322 COUNTY AND KEGIONAL GEOLOGY. 



No. 2. Bluish, clayey shale, passing upward into grayish and light 



bluish stratified, impure clays 36 feet. 



No. 1. Bluish, clayey shale, containing occasional thin layers of 



impure limestone 5 feet. 



Total 85 feet. 



It is along the valley of Grand river, and those of its tribu- 

 taries which have their confluence with it in this county, that 

 all the exposures of strata yet observed are to be found. 

 The Drift Deposit is very thick here, as is shown by the fact 

 the exposures of strata, which are found only in the valleys, 

 are seldom, if ever, less than a hundred feet below the general 

 level of the uplands. The section on preceding page, (Fig. 

 17), is the most extensive one measured in the county, the 

 exposures it represents having been observed near Davis' 

 mill in the valley of Grand river, about eight miles south- 

 ward from Leon, the county seat, and four miles northward 

 from the south boundary of the county. 



No. 1 is referred to the upper part of the Middle coal- 

 measures, and all the remainder to the Upper coal-measures. 

 Near the mill, the clayey shales of the lower portion of No. 

 2 are crowded with specimens of the minute ostracoid crus- 

 tacean, Beyricliia Americana. 

 Below Davis' mill, to the southern boundary, there are 

 FlG - 18 - very few exposures of strata, but 



all that appear are equivalent to 

 some part of the preceding sec- 

 tion. Going up the valley, from 

 that point, the next exposures 

 found, are upon both banks of 

 the river near the village of Terre 

 Haute. The accompanying sec- 

 tion, (Fig. 18), was measured at an 

 exposure there immediately upon the left bank of the river. 



Section at Terre Haute. 



No. 5. Gray marley fossiliferous clay 3 feet. 



No. 4. Hard, gray limestone, with marly partings 12 feet. 



