An Investigation Beside the Seats
A fourth-grade class visited the outdoor amphitheater in Alder City Park. Grass and paved paths now surround its seats. Beside the amphitheater, two natural rock faces rise above the ground. The rocks were not brought in to build the park. A park geologist helped the class investigate what the rocks could reveal about earlier landscapes.
Step 1: Students stayed on the marked path and photographed the west rock face. They did not climb, chip rocks, or collect fossils. The geologist checked that its four layers had not been overturned or mixed. In this undisturbed stack, lower layers formed before the layers above them. The class labeled the layers A through D, starting at the bottom.
Step 2: Students examined enlarged photographs. They recorded each layer's rock description and fossil groups separately. The geologist identified the fossils using their shapes and other features. Keeping the records separate would let students connect each fossil observation with its place in the stack. The class did not measure the ages of the rocks in years.
Step 3: The class used a habitat reference card. The identified coral and clam groups lived in salt water. The identified snail and water-lily groups lived in freshwater ponds. Tree stumps with roots still attached in their growing positions showed that trees had grown at that location. A loose fossil carried from somewhere else would give less certain evidence about that spot.
Step 4: Students repeated their photo observations at the east rock face, across the amphitheater lawn. They kept the same recording method and compared rock descriptions, fossil groups, and layer order. The upper part of the east face was hidden by soil and grass. The class recorded what was visible without guessing what lay behind the covering.