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Isle Royale National Park, Michigan. Tuff-breccia overlying the Greenstone Flow. Fragmental character is clearly evident in this outcrop, which is close to the base of the pyroclastic unit on the north shore of Tobin Harbor near Newman Island. The knife is 7 centimeters long. Circa 1971. Figure 20, U.S. Geological Survey Professional paper 754-C; Figure 20, U.S. Geological Survey Bulletin 1309.
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Isle Royale National Park, Michigan. Slabby sandstone outcrop on Stone House Island. Circa 1971. Figure 28, U.S. Geological Survey Bulletin 1309.
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Isle Royale National Park, Michigan. Chlorastrolite amygdules showing characteristic segmented pattern. Circa 1971. Figure 72, U.S. Geological Survey Bulletin 1309.
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Yosemite National Park, California. Glacial till, an unsorted mixture of boulders, sand, and clay exposed along the Tioga Road at Siesta Lake. Figure 60, U.S. Geological Survey Bulletin 1595.
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Isle Royale National Park, Michigan. Copper Harbor Conglomerate sloping gently southeast into Lake Superior near Attwood Beach. Circa 1971. Figure 26, U.S. Geological Survey Bulletin 1309.
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