Earth Sciences 1000

Question 1

What is Physical Geology?

Answer 1

The study of the materials and processes which compose and operate on the surface of, and within, Earth.

Question 2

What is Historical Geology?

Answer 2

The study of the origin and evolution of Earth’s continents, oceans, atmosphere, and life.

Question 3

What do scientists think is the most pressing issue facing humanity today?

Answer 3

Overpopulation

Question 4

When did the Universe form?

Answer 4

14 billion years ago, because of the Big Bang

Question 5

Describe the Solar Nebula Theory.

Answer 5

This theory states that the Earth and entire solar system was formed from a rotating nebula cloud about 4.6 billion years ago.

Question 6

What are the Terrestrial planets?

Answer 6

Mercury, Venus, Earth, Mars.

Question 7

What are the Jovian planets?

Answer 7

Jupiter, Saturn, Uranus, Neptune.

Question 8

What are the three main layers of the Earth?

Answer 8

The core, the mantle, and the crust.

Question 9

What is the Earth’s core composed of?

Answer 9

A solid inner core and a liquid outer core, composed mainly of iron and some nickel.

Question 10

What are the sub-layers of the Earth’s mantle?

Answer 10

The solid lower mantle, the partially molten asthenosphere, and the solid upper mantle; the mantle is composed of peridotite, an igneous rock made from olivine.

Question 11

What are the two types of crust on Earth?

Answer 11

The oceanic crust and the continental crust.

Question 12

What are the four main ways plates move?

Answer 12

They converge, diverge, slide sideways past each other, and subduct.

Question 13

Define mineral.

Answer 13

A naturally occurring inorganic solid with identifiable physical properties and a semi-definite chemical composition.

Question 14

Define rock.

Answer 14

A solid aggregate of one or more minerals.

Question 15

What is an intrusive igneous rock?

Answer 15

Forms when magma cools and solidifies under the Earth; also called plutonic rock.

Question 16

What is an extrusive igneous rock?

Answer 16

Also called explosive rock, forms when lava cools and solidifies on the surface.

Question 17

What is a sedimentary rock?

Answer 17

Rocks that are formed from layers of other rock/mineral fragments, precipitation of minerals from solution, or the compaction of plant and animal remains.

Question 18

What is a metamorphic rock?

Answer 18

A new rock formed from the alteration of another rock by heat, pressure, and or chemically active fluids.

Question 19

What are the most common elements in the Earth’s crust?

Answer 19

Oxygen and silicon.

Question 20

What is the most common type of mineral?

Answer 20

Silicates, which are composed of silica tetrahedra.

Question 21

What are the two main types of silicate groups?

Answer 21

Ferromagnesian and non-ferromagnesian silicates.

Question 22

Define a ferromagnesian silicate.

Answer 22

Silicates that contain iron or magnesium or both; they are usually denser and darker in colour.

Question 23

Define a nonferromagnesian silicate.

Answer 23

Silicates that lack iron and magnesium, but may contain potassium, calcium, aluminum, and or sodium; often lighter coloured.

Question 24

Define the carbonate mineral group.

Answer 24

Minerals that contain carbonate (CO3)^-2; commonly found in sedimentary rocks limestone and dolostone; also derived from the shells of organic organisms.

Question 25

Define the sulfide mineral group.

Answer 25

Minerals that contain sulfur plus a metallic element such as galena (PbS) and pyrite (FeS2); commonly found along mid-oceanic ridges.

Question 26

Define the sulfate mineral group.

Answer 26

Minerals that contain a sulfate radical (SO4^-2), such as gypsum; commonly found in deserts, formed from the evaporation of water.

Question 27

What is a resource?

Answer 27

Any solid, liquid, or gaseous substance in rocks whose
profitable extraction is potentially feasible now or in the future.

Question 28

What is a reserve?

Answer 28

A resource that can be economically extracted under
current conditions.

Question 29

What are factors that prevent resources from becoming reserves?

Answer 29

Remote regions without roads
Wars and political unrest
Environmental regulations, sites designated as parks, etc.
Labor costs
Fluctuating and unstable markets for the resource
Too expensive to extract with current technologies

Question 30

What are the three main types of resources?

Answer 30

Renewable resources, nonrenewable resources, and energy resources.

Question 31

What are the three main composition types of magma/lava?

Answer 31

Felsic, which is silica rich and iron and magnesium poor; high viscosity.
Intermediate, between felsic and mafic.
Mafic, which silica poor and iron and magnesium rich; low viscosity.

Question 32

What is Bowen’s Reaction Series?

Answer 32

Describes the sequence of mineral crystallisation in cooling magma; minerals at the top of the series commonly occur in mafic magma (olivine) and minerals at the bottom of the series commonly occur in felsic magma (quartz).

Question 33

What are the two main branches in Bowen’s Reaction Series?

Answer 33

The discontinuous series which produces ferromagnesian minerals, and the discontinuous series which produces a range of plagioclase feldspars.

Question 34

How does magma form at spreading ridges?

Answer 34

High temperatures combined with a decrease in pressure and increased water content.

Question 35

What are the three main ways the composition of magma changes?

Answer 35

Crystal settling, when formed minerals settle at the base of the magma chamber, removing some of the iron and magnesium and enriching the remaining magma in other elements.
Assimilation of country rock, because of processes such as stoping.
Magma mixing, which can occur when two different magmas blend together if their viscosities are similar enough, or when magmas mingle is their viscosities are different enough.

Question 36

Define texture.

Answer 36

The size, shape, and arrangement of grains in a rock.

Question 37

What are the two broad groups of texture?

Answer 37

Aphanitic, or fine-grained, which is present in volcanic rocks and phaneritic, or coarse-grained, which is present in plutonic rocks; there is also poryphyritic, which indicates a complex cooling history.

Question 38

What are two examples of ultra-mafic rocks?

Answer 38

Peridotite, komatiites.

Question 39

What are three plutonic/volcanic pairs?

Answer 39

Basalt-Gabbro, both of mafic composition; volcanic-plutonic.
Rhyolite-Granite, both of felsic composition; volcanic-plutonic.
Andesite-diorite, both of intermediate composition; volcanic-plutonic.

Question 40

Define pluton.

Answer 40

Bodies of igneous rock which have intruded in country rock, or have formed in place far beneath the surface.

Question 41

What are the two types of plutons?

Answer 41

Concordant, meaning they form parallel to rock layers (includes sills and laccoliths).
Discordant, meaning they cut across layering in the country rock (includes dikes, volcanic necks, batholiths, and stocks).

Question 42

What is a batholith?

Answer 42

The largest type of pluton, it has more than 100 km^2 of exposed area.

Question 43

How can volcanic activity be constructive?

Answer 43

Volcanic activity is responsible for the origin of many islands, fertile farmland, and critical atmospheric gases (primarily water vapour).

Question 44

What are some of the different types of lava flows?

Answer 44

Aa, pahoepahoe, pillow lavas, and columnar joints.

Question 45

What are the different sizes of pyroclastic materials, ranked in order of size?

Answer 45

Ash lapilli, bombs, blocks.