review geo unit 1
Rock cycle: refer to chart
igneous rocks form by melting pre existing rocks, and solidifcation of that magma,
sedimentary rocks form from the weathering and erosion of pre existing rocks, depositions and litification
metamorphic rocks from by the application of heat/and or rpessure to or by chemical reactions in pre existing rocks
crystal to type
intrusive: crystals are larger ( more time to grow)
extrusive: crystals are smaller - faster reaction
if magma is thin ( low visocisty) easier for large crystals to form
b.jkb.
Porphyry
2 crystals sizes, record 2 cooling stages of the magma
felsic magma is thick, mafic magma is thin
h;k
Mafic compistions
magneisum and iron
felsic ( or siliac) comp
silicon and alumunim
Bowens reaction series def
explains order in which minerals crystals form from a melt as it cools
lithification
turining sediments into solid rock
mud cracks
sedimentary structures formed as muddy sediment dries and contracts
buried lava flow
- extrisve layer of lava that has been covered by soil,ash or other materials over time. Deposited on top of existing rock
Compisite Cone
- upside down ice cream cone - steeper
alternate layers of lava and ash/rock
Lava dome
rounded like adome , made from thick lava piles up near vent , just lava
Pyrcoclastic
pyrcoclastic refers to anything that comes from a volcano during an explosion.
At higher pressures, rocks often show increased grain size
metamorphic grade
cap rock
A cap rock is a layer of rock that forms the uppermost part of a geological formation and serves to trap or seal underlying materials (like oil, gas, or water) from escaping. It acts like a "cap" over the other layers. The cap rock is typically made of impermeable materials, meaning fluids can't easily pass through it.
Lower temp magma allows for it to have higher silica content, but will also be higher viscoisty ( all of these go hand in hand)
jll/k
mafic magma - is higher temp, has a low silica content , and has lower viscosity ( higher temp makes it runny), ( more runny also means less mean explosion- less gas trapped)
n,
permable
allows liquids or gases to pass thru