When the more violent disturbances shook the fractured region, great slabs of granite one hundred feet thick and miles in area, were in places thrust out almost horizontally through the comparatively newer rocks and shales, and these granitic intrusions have puzzled geologists, and turned aside the tides of oil prospectors from time to time. Granite and Red Beds have been discouraging features to oil geologists : yet daring prospectors have drilled through these granite barriers into the shales below,. and others have found best qualities of petroleum in Red Bed anticlines.

West and east of these sunken mountains are faults and folds, synclines and anticlines. In Kansas and Oklahoma are battery after battery of perforations, where the oil drill has penetrated the upper sediments and covering caps, and from these pour steady streams of oil, and gas wells bring forth elements for the service of mankind. And so Nebraska may some soon day yield from her interior store, rich contributions for her people.

West of this mountain range rolled the waves of the last Cretaceous sea -- the vast marine water which divided the American continent. Perhaps a low coastal range separated it from the Gulf, and it probably extended, widening, to the arctic circle.

Between the Nebraska-Kansas range and the Ozarks there was an estuary, which might be called Topeka bay, and on the western shore of the sea were others, and into these the ebb and flow of tide and current carried spongelike woods, where water-logged and slimeburdened they settled down, and after ages they became coal beds.