Geological processes

Question 1

Earth formation

Answer 1

4.6 billion years ago, proto earth with heavier elements sink to bottom (iron/nickel) and light elements in crust (silicon/oxygen)

Question 2

structure of earth

Answer 2

solid inner, liquid outer, mesosphere, asthenosphere, lithosphere (rigid)

Question 3

continental

Answer 3

less dense, granite

Question 4

oceanic

Answer 4

more dense, basaltic

Question 5

mantle

Answer 5

convection in upper mantle which breaks tectonic plates

Question 6

how many plates

Answer 6

7 large, 8 small

Question 7

hotspot

Answer 7

magma hotter than surrounding magma, use hotspots to see how continents moved

Question 8

theory of continental drift

Answer 8

alfred wegner, said continents fit into a jigsaw and was one supercontinent

Question 9

evidence of continental drift

Answer 9

fit of continents have similar rocks/geological sequences/fossils/climatic zones, paleomagnetism (measures how continents moved)

Question 10

equation for continents moved

Answer 10

motion=distance/age

Question 11

rate of tectonic movement per year

Answer 11

0.6cm-18cm

Question 12

billion years

Answer 12

Gyr (duration), Ga (date)

Question 13

million years

Answer 13

Myr (duration), Ma (date)

Question 14

thousand years

Answer 14

kyr (duration), Ka (date)

Question 15

years

Answer 15

yr (duration), date (a)

Question 16

to work out duration

Answer 16

take away years before and after, make sure to convert units to make them the same

Question 17

BLAG spreading rate theory

Answer 17

rate of tectonic movement, faster movement means more subduction/extension and more volcanism so more co2 and more climate change, slower movement means less

Question 18

uplift weathering theory

Answer 18

when tectonics move crust up theres more weathering and makes silicates/hydrocarbonic acid which moves to ocean and forms calcium carbonic acid and removes co2 from atmosphere

Question 19

thermohaline circulation

Answer 19

driven by density/temp/salinity differences, ocean cools becomes denser and sinks to bottom and travels to equator then heats up rises and travels to poles, strong in cretacous

Question 20

gateway

Answer 20

antartica was connected to south america but disconnected when warm currents moved to south america and drake passge opened up with cold currents