History of the Water Supply of the World / arranged in a comprehensive form from eminent authorities, containing a description of the various methods of water supply, pollution and purification of waters, and sanitary effects, with analyses of potable waters, also geology and water strata of Hamilton county, Ohio, statistics of the Ohio river, proposed water supply of Cincinnati.

by Thomas J. Bell

CINCINNATI ANTICLINAL.

The term, Cincinnati Group, is now applied to the blue limestone series, and is an equivalent, in the geological nomenclature, to the Hudson Group of New York.

Its thickness is estimated at 1,000 feet. The line of upheaval passes from the south line of Tennessee, with a direction a little east of north, through Cincinnati to Lake Erie. Throughout its whole length the strata are raised in a distinct arch, from which they dip away, on the one side under the Alleghany coal-field, on the other beneath the coal basin of Indiana and Illinois.

The bearing of this axis of elevation is nearly parallel with that of the folds of the Alleghanies; that the date of its upheaval was subsequent to the carboniferous, and anterior to the Triassic period. The line, north of Cincinnati, extends from the Ohio River in a direction a little east of north to the lake shore, between Sandusky and Toledo. In consequence of the erosion, which all the region bordering the Cincinnati Arch has suffered, the line of the axis presents no conspicuous topographical features. About Cincinnati the summit of the arch has been much more deeply and extensively removed than farther north, yet this is still higher than its northern prolongation.

There is every reason to believe, therefore, that this was originally the highest part of that portion of the arch within Ohio, and, in common with the Blue Grass district of Kentucky, the blue limestone area about Cincinnati is the most elevated portion of the ridge; that which has been the longest above the sea level and suffered most from surface erosion. We find here a line or tract from which the strata dipped on both sides in opposite directions.

The strata, that are found in the tops of the Cincinnati hills, can be followed to the eastern side of Brown County, where they seem to disappear beneath the river with a marked easterly dip; while below Cincinnati, near Madison, Indiana, the same beds are carried beneath the river by a strong westerly dip. The Cincinnati anticlinal, unlike the folds of the Appalachian system, generally has its longer slope to the westward, and its steeper descent towards the east, estimated at 35 feet per mile. In the western half of the State, and especially along the summit of the Cincinnati Arch, the dip of the strata is strongly northward, amounting to about 1,000 feet between the Ohio and the lake. The surface of the Cincinnati Group is in Highland County, about 500 feet above Lake Erie, while on the lake shore it is nearly 400 feet below the lake. These figures do not represent the entire dip, inasmuch as the crown of the arch is extensively eroded where it crosses the Ohio in Clermont County. The Cincinnati section was originally crowned, there is little reason to doubt, with the Lebanon beds [the highest rocks of the Cincinnati group] in whole or in part, which suffered by erosion, forming our valleys of to-day.

The surface of the blue limestone, near Lebanon, is 441 feet above Lake Erie, while the same rocks were found in the Columbus well to be 721 feet below Lake Erie, a dip of 1,167 feet in a distance of about 70 miles by an air line, or 16.6 feet per mile.

Toward the northern extremity of the arch the dip is north-west and more rapid, the strata descending under the Michigan coal-field. Near the lake-shore the minimum dip is 20 feet to the mile, while on the Ohio it is 40 feet. The easterly dip is a succession of steps or waves beneath the trough of the Alleghany coal-field, the axis of which passes near or beyond our eastern border. This dip is so great that the lowest stratum exposed on the crown of the Cincinnati arch is on the eastern side of the State, buried about 2,000 feet beneath the surface. East of the Ohio all the rocks rise again, and not only the lowest exposed in our State, but even those which underlie them, crop out on the flanks and summits of the Alleghany Mountains. Along the Kentucky River from Frankfort to Nicholasville, and at Murfreesboro, Tennessee, the basal portion of the blue limestone series is exposed to view; and if it was originally as thick at these points as elsewhere, not less than 800 to 1,000 feet of the upper part have been removed.

HAMILTON COUNTY.

Strictly speaking there are no hills in Hamilton County, the surface being all referable to the tablelands and to the valleys worn in them. The elevated lands, called hills, are merely isolated remnants of the old plateau, which have, thus far, escaped the long continued inundation. This isolation is effected by the Little Miami, the Ohio, the Millcreek Valleys, and the abandoned channel of the Great Miami.