1. Earth History January to April 2018 Labs Tue & Wed
Geology 1023
Earth History
January to April 2018
Labs Tue & Wed

2. Geology 1023
Contact information
David McMullin
HSH 305
Office hours:
11:30 – 1:00 Tu & Th (or appt.).

3. Geology 1023 Schedule Assistants posted on ACORN
Tuesday: Peyton Barney & Kyle Kucker
Wednesday: Kyle Kucker & Heather McGuire

4. PowerPoints and Answer keys
On lab website
Link to website also on ACORN

5. Grading & Philosophy Grading
11 labs worth 25%
2 tests worth 15%
GEOL 1023 more about getting to understand how information garnered in GEOL 1013 is used and integrated (i.e., grammar instead of vocabulary).

6. Materials Work in pencil
Coloured pencils (for structure and correlations)
Ruler
Protractor
Other (calculator, sometimes)

7. Questions?

8. Geology 1023
Lab # 1
Plate Tectonics

9. Plate tectonics Plates and boundary exercise
Map of earthquake epicentres
vast majority of earthquakes occur in narrow zones, which commonly have a surface expression (fault)
clearly demonstrate the margins of major plates
Use the map in textbook to do the exercise (p. 17, p. 16 in 6e)
Purpose of the exercise is to familiarize you with the major plates and boundaries

10. Polar wander
The remnant magnetism of rocks indicates that poles appear to have moved as time passes.
Initially thought that the magnetic field moved considerably.
Studied various different continents. Found that the paths didn’t match.
If the continents were fixed then the paths should be the same

11. But, because it’s easier to draw, manipulate and understand (a) we call them apparent polar wander paths.

12. Polar wander paths exercise
Draw the apparent polar wander path (APWP) for N. America using the information given
i.e., the pole for N. Am. at a given time is the distance given at the bottom of the page from the head of the arrow, and in the direction indicated by that arrow.
Trace N. America and its APWP
Overlay the traced N. Am. APWP on the Europe APWP.
Part will look the same = time during which N. Am. and Europe behaved as one (i.e., they were joined)
Part of the traces will be different = time during which N. Am. and Europe behaved differently (i.e., they became two separate continents)

13. Cambrian rocks deposited here (at tip of the arrow)

14. Paleomagnetic
measurements indicate that the pole was 12,000 km away (in the direction of the arrow)

15. Therefore, measure 12,000 km (8 cm at the scale of the map) in that direction

16. Do the same with the other arrows and connect the resulting dots in a second zig-zag line. This line is the APWP for N. America. C

17. Polar wander paths exercise
Draw the apparent polar wander path (APWP) for N. America using the information given
i.e., the pole for N. Am. at a given time is the distance given at the bottom of the page from the head of the arrow, and in the direction indicated by that arrow.
Trace N. America and its APWP
Overlay the traced N. Am. APWP on the Europe APWP.
Part will look the same = time during which N. Am. and Europe behaved as one (i.e., they were joined)
Part of the traces will be different = time during which N. Am. and Europe behaved differently (i.e., they became two separate continents)

18. Plate divergence (spreading) exercise
Figure 3 shows three stages in divergence of two continental fragments
Questions are intuitive
Q 3 (b) Note that the two positions marked C have reached their present position in 10 Ma. That is, distance C-C happened in 10 Ma.
Pay attention to units and unit conversion (i.e., 100,000 cm per km and 1,000,000 years per Ma)

19. Magnetic profile caused by “stripes” of basalt of alternating polarity

20. Correspondence between magnetic profile (as measured across the ocean floor)
and the magnetic time scale

21. Magnetic stripes exercise
The “profiles” show the magnetization across the ridge
Correlate changes from positive to negative
Colour up according to your legend

27. Questions?