Geoheritage Sites for UPSC Exam - Testbook.com

The 'Natural Arch' from the Jurassic Age in Odisha

The Odisha state unit of the Geological Survey of India (GSI) has recommended the declaration of the ‘Natural Arch’ located in the Kanika range of Sundargarh forest division as a Geo Heritage Site. This geological marvel is believed to be a relic from the Jurassic period.

Image source: www.newindianexpress.com

• The ‘Natural Arch’ in the Kanika range of Sundargarh forest division, which has its roots in the Jurassic period, is on the verge of being declared a Geo Heritage Site .
• The site is nestled in the dense Chhengapahar reserve forest near Brahmani village in the Kanika range of Sundargarh.
• Once declared, it will become the largest natural arch in the country to be bestowed with the Geo Heritage tag. .
• The oval-shaped arch spans 30 metres at the base and stands 12 metres high. The alcove of the natural arch reaches a maximum height and width of 7 metres and 15 metres respectively .
• In addition to the Sundargarh arch, India is home to two more natural arches – one at Tirumala hills in Tirupati and another in the Andaman and Nicobar Islands.

Exploring the Geoheritage Sites of Jhamarkotra and Zawar

The Geological Survey of India (GSI) is responsible for declaring geo-heritage sites/national geological monuments, ensuring their protection and maintenance.

• In the vibrant state of Rajasthan, two sites of geological importance have been identified.
• One is the 1.8-billion-year-old fossil park at Jhamarkotra, and the other is the world’s oldest zinc-smelting site at Zawar.

Jhamarkotra:

• Jhamarkotra is home to a stromatolite fossil park.
• Stromatolite is a type of layered sedimentary rock that is formed by the activity of microorganisms.
• The stromatolites at Jhamarkotra are approximately 1.8 billion years old and exhibit a wide array of textures and sizes.
• Stromatolite fossils carry the imprints of the earliest known life forms on Earth, the cyanobacteria, also referred to as blue-green algae.
• These fossils are rich in phosphate due to the sediments trapped within them, which are primarily phosphate minerals. This is one of the reasons why the region is a hub for mining activities today.
• The phosphate extracted from this site is used in the production of agricultural fertilizers.
• However, as mining activities in the region have intensified, they pose a threat to these ancient fossils, potentially damaging or destroying these invaluable records of our geological history.

Zawar:

• Located 40 km from the city of Udaipur, Zawar is the site of the world's oldest known zinc-smelting operation.
• Zawar holds significant value from both metallurgical and archaeological points of view.
• Evidence of ancient zinc mining and smelting operations can be found throughout the landscape of Zawar, including trenches, chambers, open-pit mines, galleries, and shafts.
• The presence of earthen retorts, such as brinjal-shaped, long-necked vessels, attests to Zawar's unique legacy of zinc-smelting.
• The extraction was performed using a distillation process that required a retort and an external condenser.
• This is a testament to the metallurgical expertise of the time.
• The zinc-smelting operations at Zawar have a history dating back 2,000 years. In 1988, the American Society of Metals acknowledged it as the earliest known zinc-smelting site in the archaeological record.
• Historical records also point to the use of zinc in ancient medicine and in the production of medieval weapons.
• The people of the region had established trade relations with far-off lands like China and Japan.