Deck 2: Rock-Forming Minerals and Rocks

Question 1

The radioactive isotope of carbon is

A) carbon 15.
B) carbon 14.
C) carbon 13.
D) carbon 12.

Answer 1

B

Question 2

Silicon has an atomic number of 14, meaning that all atoms of silicon have

A) 14 nuclei.
B) 14 neutrons.
C) 14 protons.
D) 14 electrons.

Answer 2

C

Question 3

Hematite is an example of the major mineral group called

A) sulfates.
B) carbonates.
C) silicates.
D) oxides.

Answer 3

D

Question 4

Minerals containing the complex ion SO₄^2- are called

A) sulfides.
B) sulfates.
C) oxides.
D) silicates.

Question 5

Of the siliciclastic rocks that have mainly sand-sized grains, the one with at least 25% percent feldspar sand grains is called

A) arkose.
B) breccia.
C) graywacke.
D) lithic sandstone.

Question 6

A sedimentary particle that is 1/128 millimeter in diameter is classified as

A) clay.
B) silt.
C) sand.
D) pebble.

Question 7

__________ are sediments consisting of nearly spherical grains, which grow in modern seas by rolling around and accumulating aragonite needles on their surfaces.

A) Oolites
B) Ooids
C) Cherts
D) Coals

Question 8

Mud is a mixture of

A) sand and silt.
B) silt and clay.
C) pebbles and sand.
D) pebbles and cobbles.

Question 9

__________ precipitates directly from seawater as tiny needle-like crystals, which accumulate on the shallow sea floor as __________.

A) Calcite; calcite crystals
B) Halite; evaporite minerals
C) Aragonite; carbonate mud
D) Calcite; coral skeletons

Question 10

__________ consist of a unique kind of atom.

A) Chemical elements
B) Atomic masses
C) Molecules
D) Chemical compounds

Question 11

Of the major mineral groups, the one that is dominant in all igneous, sedimentary, and metamorphic rocks is called

A) sulfates.
B) carbonates.
C) silicates.
D) sulfides.

Question 12

The outermost shell of the chlorine atom, prior to bonding with sodium to form a common mineral (NaCl), contains how many electrons?

A) 8
B) 7
C) 6
D) 5

Question 13

In the atomic structure of diamond, each carbon atom is covalently bonded with _________ other carbon atom(s) in the diamond structure shown.

A) four
B) three
C) two
D) one

Question 14

Ionic bonding occurs in

A) seawater.
B) halite.
C) diamond.
D) graphite.

Question 15

Coarse grain size (or crystal size) is usually found in

A) flood basalts.
B) pillow lavas.
C) plutons.
D) tuffs.

Question 16

The main chemical process that occurs during lithification is called

A) compaction.
B) cementation.
C) weathering.
D) evaporation.

Question 17

__________ is a kind of igneous rock that is high in silica and contains two types of feldspars.

A) Granite
B) Gabbro
C) Felsic
D) Basalt

Question 18

Dolomite resembles calcite in many ways, but in approximately half of the sites where there could be calcium ions in dolomite's crystal structure, there is instead a(n) _________ ion.

A) magnesium
B) iron
C) strontium
D) carbon

Question 19

In some places, the strontium ion substitutes for the __________ ion within the calcium carbonate crystal structure.

A) sodium
B) calcium
C) chlorine
D) carbon

Question 20

Chert can form by biogenic processes (for example, as deposits from silica-rich solutions moving through rock) or by the process of

A) evaporation of seawater.
B) direct precipitation from seawater.
C) compaction and cementation.
D) Native Americans making arrowheads.

Question 21

This sedimentary structure formed when sediments were exposed to air.

A) Graded bed
B) Mudcracks
C) Cross-bedding
D) Ripples

Question 22

__________ is the word used to indicate the levels of temperature and pressure of metamorphism.

A) Thermometer
B) Barometer
C) Assemblage
D) Grade

Question 23

The average direction of the slope of __________ indicates the general direction of prevailing winds when ancient sands were deposited, thus forming a sand dune.

A) mudcracks
B) cross-bedding
C) graded beds
D) ripples

Question 24

When an asteroid strikes the Earth, rocks that border the impact crater are affected by __________ metamorphism.

A) contact
B) shock
C) regional
D) fault-zone

Question 25

The mica-like, green mineral chlorite occurs primarily in

A) schist.
B) marble.
C) gneiss.
D) slate.

Question 26

The form of metamorphism that is most closely associated with the heat or "baking" resulting from an igneous intrusions is

A) a fault-zone.
B) regional.
C) hydrothermal.
D) contact.

Question 27

Banded iron formations are complex rocks that consist of

A) oxides, sulfides, or carbonates of iron interlayered with thin beds of chert.
B) interlayered thin beds of calcite and aragonite, and beds of chert.
C) interlayered beds of limestone and dolostone, and beds of chert.
D) thin beds of chemical and biogenic sediments, which are interlayered with chert.

Question 28

What sedimentary structure formed on a beach and is (are) produced by wave motion in water that oscillates back and forth?

A) Cross-bedding
B) Ripples
C) Mudcracks
D) Graded beds

Question 29

The type of metamorphism associated with the percolation of hot watery fluids through rock is called

A) contact.
B) hydrothermal.
C) burial.
D) shock.

Question 30

An igneous rock that forms under water is called

A) pumice.
B) flood basalt.
C) pillow basalt.
D) tuff.