LAB EXERCISE 10.13 Interpreting Simple Geologic Maps
(Q004) Part 4.a. Describe the angle and direction of dip of the Silurian and Devonian strata on Map A.
43 to 56 degrees to the west
(Q003) Part 3.a. Describe the angle and direction of dip of the Triassic and Jurassic strata on Map A.
6 degrees to the north1
Part 1.a. What are the ages above and below the unconformity shown in Map A?
Above: Triassic and Jurassic/Below: Devonian-Silurian
(Q011) Part 4.c. What are the ages of the rocks above and below the unconformity?
Cretaceous-Devonian
(Q006) Part 2.b. What type of intrusion is located in the western portion of the folded layers on Map B? Include age, rock, and type of intrusion.
Cretaceous; granite; pluton
(Q008) Part 1.c. Describe the geologic features of Map C. Include the trend of the fault and the age and orientation of the strata it cuts across.
Fault is trending about 110; strata has a strike of approximately 025, tilting 12 degrees west
(Q009) Part 2.c. What type of fault is present on Map C and what can you determine about the relative motion of the rocks on either side of the fault?
Left-lateral strike slip; rocks are moving to the left
(Q007) Part 3.b. What type of intrusion cuts across both the folded layers and the intrusion described in the previous question? Include age, rock, and type of intrusion.
Tertiary; basalt; dike
(Q002) Part 2.a. What type of unconformity is present on Map A?
angular unconformity
(Q005) Part 1.b. Describe the fold present on Map B. Include the type of fold, the age of the strata in the fold, whether the fold is plunging, and describe the symmetry of the fold.
anticline; Devonian and Silurian; non plunging; asymmetrical (dip is steeper for one limb than the other)
(Q010) Part 3.c. What type of unconformity is present on Map C?
disconformity
(Q012) Part 1.d. If you walk along the southern edge of Map A, in what direction do you need to go to walk "up-section" (i.e., into rocks of progressively younger age) or "down-section" (i.e., into rocks of progressively older age)?
up-section: west/down-section: east