Introduction

Question 1

What is the Nebular Hypothesis?

Answer 1

Solar system began as a giant rotating cloud of gas and dust called the solar nebula. Rotating nebula began to contract about 5 billion years ago and developed into a flat, disk shape with the proto-Sun at the center. Inner planets formed from metallic and rocky substances. Larger outer planets formed from fragments of ices that accumulated around rocky cores.

Question 2

A nebula is composed mostly of what?

Answer 2

Hydrogen and helium

Question 3

The larger outer planets formed from what kinds of ice fragments?f

Answer 3

H20, CO2, NH3 (ammonia), and CH4 (methane)

Question 4

What happens as a nebula cools?

Answer 4

Tiny solid particles condense and coalesce into asteroid-size bodies. These in turn accrete (coalesce) into planets.

Question 5

How long did it take for the solar system to form?

Answer 5

A few tens of millions of years

Question 6

Hot, softened inner (terrestrial) planets separated into layers based on what?

Answer 6

The densities of different materials. Heavy metals (mostly iron) sank to the center while lighter, molten materials migrated towards the surface to produce a primitive crust. This chemical separation established the basic divisions of Earth’s interior and surface.

Question 7

What is physical geology?

Answer 7

The study of the materials that compose Earth and the processes that operate on and beneath its surface.

Question 8

What is historical geology?

Answer 8

The study of the origin of Earth and its development through time.

Question 9

What are some issues addressed by geology?

Answer 9

Natural hazards, mineral resources, world population growth, environmental issues.

Question 10

What is Earth System Science

Answer 10

The study of Earth as a system composed of numerous interacting parts or subsystems.

Question 11

What is a system?

Answer 11

Any size group of interacting parts that form a (more) complex whole.

Question 12

What is an open system?

Answer 12

A system that allows energy to freely flow in and out. e.g. leaf, ocean

Question 13

What is a closed system?

Answer 13

Energy moves freely in and out of a closed system, while matter does not enter or leave the system. e.g. Earth

Question 14

What kind of systems are the “spheres” that comprise the Earth?

Answer 14

Open systems

Question 15

What are igneous rocks?

Answer 15

Rocks formed from cooling and solidification of magma (molten rock). e.g. granite, basalt

Question 16

How are sedimentary rocks formed?

Answer 16

Sediments are derived from weathering of preexisting rock. Sediments accumulate as layers at Earth’s surface. Buried sediments are converted into rocks. e.g. sandstone and limestone

Question 17

How are metamorphic rocks formed?

Answer 17

By “changing” preexisting igneous, sedimentary, or other metamorphic rocks. The driving forces are increased heat and pressure. e.g. gneiss (pronounced “nice”) and marble

Question 18

What is the rock cycle? Give an example.

Answer 18

The loop that involves the processes by which one rock changes to another. Any rock type can be converted to another rock type under appropriate conditions.
High temps melt rock to form magma which cools and solidifies into igneous rock. Weathering breaks down this igneous rock into sediment. Sediment is then buried and converted to sedimentary rock. Higher heat and pressure convert this sedimentary rock into metamorphic rock. Melting of metamorphic rock produces magma.

Question 19

Give the planets in order.

Answer 19

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
(My Very Excellent Mother Just Served Us Noodles)

Question 20

Which are the terrestrial planets?

Answer 20

Mercury, Venus, Earth, and Mars.

Question 21

Describe the terrestrial planets

Answer 21

They are the closest to the sun. Generally small, rocky bodies with densities greater than 3gm/cm^3.
Composed mainly of silicates, Fe and Ni (iron and nickle). Volcanism mostly basaltic.

Question 22

Which are the Jovian (giant) Planets.

Answer 22

Jupiter, Saturn, Uranus, and Neptune.

Question 23

Describe the Jovian Planets.

Answer 23

Each has solid rocky core surrounded by layers of frozen or liquid hydrogen, helium, methane, and ammonia. They have multiple moons and ring systems composed of dust to boulder-sized particles of mostly ice.

Question 24

Describe the Earth as it was 4.5 billion years ago.

Answer 24

Initially a magma ocean hundreds of kilometers deep. Magma ocean cooled and crystallized from the bottom up over millions of years to form a solid mantle capped by a primitive crust of basalt.

Question 25

What are the Earth’s major subdivisions?

Answer 25

• Atmosphere
• Crust
• Mantle
• Core

Question 26

Describe the oceanic crust.

Answer 26

• Ranges from 0 - 10 km thick

- Average composition of basalt

Question 27

Describe the Continental Crust.

Answer 27

• Ranges from 33 - 70 km thick

- Average composition close to granite

Question 28

Describe granite.

Answer 28

The large crystals of light-colored minerals in granite result from the slow cooling of molten rock deep beneath the surface. Granite is abundant in the continental crust.

Question 29

Describe Basalt.

Answer 29

Rich in dark minerals. Rapid cooling of molten rock at Earth’s surface is responsible for the rock’s microscopically small crystals. Oceanic crust is composed mainly of basalt.

Question 30

What does the lithosphere include?

Answer 30

Crust and solid upper portion of mantle, which include the asthenosphere.

Question 31

The upper mantle is composed of?

Answer 31

Mg-Fe silicate rock called peridotite. (magnesium and iron)

Question 32

Rigid lithosphere glides over?

Answer 32

Weak asthenoshpere

Question 33

Describe the mantle below the asthenosphere.

Answer 33

• Below the
asthenosphere, the
mantle is solid down
to a depth of ~2,900
km where it meets the
outer core
• Lower mantle
composed of a high-density, Mg-silicate
rock called perovskite

Question 34

Describe the outer core.

Answer 34

- Extends from 2,900
km to 5,100 km depth
- Consists mainly of
molten (liquid) iron
- Source of Earth’s magnetic field

Question 35

Describe the inner core.

Answer 35

- Extends from 5,100
km depth to the center
of the Earth
- Composed mostly of
solid iron and nickel

Question 36

What is the difference between relative dating and absolute dating?

Answer 36

• Relative dating:
– Geologic events and materials are placed in their proper sequence or
order of occurrence without knowing their ages
• Absolute dating:
– Uses radioactive isotopes to assign actual ages to rocks and events