THE KANSAS UNIVERSITY 

 SCIENCE BULLETIN. 



Vol. V, No. 1] OCTOBER, 1909. [^oI^xVnT! 



THE DAKOTA-PERMIAN CONTACT IN NORTHERN 



KANSAS. 



BY F. C. GREENE. 



Plates I to IV. 

 INTRODUCTION. 



r^URING the summer of 1906, while working on the Uni- 

 ^^ versity Geological Survey of Kansas, under the direction 

 of Dr. J. W. Beede, the Permian-Cretaceous contact in Kansas, 

 north of the Smoky Hill river, was mapped. The most of the 

 northern third of the region was mapped jointly with Doctor 

 Beede and the remainder mapped individually, in alternate 

 stretches. 



The region covered in this account lies in Washington, Riley, 

 Clay, Dickinson and Ottawa counties, and is included in the 

 Washington, Marysville, Clay Center, Abilene, and a comer 

 of the Minneapolis topographic sheets of the U. S. Geological 

 Survey. The area lies in the drainage basins of the Little 

 Blue, Republican, Smoky Hill and Solomon rivers. 



The topography is characterized by bold bluffs of the Da- 

 kota sandstone and smaller benches of the harder Permian 

 limestones and shales. There is one peculiar feature of the 

 topography throughout the region: northern slopes of the 

 divides are generally steep, while the southern slopes are very 

 gradual, and often without rock exposures. The effect is as 

 if the land had been tipped to the south, or as if there had been 

 an interruption of a southeastern drainage which turned the 

 master streams to the east, thereby causing the streams to 

 erode their southern banks. 



In regions of the Dakota formation, this often results in 



