Chapter 2: earth tectonics and systems

Realms

earth system compenets that exchange materials and energy with one another components

Biosphere

region inhabited by life; “our zone”

Hydrosphere

water; 97% ocean, 3% frehswater

cryosphere

frozen hydrophere

Tectonic activity 

geological processes that produce topographic structures 

Differentiotial

separation into layers

Mineral requirements

1. naturally occurring

2. genetically inorganic 

3. homogenous (same structure) 

4. Solid crystalline structure 

5. definable chemical compounds

Rock requirements

1. coherent

2. naturally occurring

3. aggregate of grains

Igneous rock

formed by molten rock  

• intrusive: inside 

• extrusive: kaboom

Sedimentary rock

formed from burying and liquification of sediments

Ex. Limestone

Sediment

accumulation of non-concentrated loose grains

Ex. sand

Metamorphic rock

Rock undergoes change without first being melted

Ex. parallel layers that flatten from pressure 

Ex. Marble is pressurized limestone

Lithosphere

rigid outer layer, crust and mantle top

astenosphere

mantle area that is hot enough for plastic flow

Abyssal plains

broad, flat surfaces

the midwest but underwater

mid-ocean ridges

ocean mountains

Fracture zones

steep drops/juts; indicate age

deap sea trench

oh look a hole to hell underwater

seamount

underwater peak

continental shelves

area where depth is less than .5 km

sesimic belts

area where most earthquakes happen 

seafloor spreading

new crust comes up, emerges, old crust forced to side (movement)

divergent boundaries

2 plates move apart via seafloor spreading

transform boundary

one plate slips sideway; grating against each other

collision

2 buoyant plates collide; subduction zone “closes”

rifting

stretching and breaking on continental lithosphere

hot spots

place in pater interior with a volcano; pocket of lava underground 

Slab-pull force

drags plates towards convergent boundaries (plates forced towards subduction zone; “down force”) 

ridge-push force

same thing as slab pull??

asthenosphere convection  

asthenosphere moves relative to lithosphere

brittle deformation

rock cracking under stress (pretzel) 

plastic deformation

material changing shape without cracking (tootsie roll) 

Joint

naturally cracked rokc (no shearing involed)

faults

fracture that sliding occurs on

fold

curve in rock layer (Shapes and colors)

foliation

layering of metamorphic rocks

Uniformitarianism

idea that the same processes we have today acted in the same way in the past/future