Why in News?

• Citizens join hands to preserve the geological marvel of Erra Matti Dibbalu in Visakhapatnam.

What is Erra Matti Dibbalu?

• Located between Visakhapatnam and Bheemunipatnam, the Erra Matti Dibbalu are rare red sand dunes that are a reminder of the million years of geological processes.
• Its towering red sand dunes with patches of greenery is like a meandering maze.
• The width of the dunes, which runs for five kilometres along the coast, varies from 200 metres to two kilometres.
• It is listed among the 34 notified National Geological Heritage Monument Sites of India by the Geological Survey of India.

Its formation:

• Studies indicate that the area was tectonically active between 2.5 million years and 11,000 years ago.
• The sediments are mainly derived from the Khondalite rocks from the hinterland of the Eastern Ghats.
• Geologically these red sand dune sediments particularly hold significance.
• They are the result of the combined effect of numerous factors including global climatic changes, sea-level Variations, Monsoonal Variability and as a result serves as valuable Paleo-Environment Indicators.