The correct option is (c) 1 and 3 only.
Explanation
The Aravali Hills are one of the oldest geological features on Earth, classified as old fold mountains. They form a distinct physiographic boundary in northwestern India, separating the semi-arid regions of Rajasthan from the fertile plains.- Statement 1 is Correct: The Aravali Hills constitute the western and northwestern margins of the Peninsular Plateau. They act as a boundary separating the Peninsular region from the Great Indian Desert (Thar Desert) to the west.
- Statement 2 is Incorrect: The Aravalis are old fold mountains, not young fold mountains (like the Himalayas). Originating in the Precambrian era, they have undergone extensive denudation and erosion over millions of years. Consequently, they are now classified as relict mountains with relatively low elevation, rather than high peaks with no erosion.
- Statement 3 is Correct: The range extends for approximately 800 km in a southwest-northeast direction. It starts from Palanpur in Gujarat, passes through Rajasthan and Haryana, and terminates at the Delhi Ridge in Delhi.
Key Takeaway: The Aravali Range is an example of old relict fold mountains, characterized by high erosion and low residual elevation, extending SW-NE from Gujarat to Delhi.