Natural varnish found on rocks in Ladakh, HP could help develop bio-friendly paints, water-resistant material and UV protectors: Researchers

During the study, a team member accidentally spilled a few drops of water on rock varnish and it was observed that droplets did not spread on the surface but instead adhered to it

The researchers concluded that manganese and iron, along with surface hydrophobicity, play an important role in shielding the inner biotic entities in extreme conditions. iStock

Tribune News Service

Vijay Mohan

Chandigarh, August 20

In a novel study, scientists have found that natural varnish present on rocks in arid regions like Ladakh and Lahaul Spiti area of Himachal Pradesh could help in the development of bio-friendly paint, pigments, water-resistant materials as well as natural UV protectors.

According to a study carried out in Ladakh, interactions between minerals and microbes present in rocks in arid regions result in a super substance called rock varnish, which is an orange-yellow to black coating found on exposed rock surfaces in these areas.

Researchers said this natural substance which shields the rocks from further weathering and could help also in the design of similar bio-inspired products and raw materials.

“Introducing the concept that surface chemistry and hydrophobicity could play a crucial role in facilitating microbial processes related to varnish formation, a perspective not extensively explored before, the study paves new avenues in the field of bio-inspired materials as rock varnish possesses characteristics that make it a unique geo-material,” a statement issued by the Ministry of Science and Technology read.

Intrigued by rock varnishes found on big boulders in cold, arid areas of north-western India, researchers led by Dr Anupam Sharma and Dr Amritpal Singh Chaddha from the Birbal Sahni Institute of Palaeosciences, chiselled samples from them for laboratory analysis to study their formation.

During the study, a team member accidentally spilled a few drops of water on the rock varnish and it was observed that the droplets did not spread on the surface but instead adhered to it.

To further investigate the observations, complete geochemical fingerprinting with surface wettability analysis was performed. Microbial fingerprinting using organic biomarkers and isotopic analyses along with electron microscopy revealed the presence of organic matter such as fatty acids and other compounds.

The research sheds light on the intricate relationship between microbial communities, surface characteristics and organic biomarkers in the formation and stability of rock varnish in extreme environments, the ministry’s statement said.

The study suggests thatthe nearly hydrophobic characteristic of the rock-varnish layer, that is the tendency to repel or fail to mix with water, creates a niche for microbial life to thrive at the interface between the host rock and varnish layer while providing protection against environmental factors like UV radiation, particle abrasion and extreme temperature fluctuations.

This hydrophobic feature of the varnish layer may contribute to its longevity, as evidenced by the preservation of petroglyphs, which are prehistoric rock carvings, discovered worldwide over thousands of years. The researchers concluded that manganese and iron, along with surface hydrophobicity, play an important role in shielding the inner biotic entities in extreme conditions.

#Ladakh #Lahaul and Spiti