World's Oldest Mountain Range: Aravalli Formation Story

The Aravalli is the world's oldest mountain range, located primarily in the state of Rajasthan, India. Its history dates back 1.8 billion years, making it a living museum of Earth's early geological processes.

The Aravalli mountain range is approximately 1.8 billion years old. Its formation began during the Proterozoic Era, a time when Earth's continents were still taking shape.

The Aravalli range was formed through a process called orogeny, which is mountain building. It was the result of a colossal collision between two ancient landmasses, the Aravalli Craton and the Bundelkhand Craton, about 1.8 billion years ago.

The Proterozoic Era was a geological period that began approximately 2.5 billion years ago. It was a crucial time in Earth's history when oxygen first started to appear in the atmosphere and early life forms, like stromatolites, began to flourish in the oceans.

This collision was the primary geological event that created the Aravalli mountains. The immense force of the two cratons colliding caused the sedimentary and volcanic rocks on the ancient ocean floor to buckle, fold, and thrust upwards, forming the mountain range.

The Banded Gneiss Complex (BGC) is Rajasthan's oldest rock formation, dating back over 2.5 billion years. It formed during the collision of the cratons and consists of metamorphic rocks like granite, gneiss, and amphibolite, which indicate conditions of extreme pressure and high temperatures.

Stromatolites are layered structures formed by ancient, oxygen-producing microbial life in shallow waters. In Rajasthan's Jhamerkotra region, 1.8 billion-year-old stromatolite fossils can be found, providing direct evidence of ancient marine life in the area during the Proterozoic Era.

1.8 billion years ago, Rajasthan was completely different from the desert landscape of today. It was covered by vast oceans where sedimentary rocks and volcanic materials were deposited on the seafloor, which later formed the Aravalli mountains.

Orogeny is the geological term for the process of mountain formation. It typically occurs when sections of the Earth's crust, like continental plates or cratons, collide, causing the land to fold and be pushed upwards to create mountain ranges.

Cratons are large, stable, and ancient parts of the continental lithosphere. The Indian subcontinent was composed of several cratons, including the Aravalli, Bundelkhand, and Marwar Cratons, whose movements and collisions shaped the region's geology.

The foundation of the Aravalli range, the Banded Gneiss Complex, contains metamorphic rocks like granite, gneiss, and amphibolite. These were formed under extreme heat (600-800°C) and pressure during the mountain-building event.

Yes, the rocks of the Banded Gneiss Complex and the presence of 1.8 billion-year-old stromatolite fossils in Jhamerkotra are direct evidence that the region was once covered by vast oceans during the Proterozoic Era.

No, the Aravalli is an old, eroded mountain range. Unlike young, growing ranges like the Himalayas, the Aravalli's tectonic activity has long ceased, and it has been weathering down for millions of years.

The Aravalli Supergroup refers to the sequence of sedimentary and volcanic rocks that were deposited in the ancient ocean and were subsequently folded and uplifted to form the first Aravalli mountain range. It represents the material that makes up the mountains themselves.

It is considered a treasure because its rocks provide a rare window into Earth's early history, specifically the Proterozoic Era. It preserves evidence of ancient life, continental collisions, and the processes that shaped our planet billions of years ago.