. A treatise on rocks, rock-weathering and soils;. Petrology; Soils. 124: AQUEOUS EOCKS in beds which, when compared with other rocks of the earth's crust, are of comparatively insignificant proportions, but which are nevertheless of considerable geological importance. Though deposits of this material are still forming, and have been formed in times past at various periods of the earth's history, they appear most abundantly associated with the Tertiary formations. The beds are wide-spread, and some of them of economic importance. A deposit in Biln, Bohemia, is some 14 feet in thickness, and is
. A treatise on rocks, rock-weathering and soils;. Petrology; Soils. 124: AQUEOUS EOCKS in beds which, when compared with other rocks of the earth's crust, are of comparatively insignificant proportions, but which are nevertheless of considerable geological importance. Though deposits of this material are still forming, and have been formed in times past at various periods of the earth's history, they appear most abundantly associated with the Tertiary formations. The beds are wide-spread, and some of them of economic importance. A deposit in Biln, Bohemia, is some 14 feet in thickness, and is estimated by Bhrenberg to contain 40,000,000 shells to every cubic inch. Beds occur in the United States at South Beddington, Maine; Lake Umbagog, New Hampshire; in. Fig. 10.—Section through lake basin showing the formation of diatomaeeoua earth. «, bed rock; &&, floating peat; cg, decayed peat; d, diatomaceous earth. Morris County, New Jersey; near Richmond, Virginia; in Cal- vert and Charles counties, Maryland; in New Mexico; Graham County, Arizona; near Reno, Nevada, and in various parts of California and Oregon. Chemically the rock is impure opal, as shown by the following analyses of samples from (I) Lake Umbagog, New Hampshire, (II) Morris County, New Jersey, and (III) Pope's Creek, Mary- land: Chemical Composition of Diatomaceous Earth. CONSTITTJBNTS Silica (Si02) Iron oxides (FeaOa and TeO) Alumina (AlaOg) Lime (CaO) Water (H2O) Organic matter II % III Number III showed also small amounts of potash and soda. (2) The Calcareous Group. — These rocks are made np of the more or less fragmental remains of molluscs, corals, and. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Merrill, George
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectpetrolo, bookyear1913
