The age of the earth as determined by current methods of radiometric dating is about 4600 million years. Before the discovery of radiometric dating, several attempts were made to determine the age of the earth. The important one’s are as follows.
From the history of organic evolution.
From the rate of sedimentation.
From salinity of seawater.
From the rate
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.