Assignment 4: Part 1 Paper: Cretaceous Paleobiogeography of Western North America PDF

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Part 1 of the assignment....

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Assignment 4 - Part 1 Paper: Cretaceous Paleobiogeography of Western North America PART 1 - Begin here 1.

Use the map labelled “Fossil locations in North America” in the Resources Package to match numbered positions to geographic locations. Look carefully for the faint provincial and state boundaries, and simply enter the number in space provided (no zeros, no spaces, just the one- or two-digit number). Named location

2.

3.

Numbered dot (enter values here)

Close to the Saskatchewan / Manitoba boundary

9

Middle of Saskatchewan

13

Canadian Gulf Islands

10

Alberta / Northwest Territories boundary

7

Central Yukon Territory

3

North central British Columbia

6

The Gulf Islands of Washington State

11

Fossils found at these locations fall into one of the seven general fossil types shown in the two pages labelled “Fossil and Specimen types” in the Resources Package. Identify the type of environment in which each of specimen type will have lived. In the blanks, enter either Land, Shallow (or coastal) sea, or Deep ocean. Hint: In general, ammonites and coccoliths lived in much deeper, offshore waters when compared with the other marine animals considered here. Fossil types

Type of environment in which the fossilized organism lived

St 1

land

St 2

land

St 3

land

St 4

shallow coastal

St 5

shallow coastal

St 6

deep ocean

St 7

Deep ocean

The following table lists fossil types found at each location on the ‘Fossil locations in North America’ map in the Resources Package, in geological formations that were dated using a nearby volcanic ash layer to be roughly 85 Ma years old. Ash layers help date formations in many parts of the world. In blank spaces, indicate which type of environment likely existed at each location at that time.

For example, as stated in the hint above for Question 2, St #6 lives in deep water. In the table below, St #6 is found at locations 2 and 4. So we can write “deep” in the space for ‘most likely environment at that location 85 million years ago’. NOTE: Eight of these fossil locations are not real finds, although they are plausible. The other five are real fossils and locations. We will come back to look at these in more detail during Assignment 5 in Module D.

4.

Location

Type of fossils found at that location, correlating with the 85 Ma age marker

Most likely environment at that location roughly 85 million years ago

1

St 2

land

2

St 6

deep

3

St 2

land

4

St 6

deep

5

St 5

shallow

6

St 1

land

7

St 7

deep

8

St 4 & St 5

shallow

9

St 4

shallow

10

St 2 & St 3

land

11

St 2

land

12

St 5

shallow

13

St 7

deep

Use this table to indicate paleo-environments for fossil types found near each numbered location in different geological formations that were dated using a second volcanic ash layer to be roughly 65 Ma years old. (Hint: Once again, use your data from Question 2 to figure out the relevant environment for each location, just like you did for Question 3.) Location

Type of fossils found at that location, correlating with the 65 Ma age marker

Most likely environment at that location roughly 65 million years ago

1

St 1

land

2

St 4

shallow

3

St 3

land

4

St 4

shallow

5

St 3

land

6

St 2

land

7

St 4 & St 5

shallow

8

St 2

land

9

St 1

land

10

St 2

land

11

St 2

land

12

St 3

land

13

St 1, 3

shallow

5.

Now list the numbered locations (if any) that were deep ocean locations around 85 Ma. (Hint: The answer ‘none’ is possible.) ________2 4 7 13________________

6.

Also list the locations (if any) that were shallow or coastal locations around 85 Ma. (Hint: The answer ‘none’ is possible.) ________5 8 9 12________________

7.

List the locations (if any) that were deep ocean locations around 65 Ma. (Hint: The answer ‘none’ is possible.) ________none________________

8.

Finally, list locations (if any) that were shallow or coastal locations around 65 Ma. (Hint: The answer ‘none’ is possible.) ________2 4 7 13_____________ For the fossils dated to 85 million years old, label the locations with the type of environment that best describes them: land, shallow or deep.

9.

10. Now, for the fossils dated to 65 million years old, label the locations with the type of environment that best describes them: land, shallow or deep.

Now that you have gathered all your fossil data, go back on to the course website and access Assignment 4 – Part 2 where you will use the data you have gathered here to work through an exercise which demonstrates how this fossil data provides you with information that can be used to unravel past events in western North America. Note that you can open the question set and work on it and then close it again as many times as you like during the time that the assignment is open. Just don’t press ‘save and submit’ until you are sure you are happy with your work as you will not be able to reaccess it once you do that. At that point, it will be formally submitted for grading.

Based on the paleo-information, biologists could do further research on how the ancient animals changed their living areas and why they did that. Let’s wrap up this exercise with a summary paragraph. Type in the correct word from the following list: north, south, east, west, increased, decreased, more, less. Use only the words provided, do not add any punctuation, do not capitalize. Be careful for spelling errors or you won't get the point! During the period before 85 Ma when the Pacific plate was moving -ward, elevations in mountain ranges and elevations in foreland basins . Consequently the inland sea in size. After that (towards 65Ma), when Pacific plate motion shifted to moving -ward, the inland sea’s sea-level will have steadily . This is a simplification because there were many faults in what is now British Columbia, Yukon and Alaska. The Tintina fault is one example; since the end of the Cretaceous, the western side of this fault has moved in a roughly - -ward direction relative to its eastern side (Hint: check Figure C24). These tectonic processes will have made it likely that dinosaur populations communicated east to west and likely that they communicated in roughly north to south directions. Consequently, dinosaurs whose fossils were found to the of the Rockies were likely to be genetically similar to dinosaurs in Asia and probably like those living near the inland sea, of the Rockies. Quiz saved at 9:13pm...