188 ProcPcdliKjs of the Hoi/al Socu'ty of Victor la. 



certain area, or indeed to certain horizons in the glacial series. 

 And we would point out that the collection of the different kinds 

 of rock material in the glacial beds with their position accurately 

 marked, locally and in their proper horizon, would be a most 

 valuable help in the unravelling of the glacial story. 



Scflj-ed rock surfaces. One of the most striking features of the 

 glacial geology of the district in the occurrence of scored rock 

 surfaces and roches moutonnees. They are confined to the 

 neighbourhood of the Pyrete Creek, and the exact positions of 

 the better marked surfaces is indicated on the map. An exceed- 

 ingly good example is seen on the Pyrete Creek about a mile 

 below the bridge. The stream has here removed the glacial drift 

 from the underlying hard Silurian sandstones, which now present 

 the rounded and smooth appearance of typically glaciated rocks. 

 These rocks, which extend for about 70 yards along the left bank 

 of the strean), form two main masses, separated by an interval 

 covered by alluvium, and for convenience in reference we have 

 called them the " Pyrete Twins." In addition to the smoothed 

 and rounded appearance may be noticed very distinct scorings and 

 groovings, the general direction of which is from S.W. by W. to 

 N.E. by E. Several hundred yards N.E. of the " Pyrete Twins" 

 the Silurian again crops out at a higher level and exhibits a 

 beautifully scored surface. There must have been at one time a 

 considerable area of striated pavement exposed here, but unfortu- 

 nately portions of it have been removed to fu'rnish building stone 

 for an adjacent cottage. The area remaining shows well marked 

 grooves and striae running in a S.W. to N.E. direction across a 

 beautifully smoothed and polished surface Both at this surface, 

 which we have named " Wightman's Kock," and the "Pyrete 

 Twins," the scorings correspond in direction neither with the 

 strike nor the dip of the Silurian, but lie between the two. 

 After very careful examination of these two instances we have no 

 doubt that the glacier ice to whicli the scorings are due, came from 

 the S.W. About a third of a mile further down the creek is a 

 section showing the glacial conglomerate overlying the Silurian. 

 The latter is again well scored and grooved, the direction being 

 about N.E. In a small gully running parallel with Jhe Melton 

 lioad, half a mile out of Coimaidai, another well scored surface 

 can be seen, the direction of the uroovinos there beinc; N. 3")° E. 



