II.—The Origin of the Clays and Boulder-clays, Federated Malay States

Abstract

Since the earlier edition on the geology of Kinta was written much fresh evidence has been brought to light on the subject of the origin of the clays and boulder-clays and the tin-bearing deposits showing bedding at Gopeng. The effect of this evidence has not been to lessen the objections to the glacial hypothesis put forward by myself, but at the same time it still remains the only explanation that meets the facts in a way that can be called at all satisfactory. It may be that long acquaintance with the subject has made me see difficulties in the way of other explanations where in fact no difficulties exist, and my position regarding the question is somewhat akin to that of a doctor versed in tropical medicine who once informed me that the result of many years study of the etiology of beri-beri was that he felt he could raise fatal objections to any theory that had been proposed. I have not seen sufficient reason as yet, however, to change my views on the subject of these clays and boulder-clays. Certain sections to be noted later militate against a glacial origin, but the evidence of these deposits, including those showing bedding at Gopeng, being older than the granite of the Main Range is stronger than it was before. In the following paragraphs I will attempt to give briefly a statement of the points for and against all possible explanations of the peculiarities observed in these important sources of tin-ore.