rock route: Students of Makaut University explore the Yelbong River Canyon in Kalimpong district
Recently, the Geological Survey of India (GSI), a government agency responsible for conducting geological surveys across the country, identified the badlands of Gangani Danga — the grand canyon of Bengal — as a geoheritage site. Such sites are areas of significant geological features, such as rock formations, fossils, minerals or landforms, which are scientifically important for understanding Earth’s processes and history. In other words, they serve as valuable resources for learning about geology and Earth science.
The Gangani badlands are located on the right bank of the Silabati river in West Midnapore. This unique landscape is characterised by extensive soil erosion caused by rainfall and the river — resulting in steep slopes, cliffs, towering rocks, pillars, ridges — forming a spectacular natural sculpture. “Gangani is a natural canyon situated near the town of Garhbeta... It is almost 70 feet deep and is formed due to natural erosion of the Silabati river,” reads a post on X by the GSI. Formed during the Pleistocene Age (between 2.58 million and 11,700 years ago), it provides valuable data for geological research and for educating students about Earth science.
The GSI identifies and protects geoheritage sites, which are then known as National Geological Monuments. It organises field visits for students to promote awareness and understanding. “Our Earth as a whole is a geological site. The various landscape features are painted through complex natural processes over millions of years, such as erosion, transportation and deposition,” says Malay Mukhopadhyay, former head of the geography department at Visva-Bharati in Santiniketan. “To understand geological features, students must be taken on a guided tours of these places that are nature’s laboratories.”
Gangani happens to be the first geoheritage site recognised by the GSI in Bengal. In 2022, the organisation designated limestone or dolomite formation at Mamley near Namchi in South Sikkim as a geoheritage site. This site showcases stromatolite structures that are layered sedimentary formations, primarily composed of calcium carbonate, which are created by fossilised microbial mats, particularly cyanobacteria. These are built over billions of years through the trapping, binding and precipitation of minerals by the microorganisms and represent some of the earliest evidence of life on Earth.
In the same year, the Siwalik Fossil Park at Saketi, Himachal Pradesh, was tagged as a geoheritage site. It displays a rich collection of vertebrate fossils recovered from the Siwalik rocks.
Although not yet recognised as a geoheritage site by the GSI, the Yelbong River Canyon in Kalimpong, West Bengal, is a significant geological formation carved by the Rumti river — a deep, narrow gorge with steep, rocky cliffs. The spectacular canyon was formed by an erosion process known as downcutting that deepens the channel of the river. The geological process has carved out a fascinating landscape with waterfalls that can be explored through activities like canyoning and rappelling. Shreya Hazra, a student of robotics and additive manufacturing technology at Makaut University in Kalyani recently visited Yelbong. She says, “The canyon is exceptionally beautiful. I hope the area gets designated as a geopark or a geoheritage site.”
The Amkhoi Wood Fossil Park, near Ilambazar in Birbhum, is also an important geotourism site. It contains fossilised wood aged between 15 and 20 million years. In 2006, the angiosperm (flowering trees) wood fossils were found by villagers while digging a pond. The fossils that look like semi-precious stones are petrified wood and proof that a vast evergreen forest extended from here till the Rajmahal Hills of today’s eastern Jharkhand, millions of years ago. The fossils found here belong to the Dipterocarpaceae, Anacardiaceae, Combretacea and Leguminosae families of plants, showcasing how plants evolved through the ages.
Umashankar Mandal teaches geography at Jangipur High School in Murshidabad and takes students to visit such geological sites. He says, “Guided tours to geoheritage sites are valuable educational tools when integrated with relevant textbook content.” According to him, students should also be taken to spots that help them understand the geological history of their neighbourhood. This will help them understand the formation of specific landforms and the impact of geological processes on the landscape.
Mandal says, “Such understanding will make them environmentally conscious, and they will become responsible citizens capable of appreciating the world around them.”
The writer is a lecturer in geography at a Barrackpore college