paper 1 Flashcards
pillow lava’s formation
lava continuously extruded from under the sea floor forming a glassy texture
sources of geothermal energy
radioactive decay - 50%
formation of the earth
frictional heating - heat from friction of denser minerals sinking
engineering strategies to reduce impact of seismic waves
1) deep foundations
2) counter weighting eg steel pendulum
3) strong flexible steel structure
liquefaction
vibrations in the ground from an earthquake cause the ground to become less viscous therefore allowing buildings to slide down due to grains being forces apart
evidence of tectonic plate movement
1) Mesosaurus found in south america and south Africa which would not be possible in today’s current climate meaning they had to be closer together at one point.
Igneous crystal shapes
1) Euhedral- well formed with sharp recognisable faces.
2) Anhedral- no well-formed crystal faces.
3) Equant- crystals have all axes the same length.
4) Equigranular- all crystal faces the same size.
5) Amygdaloidal- large vesicles filled with secondary mineral.
6) Carbonation- the reaction between carbonic acid and a mineral.
7) Porphyritic- large crystals are completely surrounded by small crystals.
silica contents
silicic - >66%
intermediate - 52-66%
mafic - 45-52%
ultramafic - <45%
amphibian adaptations
1) Formation of eyelids – wasn’t needed in water.
2) Tongues - help catch prey on land.
3) Ears – help hear on land.
4) First evolved from marine animals in the Devonian.
Elastic rebound theory
Shear strain deforms the crust as it moves in opposing directions. Elastic strain energy builds up over many years at specific points on the crust, stress builds until it exceeds the strength of the rock causing it to have a sudden release of the energy which causes an earthquake. The energy released is in seismic waves.
Rift valley
lowland between several highlands or mountain ranges produced by geological rifts.
Rift
divergent plate margin pulling apart the lithosphere.
Secondary enrichment
Concentrates minerals by weathering and erosion in oxidation zones above the water table. E.g., copper
Placer deposits
deposition of minerals from decreased water energy.
Connate water
water trapped in the pores of sedimentary rocks.