History of Westchester County, New York, Vol. II
Clumsily, I have sought to assist, and in reading the rocks, I find the story of the ancient sea, the islands and the antecedent streams of our own state, and this particular part thereof, written legibly upon the cliffs, and in the hills and valleys. So while the floor of the world is granite, we find above that floor, Nebraska, even as it stood in the midst of the first landed area of the earth, while the waves of the Cambrian sea beat upon shores in Wyoming, Ohio and Oklahoma.
And here, the first live creatures of the world crawled from the primal slime, upon the shore of the primeval sea. But later, when the- entire Mississippi valley was in the bottom of the Silurian ocean, Nebraska also took the plunge.
Again nearly all of the North American continent emerged in the lower Devonian, and was connected to Asia by way of the Behring straits. At that time the Omaha, Lincoln, Witchita mountain range was a particular scenic attraction of Nebraska and Kansas. Its axis was a little east of the present site of Lincoln, and could you sweep away the coverings, you would still find its rugged peaks and canyon beauty.
During the Carboniferous period this granite range was there. Around it is spread the sedimentaries of the Mississippian, and over it the Pennsylvanian formations, for the greater part of Nebraska took another plunge into the sea. Eastern Nebraska came up from the ocean, with almost all of the North American continent at a little later date. But an estuary from the Pacific covered that part of the state west of the one hundredth meridian, and it also covered western Kansas, Oklahoma, through the varying ages, came down to a time comparatively and geologically modern.