1. ROCKS!

2. Rock – a mixture of minerals, mineraloids, glass, and/or organic matter

3. James Hutton
James Hutton, known as the father of geology, suggested that the Earth was much older and that processes occurring in the present were the same processes that had operated in the past, and would be the processes that operate in the future.
This concept became known as uniformitarianism and can be summarized by the phrase "the present is the key to the past"

4. James Hutton The Father of Modern Day Geology A Philosopher
A Scientist
An Author

5. Rock Cycle – a cycle which shows how one rock type changes into another rock type (it’s a never-ending cycle)

6. The Three Rock Families
1. Sedimentary
2. Igneous
3. Metamorphic

7. 8 processes that show how one rock changes into another:
weathering
erosion
compaction
cementation
melting
cooling
heat
pressure
Sedimentary Rocks
Igneous Rocks
Metamorphic Rocks

8. The Rock Cycle

9. Igneous Rocks

10. Igneous rocks – formed when magma or lava cools and hardens
The classification of Igneous Rocks is based on two things:
1. Cooling location
2. Mineral composition

11. 1. Classification based on cooling location
Intrusive
Extrusive
Porphyry

12. Intrusive Igneous Rocks – rocks that form by slow cooling beneath Earth’s surface and form large mineral grains (coarse grains)
Cool very slowly from magma underground
Form large (coarse) mineral grains (this happens because time allows the atoms of the minerals to arrange themselves in a pattern that we can see)
Also called plutonic igneous rocks

13. Intrusive Igneous Rocks
Granite
Diorite
Large/Coarse Grains = Slow Cooling Rate

14. Extrusive Igneous Rocks – rocks that form by fast cooling on or near the Earth’s surface and form small mineral grains (fine grains)
Cool quickly from lava above ground
Form small (fine) mineral grains or no mineral crystals at all (no mineral grains form when very rapid cooling occurs)
Also called volcanic igneous rocks

15. Extrusive Igneous Rocks
Obsidian
Basalt
Small/Fine grains or no grains = fast cooling rate

16. Porphyry – rocks that form by both fast and slow cooling
Cool fast and slow, therefore have both large and small mineral grains
Large Grains
Small Grains

17. 2. Classification based on mineral composition
Basaltic
Granitic
Andesitic

18. Basaltic – dark colored, high density, rich in iron and magnesium, made from thin, runny mafic lava
Examples
Basalt
Scoria

19. Granitic – light colored, low density, rich in oxygen and silicon, made from thick, sticky felsic lava
Examples
White Granite
Red Granite

20. Andesitic – mineral compositions in between basaltic and granitic, made from lava in between basaltic and granitic
Examples
Diorite
Andesite

22. Formation of Sedimentary rocks:
They can form when sediments precipitate (or become a solid) out of solution.
2. They can form when rocks are weathered and eroded into sediments, the sediments are deposited in layers (usually in the ocean), and then the pressure from the upper layers pushes down on the lower layers to compact and cement the sediment to form rock.

23. Sedimentary rocks form in layers:
Youngest
Layer 2
Layer 1
Oldest
Law of Superposition – in an undisturbed sequence of sedimentary rock, the oldest rocks are found at the bottom and the youngest are at the top

24. Sedimentary Rock in Layers
We call this layering characteristic in sedimentary rock stratification

25. Classification
Sedimentary rocks are classified based on the make-up of the rock

26. Clastic (detrital) – made from pieces of other rocks that are pressed and cemented together
Shale
Conglomerate
Sandstone

27. Chemical – made when water evaporates from salt lakes and shallow seas
Limestone
Rock Salt

28. Coquina Bituminous Coal Chalk
Organic – made when dead plants or shells form thick layers and get pressed and cemented together
Coquina
Bituminous Coal
Chalk

29. Some Unique Characteristics of Sedimentary Rock
Fossils
Ripple Marks
Geodes
Mud Cracks

30. How was coal formed?

31. More about coal
Coal is a combustible black or brownish-black sedimentary rock composed mostly of carbon and hydrocarbons. It is the most abundant fossil fuel produced in the United States.
Coal Vein

32. Coal is a nonrenewable energy source because it takes millions of years to create.
The energy in coal comes from the energy stored by plants that lived hundreds of millions of years ago, when the earth was partly covered with swampy forests.
For millions of years, a layer of dead plants at the bottom of the swamps was covered by layers of water and dirt, trapping the energy of the dead plants.
The heat and pressure from the top layers helped the plant remains turn into what we today call coal.

33. Types of Coal
Coal is classified into different types depending on the amounts and types of carbon it contains and on the amount of heat energy it can produce.
The rank of a deposit of coal depends on the pressure and heat acting on the plant debris as it sank deeper and deeper over millions of years. For the most part, the higher ranks of coal contain more heat-producing energy

34. 4 Main Stages of Coal Peat Lignite Bituminous Coal (Sedimentary)
Anthracite Coal (Metamorphic)

35. Lignite is the lowest rank of coal with the lowest energy content
Lignite is the lowest rank of coal with the lowest energy content. Lignites tend to be relatively young coal deposits that were not subjected to extreme heat or pressure. Lignite is crumbly and has high moisture content.

36. Bituminous coal contains percent carbon, and has two to three times the heating value of lignite. Bituminous coal was formed under high heat and pressure. Bituminous coal in the United States is between 100 and 300 million years old. It is the most abundant rank of coal found in the U.S.,
accounting for about
half of U.S. coal
production.

37. Anthracite contains percent carbon and its heating value is slightly lower than bituminous coal. Anthracite is very rare in the United States. The only anthracite mines in the United States are located in northeastern Pennsylvania.
Anthracite Coal is a Metamorphic Rock that is made after Bituminous Coal undergoes heat and pressure

38. Metamorphic Rocks
ROCKS

39. Metamorphic rocks – rocks that have changed due to temperature and pressure increases
Metamorphic rocks can undergo changes in composition.
Metamorphic rocks can be formed from changes in igneous, sedimentary, and even other metamorphic rocks.

40. Metamorphism can be regional or local
Regional – mountain building
Local – smaller areas
Contact – hot magma melts nearby rocks
Deformational – high pressure areas at faults

41. Local
vs.
Regional

42. Classification
Metamorphic rocks are classified based on the texture of the minerals
in them

43. Types of Metamorphic Rocks
Two types of Metamorphic rocks:
Foliated
Nonfoliated (Unfoliated)

44. Examples of Foliated Metamorphic rocks:
1. Foliated – formed when existing rock (parent rock) is placed under great heat and pressure and the mineral crystals flatten out into parallel bands
Examples of Foliated Metamorphic rocks:
Parent
Rock
Metamorphic
Granite
Gneiss
Basalt
Schist
Shale
Slate

45. Foliated Examples
Slate
Gneiss
Schist

46. Before and After
Granite
(Igneous Rock)
Gneiss
(Metamorphic Rock)

47. Examples of Unfoliated Metamorphic rocks:
2. Unfoliated – form when existing rock (parent rock) is placed under great heat and pressure and the mineral crystals are not arranged in parallel bands
Examples of Unfoliated Metamorphic rocks:
Parent
Rock
Metamorphic
Sandstone
Quartzite
Limestone
Marble

48. Unfoliated Examples
Quartzite
Marble