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Alumina Alumina and oxide anticlinal Appalachian argillaceous axis band basin beds belt beneath Blue Ridge bluish calcareous Carbonate of lime Carbonate of magnesia Carbonic Acid character Cheat river clay coal measures coal region coal seams coarse colour compact conglomerate containing creek deposit distance district east eastern Eocene Epidotic exposed exposures extending feet felspathic ferruginous flexures formation fossils fracture fragments furnace geological Gneiss grains green sand grey gypsum hills Hornblende James river layers limestone localities lower lying margin marl mass materials Mica micaceous middle secondary miles mineral Miocene mountain mouth nearly northwest numerous observations occurs oxide of iron places points portion Potomac present quarry quartz region rocks sandstone sandy seen shales shells side Silica slate slaty specimens springs strata stratum structure Sulphate surface synclinal Tertiary texture thickness thin tion tract upper valley variety veins vicinity Virginia western
Page 713 - and then suddenly brought down again to the floor; the air under it being by this means propelled, will pass along, till it escapes at the opposite side, raising the cloth in a wave all the way as it goes. In like manner, a large quantity of vapor may
Page 835 - Red Sandstone.—A series of sandy, argillaceous, and often calcareous strata, the predominant colour of which is brick-red, but containing portions which are of a greenish grey. These occur often in spots and stripes, so that the series has sometimes been called the variegated sandstone. The European formation so called lies in a geological position immediately above the coal measures.
Page 835 - Petroleum.—A liquid mineral pitch, so called because it is seen to ooze like oil out of the rock. Pisolite.—A stone possessing a structure like an agglutination of peas. Pit Coal.—Ordinary coal; called so because it is obtained by sinking pits in the ground. Pitch Stone.—A rock of a uniform texture, belonging to the
Page 837 - Silt.—The more comminuted sand, clay, and earth, which is transported by running water. It is often accumulated by currents in banks. Thus the mouth of a river is silted up when its entrance into the sea is impeded by such accumulation of loose materials.
Page 837 - Stalagmite.—When water holding lime in solution drops on the floor of a cavern, the water evaporating leaves a crust composed of layers of limestone: such a crust is called stalagmite. Stilbite.—A crystallized simple mineral, usually white, one of the Zeolite family, frequently included in the mass of the Trap rocks. Strata,
Page 832 - Fault, in the language of miners, is the sudden interruption of the continuity of strata in the same plane, accompanied by a crack or fissure varying in width from a mere line to several feet, which is generally filled with broken stone, clay, &c.
Page 830 - or trough, formed of older rocks, sometimes used in geology almost synonymously with "formations," to express the deposites lying in a certain cavity or depression in older rocks. Bitumen.—Mineral pitch, of which the tar-like substance which is often seen to ooze out of the Newcastle coal when on the fire, and which makes it cake, is a good example.
Page 525 - field, and separated by about three miles of primary rocks, lies the small coal tract, known as the Springfield and Deep Run basin. It is about two miles in length and a quarter of a mile in width, its most southern termination being near Deep Run church, its most northern a short distance south of Chickahominy river. CHAPTER