1. Lab evaluations Go to Acadia Central http://central.acadiau.ca/my http://central.acadiau.ca/my Log in Click on Online Registration Click on Information Click on GEOL1010L(A,B,C)1 Click on Evaluate

2. Some comments

3. Vertical exaggeration On all the profiles you’ve drawn the vertical and horizontal scales are not the same Whelan Cove – Canning: vertical scale is 1:5000, horizontal scale is 1:50 000 This is ten times vertical exaggeration

4. This: …should be this.

5. This… …should be this.

6. And this… …should be this.

7. Much easier to compare the shape of these two than…

8. … these two, even though here their vertical scales are identical.

9. Calculating vertical exaggeration Vertical exaggeration (VE) is the vertical scale divided by the horizontal scale Remember that scales are ratios to begin with If vertical scale is 1:5000 and horizontal scale is 1:50000 the VE is = (1/5000)/(1/50000) = 50000/5000 = 10 If vertical scale is 1:20000 and horizontal scale is 1:50000 the VE is = (1/20000)/(1/50000) = 50000/20000 = 2.5

10. Structure and Geological Maps

11. Rule of Vs (vees) Helps in reading geological maps As a contact changes elevation, when viewed from overhead (map view), it shifts in the direction of dip i.e., a contact “vees” in the direction of dip

12. Rule of Vs a)Shallowly dipping contacts make “large” Vs b)Horizontal contacts run parallel to the topographic contours c)Steeply dipping contacts make “small” Vs d)Vertical contacts run straight across topographic contours

13. Shallowly dipping contacts

15. Horizontal contacts

19. Steeply dipping contacts

21. Vertical contacts

23. Horizontal (parallel to contours) Shallow dip (big “vees”) Steep dip (small “vees”) Vertical dip (runs straight across topo)

24. Question 1 what is the value of the contours?

25. Question 1 position the contours

26. Question 1 draw the surface

27. Question 1 where do the contacts cut the surface?

28. Question 1 what is the orientation of the contacts? Hotizontal!!! (contacts follow contours)

29. Question 1 fill the units

30. Question 1 finished! At least part (a)

31. Question 2a 3 is younger than 2 is younger than 1

32. Question 2a therefore contact between 3 and 2 slopes towards 3 (i.e., 3 is on top of 2)

33. Question 2a likewise contact between 2 and 1 slopes toward 2 (i.e., 2 is above 1)

34. Question 2a contacts between 3 and 2 join; separate 3 from 2 everywhere

35. Question 2a separate 2 from 1

36. Question 2a colour/shade

39. Question 2a label

40. Question 2b let’s just focus on the boundary between layers 2 and 3

41. Question 2b rule of vees tells us that the 2/3 boundary on the west side dips…

42. Question 2b …to the east

43. Question 2b rule of vees tells us that the 2/3 boundary on the east side dips…

44. Question 2b …vertically

45. Question 2b complete the line…and draw the others in the same way!

46. A couple of points… Rock units are assumed to be planar and of equal thickness throughout the area Wider outcrop in one place and narrower outcrop in another indicates differences in dip When drawing sections try to maintain thickness of units around folds.

47. Contacts are parallel and units maintain thickness

48. Structure labs/drawing Recent labs often “sloppy” Take time to draw contacts properly –Units must maintain thickness –Contacts should be parallel and “smooth” –Contacts should be in the right place –Angles should be approximately correct (use a protractor if you cannot draw angles to within 10°) and consistent

49. Block diagrams… See if you can work these ones out for yourself But ask questions Hint: look at the strike and dip symbols.

50. Dykes and faults This exercise is fairly intuitive Note: we cannot tell the absolute sense of motion on a fault thus we indicate relative motion with two “half” arrows

51. Strike and dip Put strike FIRST (up to 3 digits) Then DIP (only 2 digits) Then DIP direction 110 / 25 NE

52. Drawing a strike and dip symbol (important for final test) What is the orientation determined? 115/37 NE

53. Drawing a strike and dip symbol 115/37 NE What is the strike? 115 What is the dip direction? NE What is the dip? 37 Done! Remember that if it is a cleavage measurement, the symbol is like this… N

54. Geological Maps

55. Wolfville map Information is available on the: MAP …on the LEGEND …and on the CROSS-SECTIONS Also some more detailed information in the “Descriptive Notes”

56. Wolfville Map questions 6 – 13 13 (relatively straightforward) questions Some hints –Use the legend and cross-sections –“a deep well” means hundreds of metres (scale of the cross sections) –Contacts are: Conformable (bedding) Cross cutting (faults, intrusions, unconformities) –For question 12, think of the rule of vees –For question 13, think of your fieldtrip to Black River