432 Levereti — Observations on Graigton Lake. 



Art. XXXIV. — Observations on Graigton Lake /* by Frank 



Leverett. 



The announcement made by Prof. G. D. Hubbard in the 

 May number of this Journal that Lake Craigton, a small gla- 

 cial lake in north-central Ohio, has tilted shore lines, was 

 received by the writer with considerable distrust ; for this lake 

 lies outside the uplifted area of the Great Lakes region and 

 adjoining an area in which the shore lines of the glacial waters 

 occupying the Erie basin are horizontal. The amount of tilt- 

 ing reported, 4 feet per mile, is far greater than that of the 

 southern part of the uplifted Great Lakes area, which shows 

 only a few inches per mile. This region had been examined 

 by the present writer before publishing his report on the 

 Glacial Formations and Drainage Features of the Erie and 

 Ohio Basins,f and he had noted no evidence of a tilting of 

 shore lines. Peculiar drift embankments were, however, 

 observed along the valley borders, which occur at lower and 

 lower levels as one passes southward, but which were thought 

 to be due to the presence of an ice tongue in the valley which 

 was subsequently occupied by Craigton Lake and its outlets.^: 

 Furthermore, such lake action as the writer could discover 

 was confined to lower positions than these drift embankments, 

 and the shore features were found to be very faint and frag- 

 mentary. In this valley as well as in others in Ohio and Penn- 

 sylvania there seems to have been a very short-lived ponding, 

 and for that reason it hardly seemed worth while to name the 

 ponded waters. Their short duration was due to the slight 

 amount of cutting down in their outlets necessary to effect 

 more or less complete drainage. The statements in Professor 

 Hubbard's paper put the matter in such a different light in 

 reference to Craigton Lake that the present writer took occa- 

 sion, when passing through Ohio in June, to stop off and 

 examine the field again. Topographic maps are now available 

 which greatly aid in determining the relations of the ponded 

 waters to the outlets, of which two were found to have been 

 operative. No such maps were in existence at the time of the 

 earlier studies, and the map embracing the southern end of the 

 lake§ has appeared since Professor Hubbard made his investi- 

 gations.! 



* Published by permission of the Director, U. S. Geological Survey. 



\ Monograph XLI, U. S. Geological Survey, Washington, 1902. 



iOp. cit., pp. 390-392. 



§ Loudon vi lie topographic sheet. 



|| The accompanying map, fig. 1, is based upon parts of the West Salem 

 and Loudonville topographic sheets, but in order to obtain clearness of 

 representation roads are omitted, and only 100 foot contours are reproduced. 



