Explain the mode of formation of each of the following :
(i) coal
(ii) Limestone
(iii) Rock Salt
(iv) Breccia
(v) Quartzite
(vi) Laccolith
(vii) Basalt
(viii) Dykes
(ix) Sill
(x) Gneiss
Answers
Answer:
Coal can be moved directly by railroad, truck, pipeline, barge or ship; energy obtained from coal can be transported as a liquid or gaseous fuel or as electricity. ... Of the rail modes, 20% of the total is by unit train, and 80% is by conventional rail.
Limestone is formed in two ways. It can be formed with the help of living organisms and by evaporation. Ocean-dwelling organisms such as oysters, clams, mussels and coral use calcium carbonate (CaCO3) found in seawater to create their shells and bones. ... The water pressure compacts the sediment, creating limestone.
It is typically formed by the evaporation of salty water (such as sea water) which contains dissolved Na+ and Cl- ions. ... One finds rock salt deposits ringing dry lake beds, inland marginal seas, and enclosed bays and estuaries in arid regions of the world.
According to this source, the modes of formation of breccias can be grouped in to three major types i.e., Igneous, Sedimentary and Tectonic. ... They are often associated with various igneous processes and are recognized by their angular fragments and brecciation processes, used as a diagnostic signature.
Quartzite is a metamorphic rock formed when quartz-rich sandstone or chert has been exposed to high temperatures and pressures. Such conditions fuse the quartz grains together forming a dense, hard, equigranular rock.
A laccolith is a lensoid igneous intrusion that is concordant with the stratification or other type of banding in the host rock. ... Doming associated with laccolith formation is due to magmatic pressure unassisted by tectonic stress.
Basalts are formed by rapid cooling of basaltic lava, equivalent to gabbro–norite magma, from the interior of the crust and exposed at or very close to the surface. These basalt flows are thick and extensive in which gas cavities are nearly absent.
fracture in a pre-existing rock body. Dikes can be either magmatic or sedimentary in origin. Magmatic dikes form when magma intrudes into a crack then crystallizes as a sheet intrusion, either cutting across layers of rock or through an unlayered mass of rock.
In geology, a sill is a tabular sheet intrusion that has intruded between older layers of sedimentary rock, beds of volcanic lava or tuff, or along the direction of foliation in metamorphic rock. ... Stacking of sills builds a sill complex and a large magma chamber at high magma flux.
Gneiss is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Orthogneiss is gneiss derived from igneous rock (such as granite). Paragneiss is gneiss derived from sedimentary rock (such as sandstone)....
Explanation: