 Sterrett1 that we may quote his description almost without modification. After stating that the pegmatites of North Carolina occur mainly in the Roan gneiss, which is a series of hornblendic gneisses and schists, and in the Carolina gneiss which is nonhornblendic,...  Bulletin of the United States Geological Survey - Seite 403von Geological Survey (U.S.) - 1907Vollansicht - Über dieses Buch
 | Good Roads Institute, Chapel Hill, N.C. - 1897 - 1172 Seiten
...cutting from one layer to another across the bedding. Locally, there is an elbowing or bulging-out on one wall, without a similar irregularity on the...yards in thickness. The limit of size below which they cannot be profitably worked for mica might be placed arbitrarily at from 1 to 2 feet for rich and regular... | |
 | Good Roads Institute, Chapel Hill, N.C. - 1908 - 772 Seiten
...they are directly associated with those rocks, most of the deposits are found in small biotite gneiss or schist masses included in the hornblende areas....profitably worked for mica might be placed arbitrarily at 1 to 2 feet for rich and regular "veins." In the very large pegmatites the mica is not, in general,... | |
 | 1908 - 916 Seiten
...commonly occurs in overlapping lenticular-shaped bodies and sheets of more persistent extent. The deposits range from a fraction of an inch up to many yards in thickness, and the length of the lens-shaped masses may be from two or three times to more than twenty times their... | |
 | United States. Bureau of Mines - 1908 - 906 Seiten
...commonly occurs m overlapping lenticular-shaped bodies and sheets of more persistent extent. The deposits range from a fraction of an inch up to many yards in thickness, and the length of the lens-shaped masses may be from two or three times to more than twenty times their... | |
 | Charles Willard Hayes - 1910 - 764 Seiten
...they are directly associated with those rocks, most of the deposits are found in small biotite gneiss or schist masses included in the hornblende areas....to many yards in thickness. The limit of size below wluch they can not be profitably worked for mica might be placed arbitrarily at 1 to 2 feet for rich... | |
 | 1922 - 434 Seiten
...of hornblendic gneisses and schists, and in the Carolina gneiss, which is nonhornblendic, he says: Pegmatites occur in irregular masses, streaks, lenses,...fraction of an inch up to many yards in thickness. * * * Horses, or inclusions of wall rock, are common in pegmatite. Some of them are in the form of... | |
 | Heinrich Ries, William Shirley Bayley - 1922 - 404 Seiten
...hornblendic gneisses and schists, and in the Carolina gneiss, which is nonhornblendic, he says: fegmaliles occur in irregular masses, streaks. lenses, augen,...balls, some of them having no visible connection with oilier pegmatite bodies. They range from :i fraction of an inch up to many yards in thickness. * *... | |
 | North Carolina. Department of Conservation and Development - 1925 - 298 Seiten
...of hornblendic gneisses and schists, and in the Carolina gneiss which is nonhornblendic, he says : . Pegmatites occur in irregular masses, streaks, lenses,...fraction of an inch up to many yards in thickness. . . . Horses, or inclusions of wall rock, are common in pegmatite. Some of them are in the form of... | |
 | North Carolina. Division of Mineral Resources - 1925 - 138 Seiten
...of hornblendic gneisses and schists, and in the Carolina gneiss which is nonhornblendic, he says : Pegmatites occur in irregular masses, streaks, lenses,...fraction of an inch up to many yards in thickness. . . . Horses, or inclusions of wall rock, are common in pegmatite. Some of them are in the form of... | |
 | 1921 - 650 Seiten
...series of hornblendic gneisses and schists, and in the Carolina gneiss which is nonhornblendic, he says: Pegmatites occur in irregular masses, streaks, lenses,...fraction of an inch up to many yards in thickness. . . . Horses, or inclusions of wall rock, are common in pegmatite. Some of them are in the form of... | |
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