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Indiana University Studies 



overlap is quite notable in the CjnDress sandstone, so that this 

 latter formation may be expected to lie on lower and lower 

 strata to the east. 



The Beech Creek limestone outcrops along Beech Creek 

 and its tributaries high above the valley floor, and along 

 Clifty Creek to its junction with Plummers Creek valley. In 

 the latter case it comes down to the valley level, and in places 

 is hidden by the valley alluvium. It outcrops only in the 

 easternmost ravines of Bridge Creek, and is below the level 

 of the flat ''American Bottoms" valley. In the northeast 

 corner of the area it does not seem to have been deposited at 

 all. It is a rather curious fact that the area where the Beech 

 Creek limestone has not been deposited should be coterminous 

 with the area characterized by the development of the massive 

 phases of the Elwren sandstone and the notable disconformity 

 at its base. This raises a question the discussion of which 

 cannot be undertaken in the present paper. 



The Beech Creek limestone is of great importance from 

 both the topographic and physiographic standpoints. Along 

 its outcrop it frequently stands out as a wall-like bench, partly 

 on account of the shale which characteristically underlies it, 

 and partly because of its recession eu masse on weathering. 

 Its highly jointed condition allows it to collect waters from 

 the overlying sandstone into concentrated streams, the out- 

 flow of which in steep-headed ravines and gorges makes it 

 perhaps the most extensive and persistent spring-bearing 

 horizon in the Mississippi valley. It possesses this character 

 because of its relation to the massive overlying sandstone 

 which has a high porosity. These springs often yield a con- 

 siderable volume of water, and the characteristic steep-headed 

 gorges with their high walls of solid rock are common thruout 

 the region of the outcrop of this formation, especially where 

 the limestone is rather high above the drainage level. The 

 Ray's Cave gorge is typical (Fig." 1). Another example, well 

 outside the region in question, is 'The Gorge" southeast of 

 French Lick, w^hose scenic beauty has been commercialized, 

 so that any visitor who cares for an out-of-town dinner may 

 partake of one of the excellent chicken dinners for which the 

 place is noted. As may be inferred from the presence of 

 these gorges with such large volumes of water coming from 

 their steep-walled heads, the solution of the limestone along 



