My Notes: Metamorphic Rocks, Geology of Saskatchewan, and Meteorites Flashcards
(34 cards)
What are the 3 things that result from groundwater?
- concretions and nodules
- veins
- cement, fossil replacement
What are plastics made from?
petroleum
What rocks are the most economically useful?
sedimentary
What are the two types of metamorphism?
Contact and Regional
What does the type of metamorphism depend on?
the temp that was reached
When does the metamorphic process begin?
at ~250 degrees celsius
Which melts at a lower temp, granite or basalt?
granite
How does a mineral with an atomic lattice structure break down?
Slowly as atoms are freed from the crystal lattice by increased vibration. Breaks electron bonding with adjacent atoms and combines with other atoms.
What is the temp of medium grade meta. rx?
450-550
What is the temp of low grade meta. rx?
250
What the temp of high grade meta rocks?
650
What is the temp that all rocks, regardless, will melt at?
1200
What does recrystallization result from
“solid state ion diffusion” which increases with temperature (pressure a bit)
What is the melt temp at contact metamorphism usually?
700
What is contact metamorphism?
- Batholith exposed by erosion
- Beside that body, there is a zone where country rock is metamorphosed. Fades away as it moves away from the batholith’s heat.
What are 3 forms of evidence of asteroid and meteoroidal impacts?
- impact craters
- meteorites
- tektites
What happens with big meteorites?
They disintegrate through atmosphere, hit ground with explosive force pound for pound, and explode when they hit and vaporize.
- Leave no record except microscopic vapour
- Leave impact crater
Why is the Earth not covered in impact craters like the moon is?
Earth is not full of impact craters because of geological processes that wipe them out –> subduction, burial, erosion, filled with stone, etc.
How many impact craters are left in Saskatchewan? How many are buried, of those how many are left?
- 6
- 3
- 2
What was buzzard coulee?
Fireball —> exploded –> left pieces that exposed –> 6 explosions total
How high was buzzard coulee? How long was it is the atmosphere and how fast did it go?
- 80 km high
- 20 km/sec
- 5 seconds in atmosphere
What are pits in meteorites due to? What are they good for?
Irregular melting and help identify meteorites
What is the difference between meteorites and meteors/meteoroid?
- Meteorites are not hot or radioactive when they land. They make it to ground.
- Meteors are in air or in space
What is on the inside of the majority of iron meteorites?
a crystal structure
