Grade 8 Final Review Topics

Grade 8 Final Review Topics

Cartography

1. map

2. History- Eratosthenes, Columbus

3. reference point

4. equator

5. prime meridian

6. international dateline

7. cardinal directions-NSEW

8. Be able to locate points on a map given latitude and longitude. Read latitude and longitude of a point on the map.

a. latitude

-parallels- 0-90 N/S

b. longitude

- meridians- 0-180 E/W

9. poles

10. compass rose - Be able to draw and label a compass rose.

11. magnetic declination

12. Be able to compare and contrast representations of the earth (shape, accuracy, etc.)

a. globe

b. mercator projection

c. conic projection

d. azimuthal projection

13. remote sensing

14. aerial photography

15. map information - Be able to draw a map and include the info in 19.

a. title

b. date

c. key or legend

d. compass rose

e. map scale (verbal and graphical)

16. topographic map - Be able to draw a topographic map with rivers, depressions, steep slopes, and mountains. Be able to interpret graphics on topographic map.

a. contour line

b. elevation

c. index contour

d. contour interval

e. relief

Rocks and Minerals

1. Silicate(contain silica and oxygen) minerals

2. Nonsilicate minerals- native element, carbonates, halides, oxides, sulfates, and sulfides

3. Identifying minerals

a. color

b. streak (streak plate made of porcelain)

c. cleavage and fracture- pinacoidal, prismatic, cubic, octahedral, conchoidal

d. hardness (know Moh’s hardness scale)

e. density

f. special properties

1. fluorescence- calcite and fluorite glow under UV light

2. chemical reaction- calcite fizzes

3. Taste- halite

4. radioactivity- uranium

5. magnetism- magnetite

6. optical properties- calcite-see double image

g. luster- adamantine, vitreous, pearly, earthy, resinous, metallic, dull metallic

4. Mining – surface and deep mining

a. Ore- gold calculations—carat vs. karat

b. Reclamation

5. Formation-

a. near surface-

i. evaporating saltwater

ii. hot water solutions

iii. limestone

b. below surface

i. metamorphic rocks

ii. pegmatites- large crystals

iii. plutons

6. Rock cycle- be able to draw the rock cycle. Composition and texture are both important in classifying rocks.

a. Sedimentary rock- weathered and eroded particles compact and cement together

i. Strata- layers/ stratification

ii. Clastic, organic, and chemical sedimentary rocks

iii. Coarse grained and fine grained

b. Metamorphic rock- heat and pressure

i. Contact and regional metamorphism

ii. Foliated and nonfoliated

c. Igneous rock- melting and cooling

i. Intrusive and extrusive

ii. Mafic and Felsic

Earth History

1. uniformitarianism- James Hutton (The Theory of the Earth), Sir James Hall, Charles Lyell (Principles of Geology)

2. catastrophism- religion-supported

3. Actualism- mix of two theories.

4. Relative Dating- superposition

- geologic column

- types of disturbances of geologic column-

a. fault

b. intrusion

c. folding

d. tilting

e. gaps or unconformity

1. disconformity (layers are missing-layers underneath)

2. nonconformity (layers are missing- no layers underneath)

3. Angular unconformity (layers are tilted of folded)

5. Absolute Dating- radioactive decay (unstable isotope breaks down to a stable isotope)

-Marie and Pierre Curie, Henri Becquerel, William Libby

- radiometric dating- determine age by ratio of parent material to daughter material

- half-life

- Uranium-lead method (10 million years and older)

- Potassium-Argon method (100, 000 years and older)

- Carbon-14 method (less than 50, 000 years)

6. Fossils-trace fossils (track, burrow, coprolites)

- mold vs cast

- need to buried in fine sediment with little oxygen

- ways to form fossils

a. permineralization

b. petrification

c. amber

d. frozen fossils

e. Tar pits (La Brey Tar pits)

-uses- to interpret the past

- to date rock (index fossil-should be spread world-wide but on earth for a limited time)

7. Geologic Time Scale- be able to use it to find starting, ending and durations of eon, eras, periods, epochs

The Earth’s Structure

1. parts by composition- crust, mantle and, core

2. parts by structure- lithosphere (tectonic plates)

- asthenosphere (TP float on this layer)

- mesosphere (lower part of mantle)

- outer core (liquid)

- inner core (solid)

3. Restless Continents

- Alfred Wegener’s continental drift

-explained a. fossils of same plant and animal in Africa and South America

b. glacial groove path

c. continents fit

- Early land masses (pangaea (245 mya)---> laurasia and gondwana (65 mya)----> present day)

- Sea-floor spreading moves continents----magnetic reversals

4. Plate tectonics

a. Causes of motion- ridge push, slab pull, convection

b. PT boundaries- Convergent- continental/continental---> mountains

- continental/oceanic ---> ocean goes under

- oceanic/ oceanic -----> one goes under

- Divergent- new lithosphere forms

- Transform- slide past each other (fault)