, In the photo above, Dave and Kym are discussing a model of the Waterpocket Fold in Capitol Reef National Park. The Waterpocket probably formed in the same way as the Front Range of the Rockies. This involved: , A., The spreading of Death Valley pinched Utah into Colorado. B., A subduction zone in western Utah squeezed eastern Utah (Capitol Reef) and Colorado (Front Range). C., Especially warm sea floor in the subduction zone off the west coast rubbed along under western North America and squeezed or wrinkled the rocks, folding them (probably with a push- together fault somewhat deeper under the fold). D., An obduction zone in western Utah squeezed eastern Utah (Capitol Reef) and Colorado (Front Range). E., The low region, in Dave’s left hand, dropped relative to the high region, in Dave’s right hand, along a Death-Valley-type fault, and something similar happened in dropping Denver relative to the Front Range. We’re still arguing about the West, but it is clear that the west-coast subduction zone, which started with old, cold sea floor going down, slowly warmed as the subduction zone and the spreading ridge came closer together. Warmer sea floor would be more buoyant, and so would sink more slowly, or float better. And that would create more friction, squeezing and rumpling with the overlying continent. As the sea floor warmed, squeezed-up/rumpled-up features developed in the West. So we think this makes sense. , Points Earned:, 1/1
Your Response:, C (#5) Practice Quiz #5 Your response has been submitted successfully. /// , 2 Points Missed , 3 Percentage , 40% 1. , Most landslides happen when: , A. , The unconsolidated materials on hillslopes are dry, so the grains roll easily downhill. B. , The unconsolidated materials on hillslopes are damp, so the grains are made slippery by the water. C. , The unconsolidated materials on hillslopes are very wet and thus heavy and slippery, and the water doesn’t have to “break” as the grains move. D. , The unconsolidated materials on hillslopes are paved with blacktop. E. , The unconsolidated materials on hillslopes are paved with concrete. Dry sand can move, but even very dry times on hillsides usually don’t cause landslides. But let a hurricane really saturate things, and all heck can break loose. Paving causes lots of changes, but landslides are not usually the result. , Points Earned: , 0/1 Correct Answer: , C Your Response: , B 2. , What is accurate about the planet’s climate system? , A. , The wind blows because heating of the poles drives convection cells in the atmosphere, and the winds appear to curve to the left or right over the surface of the planet because of the planet's the planet is spherical shape .