BOTANICAL STKYEY— HUUAE GROVE REGION 251 



factors ar(' too complex for detailed presentation here, and indeed have 

 not heen at all understood by geologists until recently when they have 

 been worked out by Dr. J. E. Hyde for the Geological Survey of Ohio. 

 The writer had the good fortune to liave the company of Mr. Hyde 

 on several field trips during wliicli hi^ obtained a considerable amount 

 of information as yet unpublished which has helped him greatly toward 

 an understanding of the geology of the country. Suffice it to say that 

 the heavy sandstone is an old delta with all the peculiarities of cross 

 bedding and local cut and fill usually found in such deposits. Condi- 

 tions of deposition have also been such as to accentuate and apparently 

 increase the easterly dip of the strata which is general over all of 

 central Ohio. On the eastern edge of the area the sandstone thins out 

 and is carried under cover so rapidly that the character of the country 

 changes greatly within short distances, as for example between Little 

 Rocky Branch (Laurel Township) where the cliffs are so high as to 

 prevent lumbering, and Kocky Branch only a mile away where they 

 are low enough to permit ch^aring and pasturing. On the oi)i)Osite 

 edge of the area about four miles to the westward on the other hand, 

 the conglomerate l)ecomes simply a capstone on the tops of the hills, 

 which are further and further apart until the bottom-lands between 

 them are large enough to have made tillage profitable with the conse- 

 quent destruction of the natui'al vegetation. The highest cliff's occur 

 in the canyon of Queer ("reek near the southern edge of the area where 

 in one place nearly 190 feet of rock are exposed, (fig. 1) South of this 

 point the sandstone thins out rapidly so that the character of the vegeta- 

 tion undergoes a distinct change within a mile or two. On the north oc- 

 casional outcrops of the sandstone occur far beyond our area but the 

 physiognomy and plant covering of the country are decidedly modified 

 by the presence of a sheet of glacial drift of Wisconsin age, the ter- 

 minal moraine of which marks the northern boundary of the region. 



The area lies therefore wholly below the boundary of the glacial 

 drift, and its soils, except the bottom lands of the largest streams, are 

 entirely residual derived from the decay of the several rocks under- 

 lying the land. 



The order of succession an<l ap{)roximate thickness of the forma- 

 tions which are exposed within the area are shown in the subjoined 

 table for which I am indebted to Prof. W. C. Morse who has kindly 

 loaned me his field notes containing numerous sections taken from 

 exposures in and adjoining our area, from which I have constructed 



