1. PreQuiz Describe the strength of bonds between atoms in a solid.
What is a mineral?
True or False: Only eight elements make up the bulk of the minerals found in Earth’s crust.
What is the most common mineral group?
carbonates b. silicates c. oxides d. halides
What are rock-forming minerals?
What are some common properties of minerals?

2. 3.1 The Rock Cycle
rock- any solid mass of mineral or mineral-like matter that occurs naturally as part of our planet
Mixtures of minerals and sometime nonmineral material
3 major types of rocks:
Igneous
Sedimentary
metamorphic

3. Rock Cycle

4. Summary Questions
Use your own words to describe the sequence of processes that result in igneous rocks. Describe a specific example of a sedimentary rock becoming an igneous rock.
Use your own words to describe the sequence of processes that result in sedimentary rocks. Describe a specific example of a sedimentary rock becoming a new type of sedimentary rock.
Use your own words to describe the sequence of processes that result in metamorphic rocks. Describe a specific example of a sedimentary rock becoming a metamorphic rock.

5. Igneous Rocks Formation Intrusive Igneous Rocks
Rocks that form when magma hardens beneath Earth’s surface
Magma- molten material below earth’s surface
Extrusive Igneous Rocks
Rocks that form when lava hardens on Earth’s surface
Lava- molten material on or above earth’s surface
granite
rhyolite

6. Texture of Igneous Rocks
Igneous Rocks are classified by texture and composition
Textures
Coarse-grained- slow cooling results in large crystals
Fine-grained-rapid cooling results in rocks with small, interconnected mineral grains
Glassy- cools so quickly that ions cannot arrange themselves into a network of crystals
Glassy does not mean they look glassy!!! (pumice)
Porphyritic- rocks experience different rates of cooling, so they have different sizes of crystals in the same rock

7. Igneous Textures
Fine-grained
Coarse-grained
Glassy
Porphyritic

8. Examples of Igneous Rocks
1. Granite
2. Rhyolite
3. Gabbro
4. Basalt
5. Obsidian
6. Pumice

9. Sedimentary Rocks Formation (5 major processes)
Weathering- breaks rocks into sediments
Sediments- smaller pieces of rocks and minerals
Erosion- movement of sediments
Agents: water, wind, ice, or gravity
Deposition- dropping of sediments because agent lost energy
Compaction- squeezing or compacting of sediments
Cementation- dissolved minerals are deposited in the tiny spaces among the sediments

10. Classification of S.R. Classified according to the way they form
Clastic sedimentary rocks- made of weathered bits of rocks and minerals
Grouped according to the size of the sediments
Conglomerate- rounded, gravel-size or larger
Breccia- angular
Chemical sedimentary rocks- forms when dissolved minerals precipitate from water solutions

11. Features of S.R.
The many unique features of sedimentary rocks are clues to how, when, and where the rocks formed
Layers show the order in which the rocks formed
Fossils hidden in sedimentary rocks show evidence of past life forms
Ripple marks and mud cracks

12. Examples of S.R.
Conglomerate
Breccia
Sandstone
Limestone
Rock salt

13. Metamorphic Rocks Metamorphism- to change form Formation Agents
Changes occur at elevated temperatures and pressures
Conditions are found a few kilometers below Earth’s surface and extend into the upper mantle
Agents
Heat- provides energy needed to drive chemical reactions, which may cause minerals to recrystallize
Pressure- may cause the spaces between mineral grains to close or cause the mineral to recrystallize
Hydrothermal Solutions- hot water solutions promote recrystallization by dissolving original minerals and then depositing new ones

14. Classification of M.R. Classified by texture and composition Texture
Foliated-rocks with layered or banded appearances
Formed when rocks undergo intense pressures causing the rock to be more compact or even recrystallize the rock
Nonfoliated- rocks without banded appearances
Contain only one mineral

15. Contact vs. Regional Contact Metamorphism Regional Metamorphism
When magma intrudes rock
Produces low-grade metamorphism = minor changes
Ex: Marble
Regional Metamorphism
During mountain building, rocks are exposed to extreme pressures and temperatures
Produces high-grade metamorphism = intense changes

16. Examples of M.R.
Parent rock- original rock before metamorphism takes place
Metamorphic Rock
Parent Rock
Slate
Shale
Gneiss
Schist, Granite
Marble
Limestone
Quartzite
Sandstone
Schist
Phyllite
Anthracite
Bituminous Coal