166 Lieut. J. B. Scrivenor — Origin of Clays and 



the exception, of one section at Kacha mentioned earlier in this 

 chapter, but which cannot be seen now, the claj's and boulder-clays 

 have only been seen resting on limestone. An exposure of them above 

 argillaceous or arenaceous rocks, or above any rock not soluble to the 

 extent that limestone is soluble, would remove all doubt of their 

 having been deposited as clays and boulder-clays, but no such section 

 can be pointed to. 



The deposits that were described first as the "Gopeng Beds" differ 

 from the foregoing in being in part stratified. Sections in the deep 

 excavations now being worked and other sections show that this 

 stratification is more distinct than was formerly thought to be the case, 

 but there are associated clayey beds with isolated boulders such as those 

 figured in the earlier edition (pi. v, fig. 3 ; pi. vii, fig. 3; pi. xvi, fig. 1), 

 and when that edition was prepared a glacial origin for them was the 

 only satisfactory explanation. Nothing further has been learned 

 about the first two cases illustrated by the figures, but other sections 

 have been seen where the boulder-beds are immediately above lime- 

 stone and could be interpreted as stratified beds disorganized by 

 sinking over limestone. This includes deposits invaded by kaolin- 

 veins. I am still uncertain that this view of pebble-beds being broken . 

 up and mingled with clay to simulate boulder-beds is the best. It is 

 insufficient to explain the section in which the big boulder figured in 

 pi. V, fig. 3, of the earlier edition occurred ; and the boulder figured 

 in pi. xvi, fig. 1, and other isolated boulders occurred on some of the 

 highest land. 



It is difficult to believe that the corundum boulders found at Pulai 

 and on the Tekka Ltd. mine were deposited in their present position 

 by water-action. An alternative view to their being dropped from ice 

 into fine silt is suggested, however, by an exposure on Tekka which 

 has only recently been laid bare. lu stiff clay overlying the lime- 

 stone corundum boulders were found in great numbers, many being 

 over 100 lb. in weight. When the limestone floor was exposed, it 

 seemed possible from the distribution of the boulders and the position 

 of some of them that they had formed a vein in the limestone. No 

 corundum could be found embedded in the limestone, but that, of 

 course, is not a fatal objection to there having been a vein, the walls 

 of which were dissolved away. Some of the corundum boulders are 

 angular, some well rounded. Like other specimens found at Pulai 

 and Tekka, the surface of the boulders is often pitted as though some 

 mineral intergrown with it had been dissolved away. I have not 

 obtained any evidence that it was calcite from the form of the cavities, 

 but that is possible. 



In Selangor evidence has been found by Mr. Jones of faulting in 

 recent alluvium. Figures in the older edition show complicated 

 faulting in the deposits under discussion, and we have to consider the 

 possibility of the latter being recent alluvium faulted and in part 

 disorganized owing to the solution of the underlying limestone. It 

 is, I suppose, possible that faulting such as this could be produced by 

 such a cause, but it is unlikely ; and the evidence of the kaolin-veins 

 is directly opposed to the beds being recent. Accumulated observa- 

 tions of the form of the kaolin-veins and their junction with the clay 



