Exfoliation dome
Topic: Geomorphic Processes: Weathering, Mass Movement, Erosion and Soil Formation · NCERT: Class 11, Ch 5 "Geomorphic Processes"
Meaning
An exfoliation dome is a large, smooth, rounded hill of massive rock, usually granite. It forms mainly through unloading. Granite forms deep underground, as laccoliths or batholiths (bodies of cooled magma). When erosion removes the rock above, the granite expands and cracks into curved sheets. These sheets peel off one by one, and a rounded dome is left behind.
Example
Savandurga in Ramanagara district, near Bengaluru in Karnataka, is a huge rounded granite hill. It is one of many domal granite hills on the Karnataka plateau.
Don't confuse with
- Tor: a tor is a pile of separate rounded boulders on a hilltop. It forms by weathering along joints (cracks) mainly through thermal expansion, not by sheets peeling off a single dome.