The city of Visakhapatnam is blessed with a number of sites that have geological importance. One among them is the coastal red sand dunes, popularly known as Erra Matti Dibbalu.

 

About the site

  • The site is located along the coast and is about 20 km northeast of Visakhapatnam city and about 4 km southwest of Bheemunipatnam.
  • This site, spread across an area of about 20 sq km, was declared as a geo-heritage site by the Geological Survey of India (GSI) in 2014 and the Andhra Pradesh government has listed it under the category of ‘protected sites’ in 2016.
  • This site needs to be protected to study the impact of climate change, as Erra Matti Dibbalu have seen both the glacial and the warm periods.
  • The site is probably about 18,500 to 20,000 years old and it can be related to the last glacial period.

 

Distribution

  • Such sand deposits are rare and have been reported only from three places in the tropical regions in south Asia such as Teri Sands in Tamil Nadu, Erra Matti Dibbalu in Visakhapatnam and one more site in Sri Lanka.
  • They do not occur in equatorial regions or temperate regions due to many scientific reasons.

 

Significance

  • The uniqueness of this site is that the red sediments are a part of the continuation of the evolution of the earth and represent the late quaternary geologic age.
  • With a height of up to 30 m, they exhibit badland topography with different geomorphic landforms and features, including gullies, sand dunes, buried channels, beach ridges, paired terraces, the valley in the valley, wave-cut terrace, knick point and waterfalls.
  • It is a lively scientific evolution site, which depicts the real-time effects of climate change.
  • The site also has archaeological significance, as studies of artefacts indicate an Upper Palaeolithic horizon and on cross dating assigned to Late Pleistocene epoch, which is 20,000 BC.