Question 1

What was the initial composition of the melt that the Palisades sill formed from?

Accepted Answer

A) mafic 
B) intermediate 
C) felsic 
D) ultramafic 
A) mafic 
B) intermediate 
C) felsic 
D) ultramafic A

Question 2

Andesite is an example of a(n)__________ igneous rock.

Accepted Answer

A) felsic 
B) intermediate 
C) mafic 
D) ultramafic 
A) felsic 
B) intermediate 
C) mafic 
D) ultramafic B

Question 3

How do we know that the initial composition of the melt that the Palisades sill was mafic?

Accepted Answer

A) There is basalt in the contact zone where the melt chilled. 
B) The sill material contains feldspar. 
C) The sill material contains pyroxene. 
D) The magma in sill underwent fractional crystallization. 
A) There is basalt in the contact zone where the melt chilled. 
B) The sill material contains feldspar. 
C) The sill material contains pyroxene. 
D) The magma in sill underwent fractional crystallization. A

Question 4

What geologist is credited with figuring out the origin of granite?

Accepted Answer

A) N)L.Bowen 
B) Charles Darwin 
C) James Hutton 
D) Alfred Wegener 
A) N)L.Bowen 
B) Charles Darwin 
C) James Hutton 
D) Alfred Wegener

Question 5

How much partial melting of upper-mantle peridotite is needed to generate some basaltic melt?

Accepted Answer

A) 1% to 2% volume 
B) 10% to 15% volume 
C) 20% to 30% volume 
D) more than 50% 
A) 1% to 2% volume 
B) 10% to 15% volume 
C) 20% to 30% volume 
D) more than 50%

Question 6

The main difference between intrusive and extrusive igneous rocks is

Accepted Answer

A) silica composition. 
B) where they solidify. 
C) viscosity. 
D) intrusive rocks are more felsic. 
A) silica composition. 
B) where they solidify. 
C) viscosity. 
D) intrusive rocks are more felsic.

Question 7

What type of rock makes up most of the Hawaiian Islands?

Accepted Answer

A) andesite 
B) basalt 
C) granite 
D) peridotite 
A) andesite 
B) basalt 
C) granite 
D) peridotite

Question 8

What is the correct sequence of rocks (bottom to top)of an ophiolite suite? 1 = deep-sea sediment,2 = gabbro,3 = peridotite,4 = pillow lava,5 = sheeted dike complex

Accepted Answer

A) 1,2,3,4,5 
B) 1,3,5,2,4 
C) 1,4,5,2,3 
D) 5,4,3,2,1 
A) 1,2,3,4,5 
B) 1,3,5,2,4 
C) 1,4,5,2,3 
D) 5,4,3,2,1

Question 9

In order to rise through the crust,magmas make space by all of the following processes,except

Accepted Answer

A) breaking off large blocks of rock that sink into the magma chamber. 
B) following preexisting networks of caverns. 
C) melting surrounding rocks. 
D) wedging open the overlying rock. 
A) breaking off large blocks of rock that sink into the magma chamber. 
B) following preexisting networks of caverns. 
C) melting surrounding rocks. 
D) wedging open the overlying rock.

Question 10

Geologists studying magmatic differentiation had difficulty explaining the unexpectedly large volume of

Accepted Answer

A) andesite. 
B) gabbro. 
C) diorite. 
D) granite. 
A) andesite. 
B) gabbro. 
C) diorite. 
D) granite.

Question 11

How can a sill be distinguished from a lava flow?

Accepted Answer

A) A sill is generally finer-grained than a lava flow. 
B) Rocks above and below a sill will show evidence of heating,but only the rocks below a lava flow will show evidence of heating. 
C) Sills generally have vesicles; lava flows generally do not have vesicles. 
D) Sills generally overlie soils; lava flows do not generally overlie soils. 
A) A sill is generally finer-grained than a lava flow. 
B) Rocks above and below a sill will show evidence of heating,but only the rocks below a lava flow will show evidence of heating. 
C) Sills generally have vesicles; lava flows generally do not have vesicles. 
D) Sills generally overlie soils; lava flows do not generally overlie soils.

Question 12

Approximately how much basalt forms annually at mid-ocean ridges?

Accepted Answer

A) 0.1 km3 
B) 1 km3 
C) 20 km3 
D) 100 km3 
A) 0.1 km3 
B) 1 km3 
C) 20 km3 
D) 100 km3

Question 13

Typically,__________ volume percent partial melting of upper-mantle peridotite occurs to generate basaltic magmas beneath mid-ocean ridges.

Accepted Answer

A) 1 to 2 
B) 10 to 15 
C) 15 to 20 
D) 30 to 50 
A) 1 to 2 
B) 10 to 15 
C) 15 to 20 
D) 30 to 50

Question 14

Magmatic stoping is the term used to describe how magmas

Accepted Answer

A) differentiate. 
B) form. 
C) move through the crust. 
D) solidify. 
A) differentiate. 
B) form. 
C) move through the crust. 
D) solidify.

Question 15

Which of the following magma compositions will be produced by partial melting of the upper mantle?

Accepted Answer

A) felsic 
B) intermediate 
C) mafic 
D) ultramafic 
A) felsic 
B) intermediate 
C) mafic 
D) ultramafic

Question 16

Which of the following rock types are best mined for rare elements,such as lithium and beryllium?

Accepted Answer

A) dacites 
B) gabbros 
C) pegmatites 
D) tuffs 
A) dacites 
B) gabbros 
C) pegmatites 
D) tuffs

Question 17

Which of the following igneous rocks has the lowest silica content?

Accepted Answer

A) felsic 
B) intermediate 
C) mafic 
D) ultramafic 
A) felsic 
B) intermediate 
C) mafic 
D) ultramafic

Question 18

Ultramafic lava flows were more common in the early history of the earth than now because

Accepted Answer

A) ultramafic melts were more common in the past. 
B) Earth's crust was hotter in the past. 
C) Earth's mantle was cooler in the past. 
D) plate tectonics had not been initiated. 
A) ultramafic melts were more common in the past. 
B) Earth's crust was hotter in the past. 
C) Earth's mantle was cooler in the past. 
D) plate tectonics had not been initiated.

Question 19

What type of magma forms when the upper mantle undergoes decompression melting?

Accepted Answer

A) felsic 
B) intermediate 
C) mafic 
D) ultramafic 
A) felsic 
B) intermediate 
C) mafic 
D) ultramafic

Question 20

When generating granite from basalt via crystal fractionation we would need approximately ____ of basalt for every km of granite produced.

Accepted Answer

A) ½ cubic km 
B) 1 cubic km 
C) 5 cubic km 
D) 10 cubic km 
A) ½ cubic km 
B) 1 cubic km 
C) 5 cubic km 
D) 10 cubic km

Exam 4: Igneous Rocks: Solids From Melts

What was the initial composition of the melt that the Palisades sill formed from?

Andesite is an example of a(n)__________ igneous rock.

How do we know that the initial composition of the melt that the Palisades sill was mafic?

What geologist is credited with figuring out the origin of granite?

How much partial melting of upper-mantle peridotite is needed to generate some basaltic melt?

The main difference between intrusive and extrusive igneous rocks is

What type of rock makes up most of the Hawaiian Islands?

What is the correct sequence of rocks (bottom to top)of an ophiolite suite? 1 = deep-sea sediment,2 = gabbro,3 = peridotite,4 = pillow lava,5 = sheeted dike complex

In order to rise through the crust,magmas make space by all of the following processes,except

Geologists studying magmatic differentiation had difficulty explaining the unexpectedly large volume of

How can a sill be distinguished from a lava flow?

Approximately how much basalt forms annually at mid-ocean ridges?

Typically,__________ volume percent partial melting of upper-mantle peridotite occurs to generate basaltic magmas beneath mid-ocean ridges.

Magmatic stoping is the term used to describe how magmas

Which of the following magma compositions will be produced by partial melting of the upper mantle?

Which of the following rock types are best mined for rare elements,such as lithium and beryllium?

Which of the following igneous rocks has the lowest silica content?

Ultramafic lava flows were more common in the early history of the earth than now because

What type of magma forms when the upper mantle undergoes decompression melting?

When generating granite from basalt via crystal fractionation we would need approximately ____ of basalt for every km of granite produced.

The Earth System

Plate Tectonics: The Unifying Theory

Earth Materials: Minerals and Rocks

Sedimentation: Rocks Formed by Surface Processes

Metamorphism: Alteration of Rocks by Temperature and Pressure

Deformation: Modification of Rocks by Folding and Fracturing

Clocks in Rocks: Timing the Geologic Period

Early History of the Terrestrial Planets

History of the Continents

Geobiology: Life Interacts With Earth

Volcanoes

Earthquakes

Exploring Earths Interior

The Climate System

Weathering,erosion,and Mass Wasting: Interactions Between the Climate and Plate Tectonic Systems

The Hydrologic Cycle and Groundwater

Stream Transport: From Mountains to Oceans

Winds and Deserts

Coastlines and Ocean Basins

Glaciers: the Work of Ice

Landscapes: Tectonic and Climate Interaction

The Human Impact of Earths Environment

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