younger fossils looking more like living things than do older fossils is William Smith’s “law” of faunal succession, not an unconformity. Points Earned: 1.0/1 .0 Correct Answer(s): E 5. The picture above shows a muddy sandstone that was deposited on a flood plain. Dr. Alley's index finger in the lower left points along a ridge on the surface of the rock (shadows are to the lower right of Dr. Alley’s finger and to the lower right of the feature he is pointing along; his finger is above the rock, so the feature must be a ridge and not a trough). The rock is:
A) Right-side-up; you are looking at the side that was facing up toward the sky when the rock was deposited. B) Upside-down; you are looking at the side that was facing down toward the center of the Earth when the rock was deposited. C) Edge-on; the side that was facing up toward the sky when the rock was deposited is now facing toward the upper-right-hand-corner of the picture. D) Edge-on; the side that was facing up toward the sky when the rock was deposited is now facing toward the lower-right-hand-corner of the picture. E) Edge-on; the side that was facing up toward the sky when the rock was deposited is now facing toward the lower-left-hand-corner of the picture. Feedback: A story is told here. Some mud was deposited, dried and cracked. The muddy-sandy layer we are looking at was deposited on top, and the brown ridges stuck DOWN into the cracks in the mud. After the rocks were hardened, this muddy-sandy layer was split off from the muddy layer below, and then turned over, so you are looking at the bottom of the layer now. Points Earned: 1.0/1 .0 Correct Answer(s): B 6.
Look at the picture above, which shows a small section of a “fossil” sand dune (a sand dune in which the grains have been “glued” together by hard-water deposits).When the dune was first deposited, which was up (which letter is closest to the arrow that is pointing in the direction you would have looked to see the sky when the dune was deposited)? A) A B) B C) C D) D Feedback: Just above the letter “C” there is a small unconformity. The layers above are cut along that surface. Layers must exist to be cut, so the layers above that surface are older, the lower layers are younger, and “up” was toward the bottom. Points Earned: 1.0/1 .0 Correct Answer(s): C 7.
Look at the picture above which shows a region just less than a foot across, of a stream deposit from the base of the same pile of rocks that show up in Bryce Canyon. This picture was taken in the face of a cliff in Red Canyon, just west of Bryce Canyon National Park. A indicates a piece of limestone that has been rounded off in a stream; B indicates a mass of sand glued together by hard-water deposits, and C indicates another such mass of sand glued together by hard-water deposits .
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