GEOLOGICAL PATERS. 



127 



east side of the creek occur at practically the same level as on the 

 west side. Supposing them to be continuous over the territory stud- 

 ied, where not removed by erosion, the Neva limestone should have 

 been found at a depth of four and a half feet in the last well dug near 

 the quarter section-corner. Instead, the underlying shales outcrop at 

 the surface and plant remains were first met with at a depth of seven 

 feet, or just beneath the level of the under surface of the Neva lime- 

 stone series, should this have been continuous. The yellow shale con- 

 tinues at this place to a depth of eighteen or nineteen feet, when it is 

 replaced by the blue shale, which should not be encountered until a 

 depth of about fifty feet. This shows that the shales underlying the 

 Neva limestone were deposited to a greater thickness at this locality 

 than elsewhere in this territory, thus forming conditions inimical to 

 the deposition of the Neva limestone at this place. The different 

 strata of shales are considerable arched, and tend to show that this 

 immediate locality was above water while Neva limestone was de- 

 posited, and that the latter was laid down in comparatively shallow 

 water. 



w. 



Fig. 2. 

 Numbers at right correspond with those in fig. 1. No. 13 is one of the plant-bearing localities. 



Figure 2 shows the uparching of the plant-bearing shales at 13, be- 

 ing the well mentioned above. This figure represents a horizontal 

 section as measured at the locality for figure 1, and extends for a little 

 over a half-mile east and west across Mound creek. Another well was 

 dug some years ago about thirty rods north of the well shown at 13, 

 figure 2. The surface at this well lies twenty-four feet below the sur- 

 face of the well at 13 and was dug to a depth of twenty-two feet. 

 Instead of the yellowish, clayey shale, which should have been en- 

 countered, there was at the surface eiglit feet of glacial till, with 

 boulders, followed by eight feet of finely stratified sandy silt. Below 

 this to the bottom of the well occurred cross-bedded sandstone, th^ 

 higher horizons dipping to the west while those at the bottom of the 

 well dip to the east. The blue shale was not reached in this well, but 

 from another, dug lower down the slope, it was reached at a depth of 

 about eighteen feet, or at its proper horizon. 



