What is a mineral?
naturally, occuring, inorganic crystalline material with a unique chemical composition
What are the tests of a mineral properties?
Streak, color, luster, crystal shape/habit, mineral strength, cleavage, fracture, density,
luster
quality of light reflected from the surface of a mineral
streak
color of mineral in powdered form
habit
shape of crystal
hardness
the property of being rigid and resistant to pressure; not easily scratched; measured on Mohs scale
cleavage
the state of being split or cleft
fracture
any break or rupture in rock along which no appreciable movement
density
the amount per unit size
silicate minerals
four oxygen ions
feldspar
any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium
what is quartz?
common silicate mineral
dark silicate minerals
contain ions of iron and magnesium/dark
what is confining pressure
pressure applied equally on all surfaces
what is differential stress
difference between the greatest and least compressive stress
difference between confining pressure and differential stress
conf.-forces in different directions/diff.-forces applied equally
divergent plate boundaries?
plates move apart
convergent plate boundary
two plates move together
oceanic convergence
when two oceanic slabs converge, one descends beneath the other, volcanic activity
volcanic island arc
arc shaped chain of volcanic islands
continental convergence
one landmass moves toward the other bc of subduction of seafloor
continental drift
the gradual movement and formation of continents
plate tectonic theory
earth's outer shell consists of individual plates that interact in various ways and thereby create formations
elastic rebound theory
accumulation and release of stress and strain, causing a shake due to elasticity
what are the types of lava
basaltic, rhyolitic, aa, pahoehoe, pillow
basaltic lava
made from mafic/fluid, very fast
rhylotitic lava
felsic/slow
aa flow
rough jagged lava chunks
pahoehoe
freely flowing lava
how does pahoehoe turn into aa?
gas bubbles in the lava pop and turn into spikes, molten interior advances and outer crust is broken
pyroclastic flow
chaotic mix of rock, gas, and ash
dip slip faults
primarily parallel to the slope
normal fault
an inclined fault in which the hanging wall appears to have slipped downward relative to the footwall
reverse faults
dip slip faults in which the hanging block moves up relative to the footwall block
thrust fault
a geological fault in which the upper side appears to have been pushed upward by compression
strike slip fault
dominant displacement is horizontal and parallel to the trend of the fault surface
epicenter
the point on the Earth's surface directly above the focus of an earthquake
foreshock
a tremor preceding an earthquake
aftershock
a tremor occurring after the main shock of an earthquake
karst topography
a landscape with numerous caves and sinkholes and underground steams
water table
underground surface below which the ground is wholly saturated with water
porosity
the property of being porous; being able to absorb fluids
aquitard
semipervious nature that transmits water slower than an aquitard
aquifer
underground bed or layer yielding ground water for wells and springs etc
stalactite
a cylinder of calcium carbonate hanging from the roof of a limestone cave
stalagmite
a cylinder of calcium carbonate projecting upward from the floor of a limestone cave
spring
occurs when water pressure causes a natural flow of groundwater onto the earth's surface
shield volcano
shape of a broad, slightly domed structure that ressembles a warrior's shield
cinder cones
ejected lava fragments that begin to harden in flight to produce scoria, rock.
composite volcanoes
pitersque, yet dangerous. composed of both lava flows and pyroclastic material
composite volcano shape
conical shape
cinder cone shape
steep sided, deep craters
cinder cone eruption
short lived, magma plumbs connecting vent to magma source solidifying