^50 KANSAS ACADEMY OF SCIENCE. 



Limestone, shale 6 ft. 



Limestone, cuboidal blocks to bottom of quarry 15 ft. 



Limestone ledge at tank, perhaps 3 ft. 



Slope, mostly shale, but probably a hard ledge 30 ft. 



Ledge, two or three layers 3 ft. 



Shale 6 ft. 



Main spillway rock (limestone) at Forest lake 16 ft. 



Shale, with a hard ledge 6 ft. 



Bottom of spillway rock 4 ft. 



It will be seen by a comparison of these various sections that it is not easy 

 to make a generalized statement of the succession of limestones and shales 

 that would be correct for any large part of the county. There has not been 

 a sufficiently extensive examination of the fossils of the strata at any one 

 place to make them a reliable means of identification in other districts. The 

 changing of shale to limestone, and vice versa, is so common that the thickness 

 of a given layer is scarcely any guide to its identification elsewhere. At the 

 old cement quarries at Armstrong a layer of shale which on the southeast 

 side is five feet thick, on the northwest it is diminished to three feet, and is 

 more argillaceous and less calcareous there. The chert beds are more or less 

 persistent, but, notwithstanding their remarkable eastward dip at Arm- 

 strong, it ceases to be a guide, by disappearing westerly in the Kaw valley. 

 On the other hand the oolite mentioned in the last three sections is a guide 

 by some of its fossils as well as by its oolitic structure. Myalina Swallovii, 

 Athyris bovidens, and fine specimens of Productus cora are nearly always 

 there. The shells are white lime, and this is characteristic of all the inverte- 

 brate fossils in the oolitic limestone, including occasional trilobites (Phil- 

 lipsia). This oolite is found, besides the places already mentioned, in a cut 

 of the Santa Fe railway in Leavenworth county a few miles northwest from 

 Bonner Springs, and lies below the cement bed at Armstrong. 



The section at Argentine shows sandstone below a limestone, and still 

 lower sandstone shales. On the divide, in the middle of the county, between 

 Edwardsville and Pomeroy, sandstone is found at the same level as limestone, 

 as shown in exposures at and south and north of schoolhouse in district No. 36. 

 The contact of sandstone and limestone is not actually seen, but the same 

 horizon is plainly inferable. Nearly the same is seen in a road-cut east of 

 White Church. 



The bottom then of the sandstone plateau is certainly irregular. So far the 

 writer has seen no evidence that there is erosive unconformity of the strata. 

 It would appear that by gentle oscillations of level, some deep water forma- 

 tions began to give place to shore-line deposits in the old carboniferous 

 seas. The reverse of this brought on the conditions favorable for the deposit 

 of the heavy limestones at the top of the sandstones in west Leavenworth 

 county and Atchison. 



Back in the seventies a boring was made at Wyandotte to a depth of 600 

 feet, and it was said a three-foot seam pf coal was passed through. At what 

 depth there is no record to tell. It is also said that the gas well at Arm- 

 strong brick works passed through three feet of coal at a depth of 175 feet. 

 A boring was made in 1887 on the bottom south of the Kaw, pt Kansas City, 

 to a depth of nearly 2,000 feet. More recently a shaft was sunk at Rosedale 

 to' a depth of 700 feet. The records of these prospectings were, at the time, 

 kept secret, and are now probably lost, so that it is not possible to compare 

 the deeper strata with those in Leavenworth county. Still, as there is no 

 very great dip of the surface rocks, and in Leavenworth comparatively little 



