HUMAN RELICS OF LANSING, KANSAS 7^9 



scale (Fig. 13) and shows the probable limitations of the 

 deposit. The extension of the tunnel shows that it thins to trie 

 southward, while the ravine intercepts it on the west. 



The surface configuration is that of a combined basal-slope 

 and ravine-bottom deposit, i. e., of aggradation in the bottom of 

 the ravine, combined with deposits lodged on the lower slopes 

 in adjustment to the aggraded bottom. The structure of the 

 deposit is in keeping with this interpretation. The little layer 

 of calcareous clay in the tunnel seems to imply deposition in 

 standing, or slowly moving water, i. e., a valley-bottom deposit, 

 probably a back-water deposit. The absence otherwise of definite 

 stratification or assortment of the material, and its complete resem- 

 blance to secondary slope accumulations derived jointly from the 

 loess and the underlying beds seems to require its reference to 

 aggradational action. Professor Williston found the cast of a 

 clam shell with attached valves in the angle between the wall 

 and the roof of the tunnel about seven feet from the base. In 

 the absence of satisfactory evidences of fluvial action at this 

 height and in the presence of human relics, this may well be 

 referred to human agency. 



INTERPRETATIONS. 



The case is perhaps not an absolutely declared one, and a 

 wholly unreserved interpretation may not be warranted, but a 

 very strong balance of evidence seems to point in a specific 

 direction. Certain things seem to me clear : 



I. The deposit is not true original loess. It is a mixture of 

 loess-like silt, Carboniferous detritus, water-laid clay and other 

 debris. The Carboniferous detritus was obviously derived from 

 the adjacent strata, in part by disintegration, in part by wear, 

 and in part by fracture without much rounding. The loess-like 

 silt was probably derived in the main by wash from the loess 

 mantle of the adjacent hills, but in part also by winds from the 

 Missouri bottoms ; possibly also in part by creep. Its charac- 

 ter implies that some of the silt was brought to its present posi- 

 tion without complete leaching, while most portions show 

 evidences of exposure and weathering. From such differences 



