AURORAL AND MATINAL STRATA.
The second and third series are the Auroral and Matinal limestones and slates. They are of immense thickness, and cover a vast area of territory. This formation seems to have formed the bed of the ancient Appalachian sea, and is traceable, by its outcrops, from the valley of the St. Lawrence, until it is lost beneath the alluvial of the Gulf, but reappears in the West, and spreads out widely in Missouri, and on the anticlinals of the Western coal-fields.
Those limestones and slates form one of the most magnificent valleys in the world, along the Atlantic slope,—scarcely second to the valley of the Mississippi, if we consider the productiveness of its soils, the richness and variety of its minerals, and their general availability. This great region extends from Canada through New York into Pennsylvania, Mary land, Virginia, Tennessee, Georgia, and Alabama.
It is locally known by various names: as, the Newburg Valley, the Lehigh Valley, by Easton and Allentown, the Reading and Lebanon Val leys, the Cumberland Valley, the Great Valley of Virginia, the Valleys of East Tennessee, and the beautiful valley of the Coosa in Georgia and Alabama, embracing a length of about 1500 miles, and an average width of 20 miles, covering an area of 30,000 square miles.
Close to its eastern borders, over the Blue Ridge, lie the great region of magnetic ores,—from the Adirondack hills to the Carolinas; while parallel run the copper belts of the gneissic and primal formations. It is the great region of hematitic ores, which are largely developed from Pennsyl vania to Alabama.
These ores are generally the rich brown, or hydro-peroxide,—except in a few localities, as at the great magnetic deposits of Cornwall, Pennsyl vania. They not only produce the best of iron, but are invaluable as a mixture into the refractory magnetics. The extent and profusion of these
beds of ore, which extend in almost unbroken veins from end to end of this great limestone valley, cannot be realized by persons who have not witnessed the facts. We have seen masses of this brown ore, that may be literally termed mountains, in Virginia, Tennessee, and Alabama. It is as inexhaustible as the great coal-fields which lie along its western border, and which are almost everywhere accessible, and at some points quite near, —the Lehigh coal at Allentown, the Schuylkill at Reading, the Swatara at Lebanon, the Shamokin, Wyoming, and Broad Top at Harrisburg, the Cumberland at Harper's Ferry, the Kanawha and New River coals at "Central" on the New River, the Chattanooga coals at Cleveland and Dalton, and the Coosa coals in Alabama.
This great valley is drained by the waters of the Atlantic, as far south as middle Virginia, and is everywhere accessible by river and rail, from the seaboard cities. The Hudson, Delaware, Lehigh, Schuylkill, Susque hanna, Potomac, James, and Roanoke Rivers drain it from the east through the passes of the Blue Ridge ; while the New River, the Holston or Ten-. 'lessee, and the Coosa drain it from the west and south.
The hard and flinty rocks of the Primal series, including the great Pots dam sand-rock, forms the eastern confines of the valley, in a continuous and almost unbroken line, from the Lehigh to the Chattahoochee,—a vast moun tain chain that alternately rises or sinks as its strata assume a high or low degree of angle, but always a mountain, and sometimes stupendous in its grandeur.