1. [ROCKS &] SEDIMENT NOTES

2. ALL Sediments come from ROCKS!!
There are 3 Main Rock Types, each with Subtypes

3. IGNEOUS ROCKS - SUBTYPES & ORIGIN:
EXTRUSIVE
LAVA
ON EARTH’S SURFACE
INTRUSIVE
MAGMA
BELOW EARTH’S SURFACE

4. Pumice, Obsidian, Basalt Igneous EXTRUSIVE Rocks

5. Granite Igneous INTRUSIVE Rock
Granite is found in many colors due to the change in chemical composition caused by the trace elements found within and around it

6. SEDIMENTARY ROCKS - SUBTYPES & ORIGIN:
CLASTIC
FRAGMENTS
PIECES OF BROKEN ROCKS
NONCLASTIC
ORGANICS & CHEMICAL PROCESSES
LIVING THINGS & PRECIPITATES/EVAPORITES

7. Sandstone, Shale, Conglomerate Clastic Sedimentary Rocks

8. Limestone, Coal, Coral Reefs Nonclastic (Organic) Sedimentary Rocks
limestone (shells) (coal) (coral reefs)

9. Gypsum, Rock Salt, Limestone (caves) Nonclastic (Chemical) Sedimentary Rocks
(& precipitate in seawater)

10. METAMORPHIC ROCKS - SUBTYPES & ORIGIN:
FOLIATED
Minerals from parent rock align to create bands, layers or stripes
MUST KNOW PARENT ROCKS
UNFOLIATED
Minerals from parent rock seem to blend; no obvious bands or layers

11. Slate, Schist, Gneiss Foliated Metamorphic Rocks
(from shale) (from phyllite) (from granite)

12. Marble, Quartzite Unfoliated Metamorphic Rock
(from limestone) (from sandstone)

13. Can help you identify what mineral/rock the sediment is made of.
SEDIMENT COLOR
Can help you identify what mineral/rock the sediment is made of.
Helps determine its source.

14. Rounded  Traveled very far Angular  Close to its origin
SEDIMENT SHAPE
Running river water smooths out the surface of a sediment grain as it travels to the ocean.
Weathering and erosion also smooth out sediment.
The rounder the sediment is, the farther it has traveled from its source.
Rounded  Traveled very far
Angular  Close to its origin

15. ANGULAR
ROUNDED

16. SEDIMENT SIZE
Small sediments: low energy beach (little to no waves needed to move them)
Large sediments: high energy beach (big, strong waves needed)

17. Biggest  Boulders  Very high wave energy
Cobbles
Pebbles
Sand
Silt  Very low wave energy
Smallest  Clay  *Exception – clay requires very high energy to be moved

18. 4 TYPES OF SEDIMENTS Terrigenous - from continents (aka Lithogeneous)
Biogenous – plant or animal origin
Hydrogenous - precipitated from water
Cosmogenous - from outer space

19. TERRIGENOUS SEDIMENTS
Covers approximately 45% of the ocean floor
Composed of weathered rock material from land *Most common composition:          QUARTZ (SiO2)          CLAY MINERALS

20. TERRIGENOUS SED., CONT. *When found on continental margins:
- Carried to the ocean by rivers
- Coarse sediment is nearest to the shore
- Finer sediment is found offshore

21. TERRIGENOUS SED., CONT.
*When found in deep ocean basins: - Carried by turbidity currents & found near continents - Carried by wind (clay size particles) and can be found far from land

22. BIOGENOUS SEDIMENTS Covers about 55% of the ocean floor.
*From benthic organisms:    -coral reef debris & shell fragments
*From zooplankton
- Calcium carbonate (CaCO3) composition:
Foraminifera & Coccolithophores
- Silicate (SiO2)composition:
Radiolaria & Diatoms

23. Biogenous, Cont’d. Can range in size from coarse to fine
Predominantly shells and skeletons
Oozes! (consistency of thick mud; produced as shells decompose)
Calcareous ooze dredged from the Arctic Ocean Bottom. Photo: Bogdan Onac

24. HYDROGENOUS SEDIMENTS
*Manganese nodules (deep ocean basin) from:
- hydrothermal vent water
*Evaporites:
 -restricted circulation + high evaporation =
precipitation of salts
-originate from chemical reactions that
occur in the existing sediment

25. COSMOGENOUS SEDIMENTS
Always <1% of a sediment
Rain down uniformly from space, but most abundant in deep ocean sediments because not "diluted" by other kinds of sediments
*Meteorite fragments & dust
*Rare earth elements