 MAY, 1918. 27 camptonite may prove to be fine-textured essexite porphyries. The dikes range in thickness from a fraction of an inch to 25 feet, with an average of about one foot. The dikes are most numerous in or near eruptive areas. They rarely occur...  The American Journal of Science - Page 3461918Affichage du livre entier - À propos de ce livre
 | Ralph Walter Stone - 1920 - 392 pages
...embedded in shale and shaly limestones. In some places the beds of gypsum are very numerous. The beds range in thickness from a fraction of an inch to 25 feet or more. FIGURE 8. — Outline map of Michigan showing gypsum cteposits. The thinner beds are generally... | |
 | 1920 - 428 pages
...embedded in shale and shaly limestones. In some places the beds of gypsum are very numerous. The beds range in thickness from a fraction of an inch to 25 feet or more. FIGURB 8. — OnUtae map of Michigan showing gypsum deposits. The thinner beds are generally... | |
 | 1925 - 1004 pages
...embedded in shale and shaley limestones. In some places the beds of gypsum are very numerous. The beds range in thickness from a fraction of an inch to 25 feet or more. The thinner beds are generally small in area, but some of the thicker ones have been traced... | |
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