. Bulletin of the Geological Society of America. Geology. F&.3. Figure 1.—Thin-sections of oolitic and pisolitic Barite Figures 1 and 2. Pisolitic barite (3 diameters). Figure 3. Barite ring resembling travertine (3 diameters). Figure 4. Large oolites (2 diameters). Figure 5. Thin-sec- tion of oolite, showing central structure and fine lines (25 diameters). Figure 6. Thin- section of oolite without well marked concentric spheres. arranged and the spheres marked by very fine lines. It appears that the con- cretions began to form by deposition of barite in both a crystalline and earthy
. Bulletin of the Geological Society of America. Geology. F&.3. Figure 1.—Thin-sections of oolitic and pisolitic Barite Figures 1 and 2. Pisolitic barite (3 diameters). Figure 3. Barite ring resembling travertine (3 diameters). Figure 4. Large oolites (2 diameters). Figure 5. Thin-sec- tion of oolite, showing central structure and fine lines (25 diameters). Figure 6. Thin- section of oolite without well marked concentric spheres. arranged and the spheres marked by very fine lines. It appears that the con- cretions began to form by deposition of barite in both a crystalline and earthy condition, with small amounts of other minerals, and that this later continued to precipitate more rapidly in a purer condition, either as a replacement of some other mineral or in open spaces in the sand. No evidence of replacement is found unless it be the traces of calcite existing in some oolites, as the con- cretions are loose and not embedded in a solid rock. In color the oolites are white to bluish gray, and they are very smooth on the outer surface. From their appearance they were at first thought to be chert concretions, but an examination showed a specific gravity of and a flame coloration for barium, strontium, and a trace of 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 Geological Society of America. [New York : The Society]
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectgeology, bookyear1890
