Earth Science 30 Final Review Part 1

Question 1

What are the geological time periods (from smallest to largest)?

Answer 1

Eon (4) ~ 1/2 billion years or more
Era (10) ~ several hundred million years
Periods (22) ~ 10-100 million
Epochs (34) ~ 10's of millions of years
Ages (99) ~ millions of years

Question 2

What was the geological setting for the Precambrian Eon?

Answer 2

Tectonic plates of the lithosphere formed and moved. Large landmasses appeared.

Question 3

What was the geological setting and climate for the Cambrian period?

Answer 3

Geological setting- oceans and shallow seas covered most of the Earth.
Climate- warmer than today

Question 4

What was the geological setting and climate for the Ordocivian period?

Answer 4

Geological Setting- land was collected together, volcanic activity.
Climate- major glaciation happened late in this period. Lack of oxygen in water.

Question 5

What was the geological setting and climate of the Silurian period?

Answer 5

Geological setting- large glacial formations and the rise in sea level. Major mountain building.
Climate- stabilized

Question 6

What was the geological setting and climate of the Devonian period?

Answer 6

Geological setting- major volcanic activity and earthquakes.
Climate- much like present

Question 7

What was the geological setting and climate of the Carboniferous period?

Answer 7

Geological setting- tropical swamp forests and terrestrial habitats.
Climate- tropical and humid

Question 8

What was the geological setting and climate of the Permian period?

Answer 8

Geological setting- Earth’s plates arranged into Pangaea.

Climate- seasonal changes and extremem temperatures.

Question 9

What was the geological setting and climate of the Triassic period?

Answer 9

Geological setting- continents of a much higher elevation than sea level, no shallow seas.
Climate- dry and arid climate conditions

Question 10

What was the climate of the Jurassic period?

Answer 10

Climate- dry and warm

Question 11

What was the geological setting and climate of the Cretaceous period?

Answer 11

Geological setting- coast lines developed from Pangaea splitting.
Climate- seasons became more pronounced and the global climate became cooler.

Question 12

What was the geological setting and climate of the tertiary period?

Answer 12

Geological setting- mountain ranges occured.

Climate- war a dn humid, by mid-era the temperatures became cooler.

Question 13

What was the flora and fauna of the Precambrian era?

Answer 13

All life was bacterial. Increase in oxygen made it possible for algae, animals, fungi, and protists to eventually adapt.

Question 14

What was the flora and fauna of the Cambrian period?

Answer 14

Marine invertebrates that are relatives of modern crabs.

Question 15

What was the flora and fauna of the Ordocivian period?

Answer 15

Snails and clams appeared for the first time.

Question 16

What was the flora and fauna of the Silurian period?

Answer 16

Rise of jawless fish.

Question 17

What was the flora and fauna of the Carboniferous period?

Answer 17

Increase in land habitat.

Question 18

What was the flora and fauna of the Permian period?

Answer 18

Largest mass extinction recorded on Earth took place with over 90% of marine species becoming extinct.

Question 19

What was the flora and fauna of the Triassic period?

Answer 19

First dinosaurs.

Question 20

What was the flora and fauna of the Cretaceous period?

Answer 20

Dinosaurs all went extinct.

Question 21

What was the flora and fauna of the tertiary period?

Answer 21

The age of the mammals such as wooly mammoths, mastodons which increased in population and then died off during the ice age.

Question 22

What is weathering?

Answer 22

The process by which rocks on or near the Earth’s surface break down or change.

Question 23

What is erosion?

Answer 23

Removal and transport of weathered material from one area to another.

Question 24

What is soil?

Answer 24

The loose covering of broken rock particles and decaying organic matter, called humus, overlying the bedrock of Earth’s surface.

Question 25

Name and describe the factors that lead to mechanical weathering.

Answer 25

Temperature- when water freezes it expands and increases in volume. When it collects in rock cracks, the water expands and causes the rocks to split.
Pressure- when overlying layers of rock are removed, the pressure decreases causing the rock to expand and surface. Overtime, the outer layers of rock are stripped away

Question 26

Name and describe the factors that lead to chemical weathering.

Answer 26

Water- dissolves minerals and rocks, plays an active role in some reactions, serves as a medium for which reactions occur (hydrolysis).
Oxygen- can combine with other substances (oxidation)
Carbon dioxide- combines with water in the atmosphere to form carbonic acid that falls to the Earth as precipitation and reacts with minerals to dissolve rock.
Acid precipitation- caused mainly by the oxidation of suffer dioxide with water and oxygen in the atmosphere to form Sulfuric and nitric acid. Destructive to non-living things and is harmful to organisms.

Question 27

What is gravity’s role in erosion?

Answer 27

The force of gravity tends to pull material downslope.

Question 28

What is the role running water plays in erosion?

Answer 28

Can carry materials over a great distance.

Question 29

What is coastal deposition and erosion?

Answer 29

Each year, streams and rivers carry billions of metric tons of sediments and weathered materials to coastal areas.

Question 30

What is glacial erosion?

Answer 30

Glacial movements scratch and grind some surface, polish others, scrape and gouge out large sections of the landscape.

Question 31

What is wind erosion?

Answer 31

Major erosion all agent in areas that experience limited precipitation and high temperatures as these places typically have little vegetative cover to hold soil in place so these particles can easily be moved by wind.

Question 32

What is erosion by plants, animals, and humans?

Answer 32

As animals and pants carry on their life processes, they move Earth’s surface materials from one area to another.

Question 33

How does soil form?

Answer 33

1) the soil forming process begins when weathering breaks the bedrock into smaller pieces.
2) many organisms (bacteria, fungi, insects) begin to live in the weathered materials. Over time, these organisms die, decay, and add nutrients to the weathered material to form soil.
3) nutrients begin to be added to the soil, soil texture improves, and the soil’s capacity to hold water increases.

Question 34

What factors contribute to the development of soil?

Answer 34

Vegetation which, overtime, can grown and mature in soil and increase the rate of soil development. Vegetation contributes to the buildup of humus and supplies acids to promote the weathering process. Also, parent bedrock, topography, plants and animals, time, and temperature.

Question 35

What is mass movement?

Answer 35

The downslope movement of loose sediments and weathered rock resulting from the force of gravity.

Question 36

What are the variables that contribute to mass movement?

Answer 36

• material’s weight- resulting from gravity which works to pull the materials downslope.
• materials resistance to sliding or flowing
• a trigger, such as an earthquake, that works to shake materials loose from a slope.
• water

Question 37

What are the four types of mass movements?

Answer 37

1) Creep
2) Flows
3) Slides
4) Falls

Question 38

What is creep?

Answer 38

The slow, steady downhill flow of loose, weathered materials, especially soils. the effects are usually noticeable over long periods of time. Ex. Tilting of Poe’s, fences, gravestones, etc.

Question 39

What are flows?

Answer 39

In some mass movements, Earth materials flow as if they were a thick liquid. Earth flows are slow movements of soils whereas mud flows are fast movements of mud and wate.r

Question 40

What are slides?

Answer 40

A rapid, downslope movement of Earth materials that occur when a relatively thin block of loose soil, rock and debris separates from the underlying bedrock is called a landslide. It rapidly slides downslope as one block with little internal mixing. Common on steep slopes, especially when soils and weathered bedrock are fully saturated by water. A rock slide is a type of landslide that occurs when a sheet of rock moves downhill on a sliding surface.

Question 41

What are falls?

Answer 41

Commonly occur at high elevations steep road cuts and on rocky shorelines. Rocks are loosened by physical weathering processes. As they break up and fall downward, they may produce talus (cone shaped pile of debris). On human made rock walls, falls are particularily common. Less common in humid areas with lots of vegetation.

Question 42

What is suspension?

Answer 42

A method of transport by which strong winds cause particles to stay airborn for long distances.

Question 43

What is deflation?

Answer 43

The lowering of land surfaces that results from the wind’s removal of surface particles. The particles removed may be composed of any material. In areas of intense wind erosion, course material is left behind and the finer material is removed.

Question 44

What is abrasion?

Answer 44

Occurs when particles, such as sand, rub against the surface of rocks or other materials. Occurs as part of the erosion all activities of winds, streams, and glaciers. Wind picks up materials and blows them against rocks and other objects. Materials exposed to wind abrasion show unique characteristics such as rocks becoming pitted and grooved and with continual abrasion becoming polished and smooth with sharp edges.

Question 45

What are ventifacts?

Answer 45

Rocks shaped by wind blown sediments.