Fool's Gold (Pyrite), like gold, is soft and malleable. T or F
False
The earth is uniform is composition (all the same stuff) from the center to the surface. T or F
False
The minerals in igneous rocks all crystallize out of the melt at the same time and temperature. T or F
False
Minerals are always crystalline solids. T or F
True
Basalt is the most common intrusive igneous rock. T or F
False
The "discontinuous series" of Bowen's Reaction Series consists of dark colored minerals. T or F
True
Rubies and sapphires are composed of exactly the same chemicals. T or F
True
Present day geologic process are very different than those of the distant past. T or F
False
The texture of igneous rocks is determined by the cooling rate of the magma. T or F
True
There are more oxygen atoms in the crust of the earth than in the atmosphere. T or F
True
The ocean crust is formed mostly of -
D. Basalt
Rubies and sapphires are gem quality varieties of -
C. Corundum
The earth's core is inferred to be -
C. mostly iron
The premise that present-day processes have operated throughout geologic time is know as the principle of -
C. uniformitarianism
Ocean-ocean convergence zones are marked by the occurrence of -
D. volcanic island arcs
Dark minerals in igneous rocks are -
A. iron-magnesium silicates
Continental crust -
A. is compressed and thickened at converging plate margins
The steps to the library are made of
B. granite
The mid-oceanic ridges are sites of -
B. sea floor spreading
____ is a rock composed of olivine and pyroxene that similar to the composition of the mantle.
A. perodotite
Calcite is composed of -
A. calcium carbonate
Thin, sheet-like, disconcordant igneous intrusions are -
D. dikes
The tendency for some minerals to break along smooth, flat surfaces is known as -
B. cleavage
The earth is estimated to be ___ years old?
D. 4.6 billion
The most abundant mineral group in the crust is -
D. feldspar
Rapid cooling of magma results in a fine-grained texture called -
B. phaneritic
Igneous rocks that have a ___ texture have grains that can be seen with the named or unaided eye.
B. phaneritic
A natural glass formed by rapid cooling of lava is called -
C. obsidian
Basalt has the same mineral and chemical composition as -
A. gabbro
The mineral assemblage of quartz, K-spar, Na-plagioclase, with minor biotite or hornblende would be recognized readily by you as the minerals found in the rock know as -
a. granite
b. diorite
c. gabbro
d. scoria
a. granite
The dark, rock-forming minerals are rich in -
C. Fe and Mg
The early-formed light-colored mineral in a melt [magma[ is -
B. olivine
Pyroclastic rocks form by -
B. violent, explosive volcanic eruptions
Phenocrysts are evidence of -
D. two periods of cooling
Vesicles (holes) form in igneous rock (such as scoria and vesicular basalt) fro m-
D. escaping gas
The common lava extruded from stratovolcanoes is -
D. andesite
Shield volcanoes have low, angle slopes because they are composed of -
B. fluid basaltic lava
Steep-sided, classic, "volcano-shaped" cones are called -
D. stratovolcanoes
Mt. St. Helens is an excellent example of a -
C. explosive caldera
Rugged, blocky lava flows are called -
B. Aa
A volcanic rock that floats is -
D. pumice
Which one of the follow minerals can you scratch with your finger nail?
B. gypsum
An igneous rock possessing a combination of mineral grains with markedly different grain sizes is -
a. natural glass
b. formed by explosive volcanism
c. a porphyry
d. never found in nature
c. porphyry
My. Fuji in Japan and Mt. Etna on Sicily are classic examples of -
C. stratavolcanoes
The mid-oceanic ridges are -
B. sites of new oceanic material
All plate margins are characterized by -
D. high earthquake activity
Mid-oceanic ridges are sites of ____ plate boundaries
D. divergent
Rocks composed on only pyroxene and olivine may form by-
A. crystal settling
Which one of the following groups do most minerals in the earth's crust belong?
D. silicates
Most granite forms by -
A. melting of lower continental crustal material
Enchanted rock is
A. an exposed portion of granite batholiths
Dikes and sills are probably empaled in the crust by -
B. injection of magma into fractures
The first minerals of crystallize out of magma are -
D. Ca-plagioclase and olivine
___ is composed of minerals found in the mid-range of Bowen's Reaction series.
E. diorite
The minerals in the rock diorite are -
C. augite, hornblende and plagioclase
The minerals in igneous rocks that is rich in aluminum are -
C. mica and feldspar
The rock cycle implies that-
A. any rock type can form from any other rock type
The bright regions of the moon are made up of the rock -
D. anorthosite
Forty percent of the near side of the moon consists of smooth, dark plains made up of-
C. basalt
If you had to find K-spar where it occurs naturally in the state of Texas, one place that you would be certain to find it is -
