Plate Tectonics
why do plates move?
Plates are “pushed and pulled’ over the surface of the earth due to convection currents in the mantle.
Explain the three types of oxidation?
Rust- oxygen+iron=reddish brown mineral
green patina- oxygen+copper=Greenish compound
tarnish- oxygen+silver=black compound
What the difference in the formation of u and v shaped valleys?
V-shaped- carved out by a river
u-shaped- carved out by a glacier
What is the composition of soil?
Rock fragment, air, water, and decaying plants and animals
When does erosion by gravity increase?
When rocks are weakened and broke down down by weathering
What was the name of the scientist that came up with the Continental Drift theory?
Alfred Wegener
What occurs during exfoliation?
The outermost layer of earths crust breaks/peals off due to pressure buildup underground
How are dunes formed and where are they found?
Sand is deposited in an area to form a mound
they are found at beaches and desserts
What is the size, biggest to smallest, of soil?
Sand, silt, clay? Sandy’s school’s cool
What do waves in erosion create?
Sea cliffs, sea stack, sea arch, sea caves
Why are there earthquakes?
When too much energy builds up, a sudden release occurs and causes an Earthquake.
What is the difference between physical and chemical weathering?
chemical weathering changes the composition of rock whilst mechanical Weathering only breaks it down into smaller pieces
What are the two ways a lake can form?
Rain water fills a sinkhole
a glacier melts during a depression
Why do farmers rotate crops?
They plant different types of crops to replenish nutrients in the soil
name all of the types of masss wasting?
Rockfall, rock slide, sinkhole, mudflow, landslide
What is the continental drift theory? Is it a guess? What is the evidence to support this? EXPLAIN
Earth used to be one single landmass called Pangea that gradually broke and drifted apart overtime.
1)continents fit like a puzzle piece
2)mountain chains with the same age rocks on different continents
3)fossils of the same species in different continents
Name all of the types of physical weathering and how they work
exfoliation-outermost layer of earths crust breaks due to underground pressure
abrasion-when rocks rub against each other
ice wedging-rain seeps into cracks, freezes, expands, and breaks the rock
tree root growth-seed will wedge into a crack, as it grows into a tree, the roots break the rock
burrowing animals-animals that live in burrows dig up and make holes in sedimentary layered rocks
How are each type of mountain formed?
Fold-when tectonic plates collide
fault block-when forces pull earths crust apart large crystal blocks
volcanic-formed when molten rock erupt and piles on earths crust
What are the layers of soil, aka horizons, from top to bottom? What do they do?
O-humus
A-topsoil
E-sand and silt
C-parent material
What is the difference between rock fall and rock slide?
Only a few pieces of rock fall down a cliff, big boulders fall down a slope
What are the three boundaries? Explain all of them, what they do, and their effects.
Convergent- plates
Divergent
Transform
How are living organisms part of chemical and physical weathering?
In chemical, lichens and plant roots release weak acids that break down rocks
in physical, trees root growth=seeds seep into cracks of rocks, as they grow it, it becomes strong and breaks the rock/burrowing animals
How is a sinkhole formed?
acid rain dissolves limestone underground and erodes sediment to new location to carve a cave. Overtime the roof collapses due to gravity and forms a sinkholes.
Name all of the thing that make soil basically perfect for farmers
loamy, humus, moist, dark, ph7, granular
Factors that accelerate mass wasting:
1.steeper slopes
2.weathered rocks
3.water
4.slopes with no vegetation