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Wallace R. Griffitts

Publications and source records attributed to Wallace R. Griffitts.

11 recordsLinked to original sources
USGS1968

Distribution of beryllium, tin, and tungsten in the Lake George area, Colorado

Complex ore deposits are spatially associated with granitic bodies of Precambrian age in the Lake George area, Colorado. They include greisens that contain high concentrations of beryllium and subordinate amounts of tin, tungsten, and other metals associated with the Redskin Granite. Scheelite deposits in calc-silicate rocks and greisen deposits near Tappan Mountain that contain tin and tungsten minerals are associated with the Silver Plume (?) Granite. Samples of stream sediments and soils locally show anomalous concentrations of beryllium, tin, copper, lead, and molybdenum. Some of the areas of anomalous concentrations correlate with known deposits; others do not, and this fact suggests that further prospecting is warranted.

Colorado↗
USGS1962

Beryllium in the United States, exclusive of Alaska and Hawaii

This map shows most of the known occurrences of beryllium minerals and of rocks that contain 0.003 percent or more beryllium (0.01 percent Be0) in the United States (exclusive of Alaska and Hawaii). The occurrences are subdivided on the map according to genesis and size. The genetic types of deposits shown are: pegmatite, vein and replacement deposits (exclusive of tactite), tactite, disseminated beryl in granite and rhyolite, hot spring deposits, and residual materials. Deposits of each type that have a total production plus reserve greater than 24,000 lbs. of contained Be0 (equivalent to 1200 short ton units of Be0 or 190 tons of beryl) are shown by a large symbol. Names are given only for the districts that are of particular economic or scientific importance. Both published information and unpublished data gathered by the U. S. Geological Survey were used in preparing the map and text.

Mineral Investigations Resource Map↗
USGS1957

Pegmatite geology of the Shelby district, North Carolina

The Shelby district is divided into a northwestern and a southeastern province. The rocks in the southeastern province include various units in the Battleground schist formation and the Yorkville granodiorite. Those in the northwestern province include the Carolina gneiss, with its Shelby gneiss member, and the Toluca quartz monzonite. The Cherryville quartz monzonite forms a batholith that is just west of the boundary between the two provinces. Pegmatites related to both the Toluca and the Cherryville quartz monzonites lie in the Carolina gneiss and many dikes of pegmatite that are related to the Cherryville quartz monzonite are in the tin-spodumene belt that lies along the boundary between provinces. The rocks of the southeastern province have been bent into steep isoclinal folds; those of the northwestern province were bent into open folds and gently-dipping isoclinal folds. The rocks to the southeast have been metamorphosed in the epidote-amphibolite facies whereas the rocks to the northwest represent the amphibolite or granulite facies. The pegmatites related to the Toluca quartz monzonite form sills, dikes, and concordant lenses in the Carolina gneiss, as well as dikes in the Toluca quartz monzonite. The bodies are unzoned and consist mainly of gneissic microcline-plagioclase-quartz pegmatite. The pegmatites related to the Cherryville quartz monzonite form dikes and disconformable lenses in the Carolina gneiss and the Toluca quartz monzonite. These pegmatites range widely in composition and many are zoned. The dikes west of the Cherryville batholith are rich in muscovite and plagioclase and may contain no microcline or only a moderate amount of microcline. Quartz cores and microcline-rich intermediate zones are common. Similar pegmatite forms dikes along the west edge of the tin-spodumene belt. The tin-spodumene belt containes albite-microcline-spodumene-quartz pegmatite. These dikes of albitic pegmatite are largest and most nearly parallel to one another south of Kings Mountain. Farther north they lie in fractures of several sets. The main factors that affected the development of zones in the pegmatite dikes are composition of magma, temperatures of magma and wall rock, and deformation during crystallization. For best development of zones and the growth of the largest muscovite books the rate of cooling and the rate of crystal growth must be rather fast. Complete consolidation probably was reached in most dikes within a gew years after the start of crystallization.

Open-File Report↗
USGS1954

Beryllium resources of the tin-spodumene belt, North Carolina

Pegmatite dikes in the tin-spodumene belt of North and South Carolina uniformly contain about 0.05 percent BeO. The most abundant minerals in the pegmatite contain from 0. 0001 to 0.01 percent BeO. Beryl, having 12.0 to 12.3 percent BeO, is the only beryllium-rich mineral and contains more than 80 percent of the total beryllium in the rock. Beryl-bearing pegmatite crops out on hillsides near streams that flow through the pegmatite belt. Much of the pegmatite contains spodumene, feldspar, mica, cassiterite, and columbite, as well as beryl, but separating these minerals will require milling. The minable spodumene ore in the Kings Mountain area, above a depth of 300 feet contains about 40,000 tons of beryl, equivalent to 6, 000 tons of BeO, if 80 percent of the BeO is assumed to be in beryl. Other pegmatite in that area contains an additional 238,000 tons of beryl, or 35, 900 tons of BeO. On the basis of the same assumptions the spodumene ore above a depth of 300 feet 1 in the Beaverdam Creek area contains 6, 000 tons of beryl, or 800 tons of BeO, and all other pegmatite in that area contains an additional 13, 000 tons of beryl, or 1, 700 tons of BeO. The entire tin-spodumene belt contains 823, 000 tons of beryl, equivalent to 122,800 tons of BeO. Little beryllium was found in the Piedmont province outside of the tin-spodumene belt.

Circular↗