Page 306 - Laboratory Manual in Physical Geology

A CTIVIT Y 10.4 Determine Attitude of Rock Layers and a
Formation Contact

Name: ______________________________________ Course/Section: ______________________ Date: ___________

A. On the flat surface below , draw a symbol ( FIGURE 10.3 ) that indicates its horizontal attitude (orientation). On each of the

inclined surfaces , draw a strike-and-dip symbol ( FIGURE 10.3 ) to indicate exactly how its strike and dip are oriented. Based

on the north arrows and your strike-and-dip symbols, use a protractor from the GeoTools at the back of the lab manual to
measure exactly and record the strike of surfaces in both quadrant and azimuth form (Refer to FIGURES 10.3 and 10.4 ).

Under water
N N

Dry

1. Flat top surface of a rock wall 2. Inclined rock surface 3. Inclined rock surface
Quadrant strike Quadrant strike

Azimuth strike Azimuth strike
B. For each map below, record the strike of the formations and their contacts. Then use the Rule of Vs ( FIGURE 10.4 ) to

determine the dip direction and sketch formation contacts on the geologic cross section ( FIGURE 10.6 , steps 1 and 2).

1. Strike: 2. Strike:

X

N N

Y
Hint: Cut a V-shaped notch X Y
into the top edge of a 3 x 5
card. Hold card vertically and
look down on edge. See Vs at
different dips of the card.

C. This is an aerial photograph taken from directly above the

landscape. The view is 1 km wide.
1. Circle a V-shaped notch.
2. Add a strike and dip symbol to one of the flatirons.

3. What is the strike? ______________________

4. What is the dip direction? ______________________

D. REFLECT & DISCUSS Draw (pen) a possible formation
contact on the image in part C and explain why you drew
it there.
N

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