3.1 C: Geology = the Changing Earth 3.1 The Great Cooling

Question 1

What is the Cypress Hills Interprovincial Park described as?

Answer 1

An island of forest within a sea of grassland

The park is located on the southern border of Alberta and Saskatchewan.

Question 2

Why does Cypress Hills receive more precipitation than surrounding areas?

Answer 2

Due to its higher elevation

This extra moisture supports a rich forest ecosystem.

Question 3

What geological feature provides clues about Alberta’s past?

Answer 3

A 600-m thick section of sedimentary rock

This section was not removed by the advancing ice sheet during the most recent Ice Age.

Question 4

What was the area of Cypress Hills suspected to be during the last Ice Age?

Answer 4

An island of land in a sea of ice called a Nunatak

‘Nunatak’ is Inuktitut for ‘land apart’.

Question 5

What era is known as the last 65 million years of Earth’s history?

Answer 5

Cenozoic Era

The Cenozoic Era is divided into two periods: the Tertiary and Quaternary.

Question 6

What are the two periods of the Cenozoic Era?

Answer 6

Tertiary Period and Quaternary Period

Tertiary: 65 million years ago to 1.7 million years ago; Quaternary: 1.7 million years ago to the present.

Question 7

What percentage of the Cenozoic Era does the Tertiary Period represent?

Answer 7

Over 97%

The Tertiary Period is much longer than the Quaternary Period.

Question 8

What geological event occurred at the beginning of the Cenozoic Era?

Answer 8

Collision between the North American Plate and the Pacific Plate

This resulted in a rapid period of mountain building.

Question 9

What mountain range was formed due to the geological events of the Cenozoic Era?

Answer 9

Rocky Mountain Range

This mountain building process ended about 50 million years ago.

Question 10

How were the Rocky Mountains characterized at the time of their formation?

Answer 10

Round-looking mountains covered with V-shaped valleys

The valleys were cut out by erosion.

Question 11

What geological process caused Alberta and North America to migrate northward?

Answer 11

The relentless march of the tectonic plates

Question 12

How did the migration of North America affect its climate?

Answer 12

It got cooler

Question 13

What significant geological feature was formed as a result of glacial activity in North America?

Answer 13

The familiar jagged features of the Rocky Mountains

Question 14

Approximately how many years ago did the icy process that carved the Rocky Mountains begin?

Answer 14

1.7 million years ago

Question 15

What happened to the Bearspaw Sea at the beginning of the Cenozoic Era?

Answer 15

It retreated to the southwest

Question 16

What geological formation was left in southern Alberta after the retreat of the Bearspaw Sea?

Answer 16

The Bearspaw sedimentary rock formation

Question 17

What type of fossils is the Bearspaw sedimentary rock formation rich in?

Answer 17

Dinosaur fossils and other fossils

Question 18

During the Cenozoic Era, what was a new source of sedimentary rock in Alberta?

Answer 18

Runoff from the rising Rocky Mountain Range

Question 19

What geographical feature did large rivers create as they flowed down during the Cenozoic Era?

Answer 19

V-shaped valleys

Question 20

Fill in the blank: During the late Cretaceous Period, much of southern Alberta was submerged under the _______.

Answer 20

[Bearspaw Sea]

Question 21

True or False: The retreat of the Bearspaw Sea had no impact on the sedimentary rock formations in Alberta.

Answer 21

False

Question 22

What significant climatic change occurred during the first 15 million years of the Tertiary Period?

Answer 22

A significant drop in average global temperatures

This cooling affected both animal and plant life.

Question 23

What type of forests replaced tropical forests during the Tertiary Period?

Answer 23

Temperate evergreen forests scattered with rivers, lakes, and swamps

This transition marked a significant change in plant life.

Question 24

How did the temperatures during the Tertiary Period compare to the Cretaceous Period?

Answer 24

Cooler than the Cretaceous Period but still warmer than today

This indicates a gradual cooling trend over time.

Question 25

Approximately how much of the Tertiary Period is thought to have featured climate resembling present-day southern Louisiana?

Answer 25

About two-thirds of the way through the Tertiary Period ## Footnote This suggests a significant climatic shift in Alberta.

Question 26

What significant climatic change occurred during the first 15 million years of the Tertiary Period?

Answer 26

A significant drop in average global temperatures ## Footnote This cooling affected both animal and plant life.

Question 27

What type of forests replaced tropical forests during the Tertiary Period?

Answer 27

Temperate evergreen forests scattered with rivers, lakes, and swamps ## Footnote This transition marked a significant change in plant life.

Question 28

How did the temperatures during the Tertiary Period compare to the Cretaceous Period?

Answer 28

Cooler than the Cretaceous Period but still warmer than today ## Footnote This indicates a gradual cooling trend over time.

Question 29

Approximately how much of the Tertiary Period is thought to have featured climate resembling present-day southern Louisiana?

Answer 29

About two-thirds of the way through the Tertiary Period ## Footnote This suggests a significant climatic shift in Alberta.

Question 30

What period did evergreen forests begin to dominate in Alberta?

Answer 30

Tertiary Period ## Footnote This marks a significant shift in the types of forests present during this geological time.

Question 31

What type of mammals survived the Cretaceous Extinction?

Answer 31

Mainly small rodents ## Footnote These mammals took advantage of the ecological niches left by the extinct dinosaurs.

Question 32

What significant change occurred in mammal evolution by 40 million years ago?

Answer 32

Many new forms of mammals appeared in the fossil record ## Footnote These included ancestors of modern hooved herbivores, flesh-eating carnivores, and large-brained primates.

Question 33

What were the ancestors of modern hooved herbivores, flesh-eating carnivores, and large-brained primates known for?

Answer 33

They appeared in the fossil record around 40 million years ago ## Footnote This diversification marked a key evolutionary step for mammals.

Question 34

Fill in the blank: By 65 million to 40 million years ago, mammals _______ and flourish.

Answer 34

diversify ## Footnote This period was crucial for the development of various mammalian species.

Question 35

What does the fossil skull noted for its relatively large brain represent?

Answer 35

One of the earliest ancestors of modern primates ## Footnote This fossil is around 195 million years old, indicating an early development of primate traits.

Question 36

What adaptation of grasses allowed them to withstand the cooler and drier climate of the late Tertiary Period?

Answer 36

Dense root structure ## Footnote The dense root structure of grasses is crucial for survival in challenging climates.

Question 37

How many species of grasses are found worldwide?

Answer 37

About 9000 species ## Footnote Grasses are versatile and can thrive in diverse environments.

Question 38

When did the first grass species appear in the fossil record?

Answer 38

Early in the Tertiary Period ## Footnote Grasses began to dominate later in the Tertiary Period.

Question 39

What climatic changes occurred in Alberta during the late Tertiary Period?

Answer 39

Significantly cooler and drier ## Footnote These changes influenced the type of vegetation that thrived.

Question 40

What type of mammals gained a survival advantage due to the dominance of grasses?

Answer 40

Ruminants ## Footnote Ruminants can digest cellulose, which is beneficial for consuming grasses.

Question 41

What is the main component of plant cell walls that ruminants can digest?

Answer 41

Cellulose ## Footnote Ruminants have specialized digestive systems for processing cellulose.

Question 42

What is a significant advantage of grasses over other plants in response to grazing?

Answer 42

Grasses grow from the base ## Footnote This growth pattern allows grasses to recover more effectively from grazing.

Question 43

What transformation did the wetlands of the early Tertiary Period undergo?

Answer 43

Into drier woodlands and then into grasslands ## Footnote This transition reflects significant ecological changes in the region.

Question 44

True or False: The resistance of grasses to grazing is an adaptation that contributed to the transformation of Alberta's landscape.

Answer 44

True ## Footnote The ability of grasses to withstand grazing pressures allowed them to dominate.

Question 45

What type of environment became prevalent in Alberta due to the dominance of grasses?

Answer 45

Grassland ## Footnote This environment supported large herds of grazers and their predators.

Question 46

What overall trend occurred during the Tertiary Period?

Answer 46

Cooling trend ## Footnote This was one of many climate changes in Earth's past.

Question 47

What type of evidence do scientists use to study past climate changes?

Answer 47

Sedimentary rocks ## Footnote These rocks contain fossils and other indicators of historical climates.

Question 48

What do tropical plant and animal fossils found in polar regions indicate about past climates?

Answer 48

These regions were much warmer in the past ## Footnote The presence of such fossils suggests a significantly different climate.

Question 49

What does the absence of tree pollen in current tropical landscapes suggest?

Answer 49

The past climate was too cold for trees to survive ## Footnote This indicates significant historical climate variation.

Question 50

What do sedimentary rock layers provide for scientists studying the Tertiary cooling trend?

Answer 50

Many clues about past climates ## Footnote The layers contain various indicators of historical environmental conditions.

Question 51

What overall trend occurred during the Tertiary Period?

Answer 51

Cooling trend ## Footnote This was one of many climate changes in Earth's past.

Question 52

What type of evidence do scientists use to study past climate changes?

Answer 52

Sedimentary rocks ## Footnote These rocks contain fossils and other indicators of historical climates.

Question 53

What do tropical plant and animal fossils found in polar regions indicate about past climates?

Answer 53

These regions were much warmer in the past ## Footnote The presence of such fossils suggests a significantly different climate.

Question 54

What does the absence of tree pollen in current tropical landscapes suggest?

Answer 54

The past climate was too cold for trees to survive ## Footnote This indicates significant historical climate variation.

Question 55

What do sedimentary rock layers provide for scientists studying the Tertiary cooling trend?

Answer 55

Many clues about past climates ## Footnote The layers contain various indicators of historical environmental conditions.