Seventeenth annual Meeting. 107 



tlit> country. They are encountered north of Ottawa, and extend southward into the 

 Indian Territory, westward to beyond Burlington, and eastward into the State of Mis- 

 souri. How much beyond the limit indicated they extend I am unable to say, but it is 

 probable that their range is much wider. This, however, can only be determined by an 

 exploration of the adjacent country. Independent of their scientific significance, these 

 beds are important in an economic point of view, affording free underdrainage, and sup- 

 ply good and convenient material for road-making. Along the brink of mounds and 

 clitls, and often for a considerable distance removed from them, as well as on top of the 

 highest ridges and mounds, at and near the surface, the rocks often stand vertically to 

 the plane of stratification, or incline at various degrees from this line. This is notably 

 conspicuous in many places. 



Not unfrequently old landslides are to be seen projecting from the mounds, or the 

 brinks of cliffs, and extending out for hundreds of feet. Indeed the whole country 

 wears the appearance of having once formed the bed of shallow seas, divided into num- 

 erous channels of various widths. Some of the cliffs, during the recession of the water, 

 perhaps, formed coast lines, while the higher lands may have been low islands. Such 

 is the condition of things conspicuously marked over the entire area named. To what 

 cause is this great work to be attributed? It could not have been done by rivers, for the 

 pebbles, though water-worn, are too widely distributed for the work of the broadest of 

 such streams. It was not effected by glaciers, for the vast landslides, the conformation 

 of the mounds and cliffs, the vertical position of the rocks where the stratification has 

 been disturbed, the absence of erratic rocks, and the want of the commingling of the local 

 rocks, all preclude this idea. If it had been caused by glacial action, there would have 

 been an intermingling of all the rocks torn down, indifferently. This, however, is not 

 the case anywhere in the district observed. Neither are the beds composed of altered 

 drift, for if they were so they would be homogeneous in their general distribution; but 

 this is not found to be the case, for in some localities they are composed of chert alone, 

 while in others they contain small broken fragments of sand-rock alone: in each instance 

 identical with the adjacent local rocks. No erratic, trap or igneous rocks, or limestone, is 

 anywhere to be found intermingled in the beds. The absence of trap and igneous rocks 

 is to be accounted for from the fact that the glaciers did not extend so far south. The 

 absence of limestone, though the prevailing local rock of the country, will be explained 

 farther on. It was not caused by volcanic action, upheaval, or folding of strata, for the 

 under strata rest undisturbed. Though evidently not caused by any of these agencies, 

 the mounds, the terraces, the cliffs, the water-worn pebbles, and broad plains and valleys 

 are conspicuous, grand and picturesque facts which stand out in bold relief in the entire 

 district, and prove a widespread destruction of its former surface. The whole country, 

 indeed, has been denuded for from at least fifty to two hundred feet in vertical thickness, 

 leaving the more impregnable mounds and cliffs, the pebble-beds, and broad plains and 

 valleys, standing monuments to bear witness to the general destruction which, in a past 

 age, took place. The power which caused it must have been great and persistent, and 

 can only be determined by the evidence it has itself left impressed on the field of its 

 operations, and which, if correctly read, will unerringly lead to its detection. This read- 

 ing points clearly and unmistakably to water aggregated in broad and shallow seas as 

 the author of the stupendous work. 



The deposits of pebbles, clays, and soils; the great landslides; the mounds, clifls, and 

 terraces, and the inclination of the disturbed rocks, marking the country so persistently 

 and conspicuously, could have been caused in no other way. These seas were no doubt 

 connected with an ocean, or deeper and more extended waters, lying to the southward 

 and westward; but at what era of geological time is .somewhat uncertain, except that we 

 know that it must have occurred since the Carboniferous age, for the upper Coal-measure 

 and Permian rocks are those destroved. 



