Constructing knowledge on Rock Outcrops
Inselbergs are large dome shaped outcrops, of granite or gneiss. Frequently observed in South and Eastern India.
Laterite or basalt mesas are common in the Western Ghats, Konkan and Deccan plateau region
Cliffs are steep almost vertical exposed rock faces, common in mountain areas.
Inselbergs are isolated rock outcrops of granite or gneiss that rise abruptly above the surrounding plains. They occur in arid, semi-arid and humid regions in India and support specialized vegetation types associated with distinct microhabitats.
Inselbergs occur in all major climatic and vegetational zones of the world, but are particularly abundant in tropical regions. The word “Inselberg” was coined by Wilhelm Bornhardt in 1900 (from German Insel =island and Berg = mountain) to refer to rock outcrops rising abruptly above surrounding plains. They are characterized by distinct microclimatic and edaphic conditions (Porembski et al., 2000) and can be either more dry (Poremsbki et al. 1996) or more humid (Burke, 2003) sites as compared to the surrounding landscape.
The famous monolithic inselbergs in India are Savandurga near Bengaluru and Mandar hills in Bihar. Kopje or tor type of Inselbergs can be seen around Hyderbad city.
Rocky plateaus are naturally formed flat expanses of any rock type. They are often in the form of mesas atop hills.
Flat laterite-topped plateaus with steep scarp/cliff edges are common in the Western Ghats and are known as "tablelands". Most famous are the Panchgani and Kaas tablelands of Satara district of Maharashtra. These are conservation zones and heritage sites owing to their unparalleled unique biodiversity and aesthetic values.
Large parts of Maharashtra have Basalt exposed as a hill-top plateau. Many have been used as forts in historic times ex. Sinhagad, Lohgad.
Rocky plateaus of basalt, laterite, granite or sandstone are seen in southern and central India.
Lateritic plateaus(ferricrete) in Western India are well studied, and known to be rich in endemic and threatened species.
Cliffs are common in the Western Ghats, Aravallis, Balaghat ranges. They are extremely dry as hardly any water can remain on the vertical slope.
However, they are moist with cascades and streams during the monsoon.
The vegetation is dominated by Poaceae which form dense clumps that support other species.
Cliffs are used as habitats by many raptors such as eagles, vultures etc. They have also been excavated by humans and used as shelters or places of worship. Ajintha is perhaps the most well known of the Indian cave art sites, which is a World Heritage Site.
Cliffs are almost vertical scarp faces seen in the mountain regions.
The rock type varies with the local geology. Most impressive cliffs are of basalt, sandstone and granite in the Peninsular India