Describe the relief conditions of Aravalli Hills.

Relief and Geomorphological Conditions of the Aravalli Hills (अरावली पर्वतमाला):

Stretching ~800 km in a South-West to North-East strike from Palanpur (Gujarat) through Rajasthan and Haryana to Raisina Hill (Delhi), the Aravallis are the world's oldest surviving fold mountains (Precambrian Orogeny):

• 1. Highly Denuded Relict Fold Mountains (अवशिष्ट वलित पर्वत):
  • Extensively weathered and denuded over billions of years into relict residual hills, monadnocks, and inselbergs composed of quartzite, gneiss, and schist.
• 2. Topographic and Elevation Gradient:
  • South-Western Section (Highest & Continuous): High, rugged, continuous range in Southern Rajasthan (Mewar/Abu block); houses highest peak: Guru Shikhar (1,722 m on Mount Abu granite massif).
  • Central Section: Discontinuous low hills dissected by passes (Goran Ghat, Barr pass) around Ajmer and Sambhar.
  • North-Eastern Section: Low, broken ridge spurs terminating in the Delhi Ridge (Raisina Hill - site of Rashtrapati Bhavan).
• 3. Major Hydro-Climatic Divide: Serves as the great water divide between the Arabian Sea drainage (Luni, Sabarmati) and the Bay of Bengal drainage (Banas, Chambal); acts as a physical barrier preventing the eastern expansion of the Thar Desert.