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
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
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.Full Answer >
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 >
Sedimentary rocks come from the fragments of pre-existing rocks called sediments. There are three types of sedimentary rocks, each coming from different kinds of sediments. Clastic sedimentary rocks are created from the broken pieces of other rocks, while chemical sedimentary rocks form from mineral crystals like halite and gypsum.Full Answer >
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 >