1. Explain why the presence of carbon dioxide in the atmosphere is important to weathering. (2 points) 2. What are the main products of weathering of igneous rocks? (2 points) 3. Describe some of the ways that soil can be degraded if we don’t take care to look after it. (2 points) 4. How does the velocity of moving water affect the transportation of sedimentary particles? (2 points) 5. What is chert made of, what is its typical source, and in what environment is it typically deposited? (2 points) 6. Describe the tectonic origins of rift basins and foreland basins. (2 points) 7. What is the typical origin and depositional environment of normal (i.e., fining upward) graded bedding? (2 points) 8. With respect to sedimentary rocks, what are the criteria for defining a “formation”? (1 point) 9. Explain why mineral stability is important to metamorphism. (2 points) 10. Describe the nature of foliation in gneiss. (1 point) 11. Describe the geological environment in which gneiss forms. (2 points) The following questions refer to the geological map of the Mt. Polley area in central British Columbia, and are based on information in the map legend, the map symbols, the cross sections, and on the map itself: 1. What is the approximate age range (in years) of the youngest deposits in the map area? (1 point) 2. Provide the unit codes, rock type names, and ages of any three of the layered units that are entirely sedimentary in origin. (3 points) 3. Based on the map and cross-section A-A’, how would you describe the relationship between the Unnamed Cretaceous Conglomerate (Kcg) and the rocks underneath it? (You may need to refer to the “Symbols” explanations on the map.) Why is this rock called “polymictic”? (3 points) 4. The oldest unit shown on the map is primarily made up of metamorphic rocks. What are the main rock types, and in what type of metamorphic environment did they form? Where on the map can you find this rock unit? (3 points) B4: Describing and interpreting sedimentary rocks (15 points) The following questions are based on the samples in your rock/mineral kit: 1. By examining the size and shape of grains within a clastic sedimentary rock, we can gain some understanding about how far the grains were transported, and the nature of the depositional environment in which they were deposited. Study and describe the samples listed below and use your observations to complete the table. (8 points) Sample Grain size range (mm) Rounding and shape Sandstone (3) Shale (4) Conglomerate (6) Arkose (7) Sample Probable transport distance (e.g., short, medium, long) Probable depositional environment (e.g., high-energy stream, lake, ocean) Sandstone (3) Shale (4) Conglomerate (6) Arkose (7) 2. Describe the likely depositional environments of the following samples. (5 points) Sample Depositional environment Bituminous coal (1) Limestone (2) Banded iron fm. (24) Gypsum (29) Halite (32) 3. Describe the likely conditions that result in the formation of dolostone (5) (a.k.a. dolomite). (2 points) Part C: Longer Questions (35 points) Please answer the following questions. Write as much as you think is necessary to answer each question, but don’t forget that someone has to read what you write, so be as concise and clear as possible. You do not need to reference the text or the material in the course units (except images and quotations), but if you use any outside sources, please provide in-text citations. Use any referencing style you are comfortable with. 1. Describe and explain some of the factors that control soil development in general and explain why podsols are the most common soils in many parts of southern Canada. (10 points) 2. Explain what sedimentary rocks can tell us about past environments, focussing on the characteristics of sedimentary grains, the types of sedimentary structures present, and the presence and types of fossils. (15 points) 3. Discuss the role of plate boundary environments and plate tectonic processes in regional metamorphism, and explain why isostasy is important to regional metamorphism. (10 points)
