08-January-2025-Editorial

ARTESIAN WELL

Recently in Jaisalmer, Rajasthan, a significant natural event occurred where large volumes of water gushed out from underground. This phenomenon is attributed to an artesian well and has sparked discussions about the origin of this water.

Experts have ruled out any connection to the ancient Saraswati River, suggesting instead that the water may be millions of years old, possibly originating from the prehistoric Tethys Sea.

What is an Artesian Well?

An artesian well is a natural well where water rises to the surface without the need for external pumping, driven by underground pressure.

This happens when water is trapped in a confined aquifer, which is surrounded by impermeable layers like clay or rock.

Formation:

• Artesian wells form when a borehole penetrates a confined aquifer.
• The aquifer contains water under pressure due to the weight of overlying water and geological formations.

Pressure Mechanism:

• The confined water is under significant pressure.
• Once the upper layer is punctured, this pressure forces the water to rise naturally, sometimes even gushing out.

Water Flow:

• If pressure is sufficient, water flows to the surface naturally, creating “flowing artesian wells.”
• In cases of lower pressure, pumps are used to extract the water.

Global Examples:

• Artesian wells are found in the Great Artesian Basin (Australia), Dakota aquifer (USA), and parts of Africa.

Difference from Tube Wells:

• Artesian wells rely on natural pressure, whereas tube wells require external power for water extraction.

Origin of the Term:

• The term “artesian” comes from Artois, France, where such wells were widely used in the Middle Ages.

Features of Artesian Wells in Rajasthan

Water Eruption:

• In Rajasthan’s desert regions, water lies trapped beneath layers of sandstone.
• When the top geological layer is punctured, water erupts under high pressure, sometimes forming fountains.

Ancient Sea Evidence:

• The gushing water contains high salinity, indicating its origin from ancient sea remnants.
• This aligns with the theory that the water is linked to the prehistoric Tethys Sea, which existed about 250 million years ago.

Marine Clay Presence:

• Along with water, fine white marine clay (called oozes) with skeletal remains surfaced, further supporting the ancient sea hypothesis.
• The sand brought up is believed to be from the Tertiary period, around 6 million years ago.

Geological Significance:

• Jaisalmer was once a border region of the Tethys Sea.
• Fossils of giant sharks found in Jaisalmer, Japan, and Thailand point to a rich marine history.

About the Tethys Sea

Existed during the Mesozoic Era, particularly the Triassic period (250–201 million years ago).

Located between the supercontinents Gondwana and Laurasia.

Geographic Extent:

• Spanned parts of present-day Europe, Asia, Africa, and the Middle East.
• Connected the Pacific Ocean in the east and the Atlantic Ocean in the west.

Closure and Evolution:

• Began closing around the Late Cretaceous period (66 million years ago).
• This led to the formation of new landmasses, including the Indian subcontinent’s collision with the Asian plate, creating the Himalayas and the Tibetan Plateau.

Fossil Evidence:

• Hosted diverse marine life such as sharks, ammonites, and marine reptiles.
• The Tethys Sea also contributed to forming petroleum basins in regions like North Africa and the Middle East.

Other Examples of Natural Water Gushing

Hydrothermal Vents:

• Found on ocean floors near tectonic plates.
• Expel hot water and minerals from beneath the Earth’s crust.

Hot Springs:

• Surface areas where groundwater heated by Earth’s interior emerges.
• Examples: Manikaran (Himachal Pradesh) and Gaurikund (Uttarakhand).

Geysers:

• Periodically erupt hot water and steam due to underground heating by magma.
• Example: Yellowstone National Park (USA).

Mudpots:

• Bubbling pools of mud formed in geothermal areas where water mixes with clay.

Fumaroles:

• Emit volcanic gases and steam through surface cracks.
• Found near dormant volcanoes like Barren Island (Andaman and Nicobar Islands).

Saraswati River: Myths and Historical References

About Saraswati River:

• Revered in ancient Indian texts, especially the Vedas.
• Known as the holiest river during the Vedic Period (8000–5000 years ago).

Origin and Course:

• Originated in the Himalayas, flowing through Punjab, Haryana, Rajasthan, and Gujarat.
• It is believed to have disappeared around 5000 years ago due to climatic and tectonic changes.

Mentions in Ancient Texts:

• Vedas: Described as the “Best of Mothers” and the mightiest river.
• Manusmriti: Identifies the region between Saraswati and Drishadvati rivers as sacred.
• Mahabharata: Mentions its disappearance at Vinasana and importance for pilgrimages.
• Puranas: Describes its origin and cultural significance.

Conclusion

The artesian well in Jaisalmer has brought ancient geological history to light. While some speculate its connection to the Saraswati River, evidence points to its origin from the prehistoric Tethys Sea. Such discoveries highlight India’s rich natural and historical heritage and offer insights into Earth’s geological evolution.