Explanations:The question asks about the oldest mountain range in India. To understand this, we need to delve into the geological timeline of mountain formation in the Indian subcontinent. The age of a mountain range is determined by the time when the tectonic processes that formed it occurred.
The Aravali Range, located primarily in Rajasthan, is the oldest mountain range in India. It was formed approximately 1.8 billion years ago during the Proterozoic era. This range is composed of ancient metamorphic rocks and is a remnant of the ancient Aravalli orogeny, which was a period of intense mountain-building activity.
In contrast, the Himalayas, which are often considered the most prominent mountain range in India, are much younger. They began to form about 50 million years ago due to the collision of the Indian and Eurasian tectonic plates. This collision continues to this day, causing the Himalayas to rise at a rate of about 5 millimeters per year.
The Sahyadri Range, also known as the Western Ghats, is another significant mountain range in India. It was formed about 65 million years ago, during the Cretaceous period, as a result of the breakup of the Indian subcontinent from the Gondwana supercontinent. This makes the Western Ghats much younger than the Aravali Range.
Understanding the geological timeline of these mountain ranges is crucial for comprehending their formation and relative ages. The Aravali Range, being the oldest, has undergone extensive weathering and erosion over its long history, which has resulted in its current relatively low elevation compared to the younger Himalayas and Western Ghats.
Therefore, the correct answer is the Aravali Range, as it is the oldest mountain range in India, formed approximately 1.8 billion years ago. This makes it significantly older than the Himalayas and the Western Ghats, which are much younger in geological terms.