Unit 3: Earth & Space Science

Answer: C — The correct answer is C because the process of subduction occurs when one plate is forced beneath another, resulting in volcanic activity and the formation of a deep-sea trench. This is a common outcome of subduction zones, such as the one between the Pacific and North American plates. Option A is incorrect because collision between the two plates is not likely to occur in this scenario. Option B is incorrect because the Pacific plate is being subducted, not broken apart. Option D is incorrect because the Pacific plate is being subducted beneath the North American plate, not overriding it.

Answer: B — The correct answer is B because the rocks at the base of the mountain, such as shale and sandstone, are typically formed through sedimentary processes at lower pressures and temperatures, while the rocks at the summit, such as granite and gneiss, are typically formed through igneous and metamorphic processes at higher pressures and temperatures. Option A is incorrect because volcanic activity is not the primary factor in forming these rock types. Option C is incorrect because the environment in which the rocks were formed does not fully explain the difference in rock types. Option D is incorrect because weathering and plate tectonics are not the primary factors in forming these rock types.

Answer: A — The correct answer is A because the scenario describes the subduction of the Pacific Plate beneath the North American Plate, which is a classic example of lithospheric plate subduction. This process results in the formation of a deep-sea trench and potential volcanic activity as the overlying plate is subjected to increasing heat and pressure. The other options are incorrect because they describe different geological processes: continental rifting (B) involves the splitting apart of continents, seafloor spreading (C) involves the creation of new oceanic crust, and continental collision (D) involves the collision of two continental plates.

Answer: A — The correct answer is A because the Pacific plate is being subducted under the North American plate, which is a characteristic of a convergent plate boundary. This process results in the formation of deep-sea trenches and an increase in volcanic activity. Option B is incorrect because a divergent plate boundary involves the pulling apart of two plates, resulting in the creation of new crust. Option C is incorrect because a transform plate boundary involves the sliding of two plates past each other, resulting in no creation or destruction of crust. Option D is incorrect because a continental collision zone involves the collision of two continental plates, resulting in the formation of mountain ranges.

Answer: A — The correct answer, A, is based on the principle of superposition, which states that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on the bottom. This principle is a fundamental concept in geology and is used to determine the relative ages of rock layers. The other options are incorrect because while tectonic plate movement, erosion, and volcanic activity can all shape the Earth's surface, they do not directly explain the formation of the distinct rock layers observed in the Grand Canyon.