28 -PRESIDENT'S -ADDRESS 1 . 



We have now seriously to consider the question fis to the truth 

 of this deduction. To Mr. De La Mare belongs the credit of 

 having first upset our minds on this subject. As you all know, 

 he has persistently brought to our notice the fact that all 

 through this island there are two important things to be 

 noticed. 1st. That where quarries are open on the sides of 

 hills the veins of diorite, quartz or felsite are commonly bent 

 in the direction of the slope for some eight to twelve feet from 

 the surface, though true to their original position below that. 

 2nd. That the rocks are often crushed and displaced as though 

 forced along by some power acting in the same direction. 

 These points have been discussed at several meetings, but their 

 importance has been very much intensified by the facts that 

 have been noticed by the Geological Section this year. 



We have had our attention attracted to the straightness 

 of the line which separates the rock proper from the clay 

 coating in many places. No doubt can exist, I think, about 

 the fact that the clay which covers the rock does not, except 

 in a few cases, belong to the place in which we find it. It 

 exists as a mantle covering up the rock outcrops and resting 

 on rock, which was solid at the time, but is now decomposed. 

 But we should naturally expect the rock surface to be irre- 

 gular, with pointed peaks and protrusions ; this, however, we 

 do not find to be the case. The rocky slopes of the hills must 

 have been, in most cases, quite smooth before the deposit of 

 the clay. The direction in which this smoothing-off runs 

 agrees too, in the main, with the bends that Mr. De La Mare 

 has noticed. The inference, therefore, is that before the 

 deposit of the clay the hills were rounded off and smoothed 

 down in the directions of the slopes. This phenomenon, I 

 unhesitatingly say, points to ice action as a cause. 



Some time ago there were found at the St. Andrew's 

 clay quarry two pebbles which had marks on them which we 

 were justified to think may have been striae or ice scratches. 

 At the time we picked these up we had not attached the 

 importance that we should have done to the planed rock 

 surfaces, hence this additional evidence did not attract the 

 attention it would do now. The Society has, therefore, 

 during the next year, to see if the evidence it can collect will 

 go for or against the idea of glaciation. 



There are other points that should be mentioned in this 

 connection. One is that we have two different kinds of clay, 

 An unctuous blue clay, of "the origin of which we can have no 

 doubt, because we see it in course of formation on our coasts. 

 .This kind is formed directly by the disintegration of the 



