Page:The American Cyclopædia (1879) Volume I.djvu/628

592 APPALACHIAN MOUNTAINS beds dipping toward them, as if the more re- cent formations passed beneath these ancient groups. The thermal springs, which are of frequent occurrence along the Appalachian chain, and particularly so in Virginia, flow out almost universally on the lines of anticlinal axes, or of the faults. Their elevated temper- ature indicates the great depths from which they rise, and consequently that to which the folds and fractures of the stratification reach. The geological formations of the Appalachian belt, comprising all the groups from the granite to the coal, are abundantly productive in the most important ores and minerals, which espe- cially belong to these different formations. In the ancient granitic rocks which skirt the edge of the lower stratified formations, and some- times spread out over broad areas, as in the mountainous region W. of Lake Champlain, in the highlands of New York and New Jersey, are found inexhaustible repositories of magnetic iron ores, which already are worked to great extent in connection with the valuable beds of hematite ores that are found conveniently near them, ranging from Canada to Alabama along the line of the great Appalachian valley. These beds occur in great depressions in the lower limestones and metamorphic slates of this range, and sometimes in veins in the same rocks, and are worked in every one of the states through which this passes, everywhere presenting the same peculiar features. They are frequently of extraordinary extent, and though worked in several instances for more than 100 years, the actual depth to which they reach, and their real nature, have never been fully explored. Together with the magnetic ores, they furnish the supplies for a very large proportion of all the iron manufactured in the United States; and the numerous bodies of them still untouched are a provision for still larger demands for generations to come. The value of these repositories can hardly be over- estimated, particularly when considered in con- nection with the long extent of their range, not far back from the coast, and the enormous supplies of mineral coal that can be conve- niently brought to effect their reduction. Far more valuable are they than the gold found in the granitic and metamorphic rocks of the east- ern ranges, though this, judging from the pro- duction of certain localities in the southern states, would, if exposed by the great irregu- larities of the surface, like those of California, be found as rich and abundant as there. It is worked in alluvial deposits enriched from the auriferous veins; and these also contain ores of copper and lead, and occasionally of silver. These deposits and veins are met with in the valley of the Chaudiere below Quebec, and are again seen in a few localities in Vermont ; but their great development is on the eastern bor- ders of the Appalachians S. of the Potomac. The copper ores met with in the rocks of the Appalachian system have never proved of great importance. They are found along the range of the talcose and micaceous slates of the Blue Ridge, as well as associated with the gold further toward the southeast. In Virginia these slates produce some workable beds of lead ore, and display occasionally attractive appearances of copper. In New Jersey the same range produces the remarkable red ox- ides of zinc associated with Franklinite, which are worked together, the one to produce the white zinc paint, and the other a superior qual- ity of iron for the manufacture of steel. Fur- ther S. along the same belt are found, in the Lehigh valley and in Lancaster county, Pa., the valuable silicates and carbonates of zinc, called calamine, which are worked for the same pur- pose as the red oxides of New Jersey. Veins of lead ore are found in several of the forma- tions ; and in Wythe county in S. "W. Virginia a mine in the great limestone formation has been worked with some interruptions for more than 100 years. These lead veins, however, of the lower members of the Appalachian sys- tem, have for the most part proved of little importance; indeed, throughout the range of the mountains none of the formations above the metamorphic rocks are rich in any other metallic ores than the hematites which are oc- casionally met with, the red fossiliferous iron ores of Formation No. V. of the Pennsylvanian survey, called in New York the Clinton group, and the argillaceous ores of the coal measures. No rock formation is more useful to man for the variety and value of its productions than the true coal formation. It furnishes the great supplies of anthracite and bituminous coal, beds of fire clay, and west of the Alleghany ridge abundant beds of limestone. Salt water is ob- tained by boring artesian wells to lower mem- bers of the series, and the brine flows up or is pumped up into the valleys, to be evaporated by the combustion of the coal found in the neigh- boring hills. In many localities, where the salt-bearing rocks approach the surface, the brine is more readily obtained in large quanti- ties, and the coal is transported for its evapo- ration. The formations that furnish the salt also contain great beds of gypsum. Onondaga county in New York is famous for these pro- ductions, and in Washington county in S. W. Virginia solid beds of salt are struck in the midst of the most extensive plaster deposits. From one extremity of their range to the other, the Alleghanies have furnished large sup- plies of the valuable white pine ; and many of the less accessible districts of the belt still abound with it. Far toward the north, upon the better soils of the mountains, the hard-wood forests prevail the fine sugar maple, of the curly and bird's-eye varieties, and the white birch. The ash and the beech also attain their highest state of perfection in the most fertile soil of these northern mountains. Upon the poorer lands, and along the ravines of the mountains, the " black growth " flourishes the evergreens, as the different species of the pine family, the spruce, the hemlock, cedar, and