EAS 210 MIDTERM (Don't use this one lol none of the questions were actually on the midterm)

"minerals are

naturally occurring, inorganic, crystalline solids"

"minerals do not contain certain materials:

vegetation, coal, oil and gas"

"water in the form of ice is a

mineral"

"crystalline structure:

consistent, repeating internal arrangement of atoms"

"e.g. quartz, SiO2, calcite

have fixed chemical compositions"

"Formed when one or more electrons are transferred from one atom to another:

ionic bond"

"electrons are shared between atoms to achieve a stable electron configuration:

covalent bond"

"van der Waal's or Residual Bond:

weak bonds that are easily broken"

"Polymorphs are:

minerals with the same chemical composition but different crystal structures"

"minerals are crystalline because of:

their ordered internal arrangement of atoms"

"hardness:

A measure of how easily a mineral can be scratched"

"cleavage exists if:

there are directions or planes of weakness in the crystal structure of a mineral"

"a cleavage direction is always:

parallel to a potential crystal face"

"fracture describes:

the surface of failure in a crystal when it's not along cleavage"

"irregular

another word for fracture"

"lustre is dependent on two things:

the quality of the specimen and the crystal size"

"very unreliable when naming a mineral:

colour"

"streak is:

the colour of the mineral in the powdered form"

"crystal habit is:

the typical or characteristic crystal shape that a mineral will develop if it is allowed to grow under ideal circumstances"

"oxygen + silicon =

75% of the earth's crust by weight"

"generally, silicates are:

the most abundant minerals"

"the building block to all silicate minerals:

the silicon tetrahedron"

"olivine is a ______ silicate with no _______

maifc, cleavages"

"typically mafic minerals with two cleavages that intersect at 90:

pyroxene group"

"typically mafic minerals with two cleavages that intersect at 120:

amphibole group"

"both have one perfect cleavage (sheet silicates):

micas, clay minerals"

"plagioclase feldspar may have multiple/polysynthetic _____________________, whereas potassium feldspar never does

twinning striations"

"there is no solid solution between the K- and Na-feldspars for this reason:

K is about 40% larger"

"sulfates are commonly found in a certain type of rock:

evaporite sedimentary rocks"

"predominantly opaque:

oxides"

"sulfides are not chemically stable when:

exposed to the earth's oxidizing atmosphere"

"igneous rocks are formed by:

cooling of magma or lava"

"magma described in terms of three different things:

intrusive, plutonic, cooled within Earth's crust"

"lava described in terms of three different things:

extrusive, volcanic, cooled outside the crust"

"intrusive rocks have cooled __________ and are characterized by __________ crystals

slowly, larger"

"extrusive rocks have cooled _________ and have ___________ crystals

quickly, smaller/no"

"the rock is uniformly fine-grained, with interlocking, equigranular crystals that are too small to distinguish with the unaided eye:

aphanitic"

"the rock has a matrix or groundmass of aphanitic material, containing larger crystals called phenocrysts that usually exhibit fair to well-formed crystal faces:

porphyritic"

"vesicular:

bubbles"

"term for angular fragments in a full range of grain sizes:

pyroclastic/fragmental"

"term for the crystals are coarse-grained, easily seen with the unaided eye:

phaneritic"

"high in Mg and/or Fe, and low in silica (even less than 50%):

mafic rocks"

"high in silica (as much as 70%) and low in Mg and/or Fe

felsic rocks"

"mafic rocks are generally _________ and more dense than felsic rocks; in addition, they tend to be richer in ____ whereas felsic igneous rocks tend to be richer in ____ and ____

darker, Ca, Na, K"

"if SiO2 <55%, there is no:

quartz"

"if SiO2 >56%, there is no:

pyroxene"

"if SiO2 >51%, there is no:

olivine"

"quartz never occurs with either of:

pyroxene or olivine"

"if a dark prismatic mineral occurs with quartz it must be:

amphibole"

"water does something to a rocks melting point:

lowers it"

"at ~1200°C, __________ is the first to crystallize

olivine"

"olivine is initially enriched in:

Mg"

"as olivine cools it crystallizes with:

Fe"

"discontinuous reaction series involves what kind of minerals:

mafic"

"discontinuous reaction series because:

the new mineral has a different crystal structure"

"continuous reaction series because:

crystal structure is unaffected"

"as plagiocalse feldspar crystallizes it becomes enriched in ____ and less ____

Na, Ca"

"mafic/basaltic lava characterized: quite fluid and of lower __________, being depleted in SiO2; typically erupted at ____________________, it flows relatively quickly and farther before solidifying

viscosity, 1000-1200 C"

"felsic/rhyolite lava characterized: highly ___________, erupted at _____________________, and exhibits a flow rate 1/10 or less that of mafic lava

viscous, 800-1000 C"

"pyroclastics are typically associated with these types of lavas:

intermediate and felsic"

"Volcanic domes occur within:

craters"

"Cinder cones are made of________.

pyroclastic deposits"

"these are built up from alternating eruptions of lavas and pyroclastics that are of intermediate composition on average:

composite volcanoes/stratovolcanoes"

"Weathering is the physical/mechanical and chemical ___________________ of rocks exposed at Earth's surface to smaller particles that may __________ in composition from the original substance.

breakdown, differ"

"physical weathering/mechanical weathering produces smaller constituents without altered chemistry or mineralogy, usually exploiting pre-existing planes of weakness, such as these:

bedding planes, metamorphic foliation, fractures"

"physical weathering increases:

surface area, volume"

"physical weathering accelerates:

chemical weathering"

"chemical weathering does what:

weakens the rock"

"chemical weathering accelerates:

physical weathering"

"silicate minerals are more chemically stable because they are (lower temp):

further along in Bowen's Reaction Series"

"mafic rocks and minerals are less physically ___________ compared to ___________ rocks

stable, felsic"

"halite, gypsum, and calcite are less physically stable, because:

they came out of solution"

"these three are often stable because they are weathering products to begin with:

clays, oxides, hydroxides"

"minerals which weather rapidly are destroyed so they don't survive to end up in:

clastic sedimentary rocks"

"clastic sedimentary rocks are dominated by:

quartz, feldspar, micas"

"soil horizon with organic litter unrelated to parent material:

O"

"soil horizon with mixed mineral and organic matter, within the reach of plant roots; topsoil

O and A"

"soil horizon also known as the zone of leaching; characterized: it is the most strongly weathered horizon, with materials removed

E"

"soil horizon also known as the zone of accumulation, wherein materials removed from the E Horizon may accumulate, depending on solubility and groundwater movement; soluble materials may be here in drier climates as well

B"

"soil horizon where essentially physically weathered bedrock, chemically unaltered

C"

"the specifics of a soil depend on at least these six soil-forming factors:

climate, relief, parent material, time, organisms, drainage"

"consist of material derived from pre-existing rocks and minerals carried in a medium (usually a fluid):

sedimentary rocks"

"grains are predominantly of silicate minerals:

siliciclastic"

"process in forming siliciclastic sedimentary rocks:

WETS"

"what does WETS stand for?

weathering, erosion, transportation, sedimentation"

"lithification converts the unconsolidated sediment into sedimentary rock, usually through a number of processes, such as (CBC):

compaction, binding, cementation"

"4 most common cementation minerals:

silica, calcite, clays, hematite"

"all the changes that occur in sediment after deposition, up until metamorphism begins (~200 C), are collectively called:

diagenesis"

"conglomerate:

rounded clasts"

"breccia:

angular clasts"

"arenite:

synonym for sandstone"

"division between sand and mud:

1/16 mm"

"division between slit and clay:

1/256 mm"

"usually implies as well that the sediment breaks into rather thick (several cm) blocks i.e. is blocky:

mudstone"

"fissile, which means that the sediment breaks into thin sheets or slabs less than 1cm thick

shale"

"carbonates are less soluble in:

warm waters"

"the sequence of minerals that form in the evaporation of sea water is:

carbonates, sulfates, halite, potash salts"

"what forms from the evaporation of saline lakes:

trona, borax"

"Metamorphic rocks are pre-existing rocks of any type that undergo recrystallization without:

melting"

"quartz arenite metamorphoses to produce:

quartzite"