Earth and Life Science

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.