Why do clastic rocks generally form underwater?

Answer 1

Sedimentary rock most often forms in the ocean through these processes:

1. Deposition of sediments such as mud, clay, sand, sea life secretions and marine life skeletons on the seafloor.

2. Compaction of these deposited sediments by the weight of continuing depositions of sediments. The crushing weight of further overlying sediments squeezes out the water that exists between sediment particles.

3. Cementation occurs when minerals form between sediment particles. The minerals are formed through a process called "precipitation". When the particles are cemented together in this manner, the resultant solid is a clastic sedimentary rock.

Answer 2

Because sedimentary rock is created through the slow build up of sands, muds, and gravels. When these are formed underneith bodys of water any dead matter, such as seashells, fall into the sediment at the bottom and are slowly buried where after thousands of years of build up and pressure ontop of the layers, they become rock. This rock is the sedimentary rock where you now find fossilised shells.

Answer 3

Sediments collect in sedimentary basins, which are low-lying areas of terrain. Bodies of water tend to form in such low-lying areas. In many areas on land erosion rather than deposition dominates.