Metamorphism - How Rocks Change Due to Heat and Pressure (1).pdf

Metamorphism - How Rocks Change Due to Heat and Pressure

1. Metamorphism
How Rocks Change Due to Heat and
Pressure

3. Metamorphism
Metamorphism is the process where
rocks change into new types of rocks
because of heat and pressure inside
the Earth.

4. Metamorphism
When rocks are buried deep underground, the
temperature is very hot, and there is strong
pressure from the weight of other rocks
above.

5. Metamorphism
These conditions cause the minerals
inside the rock to rearrange or change,
and the texture of the rock becomes
different.

6. Metamorphism
These conditions cause the minerals
inside the rock to rearrange or change,
and the texture of the rock becomes
different.

7. Examples of Metamorphism
1.Limestone → Marble
Limestone is a soft rock.
When exposed to high heat and pressure, it
changes into marble, which is shiny, harder,
and used in buildings and statues.

9. Examples of Metamorphism
2. Shale → Slate
Shale is a soft, crumbly rock.
Under heat and pressure, it becomes slate,
which is smooth, flat, and used for roofing or
tiles.

11. Causes of metamorphism

12. Causes of metamorphism
The primary agents that cause metamorphism
are:
1.Heat - Provides the energy needed to drive
chemical reactions, causing mineral grains
to change their atomic structure, grow in
size, or combine to form new minerals.

13. Causes of metamorphism
2. Pressure - The immense weight of
overlying rock, or the directional stress from
colliding tectonic plates, forces mineral grains
to become more densely packed and aligned.

14. Causes of metamorphism
3. Chemically active fluids - Hot, ion-rich
water and gases can dissolve minerals and
transport ions, leading to the formation of new
minerals with a different chemical makeup in
a process called metasomatism.

15. Types of metamorphism

17. Types of metamorphism
Metamorphism is categorized by the specific
conditions under which it occurs:
1.Regional metamorphism - The most
widespread type, which occurs over large areas,
typically during mountain-building events where
tectonic plates collide. It involves both high
temperature and intense, directed pressure.

19. Types of metamorphism
2. Contact metamorphism - Occurs when hot
magma intrudes into cooler surrounding rock,
"baking" it. This process is driven primarily by heat
and affects a smaller area, producing rocks like
marble from limestone.

21. Types of metamorphism
3. Burial metamorphism - Takes place when
sedimentary rocks are buried deeply by overlying
sediments. The rock is subjected to high
temperatures and the great pressure of the
immense weight above, but without significant
differential stress.

23. Types of metamorphism
4. Dynamic metamorphism - Involves mechanical
deformation and intense shearing along fault
zones. Friction generates heat and crushes the
rocks, often creating a finely ground rock known as
mylonite.

25. Types of metamorphism
5. Hydrothermal metamorphism- Results from the
interaction of rock with hot, circulating fluids, often
near mid-ocean ridges. The fluids chemically alter
the rock, sometimes forming important ore
deposits.

26. Types of metamorphism
6. Shock metamorphism (Impact metamorphism)
- Occurs during meteorite impacts, creating
ultrahigh pressures that form rare, high-pressure
minerals like coesite and stishovite.

27. Quiz

28. 1. What is the process where rocks change into
new types of rocks due to heat and pressure?
A. Weathering
B. Erosion
C. Metamorphism
D. Sedimentation

29. 2. Which of the following is not an agent of
metamorphism?
A. Heat
B. Pressure
C. Chemically active fluids
D. Wind

30. 3. What type of metamorphism occurs when
magma “bakes” the surrounding rock?
A. Regional
B. Contact
C. Burial
D. Dynamic

31. 4. Which type of metamorphism occurs due to
meteorite impacts?
A. Hydrothermal
B. Regional
C. Shock
D. Burial

32. 5. When limestone undergoes contact
metamorphism, what rock is formed?
A. Slate
B. Marble
C. Schist
D. Quartzite

33. 6. Why is pressure an important factor in
metamorphism?
A. It melts rocks completely.
B. It increases the porosity of rocks.
C. It forces minerals to become more tightly
packed and aligned.
D. It reduces the density of rocks.

34. 7. Which statement best distinguishes regional
metamorphism from contact metamorphism?
A. Regional occurs over small areas; contact
occurs over large areas.
B. Regional involves magma intrusion; contact
involves tectonic collision.

35. 7. Which statement best distinguishes regional
metamorphism from contact metamorphism?
C. Regional occurs over wide areas with high
pressure and heat; contact is localized due to
magma.
D. Regional occurs only underwater; contact
occurs on land.

36. 8. Why are chemically active fluids important in
metamorphism?
A. They cool the rocks faster.
B. They dissolve and transport ions to form new
minerals.
C. They prevent mineral growth.
D. They increase rock porosity.

37. 9. During metamorphism, what usually happens to
minerals in rocks?
A. They rearrange or form new minerals.
B. They break down into sand.
C. They dissolve completely.
D. They become lighter in color.

38. 10. How does burial metamorphism differ from
dynamic metamorphism?
A. Burial is caused by magma, while dynamic is
caused by deep burial.
B. Burial occurs with high heat and pressure;
dynamic involves crushing and shearing along
faults.

39. 10. How does burial metamorphism differ from
dynamic metamorphism?
C. Burial is caused by meteorites; dynamic is
caused by water.
D. Burial involves chemical fluids; dynamic
involves wind erosion.

40. 11. A geologist finds rocks altered by crushing
and shearing along a fault zone. What type of
metamorphism is this?
A. Hydrothermal
B. Burial
C. Regional
D. Dynamic

41. 12. If magma intrudes into limestone, what
metamorphic rock will most likely form?
A. Quartzite
B. Slate
C. Marble
D. Gneiss

42. 13. Rocks at mid-ocean ridges are altered by hot
circulating fluids. What type of metamorphism is
this?
A. Hydrothermal
B. Contact
C. Regional
D. Shock

43. 14. Which of the following best compares
hydrothermal metamorphism and shock
metamorphism?
A. Hydrothermal is caused by magma; shock is
caused by wind.
B. Hydrothermal is caused by fluids; shock is
caused by meteorite impacts.

44. 14. Which of the following best compares
hydrothermal metamorphism and shock
metamorphism?
C. Hydrothermal occurs only on land; shock
occurs only in oceans.
D. Hydrothermal forms marble; shock forms
sandstone.

45. 15. A mountain range is forming where two
tectonic plates collide. Which type of
metamorphism is most likely dominant?
A. Contact metamorphism, because magma is
intruding.
B. Regional metamorphism, because of
widespread heat and pressure.

46. 15. A mountain range is forming where two
tectonic plates collide. Which type of
metamorphism is most likely dominant?
C. Hydrothermal metamorphism, because of
circulating fluids.
D. Shock metamorphism, because of meteorite
impacts.

47. 1.C. 9. A.
2.D. 10. B
3.B. 11. D
4.C. 12. C
5.B. 13. A
6.C. 14. B
7.C. 15. B
8.B.

48. Thank
You