Your plastic container contains a model of sedimentary rock layers. You will ﬁgure out what those layers are and their relative ages by taking cores using plastic straws. Don’t touch the clay of the model or remove the tape that is on the outside of the container.
1. Decide as a group where to take a core.
2. Hold the straw vertically and push straight down until the straw touches the bottom of the box. Turn and wiggle the straw to free it from the rest of the dough and then pull it out.
3. Label the straw ﬁlled with core with a label sticker that has a sample number on it. (Don't cover the end with the dough.) Some cores are not successful. If a core of play dough did not come out with the straw, try again in another spot.
4. Write the same sample number on another sticker and ﬁx it onto a pin next to the hole on the dough.
5. Repeat the process until you have taken 15 core samples and 15 locations marked on the dough. As a group decide where each core should be located. (Do you want to spread them out, core in a line, or in one small area?)
6. Put all of your cores against a sheet of white paper so that everyone in the group can see them. How many different colored layers did you ﬁnd? _________________
7. Because plate tectonics moves and tilts layers of sedimentary rocks, not all layers are found in all locations. Identify which layers are found in every location you cored. On the time line below, mark the colors of these layers with the youngest at the top and the oldest at the bottom.
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