1. ROCKS
SES2b. Relate modern and ancient geologic features to each kind of plate tectonic setting.

2. A continuous process which causes rock to change over time.
The Rock Cycle
A continuous process which causes rock to change over time.

3. THIS MAY RING A BELL
The 3 types of rocks are igneous, sedimentary, and metamorphic.
Igneous rocks form from the cooling and solidification of magma or lava
Sedimentary rocks form from deposited material within bodies of water
Metamorphic rocks form from either the heating up of a rock or putting it under pressure.

4. MAGMA vs. LAVA
Magma is the name of molten rock that is under the earth’s surface
It is found in the upper mantle and lower crust layers of the earth
Lava is the name of molten rock that is on the earth’s surface

5. Why are magma & lava so hot?
Scientists theorize that the heat is leftover from earth’s molten formation
Also, heat generated from the decay of radioactive elements are sources of earth’s thermal energy

6. How do rocks change?
Igneous—when molten material (magma) from deep within Earth; or when (lava) molten material on Earth’s surface cools—igneous rocks are formed

7. Molten material cools—igneous rock forms
The igneous rocks undergo weathering and
are broken into sediment
The sediments are eroded and carried away
where they are deposited in a new location

8. Over time the sediments continue to build up and the pressure from the overlying sediments and gravity from below causes heat to build; the rocks begin to move as hot plastic and therefore bend, stretch, the minerals in the rock may grow in size or rearrange within the rock; the rock cools and becomes a metamorphic rock specimen.
The process continues, but does not have to proceed in this exact order.

9. IGNEOUS ROCKS Igneous comes from the Latin word “ignis” = “fire”
Forms from cooling and solidification of magma
Faster cooling = smaller or no crystals
Slower cooling = larger crystals

10. Two types of Igneous rocks: extrusive and intrusive
Extrusive forms outside the Earth (or on its surface)
Intrusive forms inside the Earth
Typically found in the middle of divergent plate boundaries and in oceanic plates

11. IGNEOUS ROCK VIDEO
(4:15)

12. SEDIMENTARY ROCKS
Form from deposited material in bodies of water through the process of lithification
Lithification: the physical and chemical processes that transform sediments into sedimentary rocks
Begins with compaction
When sediments are buried 3-4 km deep, they will be able to start chemical and mineral changes to cause cementation

13. Sedimentary Rock “settling” or from Latin sedimentum
Particles of organic and inorganic material are carried from one place to the next where they are deposited and build up over time.
Water reacts with the minerals in the sediments and “cements” the pieces together to form a new rock. Particles can be so tightly pressed together that they are “compacted” into a specific rock.
Fossils are most often found in sedimentary rock.

14. Types: clastic (coarse-grained, medium grained, and fine-grained), chemical, organic, evaporated
Found where bodies of water once existed

15. SEDIMENTARY ROCK TYPES
Clastic: grain size determines this type
Coarse: has gravel-sized sediments
Medium: has sand-sized sediments
Fine: has silt-sized sediments
Chemical: during chemical weathering, minerals get dissolved and carried into lakes and oceans; as water evaporates, minerals left behind become rocks
Evaporation: form when water evaporates and leaves minerals
Organic: remains of once-living things
Fossils form this type of rock

16. SEDIMENTARY ROCK VIDEO
From Geology kitchen: (3:59)

17. Metamorphic Rocks “to change form”
May change drastically from the original parent rock.
Change is due to intense heat and pressure; causes rocks to fold, bend, twist.

18. METAMORPHIC ROCKS
Metamorphism: change in the structure of rock by natural agencies, such as pressure or heat
So, that means a metamorphic rock is one that has been heated or had pressure put on it
Where would a rock be heated or had pressure put on it?
Near a magma source
This would be known as contact metamorphism
Near a plate boundary
This would be known as regional metamorphism

19. Classification of Metamorphic Rocks
Foliated and Non-foliated
Foliated-rocks become more compacted and more dense; (Ex. Slate: minerals align in a similar direction; minerals also recrystallize and form bands (Ex. Gneiss: rocks appear to have a layered or banded appearance)

20. Non-foliated—no banded texture, most only contain one mineral (Ex
Non-foliated—no banded texture, most only contain one mineral (Ex. Calcite), crystals combine to form larger crystals (Ex. Marble)

21. METAMORPHIC ROCK VIDEO
From Mind Bites: (3:59)

22. Erosion and Deposition
Agents of Erosion (wind, water, ice, and gravity)
Loss of energy of motion, sediments are dropped (deposited) by that agent
Sediments are deposited by size; larger sediments are generally on the bottom

23. Compaction and Cementation
Lithification—turned into stone
Compaction—squeezing or pushing together of sediments with force
Cementation—dissolved minerals are deposited in tiny spaces between the sediments creating a glue that binds the sediments together