Geology Test 2
the columbia plateau in washington and oregon is _____
a flood basalt plateau
which of the following is true about rocks and minerals
a rock can contain more than one mineral, a mineral is composed of chemical elements, a single rock can include more than one mineral
which of the following best defines a mineral and a rock
a rock is a lithified or consolidated aggregate of different mineral grains
what denotes a basaltic lava flow covered with angular, congealed lava rubble
aa
Which of the following is the highest ranking, cleanest burning form of coal and is classified as a metamorphic rock?
anthracite
changing the composition of magma by incorporating surrounding host rock is known as
assimilation
What type of magma, commonly erupted along oceanic ridge systems, originates by partial melting of mantle peridotite?
basalt
a very large, discordant pluton commonly composed of granite
batholith
What is the most characteristic, original, depositional feature preserved in sedimentary rocks?
bedding
a nearly flat surface separating 2 beds of sedimentary rock
bedding plane
many limestones are
biochemical
_____ is a clastic sedimentary rock composed of predominantly angular, gravel-size particles
breccia
large volcanic depressions formed by subsidence and collapse are known as
calderas
term used to describe intrusive igneous masses that form parallel to the bedding of the surrounding rock
concordant
which of the following sedimentary rocks would you expect to have originally been desposited by fast-moving streams
conglomerate
what are sedimentary rocks
conglomerate and mudstone
which type of metamorphism occurs specifically in the heated zone around a pluton or other body of magma?
contact metamorphism
glassy igneous rocks form when the magma
cools so fast that mineral grains cannot crystallize and grow
a relatively small (under 1 km), summit depression on a volcano, marking a former eruptive vent, is a ?
crater
What term describes the complex, original stratification pattern seen in sandstones deposited in ancient sand dunes?
cross-bedding
the process whereby ions arrange themselves into orderly patterns during the cooling of a liquid is called
crystallization
Which tabular, discordant igneous rock body intrudes along a crack or fissure?
dike
a dike is a tabular, ______ type of pluton
discordant
a term used to describe intrusive bodies that cut across existing rock structures
discordant
the temple angkor wat in cambodia was built using laterite bricks. what is laterite
dried tropical rainforest soil
a sedimentary facies is the sedimentary rock's ____
environment of deposition
which of the following best describes bedded gypsum and halite
evaporates; chemical, sedimentary rocks
The sedimentary rocks salt and gypsum are deposited by what process?
evaporation
Large, dome-shaped structure, usually composed of granite, formed by sheeting.
exfoliation dome
igneous activity that occurs at the earth's surface
extrusive
term that describes rocks which contain high percentages of quartz and feldspar
felsic
An eruption in which lava is extruded from narrow fractures or cracks in the crust.
fissure eruption
what is not a common cementing agent for sandstines
fluorite
the linear arrangement of textural features often exhibited in metamorphic rocks.
foliation
the mechanical breakup f rock caused by the expansion of freezing water in cracks and crevices
frost wedging
what are the 4 most important physical processes of mechanical weathering
frost wedging, sheeting, thermal expansion, biological activity
Vents that emit only hot gases and vapors are called
fumaroles
Which of the following sedimentary features would typically be found in shales but not in sandstones
mud cracks
what mineral is a silicate
muscovite
which of the following minerals crystallize early in Bowen's reaction series
olivine
the micas, muscovite and biotite, both exhibit______ direction(s) of cleavage
one
Which variety of limestone consists mainly of sand-sized, mostly spherical grains of calcium carbonate precipitated in shallow, marine waters?
oolitic
Which form of chemical weathering specifically affects the iron contained in ferromagnesian, rock-forming, silicate minerals?
oxidation
what class of minerals form when the element O is bonded with a metal, as in the mineral hematite
oxides
which basaltic lava flow has a relatively smooth surface
pahoehoe
the rock from which a metamorphic rock was formed
parent rock
what term denotes the larger mineral grains in a porphyritic igneous rock
phenocryst
A mineral that is a good indicator of the metamorphic environment in which it formed. Used to distinguish different zones of regional metamorphism
index mineral
A mineral used to determine metamorphic grade is termed a(n) __________.
index mineral
igneous rock that formed below earth's surface
intrusive
which set of terms best describes an igneous rock in which you can clearly see the individual mineral grains comprising the rock
intrusive, phaneritic
what is the name given to an atom that gains or loses electrons in a chemical reaction
ion
the difference between ionic and covalent bonds is
ionic bonds are when atoms tare attracted electrostatistically due to positive and negative charges; covalent bonds are when atoms share the same electron(s)
red, brown, and yellow sandstones are cemented by oxides of ?
iron
Basalitc lava that solidifies in an underwater environment and is composed of numerous tube-like structures
pillow basalts
2 or more minerals having the same chemical composition but different crystalline structures
polymorphs
sandstone is a type of sedimentary rock that is classified based on its
predominant grain size
If you know the metamorphic facies of a metamorphic rock, what can you deduce about the rock?
pressure and temperature formation
A ________ texture refers to rocks composed mainly of mineral and volcanic fragments ejected during a violent volcanic eruption.
pyroclastic
what term describes fragmental volcanic material ejected during a volcanic eruption
pyroclastic
________ is a dangerous, fast moving, hot, turbulent cloud of volcanic gases and fine-sized, pyroclastic particles.
pyroclastic flow
Flint and jasper are microcrystalline forms of ________.
quartz
Under most weatheriqung conditions, which mineral component of granites and rhyolites would be most resistant to decomposition?
quartz
which mineral is composed of only silica
quartz
you are attempting to identify a mineral. you determine that it does indeed have cleavage; therefore, your mineral cannot possibly be:
quartz
associated with large-scale mountain climbing
regional metamorphism
which one of the following best describes volcanism in the cascade range, northwestern united states
related to plate subduction
the extrusive equivalent of granite is ______
rhyolite
what's the correct order of decreasing magma viscosity between: andesite, rhyolite, basalt
rhyolite, andesite, basalt
what igneous rock has a pyroclastic texture
rhyolitic tuff
Which of the following sedimentary features can each be used to determine paleocurrent directions
ripple marks and cross-bedding
which of the following does not correctly describe a mineral
it can be liquid or solid
which statement concerning mechanical weathering is not true
it involves a change in the mineral composition of the weathered material
a small igneous rock body emplaced at shallow depths by uplift and arching of the overlying, older strata
laccolith
another term for volcanic mudflow
lahar
the biggest dangers in composite type volanic eruption are
lahars (mudflows) and pyroclastic flows
magma that reaches earth's surface
lava
most common chemical sedimentary rock
limestone
The process of converting sediments to solid rock. (by cementation or compaction)
lithification
which response best represents the conditions of contact metamorphism
low pressures, shallow burial, and heat supplied by a nearby magma body
which of the following describes the light reflecting and transmission characteristics of a mineral
luster
term that describes basaltic rocks which contain high percentages of ferromagnesian minerals
mafic
what is the name given to molten rock below the earth's surface
magma
What two, metamorphic rocks are composed predominantly of single minerals?
marble and quartzite
What kind of weathering involves only a reduction in the sizes of bedrock and mineral particles?
mechanical
What is the dominant form of chemical bonding exhibited by minerals such as native gold, native copper and copper-rich sulfides?
metallic
Foliation in metamorphic rocks is mainly evident in the parallel alignment of certain mineral grains. What is the mineral?
mica
what strongly banded, metamorphic rocks show good evidence for having formed by partial melting?
migmatite
Felsic magmas/lavas are _____ viscous than basaltic magmas/lavas because they contain a _____ percentage of silica.
more...higher
small basaltic cones built during one, short, eruptive episode
scoria cones
if shale is such a common rock in the sedimentary rock world, why isn't it as prominently exposed at the surface as sandstone
shale crumbles easily, causing increased mechanical weathering, whereas sandstone resists weathering more effectively
oolitic limestone is most likely to form in what type of depositional environment
shallow, clear marine waters with vigorous current activity
A volcano composed of both lava flows and pyroclastic material; closely associated with convergent plate boundaries and subduction zones.
stratovolcano
what physical property denotes the color of a powdered mineral
streak
the 1991 pinatubo eruption in the philippines caused brilliantly colored sunrises and sunsets to be seen for the next few years. What caused this phenomenon
sulfur dioxide and other erupted gases formed aerosols in the stratosphere
how do you classify sedimentary rocks
texture and composition
lava flows are typically finer grained than intrusive igneous rocks. Why?
the extrusive magma cools quickly so the mineral grains do not have time to grow
which one of the following statements best describes erosion
the process by which weathered rock and mineral particles are removed from one area and transported elsewhere
what does bowen's reaction series describe
the temperatures at which different minerals crystallize out of a melt
what 2 factors speed up rates of chemical reaction and weathering in rocks and soils
warm temp. very moist
________ is the most abundant gaseous component dissolved in most magmas.
water
an inclusion of unmelted country rock in an ignous pluton
xenolith
mineral definition
in a mineral the constituent atoms are bonded in a regular, repetitive, internal structure
quartz is _____
-resistant to weathering and is an important component of sand in river beds and beaches -a main constituent of many igneous rocks -a main constituent of many sedimentary rocks -the most stable of all minerals at Earth's surface temp. and pressures
the ion at the center of a silicate tetrahedron is surrounded by
4 oxygen ions
in which setting would regional metamorphism be most likely
At great depths in the crust where two continents are colliding
what forms the best rock cleavage and why
Slate, because the grains are so small and so well intergrown that the rock is very strong and breaks along planes of fine micas.
One way in which sedimentary rocks are lithified. As material precipitates from water that percolates throughout the sediment, open spaces are filled and particles are joined into a solid mass
cementation
the weathering process by which the internal structure of a mineral is altered
chemical
what is a compact, microcrystalline sedimentary rock that was used by native americans to fashion projectile points (arrowheads), knives, scrappers, etc.
chert
a rather small volcano built primarily of ejected lava fragments
cinder cone
What mineral group forms by the breakdown and weathering of rock-forming silicate minerals and are important constituents of soils?
clay
a mineral property that can be observed without using a test is
cleavage
________ is composed mainly of lithified, organic debris that accumulated in ancient, heavily forested swamps?
coal
Sandstones are lithified mainly by cementation. What is the major process involved in the lithification of shales?
compaction
what is typically composed of alternating layers of lava and pyroclastic material
composite volcano
large, fairly steep-sided cones composed of lavas and pyroclastic layers
composite volcanoes
the volcanoes of southwestern alaska and the aleutian islands
composite volcanoes
what rock is likely to have the most quartz in it and why
granite, because it is an intrusive rock that formed from the cooling of relatively high silica magma
the matrix of smaller crystals within an igneous rock that has porphyritic texture
groundmass
Which evaporite sedimentary rock, composed of calcium sulfate, is an important component of plasters and wallboard?
gypsum
Moh's scale is a relative measure of which physical property of minerals?
hardness
what classes of rocks can be metamorphosed
igneous, sedimentary, and metamorphic
a broad gently sloping volcano built from fluid basaltic lavas
shield volcano
massive, gently sloping volcanoes built of successive, basaltic lava flows
shield volcano
the big volcanoes of hawaii
shield volcano
3 main types of volcanoes and 2 characteristics of each
shield, composite, cinder cone Shield- shape of a shield, runny lava composite- alternating layers, most violent type cinder cone- built from ejected lava fragments, lava flow comes out of the side
which are the most abundant minerals in Earth's crust and mantle
silicates
A structure composed of four oxygen atoms surrounding a silicon atom that constitutes the basic building block of silicate minerals.
silicon-oxygen tetrehedron
list rocks in increasing grade of metamorphism
slate, phyllite, schist, gniess
Which property of sediment describes the range of different grain sizes in a detrital sedimentary rock?
sorting
how do the electrons behave in a mineral with metallic bonding
they can move relatively easily from atom to atom inside the mineral
