228 KANSAS ACADEMY OF SCIENCE. 



parallel ridges are of it, and the loose sand at the north is wind-blown only to 

 a small extent. As far as there are dunes here, they are nearly on the site of 

 the sandstones, more or less incoherent, of which they are the debris. These 

 appearances are on sections 21, 16, and 17, of town 12, range 5 east, the two 

 harder rock patches being on section 21. The region to the west of these has 

 largely a sandy soil for several miles, and though both to the north and west, 

 and conspicuously to the south, the Permian rocks are at greater elevations, 

 here is an area of eastern prolongation of the Dakota, resting on an eroded 

 hollow of the older formations. The prolongation of a Dakota tongue on 

 the south of Dickinson county suggests that the phenomena I have described 

 might be expected. Till now, however, they have not been recorded. The 

 geological map of the state should now show Dakota in Geary county. 



The consideration of all these facts suggests other inquiries. Has the 

 the erosion of the Kaw valley spared other patches that may testify 

 to the former existence of the cretaceous further east? Is the sand mass — 

 stone or otherwise — at St George a relic of the Dakota? 



Five years ago I found, under the sandhills of the northern part of Reno 

 county, that the red beds were well developed. Over in Rice county the 

 Dakota is in force: but a remarkable erosion makes it absent where the first 

 gas well was bored at Lyons. Further north and east, the thin limestones 

 of the Benton are also found. 



In Rice county, near the Reno county line, nearly straight north of Hutch- 

 iiison, there is a region of sandhills, a large area of which is inclosed as 

 pasture. In this pasture on section 10, township 21, range 6 west, is a con- 

 tinuous sandy ridge with hard ferruginous rock appearing through it in 

 small patches for from a quarter to half a mile from west to south of east. 

 It is the Dakota sandstone with the vitreous surfaces, and people in the dis- 

 trict say it is of volcanic origin. Breaking the ferruginous surface, which 

 has the vitreous coat, I found under it only soft, dark yellow or red, somewhat 

 incoherent sandstone. It could be cut by the spade. The ferruginous streak 

 has hardened and protected it till now at this spot, while all around the 

 agencies of the weather have broken up the body of soft sandstone, and the 

 winds have piled up the incoherent mass into sand dunes, which grass is now 

 again rendering stationary. In the cut on the Rock Island railway, a few 

 miles northeast of Hutchinson (sec. 33, T. 22, R. 5 west), similar soft sand- 

 stones are exposed, and the district to the east and west is made of gi'ass- 

 grown sandhills. A small patch of the vitreous, ferruginous nodular stone 

 is also just north of the Reno-Rice county boundary in 33, 21, 6; and this, with 

 the one in section 10, is in the sandhill region, most of which has been re- 

 deemed by grass. The countj^ in the neighborhood of these two is practically 

 level, except the irregularity of the sandhills, and there is descent to the 

 north and east to the Little Arkansas and its tributaries, and southward to 

 the Arkansas, and the sheet of the Dakota was thin before its weathering 

 into sandhills began. 



Sandhills thus formed from subjacent sandstones might be described by 

 a term taken from a description of soils similarly formed, and called 

 sedentary sandhills; and it is probable that a large proportion of the sand- 

 hills of the world are so formed. It is remarkable that while sand travels 

 wdth the wind, a region of sand dunes is stationary. The mass remains; 

 the molecules are in motion. There are regions where the wind, persistent in 

 one direction, has caused an arenaceous desert to encroach on the regions 

 beyond; but it will be found that large areas are like those described above, 

 and some tertiary regions I have described elsewhere, and composed of 



