Deck 20: Introducing Rocks

Question 1

What makes a material coherent?

A) It must be naturally occurring.
B) It must be broken to separate into pieces.
C) It is made of only one substance.
D) It contains crystals.

Answer 1

B

Question 2

Composition describes the

A) degree of compaction and cementation in a rock.
B) arrangement of minerals in a rock.
C) presence of layers in a rock.
D) proportion of chemicals that make up a rock.

Answer 2

D

Question 3

What is the first step most geologists take in studying a rock?

A) using a mass spectrometer
B) examining thin sections under a microscope
C) making observations about the rock in an outcrop
D) breaking the rock into hand specimens

Answer 3

D

Question 4

Which type of rock can form by precipitation of minerals from a water solution?

A) metamorphic
B) glassy
C) sedimentary
D) igneous

Question 5

Which type of rock forms from the freezing (solidification)of a melt?

A) metamorphic
B) crystalline
C) sedimentary
D) igneous

Question 6

Granite is a type of rock that forms deep underground from magma that cools very slowly.What type of rock is granite?

A) igneous
B) sedimentary
C) metamorphic

Question 7

The changes that create a metamorphic rock occur in what state?

A) liquid state
B) gaseous state
C) solid state
D) a mixture of solids and liquids

Question 8

What is cement to a geologist?

A) the material used to make buildings and sidewalks
B) a natural form of glass
C) a collection of interlocking grains
D) the mineral materials that bond grains together

Question 9

What is the basis for classification of rocks into igneous,metamorphic,and sedimentary?

A) how old the rocks are
B) how the rocks formed
C) the types of minerals in the rocks
D) the grain size of the rocks

Question 10

How would you tell if a rock is crystalline?

A) It contains crystals that have been cemented together.
B) It does not contain crystals at all.
C) It contains interlocking crystals.
D) It contains all one type of crystal.

Question 11

Which of the following is a reliable characteristic that can be used to classify a rock?

A) mineral stability
B) texture
C) water content
D) degree of weathering

Question 12

In which of the following settings would you be most likely to find sedimentary rocks forming?

A) deep within a mountain range
B) inside a lava flow on Hawaii
C) at a mid-ocean ridge
D) at the bottom of the Mediterranean Sea

Question 13

Which of the following meets the definition of a rock?

A) a pile of damp sand still holding the form of a bucket
B) a collection of crystals that fit together like puzzle pieces
C) cobblestones cemented together to form a walkway
D) a layer of mud at the bottom of a dry riverbed

Question 14

What do geologists call the layering seen in this photo of a sedimentary rock?

A) bedding
B) foliation
C) grain size
D) cleavage

Question 15

What type of rock would you most expect to find forming in a beach environment?

A) crystalline
B) sedimentary
C) metamorphic
D) igneous

Question 16

Which of these describes an outcrop of bedrock?

A) a cut block of rock used to construct a building
B) a large boulder embedded in the soil
C) rock that is exposed where a road cuts through a mountain
D) broken and loose rocks at the base of a cliff

Question 17

What characteristic of rocks is demonstrated by inequant mineral grains arranged with their long axes pointing in the same direction,as shown in the image below?

A) grain size
B) composition
C) texture
D) layering

Question 18

Imagine you are holding a rock composed of small sand grains cemented together.What classification of rock is this?

A) metamorphic
B) sedimentary
C) crystalline
D) igneous

Question 19

What do geologists call the layering seen in this photo of a metamorphic rock?

A) bedding
B) foliation
C) grain size
D) cleavage

Question 20

What is the difference between a rock that is cemented together and a rock that has a crystalline texture?

A) A rock that is cemented contains rounded grains that are held together by cement,whereas a crystalline rock contains angular grains held together by cement.
B) Crystalline rocks contain minerals,while cemented rocks contain rock fragments; both are held together by static forces between grains.
C) Minerals are held together as interlocking pieces in a cemented rock,whereas grains are held together by minerals precipitated in pore spaces in a crystalline rock.
D) Minerals are held together as interlocking pieces in a crystalline rock,whereas in a cemented rock the grains do not fit together like puzzle pieces and instead are held together by cement.

Question 21

Which of the following rock types has a texture that is most analogous to the pieces of a jigsaw puzzle?

A) sedimentary
B) crystalline
C) foliated
D) molten

Question 22

What information can geologists discover by analyzing a thin section?

A) the abundance of different elements in the rock
B) what chemical constituents make up the rock
C) what minerals make up the rock and how grains connect to one another
D) the arrangement of atoms in the rock

Question 23

What is the definition of rock "texture"?

Question 24

Provide at least two reasons why a piece of concrete is not an example of bedrock.

Question 25

What kind of information can an electron microprobe provide about rocks?

A) the amount of radioactive minerals.
B) how atoms are arranged.
C) the atomic weight.
D) the chemical composition.

Question 26

What type of texture is shown in this photomicrograph?

A) foliation
B) crystalline
C) sedimentary
D) clastic

Question 27

In what kind of geologic setting are igneous rocks likely to form?

A) volcanic arc
B) deep ocean
C) subduction zones
D) passive margin

Question 28

Describe one example of a naturally occurring outcrop and one of a human-made outcrop.

Question 29

What is a thin section? How is it made and what is it used for?

Question 30

What are the three rock groups? Give a brief description of how each is formed.