REPORT ON FIELD WORK IN GEOLOGY. I33 



It is not unusual to observe small but high mounds which have been 

 worn to a point, as seen in c, figure i. In such cases the cap rock is 

 still present, or has only recently been removed. For if long unpro- 

 tected the sharp apex readily yields, producing a lower and rounder 

 form, as at a, of the same figure. Again, the limestone covering itself 

 yields to the solvent power of rain water. Many broad mounds and 

 bluffs are known on which the last remnants of the limestone may be 

 found, or possibly a mound with no limestone covering, the outlines 

 of which have not been greatly altered by erosion because the protec- 

 tion was so recently removed. A good example of the former is the 

 first mound to the south of Cherryvale, shown in the drawings for the 

 Cherryvale-Lawrence section. An excellent example of the latter is 

 a mound south of Lawrence, about a mile south of the Wakarusa. 



Limestone is the most common protective mantle in eastern Kan- 

 sas, but in some parts of the state sandstone strata act similarly, and 

 produce a topography akin to that observed in limestone districts. 

 This is particularly true in Cherokee county. In places the Cherokee 

 shales between the lead-bearing limestone and the Oswego limestones 

 grade into well formed sandstone beds, as is well illustrated to the 

 east of Columbus. Here a system of sandstone in almost horizontal 

 position overlies a heavy bed of friable shale in which at different 

 places a twelve to sixteen inch bed of coal occurs. The country is 

 worn into valleys, such as Shawnee creek and Brush creek valleys, 

 resembling in general features the valleys of the larger streams in the 

 state. At different places individual mounds are cut off from the 

 main lands as already described. Southeast of Columbus a few miles 

 one such mound stands out boldly in the surrounding valley, and can 

 be seen for miles. It has the form of a truncated cone, is half a mile 

 across its almost circular top, and is capped with a stratum of sand- 

 stone, below which is a thin bed of coal and a great bed of shale. 

 This is locally called Bald Mound in distinction to similar hills near 

 by covered with timber, and hence called Timbered Hills. 



Five miles east of Baxter Springs another similar mound exists, and 

 is probably capped with the same stratum of sandstone found at Bald 

 Mound. Across the state line east, in the state of Missouri, but still 

 in the same geological formation, other similar mounds exist. 



It is often observed that the horizontal distance between two con- 

 tiguous terraces is so great that one almost loses sight of their 

 relation. Figure i, to correctly represent the true condition, should 

 be elongated horizontally several times its present dimensions. In 

 places where the terraces are so far apart the westward dipping of 

 the strata produces a surface inclined westward locally. This is well 

 illustrated by the plane between Olathe and Lawrence. Olathe is 



