OGLE COUNTY. 109 



gradually rises until it attains almost the elevation of the gravel hills 

 themselves. 



These hills resemble strongly the central morraines of a vast glacier, 

 or where two glaciers meet and mingle in one ; but they also give 

 evidences of the sifting and assorting agencies of water. They are, 

 doubtless, " moraine hillocks," such as are found in many parts of 

 Northern Wisconsin. If the surface of the underlying Trenton rocks 

 could be examined, over a dozen miles in extent in this locality, they 

 would, we think, in many places be found plowed, grooved and scratched, 

 or planed smooth by the slow, silent force of the irresistable glacier or 

 iceberg. 



If the phenomena in this interesting locality indicate glacial action, 

 and we think they most unmistakably do, it was probably combined 

 with aqueous forces, and the two causes contributed to the results ob- 

 served. AYe have sought . for the manifestations of glacial action in 

 many places, while examining the drift through these counties ; but 

 while evidences of the floating iceberg and ice-floe, with their freight of 

 boulders, of peaceful atmospheric and strong aqueous forces are con- 

 stant and recurring, this is the only locality where we could find phe- 

 nomena that looked like the work of the glaciers. 



I examined with care the materials of which these gravel beds are 

 made up. Much of it is composed of metamorphic rocks, brought from 

 the regions of Lake Superior. But a large portion, from one-third to 

 one-half perhaps, is derived from the Niagara, Galena, and such other 

 limestones as are found in the Lead Basin. They are much rounded 

 and water-worn, but are not transported from the great distances from 

 whence came the granites, syenites, and other boulders and gravels : 

 Tentacitlites, from the Niagara ; fragments of Orthocera and Orthk) from 

 the Blue ; Pleurotomarias and pieces of TriJobite shields, from the Gale- 

 na, were noticed among these piles of gravel imperfect as fossils, of 

 course, but sure indications of the neighboring formations from which 

 they were derived. 



A mixed mass of gravel, like the one under consideration, would seem 

 to indicate that forces from a distance and forces near at hand, opera- 

 ting in every conceivable direction, with great force and over long 

 periods of time, all contributed to gather together these heaps of abraided 

 materials, some from the distant regions of the granite and the traps, 

 and some from the neighboring limestones of a by-gone geological age ; 

 but all equally worn smooth by the grinding of the waters and ice. 



But, leaving this interesting accumulation, we still find evidence of 

 the drift gravels all over the northern part of the county ; but the beds 

 become comparatively thin, and are underlaid by the usual clays of this 

 part of the State. The blue clays, belonging to the base of the drift, we 



