A Research on the Composition of soil, Rock cycle, Types of soil:– “what is soil ?” and “How is it formed?” Are you looking for the best answer for this? Here is new research, Key terms used in soil mechanics are defined and you can easily know about the three-phase diagram (i.e., solid, water, and air phases) is clearly described here. Soil grain shapes, sizes, and grain size distribution and Laboratory methods to determine the grain size distribution are presented here.
ORIGIN OF SOILS
Soil can be defined as an assemblage of nonmetallic solid particles (mineral grains), and it consists of three phases: solid, liquid (water), and gas (air). Commonly used terms such as gravel, sand, silt, and clay are the names of soils based on their particle grain sizes. The names quartz, mica, feldspar, etc. are based on their crystal names.
The rock cycle in illustrates the origins of a variety of soils on the earth. Most original rock starts forming from molten magma (liquid) in the deep earth (to the depth of 2885 km from the base of crust). Magma cools down and solidifies when it approaches the earth’s crust (about 4–6 km thick under the deep oceans and 25–60 km thick on the continent) due to tectonic and volcanic activities.
Thus, Igneous rock such as basalt, granite, pumice, and olivine, are formed. The next process is weathering. Solid igneous rocks on the earth’s surface are subjected to all kinds of attacks in the environment, such as erosion by water and air, thermal expansion and contraction, the intrusion of plant roots in the cracks, icing on the cracks, and chemical attack on the surface. The surface of igneous rocks is weathered and broken down to smaller sizes.
The next process in the cycle is transportation. Broken fragments of rock are displaced by means of water run, glacier, and sometimes by wind, and they eventually settle down at a certain distance from the original location (deposition).
During the transportation process, particles further suffer physical and chemical attacks, and they become smaller and rounder. Deposited materials (sediments) are one type of soil. Thus, this type of soil originates from igneous rocks, and particles have crystals similar to those in igneous rocks.
Deposited soils(origin of soil) on many occasions are subjected to many geological years of cementation and compression that transform them to sedimentary rocks such as sandstone, shale, limestone, and dolomite, as well as many others. Rocks might go through a further transformation due to high heat and pressure in deeper earth but without melting.
This process is called metamorphism, and metamorphic rocks are formed. Transformation of marble from limestone by metamorphism is a good example of this. Metamorphic rocks could be melted into magma to complete a rock cycle when they go more deeply into the earth.
Sedimentary rocks and metamorphic rocks are also subjected to weathering, transportation, and deposition processes to form sediments (soils) as shown in Figure. This is all about types of soil, Rock cycle and research on the origin of soil.