1. Mrs. Giblin Earth Science
Ch. 3 Notes Rocks
Mrs. Giblin
Earth Science

2. A Rock is… any solid mass of mineral or mineral-like matter that occurs naturally.

3. 3 Types of Rocks: Igneous – magma or lava cools and hardens.
Sedimentary – sediments settle out of a fluid and become cemented together.
Metamorphic – existing rocks are changed by heat and pressure.

5. Igneous Rocks Intrusive – cool beneath Earth’s surface.
Extrusive – cool on the Earth’s surface.
Texture: The longer the cooling time, the larger the crystal size.
Coarse-grained-large crystals, cooled slowly
Fine-grained-small crystals, cooled quickly
Glassy-very small crystals, cool very quickly

6. Composition:
Porphyritic-large crystals surrounded by fine-grained material.
Granitic-quartz and feldspar rocks-light-colored.
Basaltic-contain Mg and Fe-dark in color.
Andesitic-in between granitic and basaltic.
Ultramafic-almost entirely dark minerals.
Felsic-light in color, low in density.
Mafic-dark in color, higher in density.

7. SEDIMENTARY ROCKS

8. Deposition-dropping of particles
Formation:
Weathering-breaks down rocks
Erosion-moves particles
Deposition-dropping of particles
Compaction-squeezes sediments together
Cementation-dissolved minerals fill the spaces in between sediments.

9. Classification:
Clastic-weathered bits of sediments are compacted together.
size of particles used to group clastic rocks.
Rounded particles-conglomerate
Angular particles-breccia
Chemical or Biochemical-dissolved minerals precipitate out of water and are cemented together.
Water usually evaporates off.
Special Features:
Horizontal layering
Fossils-animals, plants
Trace fossils-tracks, footprints, mud cracks

10. CLASTIC ROCKS
Breccia
Conglomerate

11. cm –0.0004cm
Sandstone Siltstone

12. CHEMICAL ROCKS
Rock Salt
Rock Gypsum

14. Limestone

15. Coal

16. FOSSILS

19. NYS Fossil- Eurypterid

22. Sedimentary Rocks in NYS
Letchworth State Park
Sandstone, Limestone, Shale

23. Watkins Glen
Taughannock Falls
Sandstone

24. Thatcher Park-Shale

25. Metamorphic Rocks

26. Formation: Formed by increased heat and pressure.
Contact metamorphism-hot magma moves into the rock.
Regional metamorphism-large-scale deformation. A whole mountain or cliff can deform.
Agents of Metamorphism:
Heat-cause chemical reactions.
Minerals may recrystallize.
New minerals may form
From magma
Heat increases as you move closer to the mantle.

27. Classification of Metamorphic Rocks:
Pressure-increases as you get deeper also.
Increased pressure causes minerals to become more compressed…more dense as well.
Solutions-water may surrround crystals and make it easier for the ions to move.(Hydrothermal solutions-hot water solutions)
Classification of Metamorphic Rocks:
Foliated-”banding” caused by minerals realignment when crystallizing.
Shale-> slate gneiss -> quartzite
Non-foliated-no banding present
Ex. Marble, quartzite

28. Anthracite Coal

29. Schist

30. Metaconglomerate