The approximate age of the Aravallis range is

The correct answer is Option 4 (670 million years).

The Aravalli Range is one of the oldest fold mountain systems in the world, originating during the Proterozoic Era. Geological studies indicate that the primary orogenic (mountain-building) phases occurred between 2.5 billion years and 570 million years ago. Specifically, the Delhi Supergroup, which forms the core of the northern Aravallis, dates back approximately 700 to 600 million years.

Why Option 4 is correct:

• Geological Timeline: Most geological estimates for the stabilization of the range align with the late Neoproterozoic era, making 670 million years the most accurate approximation among the given choices.
• Comparison: Options 1, 2, and 3 (370–570 million years) correspond to the Paleozoic Era, which post-dates the major formation period of the Aravallis.

Though now highly denuded and classified as relict mountains, their foundational crust remains significantly older than the Himalayas, which are only about 40–50 million years old.