370 COUNTY AND REGIONAL GEOLOGY. 



railroad. The aggregate thickness of the strata exposed here 

 varies at the different points where they are seen, but the 

 highest are not quite so high in the series as the upper 

 part of the section at Wilson's, in Fremont county, and only 

 six miles below here. They comprise only the equivalent 

 of about the lower two-thirds of that section, the greater 

 part being limestone. There is evidence that in this part of 

 Mills county the equivalents of the upper portion of the 

 section at Wilson's, once existed here in their order above the 

 others, but that they have been removed by glacial action. 



Near the house of Mr. Joseph Shaw, on section 16, township 

 71, range 43, very distinct glacial scratches were seen upon 

 the upper surface of an upper layer of limestone. The 

 natural inequalities of the bedding surface had been removed, 

 leaving a plain and level surface upon which there were two 

 distinct sets of strise that are fully described in another part 

 of this report. 



A good idea of the general character of the strata exposed 

 in this vicinity, may be obtained by referring to the section at 

 Wilson's, in Fremont county, and only a few miles distant, 

 therefore no illustration of them is given here. Besides these 

 and the other exposures before described, there are a few 

 small ones of the same limestone at the base of the bluffs, 

 a little above the point at which Pony creek enters the great 

 flood-plain. These are all the exposures yet observed in 

 Mills county, the deep deposit of bluff material having 

 generally covered the strata from sight. 



Material Resources. The soil of Mills county is almost 

 wholly bluff soil, except that of the flood-plains of the rivers, 

 and this also is largely composed of the same material. It 

 is all of remarkable fertility, and the resources to be derived 

 from it in the future are in no danger of being over-estimated. 

 The other resources of the county consist almost entirely of 

 its .stone and wood, The most important stone quarries are 

 those along the base of the bluffs in the southwestern part. 

 The other exposures, although small, have a great local 

 value, but these of the southwestern part of the county, are of 



