals and soil as a result of contact with water, earth's atmosphere, acid, ice, plants and animals. The breaking up of the rocks by weathering weakens it and makes it susceptible to erosion.

Erosion in geography is the movement of rocks and sediments to another place by water, wind and ice.

For instance, In many parts of the Cross Timbers and Prairies ecoregion, the Brazos river has formed tall, steep cliffs in the rock along its banks through the processes of weathering and erosion.

it is the most commonly accepted one