BY T. GRIFFITH TAYLOR. 



333 



about 4*23 feet at tlie maximum point. It has not, however, led 

 to the formation of any area of internal drainage as is the case at 

 Lake George. 



iv. Topographical Changes since the Faulting. 

 These fall into two classes, (a) those due to erosion, (b) those 

 due to aggradation. The 

 former have affected the 

 positive forms (hills, &c.); 

 while the latter have tended 

 to fill up the negative land 

 forms, in this case the bed 

 of Lake George. The more 

 or less sharp edge left at 

 the close of the faulting has 

 been gnawed away; but, as 

 noted previously, many 



slopes of 45* 



itill be 



obtained at the northern 

 end. This is a remarkably 

 steep face for a continuous 

 range, and points to the com- 

 paratively recent character 

 of the subsidence. It may 

 be estimated that a wedge- 

 shaped slice of slate some 

 twenty miles long, with a 

 base about 300 yards wide, 

 and a depth of 500 feet has 

 been removed by erosion of 

 the scarp. This wedge of 

 eroded material might be 

 made the basis of a calcu- pjg^ 3._Map showing evolution of the 

 lation as to the age of the river-system in the Lake George area, 



fault, but a much more For topographical names, see text and 



promising method is ampli- Plate vii. The area of subsidence is 



fied in a later section (vi.). 



