What do you think will happen to these sediments after a few million years? Gizmo Warm-up Over millions of years, rocks are broken down and transformed into other rocks.

Rocks as small as tiny clay particles and larger that are moved by the water are called sediment. Fast-moving water can pick up, suspend, and move larger particles more easily than slow-moving waters.

Erosion can move sediment through water, ice, or wind. Deltas, river banks, and the bottom of waterfalls are common areas where sediment accumulates. Glaciers can freeze sediment and then deposit it elsewhere as the ice carves its way through the landscape or melts.

For sediment to become sedimentary rock, it usually undergoes burial, compaction, and cementation. Clastic sedimentary rocks are the result of weathering and erosion of source rocks, which turns them into pieces—clasts—of rocks and minerals. They are most often transported by water and deposited as layers of sediment.

Few sedimentary rocks are found deep inside the Earth because sedimentary rocks form close to the surface of the Earth.

Igneous rocks are formed from melted rock deep inside the Earth. Sedimentary rocks are formed from layers of sand, silt, dead plants, and animal skeletons. Metamorphic rocks formed from other rocks that are changed by heat and pressure underground.

Clastic sedimentary rocks are made up of pieces (clasts) of pre-existing rocks. Pieces of rock are loosened by weathering, then transported to some basin or depression where sediment is trapped. If the sediment is buried deeply, it becomes compacted and cemented, forming sedimentary rock.

Even rocks, a seemingly constant substance, can change into a new type of rock. Rocks that undergo a change to form a new rock are referred to as metamorphic rocks. In the rock cycle, there are three different types of rocks: sedimentary, igneous, and metamorphic.

Soil is not simply weathered rock. Soil is a dynamic natural resource. It is comprised of minerals, water, gases, organic material, and living creatures including soil microbes and tiny animals.

The weight of the sediments squeezes the particles together. As more and more sediments are deposited the weight on the sediments below increases. Waterborne sediments become so tightly squeezed together that most of the water is pushed out. These minerals act as glue or cement to bind the sediments together.

Over time, deposited sediments may harden into rock. Sedimentary rocks that form from sediments are called “clastic rocks. “ Clastic rocks are rock fragments that are compacted and cemented together (Figure below).

When sediments are pressed together tightly, this is called. compaction.

Compaction. The process of sediment being buried and pressed together.

The Rock Cycle is Earth’s great recycling process where igneous, metamorphic, and sedimentary rocks can all be derived from and form one another. Analogous to recycling a Coke can, where an old can will be used to produce a new can, the rock cycle is ever changing the rocks and minerals that make up Earth.

The rock cycle continues. Mountains made of metamorphic rocks can be broken up and washed away by streams. New sediments from these mountains can make new sedimentary rock. The rock cycle never stops.