Test #2 Igneous, Weathering Part A: Multiple Choice [30 pts] 1. Lava floods are defined by the usual rock that forms. (a) granite (b) basalt (c) andesite (d) diorite Name: /78 = % 2. A large collection of plutons create this formation: (a) diapir (b) intrusion (c) batholiths (d) volcanoes 3. Molten rock beneath the Earth s surface is called: (a) magma (b) lava (c) intrusion (d) batholiths 4. The area of a cooling intrusion where magma is cooling the fastest because it is next to the cool, solid country rock is called: 5. The area that separates the intrusion from the country rock: 6. Pieces of country rock that remain in the intrusion: 7. Part of the country rock that is slowly being heated by the cooling intrusion: 8. A bubble of liquid magma rising through the crust is known as a : (a) diapir (b) intrusion (c) batholiths (d) volcanoes 9. A vertical intrusion that cuts through layers of sedimentary rock, country rock, are known as: (a) dikes (b) sills (c) intrusion (d) contact 10. A horizontal intrusion that works its way across layers of sedimentary rock are known as: (a) dikes (b) sills (c) intrusion (d) contact 11. Molten rock on the surface of Earth is known as: (a) lava (b) intrusion (c) magma (d) bathloith 12. Extrusive igneous rocks are gained. (a) fine (b) coarse (c) porphyritic (d) clastic 13. A feature of our mantle which feeds many shield volcanoes and geothermal features: (a) volcanoes (b) mantle plumes (c) volcanoes (d) fault 14. A rock that is rich in silica, greater than 65% is known as a rock. 15. A rock that is very low in silica, less than 45% silica is known as a rock.
16. A rock that is close to 50% silica, relatively low in silica is known as a rock 17. A rock with silica content between 50% and 65% is known as a(n) rock. 18. When magma hardens in the throat of a volcano, then the sides of the volcano get worn away through weathering, we call it: (a) an intrusion (b) an extrusion (c) volcanic neck (d) all of these 19. A large volcanic crater is known as a : (a) big hole (b) crater (c) caldera (d) none of these 20. A gently sloped large volcano, with sides not steeper than 4 that produces a quick, runny lava: 21. A steep sided composite volcano (~30 ) that is made from alternating layers of volcanic ash and lava flows: 22. A cinder based volcano that usually forms on the flanks of shield volcanoes: 23. Weathering which changes the composition of the rock is known as weathering: (a) mechanical (b) differential (c) chemical (d) all of these 24. Weathering which simply breaks rock into smaller pieces is known as: (a) mechanical (b) differential (c) chemical (d) all of these 25. The removal of the outer layers of rock is known as: (a) sheet joints (b) jointing (c) columnar jointing (d) exfoliation 26. A collection of debris below a weathered cliff or rock face is known as: (a) weathering junk (b) talus (c) moraine (d) all of these 27. The formation of limestone caverns rely on the formation of acid. (a) Hydrochloric (b) sulfuric (c) carbonic (d) awesome 28. Different layers of soil as we get deeper are referred to as: (a) horizons (b) layers (c) clays (d) LFH 29. Nova Scotia is home to soil type. (a) Regesol (b) Cryosol (c) Solonetz (d) Pozsol 30. Which is the same soil type as NS but simply the American name: (a) Entisol (b)spodosol (c) Gelisol (d) Wet inceptisol
Part B: Diagrams 1. Diagram and label the process of limestone cave formation from the creation of carbonic acid to the end of the limestone deposit. [8 pts] 2. Diagram and explain (this means using sentences) the formation of a volcanic neck. Make sure you include a definition of a volcanic neck and an intrusive structure. [4 pts]
Part C: Rock Identification [8pts] 1. A course grained rock appears mostly light coloured, with a nice grey colour. 2. A dark coloured course grain rock has a dark grey colour to it. 3. A fine grained igneous rock has some frothy look to it which allows it to float in a tank of water. 4. A fine grained rock has a black glassy look to it. 5. A rock appears to have a porphyritic texture and appears very light in colour (silica rich). 6. A rock with porphyritic texture with a darker colour to it (silica deficient). 7. A course grained rock appears to be dark in colour with a salt and pepper look to it. 8. A fine grained rock has very rare crystals has a very dark appearance. _ Part D: Short Answer 1. Explain the difference between chemical and mechanical weathering. [6 pts] 2. What are three ways for a rock to be mechanically weathered? [3 pts] 3. What is meant by the term oxidation? [2 pts]
4. Explain the difference in grain (coarse vs fine) between intrusive and extrusive igneous rock [4 pts] 5. Explain the A, B, and C soil horizons as well as LFH layers [4 pts] 6. Describe a shield volcano and what areas on the planet it can form [4 pts] 7. What can be said about the chemical composition of the magma and the igneous rock that is formed when the magma cools? [2 pts] 8. What characteristics of volcanoes determines their violence when they erupt? [3 pts]