GSI Confirms Oligocene-Age Mud from Baratang Mud Volcano, Andaman

In News: Samples of India’s Only Active Mud Volcano in Andaman Date Back 23 Million Years: GSI

Analysis:

1. Context:
   • Baratang Mud Volcano in the Andaman and Nicobar Islands is India’s only active mud volcano.
   • Recent samples collected during October 8–9, 2025, confirm the mud belongs to the Oligocene epoch (~23 million years ago), based on lithoclast analysis.
2. Geological Significance:
   • Lithoclasts composed of sandstone and shale from the Mithakari Group, representing ancient geological formations.
   • The Oligocene epoch (33.9–23 million years ago) saw global cooling, expansion of grasslands, and evolution of modern mammals such as early elephants, cats, and dogs.
3. Mud Volcano Activity and Features:
   • Four clusters of vents observed, covering ~500 sqm with heights up to 2 m, significantly larger than earlier records.
   • Continuous ejection of liquid mud and gases, surface temperatures ranging 29.3°C–30.07°C, pH 8.0–8.3 (weakly alkaline).
   • Thin oily blackish sheen noted on some vents.
4. Possible Causes of Eruption:
   • Diapiric movement of over-pressured shale layers due to sediment loading.
   • Lateral tectonic compression or rapid subsidence.
   • Hydrocarbon generation in deep subsurface layers.
   • Expulsion of fluids along deep-seated fractures or faults.
5. Safety and Conservation Measures:
   • Public access restricted, with viewpoint construction recommended for safe observation.
   • Reinforcement of fencing and hazard signage to educate visitors about unpredictable eruptions.
6. Importance:
   • Provides insights into geological evolution of the Andaman region.
   • Highlights the need for safe tourism practices and geoscience research in unique natural phenomena.

Static Information:

• Location: Baratang, Andaman and Nicobar Islands
• Type: Active mud volcano
• Age of Mud: Oligocene (~23 million years)
• Composition: Sandstone and shale (Mithakari Group)
• Eruption Features: Multiple vents, weakly alkaline mud, occasional oily sheen
• Safety Recommendations: Restricted access, viewpoint construction, hazard signage
  
  Updated - October 19, 2025 07:52 pm  | The Hindu