Geological Series, Bulletin |
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Absorption Per cent andesitic anticline Banner coal bed Blue Wing bornite bornite and chalcocite Branch location Bucu quadrangle burned Cent Cent cent of water chalcocite chalcopyrite clay Lab Clintwood Clintwood quadrangle coal horizon Coal Shale Coal coarse color common brick Cone 05 copper country rock County Creek location deposits drainage basin Eagle east elevation epidote exposed feet of coal feet thick Garden Hole Geologic Gladeville Glamorgan gneiss granite Hagy hypogene inches of coal inches thick intergrowths Kennedy coal bed Lower Banner coal McClure River mines Mountain mouth northeast northwest Norton formation outcrops Peneplane plasticity Pound River Prater Creek probably prospect quartz residual clay Ridge road Russell Fork Russell Prater Creek sample sandstone sandy schist schistosity shaft Shale southeast southwest steel hard stiff-mud machine streams sulphides supergene surface terraces tests thin Tiller Upper Banner coal vein Virgilina Virgilina district Virginia Wise formation
Beliebte Passagen
Seite 124 - ... or by a combination of the two. Finally the item of cost of installation and operation of a suitable concentrating plant is believed to be greatly in favor of flotation. The greatest expense is that of crushing machinery, and this has to be met in either case regardless of the method of concentration used. It is not the intention of the writer to go into the question of flotation in detail. In fact, such a discussion would be out of place in a geological report. All he desires to do is to call...
Seite 9 - Devitrified rhyolite from South Mountain, Pa. CH Henderson, Analyst, Williams, GH, The volcanic rocks of South Mountain in Pennsylvania and Maryland. Am. Jour. Sci., Vol.
Seite 71 - The alteration has advanced sufficiently far in the schistose phases to destroy in most cases the original structure and minerals of the rock. "2. From structural, petrographic, and chemical evidences the rocks...
Seite 72 - ... Atlantic Coast and Lake Superior regions, shown to have been derived from an original basic eruptive rock type, has equal application to the existing rocks of the Virgilina district. "3. The rocks are pre-Cambrian in age and represent an area of ancient volcanics similar to others described as occurring along the Atlantic Coast region from Eastern Canada to Georgia and Alabama and in the Lake Superior region. "4. The rocks are cut by numerous approximately parallel quartz veins which contain...
Seite 69 - Carolina-Virginia boundary line about 140 miles west of Norfolk, Va., and 40 miles east of Danville, Va. About one-half of the area, which up to the present has been the most productive, lies within each state. The North Carolina portion, as included in the accompanying map, comprises an area about 22 miles long and 18 miles wide, and lies in the northwest portion of Granville and the adjoining northeastern corner of Person counties. The Virginia area is longer but narrower, is about 50 miles long...
Seite 74 - The region has suffered a period of severe dynamic metamorphism or mashing, consequent upon a great compressive force which squeezed the beds into enormous folds ; followed by a time of chemical alteration and mineralization ; which in turn was succeeded by a long period of erosion and weathering. The rocks have suffered to a variable degree from all these factors. In general, each formation has a massive and a mashed or schistose phase, with every gradation between the two. The passage of heated...
Seite 28 - The clay is fairly plastic, and required 38 per cent of water to work it up. The air shrinkage was 8.7 per cent, and the average tensile strength GO pounds per square inch.
Seite 74 - Wide bands of a sedimentary, slate-like rock, composed of varying admixtures of volcanic ash and land waste, have the greatest areal extent. Intercalated with these occur strips and lenses of acid and basic volcanic rocks, represented by fine and coarse-grained volcanic ejectamenta and old lava flows.
Seite 71 - Watson states his conclusions'' as follows : "1. The rocks of the area here described have been greatly altered through pressure and chemical metamorphism, as indicated in the prevailing secondary schistose structure and the abundant development of the secondary minerals — chlorite, epidote, and hornblende — and small amounts of others. The alteration has advanced sufficiently far in the schistose phases to destroy in most cases the...