TNPSC Prelims and Mains Notes-TNPSC Test Series
The continental drift theory is the theory that once all the continents were joined in a super-continent, which scientists call Pangaea. Over a vast period of time, the continents drifted apart to their current locations. Alfred Wegener first supported continental drift. Wegener’s explanation of continental drift in 1912 was that drifting occurred because of … Read more
Orogenic or the mountain-forming movements act tangentially to the earth surface, as in plate tectonics. Tensions produces fissures (since this type of force acts away from a point in two directions) and compression produces folds (because this type of force acts towards a point from two or more directions). In the landforms so produced, … Read more
The interaction of matter and temperature generates these forces or movements inside the earth’s crust. The earth movements are mainly of two types: diastrophism and the sudden movements. The energy emanating from within the earth is the main force behind endogenic geomorphic processes. This energy is mostly generated by radioactivity, rotational and tidal friction … Read more
The Crust of Earth It is the outermost and the thinnest layer of the earth’s surface, about 8 to 40 km thick. The crust varies greatly in thickness and composition – as small as 5 km thick in some places beneath the oceans, while under some mountain ranges it extends up to 70 km … Read more
Most of the knowledge we have about Earth’s deep interior comes from the fact that seismic waves penetrate the Earth and are recorded on the other side. Earthquake ray paths and arrival times are more complex than illustrated in the animations, because velocity in the Earth does not simply increase with depth. Velocities generally … Read more
Civilization and Culture of the Pallavas The Pallava rule formed a golden epoch in the cultural history of south India. The period under the Pallavas was marked by considerable literary activities and cultural revival. The Pallavas warmly patronized Sanskrit language and most of the literary records of the time were composed in that language. Due … Read more
The founder of the Chola Empire was Vijayalaya, who was first feudatory of the Pallavas of Kanchi. He captured Tanjore in 850 A.D. He established a temple of goddess Nishumbhasudini (Durga) there. Aditya I succeeded Vijayalaya. Aditya helped his overlord the Pallava king Aparajita against the Pandyas but soon defeated him and annexed the whole … Read more
Emperor Harshavardhana, better known as Harsha, lived from 590 to 647 CE and was the third ruler of the Vardhana Empire, the last great empire in ancient India before the Islamic Invasion. He ruled from 606 CE to 647 CE. After Harshavardhana’s death, however, the Vardhana dynasty came to an end and its empire dissolved. India, the land beyond the … Read more
The Gupta Empire stretched across northern, central and parts of southern India between c. 320 and 550 CE. The period is noted for its achievements in the arts, architecture, sciences, religion, and philosophy. Chandragupta I (320 – 335 CE) started a rapid expansion of the Gupta Empire and soon established himself as the first sovereign ruler of the empire. It marked the end of 500 hundred … Read more
The Kushanas: Short introduction In the early 2nd century BC, a tribe on the Central Asian frontier of China called Hsiung-nu defeated a neighboring one known as Yueh-chih. After more conflict, the survivors of the Yueh-chih were dislocated west, passing down the Ili river valley and along the southern shore of lake Issyk Kul. This … Read more