CAPE COD GEOLOGY 



73 



sand), and by the edges of sand plains and deltas that were built up against the 

 front of the ice or in open spaces within it while it was melting. The same ice 

 contact slope is seen in the steep banks of ice block holes and of some of the 

 larger kettle holes. 



Some of the terms now used in America to designate glacial deposits are 

 different from those used in Great Britain. In Scotland the term kame is applied 

 to what is here called an esker. In Ireland the term esker is used for both a kame 

 and an esker, as those terms are now used in America. Kame is here used to sig- 

 nify a mound in stratified drift. In New England these forms are at many places 

 strongly developed along the iceward margin of an outwash plain in such a way as 

 to indicate the ice contact, which is usually on the northern or iceward margin of 

 a tract of kames. In these places the outwash material was evidently built upon 

 wedge-shaped fronts of the ice sheet (as seen in vertical section), so that when 

 the ice melted the material was let down to form mounds and hollows. Farther 

 out upon the outwash plain the material was more regularly distributed, its 

 surface sloping in the direction of the drainage, except where there were outlying 

 remnants of ice of an earlier stage. 



At some places the ridges known as eskers are subdivided so as to form a 

 series of ridges enclosing rounded or oval hollows. The peaks and depressions in 

 these ridges give them the aspect of inosculating kames. On such a surface the 

 esker and the kame merge into one another and the distinction between them is 

 lost. The term kame terrace is used for a terrace-like deposit made between the 

 side of a valley and a tongue of ice lying in the valley. On melting out, the ice let 

 the deposit down, in the manner of a kame, at the ice contact border of an out- 

 wash plain. Certain tracts of submarginal moraine appear to be masses of ill- 

 assorted gravel and sand having a surface of mounds and hollows; hence the 

 name kame moraine. But if moraine is used as it is in Europe the second part 

 of this term is redundant, for a kame is a form of moraine. If kame is to be used 

 in a generic sense, it should have prefixed to it terms denoting the special form 

 of glacial accumulation it signifies. 



The term proglacial has been applied mainly to beds of glacial clay laid down 

 in bodies of water in front of an ice sheet, but it is appropriately used also to 

 designate any deposit laid down by ice or water in front of an ice sheet. The word 

 is correlated with superglacial, englacial, and subglacial in denoting a position in 

 relation to the ice sheet. 



There is perhaps some impropriety in grouping dislocated and overthrust 

 beds of preglacial age with moraines. Although these beds have been moved by 



