Q:

How are sedimentary rocks formed?

A:

Quick Answer

Sedimentary rocks are formed from preexisting rock through the combined processes of weathering, transportation, deposition, compacting and cementation. The entire series of processes is known as lithification, and the weathering portion of the process can be either mechanical or chemical. The chemical weathering process involves the preexisting material being transported as a solute or in the form of a new mineral, while the mechanical process transports the material as solid particles.

  Know More

Full Answer

The preexisting material is broken down by the forces of erosion, weather, water-wedging, root-wedging or abrasion. The particles are then transported by water, wind or glaciers to a new location, the place of deposition, where they arrive in the form of sediment. As the sediment grows layer upon layer, the pressure on earlier deposits causes them to become compacted. The compacted sediment is eventually formed into new rocks during the final cementation stage.

Learn more about Earth Science

Related Questions

  • Q:

    Where are sedimentary rocks found?

    A:

    Sedimentary rocks are found covering a majority of the Earth's upper crust. Formed from the deposition of mud and sand that is buried and compressed to form solid rock, sedimentary rocks usually begin their life underwater, rising to the Earth's surface as the waters dry up.

    Full Answer >
    Filed Under:
  • Q:

    What are sedimentary rocks made of?

    A:

    Sedimentary rocks are made of minerals and debris that have been weathered or eroded from rocks over long stretches of time. This sediment can be laid down by water, by the movement of earth or glaciers, by evaporation or by biological processes.

    Full Answer >
    Filed Under:
  • Q:

    Why are fossils only found in sedimentary rocks?

    A:

    Fossils are primarily found in sedimentary rocks because these rocks form at low temperatures and pressures. Igneous rocks form at temperatures and pressures that are high enough to destroy any organic remains. On rare occasions, fossils are found in metamorphic rocks, but they are deformed by the heat and pressure.

    Full Answer >
    Filed Under:
  • Q:

    What is the single most characteristic feature of sedimentary rocks?

    A:

    Sedimentary rocks are primarily characterized by lithification. Lithification occurs when sediment has been deposited and accumulates at the earth's surface or in bodies of water to form a rock over time. Subgroups of sedimentary rocks are defined by their specific formation.

    Full Answer >
    Filed Under:

Explore