There are two categories of geologic processes: 1) Exogenous processes occur near the surface of the Earth and are influenced by gravity, water, wind and organisms. They include weathering, erosion, mass wasting and sedimentation. 2) Endogenous processes originate under the Earth's surface and are responsible for earthquakes, continental development and shaping the crust. They involve magmatism, volcanism and metamorphism.

1. 2 Categories of geologic processes
1. Exogenous Processes
2. Endogenous Processes
Exogenous Processes – occur on or near the
surface of the earth.
- they are usually influenced or
driven by gravity, water, wind and organi-
sms.

2. Types of exogenous processes
1. Weathering
2. Erosion
3. Mass wasting
4. Sediments

3. Weathering – breakdown of rock materials at
the near earth’s surface.

4. Types of weathering
1.Physical Weathering
2.Chemical weathering
Physical weathering or mechanical weathering
- breaking smaller fragments from a
larger block or outcrop of rock.
- a process where the outer layer of the
rock peels away.

5. PHYSICAL WEATHERING

6. 5 Principal Types of Physical Weathering
1.Unloading - when the outer layers of the rock
break down away from the rest of the
rock.
- rocks are formed with layers they
become compact and become a solid
rock.
2.Freeze-thaw weathering – occurs when water
continually seeps in cracks ,freezes and
expands eventually break the rock.

7. 3. Thermal expansion – involvement of temp.
when the sun rays heating the rock in
daytime. At night ,rocks contract when
temp. go down.
4. Salt-crystal growth (salt crystalization)
- causes saltwater rocks to rapture due
to a saline solution entering a rock
through cracks and then evaporating
this causes crystal form.

8. 5.Hydration – water molecules attach to the
crystalline structure of a mineral w/o
causing a permanent change in that’s
mineral composition.

9. Chemical weathering – is the process by which
rocks break down by chemical reaction.

10. Erosion – one of exogenous process which
earth’s surface is worn by wind ,water or
ice.

11. Mass wasting – refers to the movement of large
masses of materials down a slope or steep
sided hill or mountain due to the pull of
gravity.
Forms of mass wasting
1.Debris flow
2.Mudflow
3.Slump

12. Debris flow- happens when a large amount of
sediments or rocks falls down the slope.

13. b. Mudflow – combined of soil and water flow
down a slope.
c. Slump – is a slow movement of soil along a
curved surface.

14. SLUMP

15. Sedimentation – is the accumulation of materials
such as soil, rock fragments and soil particles
setting on the ground.

16. ENDOGENOUS PROCESSES
- responsible for earthquakes, develop-
ment of continents and other related to
earth’s crust.
Endogenous process that played a role in
the evolution of landforms on earth:
1.Magmatism- happens when magma is genera-
ted and develops into igneous rocks.
magma- is the original material that make up

17. igneous rock.
magma is found beneath the surface of the
earth.
2.Volcanisms (plutonism) – is the process that
usually happens after magma is formed.
3.Metamorphism- it is the process of changing
materials that make up a rock.