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In what physical state do changes in a rock occur to make a metamorphic rock?
The solid state
What is the general term for the rock before it is metamorphosed?
What are potential sources of heat that can cause metamorphism?
- Deep in the Earth’s crust
- Close to an intrusive body
At what temperature does metamorphism usually begin?
What is confining pressure?
Pressure that is equal in all directions
In what direction do micas crystalize in a rock that has foliation?
- Perpendicular to the direction of maximum compression
- Parallel to the direction of shearing
What tectonic environment do blueschists form in?
A subduction zone
What is the protolith of marble?
What is the protolith of quartzite?
What is the state rock of California?
What happens to the carbon content of coal as it experiences higher grade metamorphism?
Carbon content increases
What is the protolith of slate?
How large are the mica crystals in a phyllite?
Larger than in slate but still microscopic
How large are the mica crystals in a schist?
What is the appearance of a gneiss?
Alternating dark and light bands
What is the principle that says layers of sediment deposited in water form horizontal (or near horizontal) beds?
The principle of original horizontality
How can tilting of sedimentary layers occur?
During mountain building
How can folding of sedimentary layers occur?
In compressional environments
What is the position of the oldest layer in a stratigraphic sequence?
What type of underlying unconformity involves igneous or metamorphic rock?
In what era do fossils of complex life forms begin appearing?
In what era did dinosaurs roam the earth?
What do we think lead to the extinction of the dinosaurs?
- Asteroid or comet impact
- Flood basalts happening in India
What is the name of the current era in geologic history?
What technique do we use to come up with absolute ages of rocks?
How many years back can we date something with 14C decay?
If we start of with 64,000 atoms of some radioactive isotope, how many radioactive atoms do we have left after three half lives?
8,000 radioactive atoms
Approximately how old is the Earth?
4.5 billion years
list from youngest to oldest
- tilting & erosion
Where is most of the water in the hydrosphere located?
Which is more porous: a sandstone or uncemented sand?
How much water is found in the saturated zone?
All the pore spaces are filled with water
How much water is found in the unsaturated zone?
Some to none of the pore spaces are filled with water
At what speeds does water usually flow through the subsurface?
Centimeters to meters per day
What factors does flow velocity in the subsurface depend on?
- Slope Angle
- Permeability of the rock
Would a unfractured granite be considered a potential aquifer of aquitard?
Would a conglomerate be considered a potential aquifer or aquitard?
What feature is formed in the water table when a well is regularly used?
A cone of depression
What is the name of the well where water is under pressure and rises above the water table?
An artesian well
What surface features form when the water table intersects the surface?
- A lake
- A stream/river
- A spring
What contaminants are not purified by the soil?
- Toxic Chemicals
What can occur when wells near the seashore pump too much water?
What is the name of the features in caves that grow up from the cave floor?
How is water heated to form hot springs and/or geysers?
- Ground water comes close to an magma body
- Ground water circulates and reaches unusual depths in the crust
What is the top of the sautrated zone in the ground called?
What type of stream has a higher discharge upstream?
A losing stream
What is the name given to a rock before it undergoes metamorphism?
What is a polymorph?
Minerals with the same composition but different crystal forms
What type of dating puts objects/events in order from oldest to youngest?
What do we think caused the mass extinction at the end of the Mesozoic?
An asteroid impact and/or flood basalts in India
What technique do we use to come up with an absolute age of a rock?
What protects us from the solar wind?
Earth's magnetic field
What are the gas giant planets mostly made of?