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

The Potsdam sandstone, the first member of the Silurian system, rests unconformably on the Eozoic rocks wherever the two are found in contact. This, as its name implies, is a sandstone, and is the first product of the invasion of the Eozoic continent by the ancient ocean, and the action of the shore waves upon the cliffs and surface.

It has been reached in the deep borings made at Columbus, Louisville, and St. Louis. Neither the Eozoic or Potsdam stones are exposed in any part of Ohio. Resting on the Potsdam stone, is a formation called calciferous sand-rock, so named in New York because there it consists of a mixture of lime and sand. This formation holds the lead of central and eastern Missouri.

Trenton limestone, with its underlying strata of chazy, Black River, and bird’s-eye limestones, rests on the calciferous sand-rock, and forms a calcareous mass of 300 to 600 feet in thickness. It is exposed in New York, Canada, Lake Superior, and Upper Mississippi, where one of its members, the Galena limestone, claims special notice as being the repository of all that rupture.

Upon the Trenton rests the Hudson group, consisting of the Hudson River and Utica slates, and composed of mixed calcareous and argillaceous sediments. This group is regarded as an equivalent to the blue limestones, or Cincinnati group, which are of special interest to the inhabitants of Ohio, inasmuch as they are the lowest rocks exposed within our territory.

These older rocks are brought to the surface by an axis of upheaval, reaching from Nashville to Lake Erie. They have been still further exposed by the cutting down of the valley of the Ohio, near Cincinnati, where 800 feet of the series are exposed to view. The wells on the upper Cumberland, in Kentucky, were sunk in rocks of the Hudson age. The earthy limestones of the Hudson period indicate a shallow and retreating sea, an approach to land conditions, and the completion of one circle of deposition.

The rocks next in order are:

The Oneida conglomerate marks a period of land subsidence, or water elevation. It is composed of coarse materials torn from the coast by shore waves. The system is found in central New York.

The Medina sandstone.—A period of mechanical sediments. In New York it is 300 to 400 feet in thickness. It has been struck in borings for oil in northern Ohio, but not well marked.

Clinton Group, in Ohio, is represented by a limestone 15 to 20 feet thick, an outcrop following the line of junction of the Lower and Upper Silurian.

Niagara Group is above the Clinton and occupies a wide-spread and more important formation, composed of equal masses of limestone and shale. This is the rock that underlies Chicago. The Niagara and Clinton overlie the Cincinnati Group.