Botdder-clays, Federated Mcday States. 165 



boulders of quartz. Some years ago one or two granitic boulders 

 were found in tbis mine, but tbe great majority are tbose just 

 described, and in 1914 a section was laid bare in tbe tributor's mine 

 that affords the strongest evidence against a glacial origin that has 

 been found. The section is in a big open-cast mine. On the near 

 side of the mine tliere is a high limestone wall and lignite. The 

 limestone extends to the bottom of the mine, which is about 

 120 feet deep, and above it, on the far side, is a section showing 

 boulder-clay on the left, and in tlie centre and on the right shale 

 and quartzite very much disturbed. About the same time that this 

 section was first seen a quartz-vein was exposed in the limestone at 

 the bottom of the mine, and, as the boulders in the clay are all quartz 

 or tourmalinized quartzite, the'facts point to the boulder-clay being 

 much disturbed quartzite and shale beds, together with a quartz- 

 vein, completely disorganized in a deep cavity in the limestone. 



This section is the only instance of a boulder-clay being exposed 

 in close proximity to bedded rocks from which the boulders could be 

 derived, but the same section showed a further point that is difficult 

 to understand. On the left of the section and some yards away from 

 the bedded rocks were two elongated patches of clay rich in 

 tourmaline. These might possibly represent portions of the bedded 

 rocks rich in tourmaline, but their form suggested that they were 

 the result of the production of secondary tourmaline in the clay, 

 in which case the formation of the boulder-clay must have been 

 pre-granitic. This, however, is by no means certain, and the 

 patches cannot be taken as an objection to the clay and boulders 

 having .been derived from the shale, quartzite, and quartz-vein at 

 some time. In this mine one must conclude that the boulders are 

 not of glacial origin, but are the remains of a tin-lode in shale and 

 quartzite overlying limestone. 



Another piece of evidence obtained since the earlier edition was 

 published concerns the huge boulders of quartz in the Kinta 

 Association mine at Tanjong Rambutan. I have been informed that 

 at one period during the work a section of a big quartz-vein was 

 exposed from which tbe boulders could have been derived. I did 

 not see this section myself. 



On the Tekka Ltd. mine, and in the sections to the south, where 

 the clay is in contact with the granite, there is another point that 

 must be mentioned. There are no boulders of any size to be seen 

 near the granite. For conclusive evidence of the clays being glacial 

 one requires boulders at the junction with the granite. They were 

 found in the Kramat Puali section, however. 



The doubt concerning the origin of the tin-bearing clay at Tronoh 

 and Tambun can be cited against tbe glacial theory. 



The absence of striae on boulders is also against this explanation, 

 but with rocks so weathered as these are, strise cannot be expected, 

 if they ever existed, except in the case of boulders of corundum or 

 tourmaline-corundum rocks. Nothing has been found that I can 

 regard unreservedly as glacial striae. A glaciated pavement of 

 limestone would be destroyed by solution. 



Lastly, a powerful argument against the glacial theory is that with 



