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but a section beneath non-indurated sandstones of the same age exposed 

 on a small stream about three miles south of this locality discloses the 

 horizontally stratified clays of the tertiary. From Lane's to the south- 

 ernmost part of the county where the outcrops cease two or three less im- 

 portant exposures occur. 



Several other outcrops are to be found in Crowley's Ridge but with one 

 or two exceptions, they are all on the west face of the ridge. The most 

 important are all in Greene county and all present practically the same 

 characters and vertical distribution. The northernmost exposure is in E. 

 19 N., 6 E., section 19, where they appear for the last time as indurated 

 sandstone. They here outcrop in and extend across the road and disap- 

 pear to the west in a low hill which rises a few feet above the Cache 

 bottoms. To the east the outcrop extends for several hundred feet into 

 the ridge, as traced in a deep ravine, where it is surmounted by a two foot 

 layer of exceedingly hard, fine-grained, flint-like sandstone. The highest 

 point above the valley which is crowned by these rocks has a barometric 

 elevation of about one hundred and fifty feet above the lowermost rocks 

 and these are in turn some forty feet above the valley. In but one local- 

 ity on the west side did fossil plants or fossils of any sort occur in this 

 sandstone. This was in 17 N., 4 E., in section 10, where after a long and 

 difficult search a small fragment of a plant was found deeply imbedded in 

 the very hardest rock which here caps the hills. It possessed very little 

 structure but it was quite sufficient to determine the rocks to be of terti- 

 ary age. However, the form was not sufficiently well preserved to tell us 

 exactly to what part of the tertiary the rock belonged but the evidence 

 which was wanting here was later supplied a little further on. We now 

 had the necessary clew and now the work of unravelling the mystery of 

 the ridge was play! To make a long story very short these sandstones of 

 supposed paleozoic age, standing isolated in the midst of tertiary rocks 

 through which they boldly protruded their waterworn and time be- 

 grimmed tops were found to be themselves tertiary and to share in the 

 common history of the region. 



A secondary problem now concerned the process or cause of induration ; 

 a process which had been so complete and left so little traces that a score 

 or more geologists had been puzzled into determining these rocks as of 

 paleozoic age. So to this task were the succeeding investigations directed. 



All of the outcrops of quartzitic sandstone occur in about the same ver- 

 tical position in the hills. They are to be found as spurs, extending in 



