﻿436 H. O. Zetois — Comparative Studies upon Glaciation. 



land. There is evidence that where the ice sheet abutted against 

 Wales, it was about 1350 feet in thickness. This is analogous 

 to the thickness of the ice sheet in Pennsylvania, where the 

 author had previously shown that it was about 1000 feet thick 

 at its extreme edge and 2000 feet thick at points some eight 

 miles back from its edge. The transport of erratics coincides 

 with the direction of striae in Wales as elsewhere, and is at 

 right angles to a terminal moraine. 



The complicated phenomena of the glaciation of England, the 

 subject of a voluminous literature and discordant views, had 

 been of high interest to the author, and had led him to redouble 

 his efforts toward its solution. He had found that it was possi- 

 ble to accurately map the glaciated areas, to separate the depos- 

 its made by land ice from those due to icebergs or to torrential 

 rivers, and to trace out a series of terminal moraines both at 

 the edge of the ice sheet, and at the edge of its confluent lobes. 

 Perhaps the finest exhibition of a terminal moraine in England 

 is in the vicinity of Ellesmere and Shropshire. A great mass 

 of drift several miles in width, and full of erratics from Scot- 

 land and from Wales, is here heaped up into conical hills which 

 enclose " kettle- holes" and lakes, and have all the characters of 

 the u kettle moraines" of Wisconsin. Like the latter, the Elles- 

 mere moraine here divides two great lobes of ice, one coming 

 from Scotland, the other from Wales. This moraine may be 

 traced continuously from Ellesmere eastward through Madeley, 

 Macclesfield, to and along the western flank of the Pennine 

 chain, marking throughout the southern edge of the ice sheetof 

 northern England. From Macclesfield the same moraine was 

 traced northward past Stockport and Staley Bridge to Burnley, 

 and thence to Skipton in Yorkshire. Northeast of Burnley it is 

 banked against the Boulsworth Hills up to a height of 1300 

 feet, in the form of mounds and hummocks. South and east of 

 this long moraine no signs of glaciation were discovered, while 

 north and west of it there is every evidence of a continuous ice- 

 sheet covering land and sea alike. The striae and the trans- 

 port of bowlders agree in proving a southerly and southeasterly 

 direction of ice movement in Lancashire and Cheshire. 



From Skipton northward the phenomena are more complicated. 

 A tongue of ice surmounted the watershed near Skipton and 

 protruded down the valley of the Aire as far as Bingley, where 

 its terminal moraine is thrown across the valley like a great 

 dam, reminding one of similar moraine dams in several Penn- 

 sylvania valleys. A continuous moraine was traced around 

 Aire glacier. Another great glacier, much larger than this, 

 descended Wenslevdale and reached the plain of York. The 

 most complex glacial movements in England occurred in the 

 mountain region about the Nine Standards, where local glaciers 



