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Algal pebbles formed chiefly of Chlorellopsis coloniata Reis in a matrix of ostracode limestone, natural size. Garfield County, Colorado. August 18, 1925. Plate 46-B in U.S. Geological Survey. Professional paper 154. 1929.
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Small area of the polished specimen in Bradley 245; this shows a part of the oolitic sandstone which contains fragments of micro crystalline calcite with ferruginous oolite grains suspended in the positions in which they formed; fragments of algal limestone consisting almost wholly of Chlorellopsis and an unusually large oolite grains that show the wide banding characteristic of all the oolites in this bed. Enlarged 5 diameters. Specimen is from the basal part of an algae reef on the north side of White River, in the SW 1/4 sec. 30, T. 1 N., R. 95 W. Rio Blanco County, Colorado. Plate 48-B in U.S. Geological Survey. Professional paper 154. 1929.
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Upper surface of a tabellate reef with spongy surface; each molariform head is more or less columnar in section, though many of them are very irregular and complexly intergrown; 75% of natural size. Specimen is from about 530 feet above the base of the Green River formation on the divide between Douglas and East Salt Creeks. Garfield County, Colorado. August 18, 1925. Plate 43-A in U.S. Geological Survey. Professional paper 154. 1929.
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Polished vertical section of a chlorellopsis reef; showing the irregular and vaguely radial arrangement of the lobate algal colonies; also a part of the oolitic sandstone upon which it rested, the lightest-gray areas are fine grained sandstone, the black grains are oolite grains and the medium toned gray areas are fragments of silty limestone, alga reefs and mud lumps. Natural size. From near the base of the Green River formation, SW 1/4 sec.30, T. 1 N., R. 95 W. Rio Blanco County, Colorado. August 11, 1924. Plate 35 in U.S. Geological Survey. Professional paper 154. 1929.
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Group of superimposed algae reefs in the upper part of the basal member of the Green River formation near the divide between west Douglas and East Salt Creeks. The man's feet are at the base of the lowest reef, which truncates the shaly sandstone beds below; his shoulders are level with a thin reef that has unusual pencillated structure. The thin dark colored bed at the top of the unit consists of algal pebbles some of which are shown Bradley photo 182. The group is bout 5.5 meters (18 feet) thick. Garfield County, Colorado. August 18, 1925. Plate 29-A in U.S. Geological Survey. Professional paper 154. 1929.