What To Do

1. Download the printer-friendly worksheets in the format of your choice (available at the beginning of Lab 4). You can also click here to download Figure 4.9 as a PNG file for editing with drawing software.

2. Draw lithostratigraphic correlation lines between the rock units A, B, and C in Figure 4.9. Use solid lines for correlations you are confident about and dashed lines for ones that are tentative.

3. Draw lines to correlate any unconformities and label them with their type.

4. Answer the questions that follow Figure 4.9.

Questions

a. Were units A, B and C deposited in terrestrial or marine environments?

b. Locate the unconformity at the bottom of units B and C and draw a dark wiggly line at its location. Name the type of unconformity at the bottom of units B and C.

c. What happens to the conglomerate from east to west?

d. In which direction was the source of sediments for the conglomerate?

e. What happens to the middle sandstone unit between B and C?

f. What depositional environment created the middle sandstone and siltstone sequence?

g. What type of regional scale unconformity could occur below the debris flow deposit?

h. The debris flow deposit could also be just a local process where a coarse-grained alluvial fan advanced over the sedimentary environment you identified in (g). What other information would you need to decide which of these two options (regional erosion, local erosion) is correct?