640 PROCEEDINGS OF THE BALTIMORE MEETING 



The next paper read was 



GLACIAL EROSION ON KELLEYS ISLAND, OHIO* 

 BY FRANK CARNEY 



Contents Page 



Introduction 640 



Discussion 641 



Direction of ice motion 643 



The deep grooves , 644 



Summary 645 



Introduction 



All are familiar with the conventional cross-section of a valley deepened by 

 glacial erosion. This paper aims to show (1) that wherever we have concen- 

 trated glacial erosion in rock, the result, whether a groove a few inches deep 

 or a modified valley over-deepened several hundred feet, is a U-profile ; (2) 

 that the grooves on Kelleys island were cut in a very short time ; that the tools 

 were largely of limestone of the formation being eroded, and that the work 

 was done not long before the ice melted back permanently from the island. 



This island is located about G miles off the mainland. Its area is approxi- 

 mately 7 square miles, and it lies north of the axis of the Lake Erie ice lobe. 

 Its surface consists of limestone bearing a slight veneer of glacial drift. 

 Locally the drift has been assorted by wave action of the lake at a higher 

 level, leaving beach gravels at the foot of the cliffs cut in the limestone. 



The region has long been known for its quarries as well as for its unusual 

 glacial erosion features. At the present time there are three principal work- 

 ings, designated the North, West, and South quarries (figure 1), operated by 

 the Kelley Island Stone and Transport Company. 



Between the West and the South quarries, during the past summer, an area 

 about 100 rods long and 4 rods wide was stripped preparatory to opening up a 

 new quarry. 2 This surface, which lies transverse to the direction of ice motion, 

 was covered by from 3 to 6 feet of glacial drift. This recently exposed area of 

 limestone presents features of ice work which, when considered in connection 

 with the scoring and grooving near by on the island, suggest some interesting 

 questions in glacial erosion. 



The area represented in figure 1, plate 108, looks northward over the area, 

 which up to a point in the distance where the rock surface appreciably rises is 

 completely smoothed and striated (figure 2, plate 108), presenting, for the 

 most part, a perfectly flat surface. Toward the north end, however, is a 

 depression in this otherwise flat expanse ; a few rods beyond this depression 

 the glaciated surface is displaced by a rising slope of limestone which shows 

 no evidence whatever of ice work. Furthermore, the camera stands on rough 

 limestone that does not give the slightest indication of ice erosion. The 

 smoothly polished area intervening is 830 feet long. A little more than three 





1 Presented with the permission of the Ohio Geological Survey, it heing understood that 

 the author is responsible for the opinions expressed. 



Manuscript received by the Secretary of the Society on February 24. 1909. 

 3 Mv attention was called to this new exposure by Mr C. R. Stauffer. 



