60 Kansas Acadcmij of Science. 



chert gravel, at a depth of twenty-eight feet, the bones of a 

 Quaternary horse, possibly E quits major DeKay. The bones 

 were those of a horse larger than those of the modern animal, 

 and, with the exception of the teeth, were badly disintegrated. 

 One molar tooth measured three and one-fourth inches from the 

 grinding surface to the beginning of the roots. The latter 

 were broken at the ends and the cavities partly filled with 

 calcite crystals. With the bones of the horse was found the 

 cast of the shell of a river mussel of the family Unionidse, and 

 near the modern species Qiiadrula plicata. 



4. The continued rise of the Ozark mountains of Missouri 

 and of the Arbuckle and Wichita mountains of Oklahoma dur- 

 ing the Paleozoic and Mesozoic eras gave the strata of Kansas 

 a dip to the northwest and southwest, which they retained 

 till the middle of the Cenozoic era. At this time the rise of the 

 Rocky mountains reversed the dip of the strata in the western 

 half of the state, greatly reduced the westward dip of the for- 

 mations in the eastern half, and changed the trend of the 

 rivers from west into the M^estern Mediterranean to east and 

 southeast into the rivers that make their way to the Gulf of 

 Mexico. At the same time the rivers were rejuvenated and 

 their work of forming a new base level was begun. 



Following these orogenic movements came two or three 

 warpings of the earth's crust in North America, which gave 

 new phases to the problems relating to the distribution of the 

 chert. 



The geologist has proofs that early in the Glacial epoch the 

 northern portions of our continent were elevated till they were 

 much higher than now. Probably the increased elevation was 

 three thousand feet at the latitude of Lake Superior and five 

 thousand in the neighborhood of Hudson Bay, according to 

 Dana. This high latitude elevation of the continent must have 

 given the south-flowing rivers a much greater velocity than 

 at present, and thus have caused them to excavate their valleys 

 very deeply and to a great breadth. The rivers of Lyon and 

 Greenwood counties have eroded their channels to an average 

 depth of more than one hundred feet below the level of the 

 highlands and to a width of from one to four miles. As these 

 river valleys must have taken their present shape and direc- 

 tion since the rise of the Rocky Mountains in the Tertiary 

 period, and have been excavated since the beginning of the 



