BY PROF, DAVID, RICHARD HELMS, AND E. F. PITTMAN. 47 



Merewether (Blue Lake) Valley during the maximum develop- 

 ment of the local glacier, as will appear presently. 



Lake Merewether [Blue Lake) and Evidence Valley {Helvis), 

 to helotv Hedley Tarn. — Splendid evidences of past glacial action, 

 including the largest and most complete moraine as yet observed 

 in this region, are to be seen at the above locality. 



If the area be approached from the west, from the direction of 

 the main Dividing Range, moraine material with ice-scratched 

 fragments of slate (phyllite) may be seen at an elevation of about 

 6,530 feet at a point about 20 chains W. of the S. W. end of 

 Lake Merewether. Up to this same level also the granite 

 rocks show evidence of having been planed down by ice-action; 

 and a few feet lower, at about 6,500 feet, they exhibit distinct 

 glacial grooves. 



Further east, at 12 to 15 chains west of Lake Merewether, the 

 surface of the gneissic granite is most wonderfully grooved and 

 dressed in a manner which could only have been accomplished by 

 a thick mass of moving glacier ice (see Plate vii.). 



The level of this rocky promontory at the spot photographed 

 is about 6,260 feet. 



It affords a fine and impressive piece of evidence as to the 

 former presence of moving glacier ice. 



Though the granite surface has been somewhat weathered since 

 the glaciation, so that all striae have disappeared, the grooves 

 remain, and in many cases are in a very good state of preserva- 

 tion. For every foot in width of granite surface, measured at 

 right angles to the trend of the grooves, there are from 4 to 5 

 grooves. The grooves are from 1 inch up to 6 inches in width, 

 and from \ inch up to about IJ inches in depth. At the 

 spot mentioned above they run in a direction of 140° (that is S. 

 40° E., is the lee side) and preserve an almost absolutely straight 

 course irrespective of the ups and downs of the granite surface, 

 their trend being straight towards the large moraine which 

 bounds Lake Merewether (the Blue Lake) on the south. Even 

 small vertical faces of granite, opposed to the path of the ice, are 



