Q:

What are the characteristics of sedimentary rocks?

A:

Quick Answer

Sedimentary rocks are characterised by their formation from the deposition and lithification of rock material. They may be formed through physical and chemical processes, such as mechanical weathering, compaction and dissolving of rock material.

Know More
What are the characteristics of sedimentary rocks?
Credit: Zach Clanton / Design Pics Perspectives Getty Images

Full Answer

Sedimentary rocks may be formed through a process called lithification, which is the accumulation and compaction of sedimentary materials into solid rocks. Transportation through water systems such as rivers and oceans may cause clay, silt and other sedimentary materials to accumulate and form into rocks such as sandstone and shale. These rocks typically have smooth and rounded edges due to erosion from constant underwater motion.

Sedimentary rocks may be formed through the chemical dissolving and reforming of materials in rocks. Water sources that have a higher rate of evaporation than precipitation may facilitate the accumulation of sedimentary material, creating an environment in which the formation of new rocks becomes possible. Chemical weathering may cause materials such as calcium carbonate to accumulate and form new rocks such as limestone. Calcium carbonate is comprised of organic material, such as shells and coral, that have been broken down and dispersed in water sources and allowed to settle. The chemical properties of these rocks may be altered to form new rocks, such as dolomite, which is the result of limestone exposed to water containing magnesium.

Learn more about Geology

Related Questions

  • Q:

    What is sedimentary rock?

    A:

    Sedimentary rocks are formed by the deposition of mud, clay, sand and other small particles on the surface of the Earth. Sedimentation can occur in many different environments, including lakes, rivers, deserts and oceans. The sediment is deposited in layers that are compressed over time and turned into solid rock.

    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:
  • 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:

    Why can't most sedimentary rocks be dated radiometrically?

    A:

    According to the Smithsonian Institute, using radiodating of sedimentary rock tells the date of formation of the original igneous rock, which, through the processes of weathering and erosion, formed the layers of the sedimentary rock. Radiodating determines the maximum age of sedimentary rock. If a layer of igneous rock forms on top of the sedimentary rock, scientists determine an age bracket for the rock sample, but not an absolute age.

    Full Answer >
    Filed Under:

Explore