Chapter 11 (Part 2)

Question 1

A radioactive parent isotope decays…

Answer 1

… to a stable daughter isotope.

Question 2

If we know the rate of decay, we can use the ratio of the two to calculate…

Answer 2

…the age of the rock or mineral they are contained in.

Question 3

After-life

Answer 3

~7-8 half-lives
Less than 1%

Question 3

Half-life

Answer 3

Amount of time it takes for ½ of
parent isotopes to decay to daughter.

Question 4

Gravity pulled heavier elements
to center of Earth to form…

Answer 4

…different layers.

Question 5

Heat emanates from the center of the Earth by…

Answer 5

conduction and convection.

Question 6

Why is the hot inner core solid?

Answer 6

Increased temperature with higher pressure.

Question 7

Core

Answer 7

Inner - -Solid iron
Outer - Molten iron; magnetic field generated

Question 8

Mantle

Answer 8

Lower - rigid (solid, silicates rich in iron and magnesium
Upper - more silicates

Question 8

Mohorovicic (Moho)

Answer 8

Separates crust from upper mantle

Question 9

Lithosphere

Answer 9

Rigid rock comprising the crust (oceanic and continental) as well as the underlying rock.

Question 9

Crust

Answer 9

Oceanic (more dense)
Continental (less dense)

Question 10

Asthenosphere

Answer 10

Plastic or mushy upper part of the mantle.

Convective movements in this layer drive movements of the crustal plates.

Question 11

Minerals

Answer 11

Naturally occurring solid
Definable chemical composition
Possess a crystalline structure
Inorganic

Question 12

Crystalline Structure

Answer 12

An ordered internal structure at the atomic scale.
Not distributed randomly.

Question 13

Inorganic

Answer 13

Minerals must be formed by geological processes such as freezing from a melt, precipitation from solution, chemical reaction.

Question 14

Igneous Rocks

Answer 14

Originates from the cooling of liquid hot magma.

Question 15

(Igneous) Intrusive

Answer 15

Rocks that cool and
harden below surface → coarse
grain texture.

Question 16

Felsic

Answer 16

High silica
Rocks light in color

Question 17

(Igneous) Extrusive

Answer 17

Rocks that cool and
harden at the surface → fine grain texture.

Question 18

Mafic

Answer 18

Low silica
Rocks dark in color

Question 19

Igneous Formations (Intrusive)

Answer 19

◦ Magma
◦ Pluton
◦ Batholith
◦ Sill
◦ Dike

Question 20

Igneous Formations (Extrusive)

Answer 20

◦ Volcano
◦ Lava
◦ Ash

Question 21

Dikes

Answer 21

Vertical cross throughs.

Question 21

Sills

Answer 21

Parallel to the layers.

Question 22

Sedimentary Rocks

Answer 22

Grains or fragments cemented together
Precipitation of minerals from water solutions
Growth of shell masses, or accumulation of organic matter