Geography Weathering

1. Presented By:
Nirmal Roshan.R
&
M.R.Balaraman

2.  Introduction
 Definition
 Weathering
 Types of weathering
 Mechanical weathering
 Agents of Mechanical weathering
 Frost Action
 Pressure Release (Exfoliation)
 Insulation
 Some minor Agents of Mechanical weathering

3.  “Weathering is the process of disintegration and
decomposition of rocks of the earth’s surface”.
 Weathering

4.  Mechanical weathering
 Disintegration by physical agents
 Composition of rock does not change

5.  Frost Action
 Weathering process by ice
 Water increases in volume by about 9% when it
freezes
 Produces about 1890 metric tons pressure for every 1
ft2
 Common in high altitude zones

7.  Pressure Release (Exfoliation)
 Metamorphic and intrusive igneous rocks are under
pressure
 Upper layer is removed by erosion
 Due to pressure release the cracks are formed

9.  Insolation
 Common in arid and desert regions
 Temperature is high in day time and low in night
 Disintegration due to expansion and contraction
 Block Disintegration
 Granular disintegration

11.  Rainfall
 Gravity
 Salt wedging