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Macroscopic sedimentary structures of the lower supratidal zone, 3.48 Ga Dresser Formation, Pilbara, Western Australia. (A) Three generations of erosive margins (numbers 1 to 3). Scale: 5 cm. (B) Edge of an erosive margin in close-up. Scale: 5 cm. (C) Fragments deposited in front of an erosive margin. (Compare Figs. 1B and 10A.) Tape for scale.
