1. Lukhdhirji Engineering College, Morbi
Degree Civil Engineering Department
Year:

2. Sub- Physical weathering
Guided By-
marvania sir

3. Prepared BY- Sr. no Name Er. no Student Mo. No 1 Gorasiya Dhansukh D. 2
Gosai Jay S. 3
Hadiya Paresh 4
Italiya Paras A. 5
Jadav Sanjay S.

4. Types of weathering Weathering is generally classified as follows:
Physical or mechanical weathering
Chemical weathering
Biological weathering

5. The weathering process
Definition
It is define as the process of decay and disintegration of rocks under the influence of certain physical and chemical of the atmosphere like wind, water, ice, sun and organisms, etc.
Example,
Rocks exposed to heating temperature of the sun in desert gradually disintegrate into smaller pieces that remain lying on or close to the parent rock.

7. Physical weathering
Physical weathering or disintegration involves application of mechanical forces.
In physical weathering a rock breaks into smaller pieces without any chemical change.
The principal factor of physical weathering are wind, river, glacier, dashing waves and tides of sea, gravity, temperature changes, wedging action of ice, etc.

8. Wind Wind causes disintegration by means of abrasion and attrition.
Abrasion means breakdown of rocks exposed along course of the wind.
Attrition means breakdown of particles carried by the wind itself.
Wind abrasion occurs when the loose particles (usually sand) carried by it strike against the exposed rocks.

9. The abrasion action of wind will be more pronounced when:
The velocity of wind is high.
The exposed rocks are soft.
The blown particles are hard.
WIND TRANSPORTS MATERIALS BY CAUSING THEIR PARTICLES TO MOVE IN DIFFERENT WAYS.
SUSPENSION – A METHOD OF TRANSPORT BY WHICH STRONG WINDS CAUSE SMALL PARTICLES TO STAY AIRBORNE FOR LONG DISTANCES.
SALTATION – CAUSES A BOUNCING OF MOTION OF LARGER PARTICLES. SALTATION ACCOUNTS FOR MOST SAND TRANSPORT BY WIND.

10. WIND EROSION IS GREATEST IN ARID CLIMATES (LOW PRECIPITATION) WITH LITTLE VEGETATION. (DESERTS AND SEA SHORES)
**ABRASION IS A PROCESS OF EROSION FOUND IN WIND, WATER, AND ICE. IT OCCURS WHEN PARTICLES SUCH AS SAND RUB UP AGAINST THE SURFACE OF ROCKS OR OTHER MATERIALS.
VENTIFACTS ARE ROCKS SHAPED BY WINDBLOWN SEDIMENTS.

11. WIND DEPOSITION OCCURS IN AREAS WHERE WIND VELOCITY DECREASES DUNES ARE PILES OF WINDBLOWN SAND THAT HAVE A GENTLE SIDE AND A STEEP SIDE.
THE GENTLER SLOPE OCCURS WHEN THE SIDE ON WHICH THE WIND IS BLOWING (WINDWARD SIDE). THE STEEPER SLOPE OCCURS ON THE SIDE PROTECTED FROM THE WIND (LEEWARD SIDE).

12. LOESS – THICK DEPOSITS OF FINE LIGHTWEIGHT PARTICLES (SILT, CLAY) THAT ARE CARRIED BY THE WIND IN GREAT QUANTITIES OF LONG DISTANCES. THEY ARE SOME OF THE MOST FERTILE SOILS.

13. 2. glacier
SNOW LINE – THE LOWEST LEVEL THAT PERMANENT SNOWS REACH IN SUMMER
HIGHEST NEAR THE EQUATOR
FIRN IS GRANULAR ICE MATERIAL FORMED IN SNOW FIELDS FROM FRESHLY FALLEN SNOW BECOMING COMPRESSED AND RECRYSTALLIZING
THE LOWER LAYERS BECOME ICE AND BEGIN FLOWING DOWNWARD OR OUTWARD BECAUSE OF OVERLYING PRESSURE.

15. THE OVERLYING WEIGHT OF SNOW AND ICE CAUSES GRAINS OF ICE TO PARTIALLY MELT AND REFREEZE. AS THIS HAPPENS ICE GRAINS SLIP PAST EACH OTHER AND MOVE DOWNHILL
GLACIERS MOVE MORE RAPIDLY AT THE SURFACE THAN AT THE BASE AND FASTER AT THE CENTER THAN AT THE SIDES. FRICTION WITH THE VALLEY WALLS SLOW THE FLOW
* FLOW AT A RATE OF A FEW CM TO SEVERAL METERS PER DAY

17. Thank you