There are dozens of theories about the origin of the Earth. In general the theories of origin of the Solar System or earth can be divided into two groups: (i) Evolutionary theories (ii) Catastrophic Theories.
Evolutionary Theories: The theories which suggest that planets are formed during the evolution of the sun, are called ”Evolutionary Theories“. Nebular Hypothesis is
Solar System The Earth is a planet. It is a member of the solar system. Nine planets and the sun are the main bodies of the ”Solar System”. The planets in the order of increasing distance from the sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Each planet moves around the
Geology is a Science, which is devoted to the study of the Earth. It deals with all the features of the earth’s surface, its origin, composition, structure, history, inhabitants, and processes of change in its features. An important part of geology is the study of how Earth’s materials, structures, processes, and organisms have changed over
Composition The composition of almost all lava of the Earth’s crust is dominated by silicate minerals: mostly feldspars, feldspathoids, olivine, pyroxenes, amphiboles, micas and quartz. Rare nonsilicate lavas can form by local melting of nonsilicate mineral deposits or by separation of a magma into separate immiscible silicate and nonsilicate liquid phases. Silicate lavas Silicate lavas are molten mixtures dominated by oxygen and silicon, the Earth’s most abundant chemical elements, with smaller quantities of aluminium, calcium, magnesium, iron, sodium,
Diagnosis of Amethyst, This post is incomplete, it will be composed soon Chemical composition and properties of Amethyst, Physical Properties of Amethyst, Structure of Amethyst, Colours and tone of Amethys, Occurrence of Amethyst, Historical Importance of Amethyst, Metaphysical Importance of Amethyst, Artificial Synthesis of Amethyst, Cultural Association of
“Metamorphic Rocks” are formed from the older rocks when they are subjected to increased temperature, pressure, and shearing stresses at considerable depth in the earth’s crust. The older rocks may be either sedimentary, igneous, or other metamorphic rocks. During metamorphism, recrystallization takes place essentially in the solid-state and new minerals and new textures are produced.
Some important sedimentary rocks are as under; (1). Conglomerate Nature: Consolidated gravels. Colour variable. Mineral Composition: Rounded pebbles are set in a fine-grained matrix. The matrix commonly consists of sand and silt and it is cemented by silica, calcium carbonate, or iron oxide. The individual pebbles may be entirely composed of quartz or maybe rock
The composition of sedimentary rocks is of two types; chemical composition and mineral composition. The chemical composition of a substance means the aggregate chemicals that constitute that substance, while the presence of different types of minerals illustrates the mineral composition of that substance. Here we will discuss the two types of compositions separately. (1). Chemical
Sedimentary rocks constitute about 75% of the total exposed rocks on the earth’s crust. They are found in different forms/structures. The important structural features of sedimentary rocks are stratification, lamination, graded bedding, current bedding, ripple marks. Besides these, there are some minor structures such as mud cracks, rain prints, tracks of terrestrial animals, etc. These
The texture of the sedimentary rocks is studied like that of the igneous rocks. Texture means the size, shape, and arrangement of grains in a rock. The particles of the sedimentary rocks are known as the ”Sediments”. As sediments contain particles of various sizes, grain size is an important factor in the description of sedimentary
