ELS-Q1-M4-Rocks, Kinds and Structures.pptx

Rocks: Types and Structure
Rocks are naturally occurring solid materials composed of minerals or mineral-like substances. They form the foundation of Earth’s crust and are classified into three main types based on how they are formed: Igneous, Sedimentary, and Metamorphic. Each rock type has distinct features, formation processes, and mineral compositions.

Types of Rocks
1. Igneous Rocks
Formation: Formed from the cooling and solidification of molten magma or lava.
Examples: Granite, Basalt, Obsidian, Pumice.
Structure:
Can be intrusive (plutonic) or extrusive (volcanic).
Types of Igneous Rocks:
Intrusive Igneous Rocks:
Form below Earth's surface from magma that cools slowly, leading to large crystals.
Example: Granite (coarse-grained).
Extrusive Igneous Rocks:
Form on or near the surface from lava that cools quickly, resulting in fine-grained or glassy textures.
Example: Basalt (fine-grained), Obsidian (glassy).
2. Sedimentary Rocks
Formation: Formed from the accumulation, compaction, and cementation of sediments (particles of other rocks, minerals, or organic material).
Examples: Limestone, Sandstone, Shale, Conglomerate.
Structure:
Often have layers or strata due to the sequential deposition of sediments.
Can contain fossils.
Types of Sedimentary Rocks:
Clastic Sedimentary Rocks:
Formed from broken fragments of other rocks (e.g., sandstone from sand).
Chemical Sedimentary Rocks:
Formed from the precipitation of minerals from water (e.g., limestone from calcite).
Organic Sedimentary Rocks:
Formed from the accumulation of plant or animal remains (e.g., coal from compressed plant material).
3. Metamorphic Rocks
Formation: Formed when existing rocks are transformed by heat, pressure, or chemically active fluids without melting.
Examples: Marble, Schist, Slate, Gneiss.
Structure:
May have foliated textures (layered appearance) due to the alignment of minerals.
Some are non-foliated with no obvious layers.
Types of Metamorphic Rocks:
Foliated Metamorphic Rocks:
Minerals are arranged in parallel bands or layers (e.g., slate, schist).
Non-Foliated Metamorphic Rocks:
No visible layers; usually formed from a single mineral (e.g., marble from limestone).
Rock Cycle
The rock cycle explains how rocks are continuously transformed from one type to another over time.
Igneous rocks weather into sediments.
Sediments compact into sedimentary rocks.
Sedimentary rocks undergo heat and pressure to become metamorphic rocks.
Metamorphic rocks can melt into magma, which cools to form igneous rocks.
Rock Structures
Layering (Stratification): Found mainly in sedimentary rocks. Layers indicate different periods of sediment deposition.
Foliation: Found in metamorphic rocks due to the alignment of minerals under pressure.
Joints and Fractures: Cracks in rocks due to cooling, stress, or tectonic forces.
Vesicular Texture: Found in some extrusive igneous rocks, characterized by gas bubbles trapped during solidification (e.g., pumice).

1. Quiz 1. ________make up the rocks beneath your feet, the soil that supports plants, and the deep rock of Earth’s mantle . 2. ________ is the study of the chemistry of minerals, crystals structures and their physical and optical properties. 3. ________ is a person who studies minerals.

2. Quiz 4-8. What are the five characteristics of Minerals Naturally occurring, inorganic, homogenous, chemical composition, crystalline pattern 9-15 What the physical properties of minerals?

3. Quiz 9-15 What the physical properties of minerals? Color, streak, cleavage, luster, hardness, diaphaneity, tenacity

4. R OCKS: Types & Properties After going through this module, you are expected to : 1. identify the three types of rocks; 2. classify rocks as to igneous, sedimentary and metamorphic rocks; and 3. appreciate the importance of rocks in our daily life.

5. Rocks is a naturally occurring solid aggregate of one or more minerals. The aggregate minerals forming the rocks are held together by chemical bonds . Grains can be different in color, texture, and sizes.

6. Petrology Petrology is the scientific study of rocks. Petrologists classify rocks based on how they were formed.

7. ROCKS

8. Three Types of Rocks IGNEOUS ROCKS formed from hardening and crystallization of magma or molten material that originates deep within the earth. Latin ignis means fire

9. Kinds of Igneous Rocks

10. Two types of Igneous rock A . Extrusive/Volcanic rock - forms when magma makes its way to Earth’s surface as lava and then cools. The crystals are very small (fine grained) since the cooling process is fast .

11. Two types of Igneous rock B . Intrusive/Plutonic - It cools slowly beneath the Earth surface and are created by magma. The intrusive igneous rocks have very large crystals (coarse grained ).

12. Classification of Igneous rock 1. Composition FELSIC - light in color; feldspar and silicates MAFIC - dark in color; made up of magnesium and iron INTERMEDIATE – between mafic and felsic ULTRAMAFIC - very dark color

13. Classification of Igneous rock 2. Texture- overall appearance of rock Aphanitic - fine grained Phaneritic - coarse grained Porphyritic - large crystals with small crystals Glassy - non-ordered solid from rapid quenching Pyroclastic - composite of ejected fragments

14. Three Types of Rocks SEDIMENTARY ROCKS provide information about surface conditions that existed in the Earth’s past . Particles of sand, shells, pebbles, and other fragments of materials called sediments , accumulate in layers and over long period of time harden into rocks.

15. Compaction-due to increase of pressure of layered sediments it bind together to form the sedimentary rocks.

16. Three types of S edimentary R ocks Clastic Sedimentary rock - formed from accumulation of clasts: little pieces of broken rocks and shells. Examples: conglomerate, breccia, sandstone, shale

17. Three types of S edimentary R ocks Chemical sedimentary rocks - formed when dissolved minerals precipitate from a solution. Example : Halite - formed when a body of seawater becomes closed off and evaporates.

18. Three types of S edimentary R ocks c. Organic sedimentary rocks - rocks formed from the accumulation of animal debris. Example : Coal - composed of organic matter in the form of plants fragments.

19. Three Types of Rocks METAMORPHIC ROCKS forms from pre-existing rocks: either metamorphic, igneous, sedimentary Formed from the exposure of sedimentary or igneous rocks to high pressure, high temperature, or both, deep within Earth’s surface

20. Kinds of Metamorphic Rocks

21. Metamorphic Rocks 2 types of Metamorphism 1. Regional -due to changes in pressure and temperature over large region of the crust 2. Contact -mainly by heat due to contact with magma

22. Metamorphic Rocks Classifications: a. Texture - refers to the size arrangement ad grains within the rock. b. Foliation - any planar arrangement of mineral grains or structural features within the rock.

23. Metamorphic Rocks Classifications: F oliated - appeared banded or layered, contains crystals Example: mica Non-foliated - made up of only few minerals

24. Rock Cycle is a basic concept in geology that describes transitions through geologic time among the three main rock types: sedimentary, metamorphic, and igneous.

25. Activity A . Fill in the table below by providing basic information about the types of rocks. You may refer to the words in the box below

26. Activity A . Fill in the table below by providing basic information about the types of rocks. You may refer to the words in the box below WORD LISTS Lithification pumice clastic Metamorphism sandstone intrusive Cooling andesite extrusive Cementation slate non- clastic Deposition marble contact

27. Activity B. Fill in the Venn Diagram to determine the similarities and differences of the three types of rocks.