UPSC Geography Notes

*🛡️The Types of Mountain*

💎 *Based on Mode of Origin* 

♟️ *Volcanic Mountains* Formed by the eruption of magma from the Earth's crust, creating peaks like those in Hawaii and Fiji. 
♟️ *Fold Mountains*  Created by the collision and folding of tectonic plates, such as the Himalayas and the Andes. 
♟️ *Block Mountains*  Formed by faulting and the movement of large blocks of the Earth's crust, leading to raised or dropped sections, like the Sierra Nevada. 
♟️ *Dome Mountains*  Created by magma pushing the Earth's crust upward, forming a dome-like structure, often exposed after erosion like Black Hills (US). 
♟️ *Plateau Mountains* These mountains resemble dome mountains but are formed by colliding tectonic plates pushing up the land, shaped by weathering and erosion. 

💎 *Based on Period of Origin* 

♟️ *Precambrian Mountains* Precambrian mountains are ancient ranges formed during the Precambrian era (4.6 billion to 541 million years ago).   
They have experienced extensive erosion and metamorphism over billions of years, leaving behind residual formations (e.g., Aravallis in India). 
♟️ *Caledonian Mountains* Formed around 430 million years ago (e.g., Appalachians).
♟️ *Hercynian Mountains* These mountains originated from the Carboniferous to Permian Period (approximately 340 million years and 225 million years) (e.g., Ural Mountains).
♟️ *Alpine Mountains* The youngest mountain systems formed during the Tertiary period(66 million years ago) (e.g., Himalayas, Alps).