Geologic Mapping Invitational Trial Event

Transcription

1 Geologic Mapping Invitational Trial Event A TEAM OF UP TO: 2 Team Name AVAILABLE TIME: 50 min Required Materials: Each team MUST have a protractor, ruler, non-programmable calculator, colored pencils, and an equal-area projection stereonet with tracing paper and pin. Permitted Materials: Each team is permitted to bring one three-ring binder (any size) containing information in any form from any source. The material must be 3-hole punched and inserted into the rings (notebook sleeves are allowable). Scoring: All questions will have been assigned a predetermined number of points. The highest score wins. Selected questions having differentiated weights will be used to break ties. Multiple Choice (2 points each) Circle the correct answer clearly. 1. Continental crust A) is composed mostly of low density basaltic rock B) is thicker than oceanic crust C) drifts through the lithosphere D) is generally younger than oceanic crust E) is made of the same kinds of rocks as oceanic crust 2. Deep sea trenches generally occur A) between divergent lithospheric plates B) along the crest of rift valleys C) above rising mantle plumes D) along the margins of some ocean basins E) at fracture zones 3. The density of the Earth s mantle is A) about the same as that of the crust B) more than that of the crust C) more than that of the core D) unknown

2 4. Identify the type of plate boundary indicated on the shaded relief map A) convergent B) divergent C) transform D) the indicated feature is not a plate boundary 5. The youngest rocks of the oceanic crust are found A) in the deep trenches B) near continental margins C) along fracture zones D) along the oceanic ridge system E) in the abyssal depths of the oceans 6. Magnetic anomalies in the oceanic crust A) indicate the age of the rock B) indicate rates of plate movement C) indicate direction of plate movement D) form from reversals of the magnetic poles E) all of the above 7. Match the type of fault motion is most likely to occur at each of the locations given. Write the correct letter next to the corresponding number: (3 points) 1) On a subduction zone A) Normal motion 2) At a mid-ocean ridge B) Reverse motion 3) At a transform plate boundary C) Strike-slip motion

3 Short Answer Complete each question according to the directions given. Point values are as indicated. 8. For each of the labeled layers below, give the corresponding name in the space provided. (5 points) A. B. C. D. E. 9. A) What name best describes this feature? (2 points) B) Assume that unit D is cretaceous and unit A is late Permian, what term best describes this feature? (2 points)

4 10. A) What direction are the folds plunging? (2 points) B) What types of folds are folds A, B, and C? (6 points) Problem Solving Complete each question according to the directions given. Point values are as indicated. 11. Calculate the bed thicknesses of units A, B, and C (12 points)

5 12. The topographic map below has been drawn using 20m contour intervals. A) Label the contours with the appropriate elevations (3 points) B) Mark the highest elevation point with a red star (2 points) C) Construct a topographic profile on the line below the map, clearly marking elevations on the vertical scale (7 pts) A Ocean B A B

6 13. Complete the tasks in the map below. A) Use the marked elevations (marked in meters) in the square below to draw a topographic map using 10m contours. Label the contours clearly (10 points) B) Mark the likely path of water from a spring originating at the star (2 points)

7 14. Using the information given on the geologic map below, draw a cross-section from A to A. Assume no faulting, as none are indicated on the map. Be sure to label the units (10 points) A A

8 15. Using basic, geologic principles, determine the order of events depicted in the cross-section below. Labels include depositional units, intrusions, faulting, and erosional horizons. Place the letters in order in the column to the right from oldest (bottom) to most recent (top) (11 points) Youngest Oldest 16. A sandstone bed outcrops at the three locations marked with stars. This area is inaccessible by foot, so you must determine the orientation of the bed from the data you have. Determine the strike and dip of the bed and circle your final answer of an aziumth, dip angle in degrees, and dip direction (8 points).