BY Dll. W. X. BENSON. 39 



'by the soundings, and the outlet passes over a rock-bar, 

 and enters Cradle Valley as a stream hanging nearly 600ft. 

 above the base of the main valley. 



Another well-marked cirque appears on the northern 

 side of Cradle Valley, about a mile above the accommo- 

 dation house. It is cut down out of Hounslow Heath 

 to a depth of about 700ft., and enters the main valley 

 ■almost at grade. There is a little morainic matter in the 

 floor of this cirque, but no lake. No well-marked cirque 

 •occurs at the head of the Cradle Valley, which has, never- 

 theless, been greatly modified by glacial action. It is a 

 broad, deep, steep-sided valley. The glacier which filled 

 it received tributaries from the Crater, Lilla and Dove 

 valleys, and escaped in part by the present Dove Valley, 

 but also a large overflow passed over the col and down 

 Smith"? Creek. Doleriteerratics have been traced down 

 the Dove River about half a mile below Cradle Valley, 

 and about a mile down Smiths Creek, and probably ex- 

 tend to the commencement of Smith's Gorge a mile or two 

 further dov/n. 



No detailed study has been made of these terminal 

 regions, in which the complex record of retreat and ad- 

 vance may ultimately be deciphered. There seem to 

 have been small gorges cut in the older glaciated valleys, 

 and some sign that these have been subsequently occupied 

 by ice, but it is not clear whether this is the work of inter- 

 glacial river action or merely of subgiacial streams. The 

 well-timbered character of these valleys prevents the 

 observer from obtaining a generaJ view of the whole. 



The last stages of the period of glacial retreat were 

 responsible for the moraines in Cl'adlc Valley. Typically 

 hummocky moraine fills the lower part of the valley and 

 extends across into Smith's Creek. A lateral moraine ex- 

 tends along the southern side of the Cradle Valley, rising 

 250ft. above the floor. An arcuate terminal moraine 

 closes the outlet of Lilla Creek, and a thin ridge of 

 moraine extends down towards the outlet of Crater Lake, 

 possibly a remnant of a small terminal moraine. It is 

 interesting as showing the mark of an overflow-channel 

 fifty feet above the present outlet. Small masses of 

 morainic material occur in most of the cirques mentioned. 



The final period of post-glacial erosion has had very 

 small results. Some morainic material has been removed, 

 and small outlet valleys notched in the terminal moraine, 

 aud patches of allu.vium have been formed. 



Summarisinsf, we may say. that though the glaciers 

 here were large enough to overfloN. their valleys, there is 



