Points Awarded15.00Points Missed0.00Percentage100%1. Which is the correct age progression, from younger (first) to older (last)?A) C, D, E, F, BB) B, F, E, D, CC) E, F, B, C, DD) B, C, D, E, FE) D, E, F, B, CFeedback: The package of sediments C, D, E, F is upside-down, as shown by the footprints and mud cracks, so C is oldest, and F the youngest of these. B is above the unconformity above all of C, D, E, and F, so is the youngest of these five.Points Earned: 1.0/1.0 Correct Answer(s):B2. Which correctly gives the order of the faults, from youngest (first) to oldest (last):B
3. Which is younger:4. Which is younger:E5. Which is accurate about the history of the Grand Canyon:A) The Kaibab limestone that forms the upper rim of the canyon is the youngest rock layer known from Arizona and surrounding states.
B) The rock record of the canyon contains exactly one unconformity.C) The canyon is wider at the top and narrower at the bottom because the river was wider D) In the deepest part of the canyon, the river cuts through rocks formed by metamorphism E) The oldest rocks are on top, with younger ones beneath, as shown by all of the footprints Feedback: The Colorado River is cutting through the metamorphic rocks from the heart of an oldmountain range. The sedimentary rocks above are right-side up, and the Kaibab Limestone slantsdown to the north beneath the rocks of Zion, which are older than the rocks of Bryce, among others. Many unconformities exist in the walls of the Canyon, including the one below the Precambrian sediments and the one above those sediments. The idea of the river narrowing over time was the hypothesis that an interested tourist presented to one of the professors and a ranger at the Canyon a few years ago. When the professor asked whether the tourist would want to go out on a narrow point with a jackhammer, the tourist said no, because the rocks might fall off and slide down into the Canyon. When the professor pointed out the many places that rocks had fallen off and slid down, the quick-witted tourist figured out that the Canyon has been widened by such rockfalls as the river has cut downward.Points Earned: 1.0/1.0 Correct Answer(s):Dwhen the region was wetter, and has narrowed as deserts spread recently.of older sedimentary rocks in the heart of a mountain range.being upside-down in the rocks of the canyon walls.
- Fall '08