Britannica
Sources used in this answer
How do granite landscapes develop domes boulder piles and other distinctive erosion features?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
continental landform
Davis's proposed landscape-development states. The morphology shown is not actually time-indicative. For example, A could be a gully system in soft sediment or a canyon such as the Royal Gorge in Colorado, which is millions of years old. The ridge-ravine topography of B would normally develop under humid conditions, but the river meandering on alluvium indicates a prior or extraneous non-humid aggrading mechanism. The riverine plain of C implies a complex history of planation and aggradation in a current fluvial mode.
Granite landscapes develop their characteristic features through a combination of structural jointing and various weathering processes.
Structural Foundations
Granite is a plutonic rock that forms at depth. As it cools and is later exposed, it develops joints—brittle-fracture surfaces. These joints often occur in vertical and horizontal sets, creating a grid-like pattern that dictates how the rock breaks down.
Erosion and Distinctive Features
- Domes: Large, massive granite formations often undergo exfoliation, where the rock sheds successive thin shells or plates. This process, often driven by the chemical weathering of minerals into clay and subsequent volume expansion, can shape massive outcrops into rounded domes.
- Boulder Piles and Tors: When granite is weathered along its joint systems, it can form tors—exposed masses of jointed, broken blocks. Through spheroidal weathering, moisture penetrates these joints, causing the corners and edges of the blocks to decay more rapidly than the centers. This leaves behind rounded, boulder-like cores surrounded by disintegrated material, resulting in the distinctive piles often seen in granite terrain.