1. Rock Cycle

2. What makes it a rock? Rocks are solid, yes! They are also…?
Crystalline
made from minerals
Inorganic
Naturally occurring
BBC
Rocks & Minerals

3. Types of rocks

4. What is the rock cycle?
Rock cycle: the continuous changing and remaking of rock
caused by interactions with water, air, land, and living things

5. Igneous rocks fire form/full of ign = __________ ous = __________
rocks formed by cooling magma or lava
Cooled magma = intrusive (think inside)
Cooled lava = extrusive (think exit)
Name two main places where igneous rock forms…
Volcanoes
Ridges/rifts
BBC Igneous
Rocks

6. Characteristics of igneous rocks
Texture – has to do with cooling time
Long cooling time = big crystals (coarse)
Short cooling time = small crystals (fine)
Where would you expect cooling time to be longer…above surface or below surface?
Igneous
Rocks

7. Characteristics used to classify igneous rocks
texture
glassy }
extrusive
fine

8. Obsidian has a glassy texture

9. Fine-grained igneous texture
Rhyolite

10. Characteristics used to classify igneous rocks
texture
coarse }
intrusive
very coarse

11. Course-grained igneous texture
Granite

12. Characteristics of igneous rocks (continued)
Composition – what it’s made of (minerals)
Judged by the amounts of light/dark materials
Felsic = light colored, lots of silica, quartz, feldspar
Mafic = dark colored, lots of iron, magnesium

13. Basalt

14. Granite

15. Classification of igneous rocks

17. Sedimentary Rocks to settle a place for Under water!
rocks formed by (1) weathering and erosion, then (2) compaction and cementation
In what type of environments do most of these rocks form?
Under water!
BBC
Sedimentary
Rocks

18. Sedimentary rock formation
Rocks are exposed to weathering and eroding -- slow wearing away of rock from wind, rain, ice
Particles move to lower areas where they settle out into layers (deposition)
Sediments are then compacted and cemented (lithification)
Sedimentary
Rocks

19. Sedimentary Rock Formation

20. Sedimentary Rocks
• Compaction is a process that squeezes, or compacts, sediments.
• Cementation takes place when dissolved minerals are deposited in the tiny spaces among the sediments.

21. 3 Types of Sedimentary Rock
Clastic – composed of weathered bits of rocks and minerals
Classified by particle size
Ex: Shale, Sandstone, Conglomerate, Grand Canyon, the Wave in Arizona

22. Shale with Plant Fossils
Shale is formed from clay

23. Sandstone
Sandstone is formed from sand

24. Conglomerate
Conglomerate is formed from pebbles and other large particles

25. The Wave, Page, AZ

26. Grand Canyon, Arizona

27. Ayers Rock / Uluru, Australia

28. 3 Types of Sedimentary Rock
Chemical – Formed when minerals dissolve out of water
Ex: rock salt, limestone (in caves)

29. Limestone, Carlsbad Caverns, NM
Stalactites
Stalagmites

30. 3 types of sedimentary rock
Organic – formed by fossils or organic matter within the rock layers
Ex: coal, oil shale, some limestone (shells,)

31. Fossiliferous Limestone
Formed from animal shells

32. Anthracite Coal
Formed from ancient swamp plants

33. Classification of Sedimentary Rocks

35. Metamorphic Rocks to change form
Rocks changed by great heat and pressure in the crust and upper mantle
NOT hot enough to melt the rock (which would make it igneous)
Rock it comes from is called “parent rock”
Parent rock
Metamorphic rock

36. Agents of Metamorphism
Metamorphic
Rocks
Agents of Metamorphism
Heat – provides the energy to drive chemical changes
Pressure – causes a more compact rock with greater density
Can cause unique folding and deformity

37. Where do metamorphic rocks form?
BBC
Metamorphic
Rocks
Form at plate collisions
Form when magma contacts existing rock
Form at great depths

38. 2 types of metamorphic rock
Foliated – looks banded or layered
the folds show the direction pressure was applied
Nonfoliated – does not look banded or layered
Amphibolite
Gneiss

39. Slate shows distinct layers
Texting in the Old Days….

40. Mica is also foliated

41. Marble — a nonfoliated metamorphic rock

42. Classification of Metamorphic Rocks