Petrology Flashcards
It is the most abundant mineral in the earth’s crust compromising 39% of earth’s crust
a. clay
b. plagioclase feldspar
c. pyroxene
d. quartz
b. plagioclase feldspar
It is one of the most abundant mineral in the earth’s crust compromising 12% of earth’s crust
a. nonsilicates
b. mica
c. amphibole
d. alkali feldspar
d. alkali feldspar
SiO2 content of ultramafic mineral
a. >66 wt. %
b. 52 - 66 wt. %
c. <45 wt. %
d. 45 - 52 wt. %
c. <45 wt. %
SiO2 content of mafic mineral
a. >66 wt. %
b. 52 - 66 wt. %
c. <45 wt. %
d. 45 - 52 wt. %
d. 45 - 52 wt. %
SiO2 content of intermediate mineral
a. >66 wt. %
b. 52 - 66 wt. %
c. <45 wt. %
d. 45 - 52 wt. %
b. 52 - 66 wt. %
SiO2 content of felsic mineral
a. >66 wt. %
b. 52 - 66 wt. %
c. <45 wt. %
d. 45 - 52 wt. %
a. >66 wt. %
Igneous rocks with this texture usually occur from the rapid crystallization of lava.
a. aphanitic
b. pegmatitic
c. glassy
a. aphanitic
This texture forms when lava from a volcanic eruption cools very rapidly such that no crystallization occurs.
a. aphanitic
b. pegmatitic
c. glassy
c. glassy
This type of texture id formed when magma cools and some minerals increase in size extensively.
a. aphanitic
b. pegmatitic
c. glassy
b. pegmatitic
form when violent volcanic eruptions throw the lava into the atmosphere creating fragmental and glassy materials.
a. porphyritic
b. phaneritic
c. pyroclastic
c. pyroclastic
This texture is seen in plutonic igneous rocks, which underwent slow crystallization underneath the surface of the earth.
a. porphyritic
b. phaneritic
c. pyroclastic
b. phaneritic
This texture is caused by the rapid change of conditions as the magma continues to cool down. The minerals that had been created earlier, by the slow cooling magma, will posses’ large crystals.
a. porphyritic
b. phaneritic
c. pyroclastic
a. porphyritic
Rocks composed mostly of pyroxene, calcium-rich plagioclase, and minor amounts of olivine.
a. ultramafic
b. mafic
c. intermediate
d. felsic
b. mafic
Their low silica and gas contents make them very fluid; i.e., they have a low viscosity, or resistance to flow
a. ultramafic
b. mafic
c. intermediate
d. felsic
a. ultramafic
Rocks composed mostly of biotite, muscovite, sodium-rich plagioclase feldspars, potassium feldspars, and quartz
a. ultramafic
b. mafic
c. intermediate
d. felsic
d. felsic
Rocks composed mostly of hornblende and plagioclase feldspars
a. ultramafic
b. mafic
c. intermediate
d. felsic
c. intermediate
Formed at spreading ridges on the ocean floor when two oceanic plates are separating
a. cinders
b. lava
c. pumice
d. tephra
e. pillow basalt
e. pillow basalt
Molten rock that flows out of a volcano during eruption
a. cinders
b. lava
c. pumice
d. tephra
e. pillow basalt
b. lava
Igneous rocks that have been airborne for a period of time before settling to the earth
a. cinders
b. lava
c. pumice
d. tephra
e. pillow basalt
d. tephra
A volcanic glass that is associated with violent volcanic eruptions.
a. cinders
b. lava
c. pumice
d. tephra
e. pillow basalt
c. pumice
Similar to pumice but usually made of iron-rich minerals found in basalt lava.
a. cinders
b. lava
c. pumice
d. tephra
e. pillow basalt
a. cinders
P increases due to the weight of the overburden and T also increases due to the geothermal gradient.
a. faultzone and impact metamorphism
b. burial metamorphism
c. regional metamorphism
d. ocean floor metamorphism
b. burial metamorphism
Interaction of heated seawater with newly-created oceanic crust at mid-ocean ridges.
a. faultzone and impact metamorphism
b. burial metamorphism
c. regional metamorphism
d. ocean floor metamorphism
d. ocean floor metamorphism
Rock in the deep portions of faults undergoes dynamic metamorphism and creates a fine grained metamorphic rock called a mylonite.
a. faultzone and impact metamorphism
b. burial metamorphism
c. orogenic metamorphism
d. ocean floor metamorphism
a. faultzone and impact metamorphism
occurs during the development of island arcs, continental arcs, and continental collision zones. It is a dynamo-thermal type of metamorphism.
a. faultzone and impact metamorphism
b. burial metamorphism
c. orogenic metamorphism
d. ocean floor metamorphism
c. orogenic metamorphism
rocks undergo metamorphic reactions due to heating (little or no pressure change). when a hot igneous intrusion (magma) comes into contact with cold country rock, it creates a metamorphic aureole
a. hydrothermal metamorphism
b. contact metamorphism
c. regional metamorphism
b. contact metamorphism
Characterized by involvement of hot aqueous fluid which passes through the metamorphosing rock that leads to changes in its chemical composition
a. hydrothermal metamorphism
b. contact metamorphism
c. regional metamorphism
a. hydrothermal metamorphism
Complex composition, many different kinds of minerals. Has many new minerals produced with a change in T/P
a. texture
b. foliated
c. equant mineral
d. non-foliated
b. foliated
Simple composition with no new minerals form with a change in T/P
a. texture
b. foliated
c. equant mineral
d. non-foliated
d. non-foliated
Started out originally with clay minerals and as a result of metamorphism, alumna-rich minerals form.
a. calcareous
b. mafic
c. pelitic
d. quartzo-feldspathic
c. pelitic
Minerals like biotite, hornblende and plagioclase form during metamorphism and commonly produce amphibolites.
a. calcareous
b. mafic
c. pelitic
d. quartzo-feldspathic
b. mafic
Usually derived from limestones or dolostones, and thus contain an abundance of Calcite
a. calcareous
b. mafic
c. pelitic
d. quartzo-feldspathic
a. calcareous
Protoliths are usually granites, rhyolites, or arkose sandstone and metamorphism results in gneisses
a. calcareous
b. mafic
c. pelitic
d. quartzo-feldspathic
d. quartzo-feldspathic
Preferred orientation of these sheet silicates causes the rock to easily break along the planes parallel to the sheet silicates
a. schist
b. phyllite
c. slate
d. pophyroblasts
c. slate
The rock developed a near planar foliation caused by the preferred orientation of sheet silicates
a. schist
b. phyllite
c. slate
d. pophyroblasts
a. schist
The clay minerals have recrystallized into tiny micas which reflect a glossy luster.
a. schist
b. phyllite
c. slate
d. pophyroblasts
b. phyllite
When non-mica minerals (quartz, feldspars, kyanite, garnet, staurolite, and sillimanite) occur with a grain size greater than the rest of the rock, they are called _________.
a. schist
b. phyllite
c. slate
d. pophyroblasts
d. pophyroblasts
These dark colored minerals tend to become segregated in distinct bands through the rock, giving the rock a __________.
a. migmatites
b. granulite
c. gneissic banding
d. gneiss
c. gneissic banding
If the temperature reaches the solidus temperature, the rock may begin to melt and start to co-mingle with the solids.
a. migmatites
b. granulite
c. gneissic banding
d. gneiss
a. migmatites
At the highest grades of metamorphism, all of the hydrous minerals and sheet silicates become unstable and thus there are few minerals present that would show a preferred orientation resulting a ___________.
a. migmatites
b. granulite
c. gneissic banding
d. gneiss
b. granulite
As metamorphic grade increases, the sheet silicates become unstable and dark colored minerals like hornblende and pyroxene start to grow.
a. migmatites
b. granulite
c. gneissic banding
d. gneiss
d. gneiss
limestone or dolostone made up only if calcite or dolomite will metamorphose to a _______.
a. amphibolite
b. hornfels
c. quartzite
d. marble
d. marble
Very fine- grained rocks that usually form as a result from magma intruding into fine grained igneous rocks or shales
a. amphibolite
b. hornfels
c. quartzite
d. marble
b. hornfels
Dark-colored rocks with amphibole as their major mineral.
a. amphibolite
b. hornfels
c. quartzite
d. marble
a. amphibolite
