Which statement correctly describes clastic sedimentary rock textures?

• A. Clastic textures indicate chemical precipitation from water.
• B. Clastic textures are defined by color and luster.
• C. Clastic textures indicate grain size and cementation in environments such as sandstone or shale.
• D. Clastic textures are formed only by biological processes.

Answer: (C)

Clastic sedimentary rock textures are all about how the fragments (clasts) come together and how they are bound into rock. The texture specifically reflects grain size, how well those grains are sorted and rounded, and whether a cementing material has lithified the grains. Saying that clastic textures indicate grain size and cementation in environments such as sandstone or shale directly captures this idea: sandstone is made of sand-sized grains that were deposited in a setting with enough energy to keep them separate but later cemented together, while shale is built from much finer particles that compact and cement into a solid rock. This focus on grain size and the cementing process is what defines clastic textures.

The other options mislead by pointing to chemical precipitation, color and luster, or biological origins, none of which define clastic textures.