1. Earth & Space Science Chapter 6
Sedimentary and Metamorphic Rocks

2. Weathering vs. Erosion Weathering:
produces sediment by breaking down rock
can be chemical or mechanical
Erosion:
transports sediment through
moving water
wind
gravity Draw a picture of each
glaciers of these factors.

3. How can rocks form from sediment?
Lithification (lithos = stone):
Compaction—compression by overlying layers (sometimes pore space left, esp. sandstone)
Cementation—mineral “glue”
Sedimentary features
Bedding (seen in hwy rock cuts)
Ripple marks
Sorting/rounding of grains
Fossils

4. Sedimentary Rock Features
Bedding (horizontal layering):

5. Sedimentary Rock Features
Most fossils are found in sedimentary rocks.

6. Types of Sedimentary Rock
Clastic—made of small bits (clasts) stuck together
Coarse (>2 mm pieces)
conglomerate
Medium (1/16 mm to 2 mm)
sandstone
Fine (1/256 mm to 1/16 mm)
siltstone
Very fine (< 1/256 mm)
shale

7. Types of Sedimentary Rock
Organic/Biochemical formed from/by living organisms
Coal
Fossiliferous limestone
Coquina
Chalk

8. Types of Sedimentary Rock
Chemical evaporites and precipitates
Rock salt
Rock Gypsum
Compact limestone
Chert/flint

9. What causes metamorphism?
Temperature
Pressure

10. Features of Metamorphic Rocks
Solid state change in minerals (remember Bowen’s reaction series?)
Foliation—parallel layers or bands—caused by pressure
Reorganization of crystals

11. Protoliths of Foliated Rocks
Granite  gneiss (banded)
Various  schist (layered)
Shale  slate (layered)

12. Protoliths of Nonfoliated Rocks
Limestone  marble
Sandstone  quartzite

13. Types of Metamorphism Low grade to high grade Regional Contact
Hydrothermal (hot groundwater)

14. Economic Importance of Metamorphic Rocks
Building/Construction
Slate, marble
Metallic mineral resources
Ores (iron, lead)
Native minerals (gold, copper, silver)
Nonmetallic mineral resources
Talc, asbestos, graphite

15. The Rock Cycle