Metamorphic Rock and Resources, Metamorphic Study Guide
T
Calcite is the main mineral constituent of the sedimentary rock limestone and of the metamorphic rock marble.
T
Every metamorphic rock has a parent rock from which it formed.
hydrothermal veins
The minerals gold, silver and mercury are often found in ________. a. alteration of limestone b. hydrothermal veins c. disseminated deposits d. the lower parts of an intrusion
slate
Which low-grade metamorphic rock composed of extremely fine-sized mica and other mineral grains, typically exhibits well-developed rock cleavage? a. slate b. quartzite c. hornfels d. schist
contact
Which type of metamorphism occurs specifically in the heated zone around a pluton or other body of magma?
marble
nonfoliated metamorphic rock consisting of mostly calcite a. hornfels b. marble c. gneiss d. phyllite
coal forms in swamps and oil/gas form in marine environments
A major difference between coal and oil/gas is ________. a. coal forms in deep marine environments and oil/gas form in shallow marine environments b. coal forms in shallow marine environments and oil/gas form in swamps c. coal forms in swamps and oil/gas form in marine environments d. coal forms on land from dinosaurs and oil/gas form from ancient fish
by regional metamorphism of volcanic rocks such as andesite and basalt
Amphibolite is a foliated metamorphic rock composed principally of hornblende and plagioclase. How does it form? a. by the impact of an asteroid on interbedded sandstone and shale b. by gouging and crushing of limestone along a fault c. by contact metamorphism of sandstone along the contact with granitic batholith d. by regional metamorphism of volcanic rocks such as andesite and basalt
F
At high pressures and elevated temperatures of regional metamorphism, silicate rocks are more resistant to flowage and deformation than at low temperatures and pressures.
fluids that readily change to gases at surface conditions
Chemically active fluids are ________. a. fluids that readily change to gases at surface conditions b. fluids that contain large quantities of oxygen which reacts with most minerals to form new minerals during metamorphism c. more basic than regular fluids d. more acidic than regular fluids
forces are applied equally in all directions
Confining pressure is where ________. a. pressure is applied in a cubic region b. forces are applied equally in all directions c. pressure is parallel to the bedding planes d. forces are applied from the top and the bottom equally
T
During metamorphism, the material undergoing deformation remains a solid.
aid in the movement of dissolved silicate constituents and facilitate growth of the minerals grains
During metamorphism, what is the major effect of chemically active fluids? a. increase the pressures in deeply buried, regional-metamorphic zones b. prevent partial melting so solid rocks can undergo very high temperature regional metamorphism c. facilitate the formation of schistosity and gneissic banding in hornfels and slates d. aid in the movement of dissolved silicate constituents and facilitate growth of the minerals grains
F
Foliated metamorphic rocks are composed largely of equidimensional grains of minerals such as quartz and calcite.
the pre-metamorphic rock was a shale or mudstone containing organic matter
Granite is identified in a particular schist. Which one of the following conclusions is justified? a. the graphite lubricated shearing movements along a fault causing a schist to form b. the rock also contain diamonds; both are crystalline forms of the element carbon c. the pre-metamorphic rock was a shale or mudstone containing organic matter d. the schist formed from a quartz rich sedimentary limestone
T
High-grade regional metamorphism produces significant and recognizable changes in the textures and mineral compositions of rocks.
100°C
In an area where the temperature increase with depth averages 20°C per kilometer, the temperature at a depth of 5 kilometers would be ________. a. 20°C b. 50°C c. 100°C d. 200°C
T
In general, recrystallization tends to produce larger crystals.
permeability and porosity
In order to get oil and gas in sufficient quantities to make a profit, an oil trap must exist with ________. a. lateral continuity that allows fluids to migrate b. shale with little or no sulfur c. no fractures or structure d. permeability and porosity
at great depths in the crust where two continents are colliding
In which setting would regional metamorphism be most likely? a. at great depths in the crust where two continents are colliding b. at shallow depths below a oceanic ridge or rift zone c. at shallow depths along major transform faults in the continental crust d. at shallow depths beneath the seafloor where water pressures are immense
chromite
Magma differentiation tends to produce deposits of ________ near the base of intrusions.
F
Metamorphism can affect only sedimentary rocks.
experiences conditions that are significantly different from those that formed the rock
Metamorphism occurs when a rock ________. a. experiences conditions that include high pressures b. experiences conditions that include high temperatures c. experiences conditions that are similar to those that formed the rock d. experiences conditions that are significantly different from those that formed the rock
F
Most of the energy and mineral resources we use are renewable.
all of the above
Mountain building causes metamorphism because _____________. a. mountains are heavy and they push shallow, cool rocks to depths where they get heated b. mountains form by the gradual buildup of material that comes from other areas and this can produce an uneven pressure on rocks c. mountains are heavy and they compress the rocks under them. d. all of the above
direction perpendicular to the compressional stress
Recrystallization during metamorphism causes grains to grow longer in the ________. a. direction of maximum differential stress b. direction perpendicular to the compressional stress c. horizontal direction d. direction parallel to the compressional stress
T
Slate and schist are both derived from metamorphism of shales and mudstones.
denser
Slate is ________ than shale. a. darker b. more planar c. denser d. lighter
F
Slate is associated with high-grade metamorphism.
marble
The common rock produced by the metamorphism of limestone is ________. a. marble b. phyllite c. mica schist d. gneiss
slate
The low grade metamorphism of shale produces ________. a. schist b. gneiss c. marble d. slate
driving chemical reactions that lead to recrystallization
The major role of thermal energy (heat) in metamorphism is ________. a. driving chemical reactions that lead to recrystallization b. providing energy for the physical changes that occur during metamorphism c. increasing the processes of dissolution and flow of different minerals d. reducing the strength of rocks so that stress can be an effective agent of change
heat
The most important agent(s) of metamorphism, according to your text, is (are) ________. a. confining pressure b. heat c. differential stress d. chemically active fluids
heat
The primary agent of contact metamorphism is ________. a. folding b. strain c. stress d. heat
26.0 km
The quartz in granite begins to melt at 650°C, so if we find a migmatite where quartz has melted in a granitic rock and we know the temperature in the region increased with depth by about 25°C per kilometer, we could estimate the depth that the rock had been at to be about ________. a. 12.5 km b. 18.0 km c. 23.5 km d. 26.0 km
the final crystallizing parts of magma
The very large crystals of quartz, feldspar, and muscovite found in pegmatites form from ________. a. the middle crystallizing parts of a magma b. the final crystallizing parts of a magma c. the early crystallizing parts of a magma d. all of the above
phyllite
What foliated, metamorphic rock is texturally intermediate between slate and schist? a. phylitte b. quartzite c. gneiss d. fault breccia
heat from a nearby magma body
What is the major source of heat for contact metamorphism? a. heat from a nearby magma body b. heat from grinding and shearing on faults c. heat from the spontaneous decomposition of micas and feldspars d. deep burial and heat from the Earth's interior
calcite grains grow larger and increase in size
What major change occurs during metamorphism of limestone to marble? a. calcite grains grow larger and increase in size b. limestone grains react to form quartz and feldspar c. clays crystallize to micas, forming a highly foliated mica-rich rock d. calcite grains are dissolved away leaving only marble crystals
micas
What platy, parallel, mineral grains are the most visual aspect of foliated metamorphic rocks? a. feldspars b. micas c. carbonates d. quartz
marble and quartzite
What two, metamorphic rocks are composed predominately of single minerals? a. mica schist and granitic gneiss b. garnet schist and hornfels c. marble and quartzite d. fault breccia and graphitic schist
schistosity
What type of foliation results from the parallel alignment of abundant, coarse-grained mica flakes in a metamorphic rock? a. gneissic banding b. phyllitic structure c. slaty cleavage d. schistosity
shale or mudstone
What type of sedimentary rock is typically metamorphosed to form slates or phyllites?
foliated
When a metamorphic rock exhibits a layered or banded appearance, it is said to exhibit a(n) ________ texture.
flatten and elongate
When rocks experience high temperatures and differential stresses deep in the Earth, their grains tend to ________. a. break in small fragments like a piece of fine crystal b. flatten and elongate c. fracture along planes of weakness d. form new minerals
gneiss
Which metamorphic rock or rocks exhibit alternating layers or bands of different light-and-dark-colored minerals?
marble
Which metamorphic rock, widely used for monuments or buildings will deteriorate significantly in contact with acid rains?
pressures are fairly low, the rock is in the upper part of the crust, and heat is supplied from a near by magma body
Which of the following best describes the condition of contact metamorphism? a. pressures are fairly low, the rock is in the upper part of the crust, and heat is supplied from a near by magma body b. pressures are very high, the rock is deeply buried, and temperatures are raised by the Earth's internal heat c. depths are fairly shallow but temperatures and pressures are so high that the rock begins to partially melt d. heat is generated by shearing and mechanical movements along faults
all of the above
Which of the following changes may occur during metamorphism? a. the rock becomes more compact b. certain minerals may recrystallize c. crystals may grow larger d. all of the above
schist
Which of the following forms at the highest grade of regional metamorphism? a. phylitte b. slate c. hornfels d. schist
bedding planes and strata
Which of the following is not an example of a foliation in a metamorphic rock? a. parallel alignment of flattened pebbles b. bedding planes and strata c. parallel alignment of platy or flat minerals d. compositional banding
slate, phyllite, schist
Which of the following lists the rock in order of increasing grain size and increasing grade of metamorphism? a. slate, schist, phyllite b. slate, phyllite, schist c. schist, slate, phyllite d. phyllite, slate, schist
slate, phyllite, schist
Which of the following lists the rocks in the order of increasing grain size and increasing grade of metamorphism? a. schist, slate, phyllite b. slate, phyllite, schist c. phyllite, slate, schist d. slate, schist, phyllite
marble
Which of the following metamorphic rocks can be used to neutralize acidic mine waters? a. quartzite b. marble c. granitic gneiss d. slate
has abundant, coarse-grained mica
Which of the following statements concerning slate is not true? a. has abundant, coarse-grained mica b. rock cleavage is common c. sedimentary features may be visible d. forms from shales and mudstones
fault movements at shallow depths
Which of the following would exhibit sheared and mechanically fragmented rocks? a. intense compression in a deep-seated, regional metamorphic zone b. heating of shales and mudstones near a pluton c. fault movements at shallow depths d. regional metamorphism of pyroclastic volcanic rocks
quartzite
Word Analysis a. phyllite b. quartzite c. slate d. schist
melting
Word Analysis a. pressure b. recrystallization c. melting d. chemical fluids
melting
Word Analysis confining pressure differential stress melting chemical fluids
hornfels
________ is a nonfoliated rock formed by contact metamorphism of shale or mudstone a. schist b. hornfels c. marble d. gneiss
gneiss
________ is composed of alternating bands of light and dark silicate minerals. a. marble b. phyllite c. gneiss d. mica schist
granitic gneiss
_________ is characterized by the segregation of light and dark colored minerals into thin layers or bands a. slate b. garnet hornfels c. quartzite d. granitic gneiss
marble
__________ forms from the metamorphism of limestone or dolostone a. marble b. quartzite c. amphibolite d. migmatite
foliation
__________ is a strong parallel alignment of coarse mica flakes and/or of different mineral bands in a metamorphic rock a. marbleizing b. rock cleavage c. stress streaking d. foliation
quartzite
____________ is typically formed by metamorphism of a sandstone a. quartzite b. slate c. marble d. amphibolite
gneiss
coarse-grained metamorphic rock with alternating bands or stringers of light and dark minerals a. hornfels b. marble c. gneiss d. phyllite
schistose foliation
composed of larger minerals which are visible to the unaided eye, platy minerals tend to dominate
phyllitic foliation
composed of platy minerals that are slightly larger than those found in slaty cleavage, generally still to small to see with the unaided eye; large size gives the foliation a slightly shiny appearance
slaty cleavage
composed of platy minerals that are too small to see, typically split along parallel, planar surfaces
gneiss banding
easiest to recognize; composed of alternating bands of dark and light minerals
phyllite
foliated fine-grained metamorphic rock formed from mudstone and shale a. hornfels b. marble c. gneiss d. phyllite
hornfels
forms by contact metamorphism of mudstones and shales a. hornfels b. marble c. gneiss d. phyllite