The rock formed from bits of rocky material settling to the bottom of rivers, lakes, and oceans is called sedimentary rock.

Here's why:

* Sedimentary rocks are formed by the accumulation and cementation of sediments, which are small pieces of rock, minerals, and organic matter.

* These sediments can come from various sources like weathering and erosion of existing rocks, volcanic activity, or biological processes.

* Over time, the sediments get buried, compacted, and cemented together by dissolved minerals, creating the rock.

Some examples of sedimentary rocks formed this way include:

* Sandstone: Formed from sand grains.

* Conglomerate: Formed from pebbles and larger rock fragments.

* Limestone: Formed from the accumulation of shells and other marine organisms.

* Shale: Formed from fine-grained clay particles.