104 KANSAS Academy of Science. 



SOME CHARACTERISTICS OF THE GLACIATED AREA OF NORTH- 

 EASTERN KANSAS. 



BY BOBEET HAT, F. O. 8. A. 



Northeastern Kansas, from the Missouri river to west of the Little Blue river, 

 and as far south as the mouth of the Big Blue and the Wakarusa, had a share in the 

 glacial submergence that affected all the northeastern and north-central part of the 

 North American continent. The theory of this ice age is, that, from some change in 

 the earth's axis, the precession of the equinoxes, or one or both of these, combined 

 with diminished solar influence, due to the attainment of the maximum eccentricity 

 of the earth's orbit, or other cosmical or terrestrial changes, producing increased 

 length of winter in the northern hemishere, the arctic conditions now fully repre- 

 sented in Greenland were expanded southerly, a great sheet of ice covering the 

 continent as far south as the 39th parallel and as far west in Dakota as the 100th 

 meridian. The change from this glacial climate to the modern conditions of the 

 temperate zone was effected by opposite cosmical or terrestrial conditions, and the 

 ice sheet melting on its southern edge retreated northward with halting steps or 

 rapid progress, according to the strength or feebleness of the operating forces. 



There are certain deposits in the region which seem to have been formed under 

 the ice, others that were forme.d of material that was on and in the ice and laid down 

 in streaks and patches as the ice melted, and others, yet again, deposited in the cold 

 waters — lakes or streams — that fronted the ice sheet both in its extension and re- 

 treat. Since the disappearance of the ice sheet, vegetation has formed the black soil 

 over the whole region. In Iowa, Michigan, and elsewhere, the finding of black soil 

 and semifossilized wood below subglacial deposits, and above other deposits as cer- 

 tainly formed in the ice period, has indicated to the observers that the whole time of 

 the glacial period was divided into two, or that there was an interglacial time, in 

 which the ice retreated and that vegetation flourished, and the ice again advanced 

 to about its former southern limit. In most of the ice region of the Mississippi val- 

 ley, the southern border of the newer ice is about coincident with that of the first 

 advance of the ice sheet, and the phenomena of the older glacial period are only to 

 be examined where drainage or well sinkers have cut below the bog and soils that 

 indicate the middle period of milder climate. Whether the first retreat of the ice 

 was only temporary or extended through a long period, is not yet positively de- 

 termined among glacialists. 



It seems certain, however, that the second advance of the ice did not overspread 

 northeastern Kansas. Remembering that the ice retreated northward, it goes with- 

 out saying that the glacial phenomena will be newer as we go in that direction 

 from the southern border of the glaciated area, and if the retreat of the ice were 

 very slow, the southern parts would have had a much longer time to be exposed to 

 the weathering and denuding agencies of post-glacial time. Northeastern Kansas 

 has an older surface far away than parts of Iowa, and topographical character is 

 no longer of a glaciated type, as in the Dakotas. 



One of the usual signs of glacial action is the presence of striiv, grooves in and 

 planing of the surface of the bed rock, done by the ice and the hard pebbles and 

 bowlders contained in it. This phenomenon is largely missing in Kansas. 



Prof. L. C. Wooster, in a short article in a recent number of the American Geol- 

 ogist, records the finding of a striated area in Nemaha county. One or two local 

 observers have known of these marks for many years, but it is only this summer 

 that they have been definitely recognized. They have been seen by Professors Woos- 



