SCIENCE-PRESENTATION-Q1-S.Y-2024-2025-METAMORPHISM-GRP-4 (1).pptx

Metamorphic rocks

1. METAMORPHISM ONE OF THE ENDOGENOUS PROCESSES OF THE EARTH

2. WHAT IS METAMORPHISM? Metamorphism is the transformation of existing rock (the protolith) to rock with a different mineral composition or texture ( mineralogical and structural adjustments of solid rocks to physical and chemical conditions differing from those under which the rocks originally formed. ).  Metamorphism takes place at temperatures in excess of 150 °C (300 °F), and often also at elevated pressure, or in the presence of chemically active fluids, but the rock remains mostly solid during the transformation.  Changes produced by surface conditions such as compaction are usually excluded.

3. WHAT IS METAMORPHISM? *( The metamorphic process can occur at almost any pressure, from near surface pressure (for contact metamorphism) to pressures in excess of 16 kbar (1600 Mpa ).

4. WHAT ARE ITS MOST IMPORTANT AGENTS?  The most important agents of metamorphism include temperature, pressure, and fluids. Equally as significant are changes caused by these that affect the inner layers that result in three categories of metamorphic processes: 

5. THE 3 PROCESSES OF METAMORPHISM 1.)Neo Metamorphism, or neocrystallization 2.) Recrystallization 3.) Metasomatism

6. Neo Metamorphism, or neocrystallization Neo Metamorphism, or neocrystallization, is a metamorphic process that results in the formation of new minerals. This is seen when shale that contains clay minerals change to produce the new mineral garnet

7. Recrystallization Recrystallization is the metamorphic process by which crystals are packed together creating a new crystal structure. With recrystallization the mineral's size and shape may change, but the basic composition remains unchanged. This is seen when limestone recrystallizes into marble.

8. Metasomatism Metasomatism is the chemical alteration of a rock by hydrothermal and other fluids. It is traditionally defined as metamorphism which involves a change in the chemical composition, excluding volatile components. It is the replacement of one rock by another of different mineralogical and chemical composition.

9. 3 MAIN TYPES OF METAMORPHISM Three types of metamorphism may occur depending on the relative effect of mechanical and chemical changes 1.)Dynamic metamorphism, or cataclasis 2.)Contact metamorphism 3.)Regional metamorphism

10. 1.)Dynamic metamorphism, or cataclasis Dynamic metamorphism, or cataclasis, is primarily the result of mechanical deformation with little long-term temperature change. The textures produced range from sharp, fragmented rock fragments in breccias to very fine-grained, granulated or powdered rocks with obvious foliation and lineation. Pre-existing mineral grains may also be deformed under stress.

11. 2.)Contact metamorphism Contact metamorphism occurs due to an increase in temperature, typically produced adjacent to igneous intrusions, causing the formation of concentric zones of different mineral assemblages.

12. 3.)Regional metamorphism Regional metamorphism is caused by a general increase in temperature and pressure over a wide area resulting in different mineral.
Typically caused by large-scale geologic processes, such as the compressive forces of continental collisions, the thrusting and folding of the Earth’s crust, and the heating and burial of sedimentary rocks. .The result of regional metamorphism is the formation of characteristic mineral assemblages that reflect both the pressure and temperature conditions.

13. MINOR TYPES OF METAMORPHISM 1.)retrograde metamorphism, the response of mineral assemblages to decreasing temperature and pressure;
2.)prograde metamorphism;the response of mineral assemblages to increasing temperature and pressure;
3.)poly-metamorphism, the effect of more than one metamorphic event;

14. MINOR TYPES OF METAMORPHISM 4.) hydrothermal metamorphism, the changes that occur in the presence of water at high temperature and pressure which affect the resulting mineralogy and rate of reaction.
5.) shock metamorphism’ or ‘impact metamorphism’, refers to the range of effects produced by the collision of two bodies, e.g., by the collision of an asteroid with the Earth. TAKE NOTE:
Various forms of metamorphism exist, including regional, contact, hydrothermal, shock, and dynamic metamorphism. These differ in the characteristic temperatures, pressures, and rate at which they take place and in the extent to which reactive fluids are involved.

15. WHAT DOES METAMORPHISM FORM? Metamorphic rocks are rocks that had  been substantially changed from their original igneous, sedimentary, or earlier metamorphic form.  Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors. Ex.  the Himalayas, Alps, and the Rocky Mountains. Metamorphic rocks are forming deep in the core of these mountain ranges.

16. MAIN TWO TYPES OF METAMORPHIC ROCKS 1.)Foliated metamorphic rocks such as gneiss, phyllite, schist and slate have a layered or banded appearance that is produced by exposure to heat and directed pressure.  2.)Non-foliated metamorphic rocks such as hornfels, marble, quartzite and novaculite do not have a layered or banded appearance.

17. MAIN TWO TYPES OF METAMORPHIC ROCKS

18. HOW IS IT STUDIED? Metamorphic petrology is the study of metamorphism. Metamorphic petrologists rely heavily on statistical mechanics and experimental petrology to understand metamorphic processes.
Metamorphic petrology is important for understanding the processes that take place within the Earth’s interior and the history of the Earth’s crust. It is also useful for identifying the sources of minerals and other resources that are found in metamorphic rocks.

19. WHY IS METAMORPHISM IMPORTANT? Geological History: Metamorphic rocks provide valuable insights into the geological history of a region. They record the conditions and events that shaped the Earth's crust over millions of years, helping geologists unravel the complex history of a specific area. Geological formations and minerals; Metamorphism is a very important benefactor to the formation of geological formations and minerals.  Common metamorphic rocks include phyllite, schist, gneiss, quartzite and marble. 

20. SUMMARY WHAT?
Metamorphism is the transformation of existing rock (the protolith) to rock with a different mineral composition or texture

21. SUMMARY WHERE?
Metamorphism takes place in temperatures excess of 150 °C (300 °F), often at elevated pressure, or in the presence of chemically active fluids, but the rock remains mostly solid during the transformation.

22. SUMMARY 3 PROCESSES:
NEO METAMORPHISM/NEO CRYSTALLIZATION
RECRYSTALLIZATION
METASOMATISM

23. SUMMARY 3 MAIN TYPES:
DYNAMIC
CONTACT
REGIONAL

24. SUMMARY MINOR TYPES? 1. Retrograde Metamorphism
2. Prograde Metamorphism
3. Poly-Metamorphism
4. Hydrothermal Metamorphism
5. Shock Metamorphism or Impact Metamorphism

25. SUMMARY 2 TYPES OF METAMORPHIC ROCKS:
FOLIATED
NON-FOLIATED

26. SUMMARY WHY?
GEOLOGICAL HISTORY AND FORMATIONS

27. SUMMARY STUDY? Metamorphic petrology

28. METAMORPHISM THIS IS THE END OF OUR PRESENTATION! THANK YOU FOR LISTENING!