415 



thin. These sinks connecting with uncler-channels are the sources of many 

 springs that abound in and at the borders of the region. 



Chester Group. On the high hills at the borders of the Flatwoods 

 region shales and shaley sandstones overlie the Mitchell. These are usually 

 about twenty-five feet thick, and upon them is a limestone usually about 

 three feet thick in the Flatwoods exposures. This group is known as the 

 First, or Lower Chester. On top of the First Chester limestone occur a 

 series of shales and sandstones, consisting of a portion of the Second 

 Chester group. This group is capped by a limestone, its last member. At 

 no place in the immediate vicinity of Flatwoods was the top of the Second 

 Chester found. 



The above general outlined stratigraphy is found in the Flatwood-; 

 region and portions directly connected with it. Some attention now will 

 be given to local details. 



The general dip of the rock of the Bloomington Quadrangle, in which 

 a portion of Flatwoods occurs, is on the average twenty feet to the mile to 

 the west, southwest. In regard to the dip of the rock structure in the 

 Flatwoods region, the following data reveal an interesting feature : 



Contract of Mitchell and First Chester, south side Flatwoods : 



In 920-foot hill, N. W. I, sec. 16, T. 9 N., R. 2 W 870 



In 900-foot hills, S. h sec. 7, T. 9 N., R. 2 W 845 



In W. part of hill N. W. i, sec. 7, T. 9 N., R. 2 W 820 



In centre of S. i, sec. 1, T. 9 N., R. 3 W 800 



One-half mile N. of above 805 



S. W. side of hill, S. E. I sec. 2, T. 9 N., R. 3 W 800 



Middle N. of N. W. i sec. 3, T 9 N., R. 3 W 720 



North side of Flatwoods : 



In 810-foot hill, Middle sec. 30, T. 10, N., R. 2 W 790 



Chambers Hill, middle of line, sec. 24-25, T. 10 N., R. 3 W 810 



The data along the southern side of Flatwoods reveals an average dip 

 of thirty-feet to the mile along a line which is as much in the direction of 

 the strike as in the direction of the dip. Again, going from the eastern con- 

 tacts toward the western, the data indicates that the first two-thirds of the 

 distance has a dip of twenty feet to the mile, and the ramaining distance a 

 dip of fifty feet to the mile. The data on the north side is very meagre, as 

 there are only a few hills high enough to x-each the Mitchell and Chester 



