Chapter 5

Question 1

Extrusive igneous rocks

Answer 1

lava and other volcanic products that have been forced onto Earth’s surface

Question 2

Intrusive igneous rocks

Answer 2

magma that has been crystallized within the crust without being exposed to the cool temperatures of the atmosphere and shallow crust

Question 3

Plutonic

Answer 3

intrusive rocks that occur at great depths within the crust or mantle

Question 4

Partial melting

Answer 4

occurs when some minerals melt while others remain solid

Question 5

Bowen’s reaction series

Answer 5

process in which magma evolves to a new chemical state that is relatively enriched in silica as a result of fractionally crystallizing ions, magnesium, and calcium-rich compounds

Question 6

Mafic

Answer 6

a contraction of magnesium and feric

Question 7

Felsic

Answer 7

a contraction of feldspar and silica

Question 8

Aphanitic

Answer 8

fine grained rocks

Question 9

Phaneritic

Answer 9

coarse grained intrusive rocks

Question 10

Porphyritic

Answer 10

a rock with two distinct textures mixed with large and small grains

Question 11

Magma differentiation

Answer 11

as magma migrates into and through the crust, its composition changes

Question 12

Dikes

Answer 12

granite is an active intruder of continental crust, forming dikes (arms of intrusive rock) that cut across other rocks in the crust

Question 13

Periodite

Answer 13

the only ultra mafic igneous rock composed of the ferromagnesian silicate mineral olivine and proxyene

Question 14

Batholith

Answer 14

granites that solidify in great magma chambers and form large intrusive structure

Question 15

Plutons

Answer 15

occur from individual bodies that intrude localized parts of the crust to massive units that form the cores of mountain ranges

Question 16

Sill

Answer 16

magma intrudes horizontally parallel to those strata taking shape as a sill