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30 feet Adobe Canyon Adobe Valley alaskite altitude average Baranof Island bedrock beds Black Bart blocks Bonnet Hill Brewer pit Capola Mountain Carolina Cedar Creek Valley chert Chrome chromite cinnabar contains County crest Cretaceous crystals depth drift dunite east exposed feet long feldspar fissure flasks fractures Franciscan formation GEOLOGICAL SURVEY grade grains granodiorite Hill inches landslide layers lenses limestone manganese oxides masses massive mica miles Mineral Ridge muscovite Nightingale northeast northwest occurs open cut Oriskany sandstone Orndorff prospect outcrop Patriquin pegmatite pegmatite bodies percent peridotite placer plate pounds power factor production Puerto area pyrolusite pyroxene pyroxenite quartz quicksilver Red Bluff Bay Ruby samples sandstone scheelite schist serpentine shaft shale shear zone sheet mica silica-carbonate rock Spruce Pine district stained stope strike sulfides surface Table Mountain tactite thick thrust fault tons topaz rock tunnel ultrabasic rocks
Page 40 - This action involves a challenge to the procedures adopted by the Bureau of Mines/ United States Department of the Interior, In assessing civil penalties for violation of health and safety standards under the Federal Coal Mine Health and Safety Act of 1969, Public Law 91-173, 30 USC §801, et seq.
Page 198 - ... concretions in the upper part. The Codell sandstone member occurs as a lentil above the Blue Hill shale member and immediately below the base of the Niobrara formation. The Codell sandstone member ranges in thickness from a few inches to as much as 20 feet where it is exposed on the outcrops, and consists predominantly of fine to very fine sand and silt. At some places where this part of the section is exposed, the Codell does not consist of a well-developed sandstone bed but of thin lentils...
Page 60 - ... along lines that trend northeast and northwest, the longest group observed being about 100 feet long. The topaz also forms narrow veinlets that cut across the foliation in the schist, and thin lenses in the planes of schistosity; and grains of topaz are disseminated in the schist at some places.****. The district contains probable reserves amounting to about 106,000 tons of rock averaging at least 15 percent topaz; this material contains roughly 16,000 tons of topaz, most of which probably can...
Page 60 - The topaz forms irregular replacement bodies, ranging in thickness from a fraction of an inch to about 10 feet, which appear to be grouped roughly along lines that trend northeast and northwest, the longest group observed being about 100 feet long. The topaz also forms narrow veinlets that cut across the foliation in the schist, and thin lenses in the planes of schistosity; and grains of topaz are disseminated in the schist at some places.****. The district contains probable reserves amounting to...
Page 130 - Fails and 5 miles south of Bracebridge. Swampy meadows about a quarter of a mile wide and half a mile long extend on either side of the outlet. A small area of grey-white diatomite which in places is 18 inches thick, but averages 1 foot, and is underlain by blue-grey silt, is exposed in the banks and bed of the creek. This deposit contains about 200 tons of the only natural white diatomite so far found...
Page 21 - Some electrical properties of foreign and domestic micas and the effect of elevated temperatures on micas ; AB Lewis, EL Hall, and FR Caldwell.
Page 120 - ... which form figures in the chapter on Mines and Prospects. HISTORY, PRODUCTION, AND USES OF MANGANESE ORES. The manganese deposits of western Virginia have been worked at times since 1834 and have yielded both manganese and manganiferous iron ores. The earliest mine to be worked was the 'Mineral Ridge mine in Frederick County. It is said to have been worked for many years before the Civil War, beginning in 1834, and for many years after the war, and the total production of this mine during the...
Page 67 - The jasper layers differ in thickness from a fraction of an inch to several feet. The same layer varies in thickness, pinching out locally In many places.
Page 110 - Jr. (pp. 79-110, with map. 30 cents..) 936-E : Manganese deposits of Ceda'r Creek Valley, Frederick and Shenandoah Counties, Virginia, by Watson H. Monroe, (pp.
Page 135 - County. the strike of the mineralized zone 60 feet, and a lower parallel drift, reached by a slope 35 feet long down the dip of the bed, is said to go in 200 feet, but it was filled with water at the time of visit. Seventy tons of manganese ore is said to have been removed from the tunnel and placed on the dump at the edge of the run, but at the time of visit most of it had been washed away by the stream. The ore is in chert beds 1 to 2 feet thick separated by thin sandy clay beds. At the entrance...