Question
A. Partial melting of regions within the oceanic crust
B. partial melting of regions with the athenosphere
C. complete melting of regions within the athenosphere
D. complete melting of regions with the continental crust
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Question
A. Mt. Tambora, indonesia
B. Krakatau, indonesia
C. Mt. Toba, indonesia
D. none of the above
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Geology 111 quiz # 4
quiz 4 for geology 111 at umw
Question | Answer |
---|---|
most mafic magmas result from A. Partial melting of regions within the oceanic crust B. partial melting of regions with the athenosphere C. complete melting of regions within the athenosphere D. complete melting of regions with the continental crust | partial melting of regions with the athenosphere |
which of the following eruptions was the largest (based on volcanic explosivity index) A. Mt. Tambora, indonesia B. Krakatau, indonesia C. Mt. Toba, indonesia D. none of the above | Mt. Toba, indonesia |
if a source rock is partially melted, the partial melt will be ___ the source rock. A. more mafic than B. more felsic than C. the same composition as D. none of the above | more felsic than |
a fairly recent, significant eruption of Mt. St. Helens in washington state A. occurred in 1980 B. had very damaging Lahars associated with it C. exploded laterally out the side of the mountain D. all of the above | exploded laterally out the side of the mountain |
which of the following is false A. many magmas probably ascend through a process called stopping B. magmas ascend because they are boyant C. magmas may undergo fractional crystallization as they ascend D. magmas may assimilate xenoliths as they ascend | none of they above |
which of the following provide evidence for eruptions under water A.ropy basaltic lava B. columnar joints in basalt C. pillow basalt D. none of the above | pillow basalts |
most felsic melts intrude or erupt A. at mid-ocean ridges B. at subduction zone C. at oceanic hotspots D. none of the above | at subduction zone |
which type of tephra will likely travel the greatest distance from the main vent A. lapilli B. Boms C. ash D. all will travel equal distances | ash |
Which of the following magma compositions has the highest silica content A. Felsic B. intermediate C. mafic D. ultramafic | Felsic |
Which of the following minerals typically crystallize out of out of a mafic magma at the highest temperature A. olivine B. amphibole C. quartz D. sodium plagioclase | Olivine |
which of the following is true A. in general, granite and rhyolite are chemically equivalent rock types B. felsic to intermideate magmas usually contain more volatiles than mafic magmas C. mafic magmas are lower in viscosity than felsic magmas D. all | all of the above |
which of the following is true regarding Bowen's reaction series and real magmas? A. most magmas began at the 'top' and make it all the way to bottom of the series B. magmas that do make it to the bottom of the series will only be about 10% of the volum | magmas that do make it to the bottom of the series will only be about 10% of the volume |
Which of the following textures is not likely to be intrusive A. porphyritic-aphanitic B. phaneritic C. pegmatitic D. all are inrusive | porphyritic-aphanitic |
Which of the following would not be typical of a shield volcano? A. small in diameter B. made up mafic lavas C. has a low angle, gentle slope D. all are typical | small in diameter |
a pyroclastic ash flow A. is synonymous with a 'nuee ardente' B. is commonly associated with composite C. can travel at >300 miles per hour D. was witnessed in 1902 on the island of Martinique (in the carribean) E. all of the above | all of the above |
which of the following is false regaurding Batholiths A. the form cores of large mountains ranges, such as the sierra nevada B. they consist of numerous felsic to intermediate intrusions C. Bowen correctly proposed the most results from fractional crys | Bowen correctly proposed the most results from fractional crystallization |
which of the following is False A. the eruption of Mt. Tambora in 1815 led to the "year without summer" 1816 B. Mt. St. Helens is considered the most dangerous volcano in the cascade range C. The eruption of Mt. Toba ~ 75,000 years... D. all of the ab | Mt. St. Helens is considered the most dangerous volcano in the cascade range |
which of the following has fissure eruptions that produced flood basalts? A. the columbia river region of NW USA B. India C. Iceland D. All of the above | All of the above |
Yellowstone (USA) is the site of A. an active continental hotspot B. geologically recent supervolcnaoe eruptions C. eruptions that seem to occur ever 600,000yrs d. all of the above | All of the above |