RAMGARH CRATER

source - Google Earth

At Ramgarh, a quiet village in Rajasthan, a 4 km hole is punched into the ground. It is a circular impact crater rising abruptly (the wall is about a km high) in the plain area surrounded by vast agricultural fields.

This structure was first noticed in 1869. Since then, it has been studied by geologists and confirmed to be a meteorite impact crater later.

Apart from some temples, there are two water bodies present within the crater filled with rainwater. Migratory birds have been observed here. This area is considered a potential Geological Heritage Site in India as it is archaeologically, biodiversity-wise, and geologically important.

Coordinates—25°20'8.90"N, 76°36'23.70"E

 

ORIGINS OF TAJ MAHAL’S MARBLE

"Agra - Taj Mahal" by micbaun is licensed under CC BY 2.0

The Taj Mahal is made of a special type of marble called Makrana marble. It is locally known as "Sang-e-Marmar".

Makrana marble comes from a town with the same name in Nagaur district, Rajasthan, about 100 km from Jaipur.

Makrana Marble is a metamorphic rock. All metamorphic rocks start their journey as sedimentary rocks, in this case, limestone (calcium carbonate (CaCO₃)).

For a long time, about 1450 million years ago (Proterozoic Eon), India was still part of a super-continent called Rodinia & the Aravalli ranges were very young.

Parts of India were submerged under the ocean where microorganisms were extracted.

Calcium and CO₂ from the seawater precipitated into calcium carbonate (CaCO₃), i.e., limestone.

When the oceans receded, new rocks were deposited on top of the limestone and it got buried deep inside the earth, where high temperatures and pressures compressed it into Makrana marble.

Over time, tectonic forces lifted up the rocks of this area and exposed them near the surface, where at present, over 800 quarries operate over an area of 30 km².

Makrana marble is commonly used in flooring, making sculptures, and garden furniture & fountains, etc.

THE AMAZING GEO-HERITAGE OF RAJASTHAN

Mines in Rajasthan such as the lead-zinc mines of Zawar, Rajpura-Dariba,& Rampura-Agucha supply India’s industrial sector with invaluable raw materials.

During Bronze Age, Gold (18000 BC) & Copper (12000 BC) were used, Carbon dating of burnt wood shows that Zinc smelting happened 3040 ± 150 years ago

There is another well known rock in Rajasthan from the time of the Dinosaurs, the yellow limestone of Jaisalmer
Quarrying has been going on for decades and it is commonly marketed as “Yellow Marble”; Yellow limestone has good demand in the markets of countries in the Middle East, Taiwan, Morocco, USA, Europe, Australia, Africa, & New Zealand.

It is mostly used in making tiles, hotel counters, statues, furniture, mausoleums etc.