depending on whether they were facing the light or in shadow; we have indicated a shadow of the human glove and of the dinosaur track to help guide your eye. Are you looking at the side that was down when the sediment was soft, or the side that was up? A) Side that was down B) Side that was up Feedback: Footprints are pushed downward into soft sediment. When more sediment is washed in, this second layer will fill the print beneath. Later, after the layers have hardened, the rock may be turned upside-down and then the layers cracked apart (or, the layers cracked apart and then turned upside-down). If you see a footprint sticking up, you are looking at the side of the second layer that originally was down. You can tell that this picture shows a track sticking up by the shadows—ridges or other things that stick up have a light on one side and a shadow on the other, as seen here, whereas holes or troughs or other things going down have light and shadow on the same side.
Table for Individual Question Feedback Points Earned: 2.0/2.0 Correct Answer(s): A 5. You are a geologist. While walking in the fog one day, you bang into a cliff. After rubbing your sore nose, you inspect the cliff, and see what is shown in the picture, in a one-foot-square area. You recognize that this cliff is made of “fossil sand dunes”, with wind-blown sand that was later glued together by hard-water deposits. You are accompanied by a student, who is carrying your tea and crumpets for you. You sketch four arrows on the cliff, label them as shown, and ask the student which of the arrows was pointing up when the loose sand was deposited. Your student is brilliant, and correctly tells you the answer. The arrow that was pointing up when the loose sand was deposited is the arrow that is closest to: A) A B) B C) C D) D
Feedback: The wind dumped sand in the lee of a dune, making the striped-looking pattern that you see behind the big B. Then the wind blew the top off, making a nearly horizontal erosion surface, followed by
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- Fall '08
- Correct Answer, Individual Question, geologist