Geology of the Malayan Peninsula

Abstract

IN some geological excursions made recently in the State of Perak, I met with some curious facts which may be of interest to many of your readers. I made boat journeys down the Perak River from Enggor to the mouth, then back again up the valley of the Kiuta, and then returning to the mouth of the Kampar, went up that stream as far as boats can go. The main chains dividing these ranges are all granitic, rising to peaks generally over 3000 but sometimes over 7500 feet high. The ranges are flanked by Lower Limestone ridges, forming detached hills about 1500 feet in elevation. The summits of these hills, as well as on the flanks, are pierced with caves, which contain a ferruginous clay with stream tin. The latter is evidently derived from granite, but as the limestone hills are quite isolated, and some miles away from the source of the ore, the denudation of the country must have been very great. Some of the caves with tin sand are 1000 feet above the plain, and have to be approached by steps cut in the face of a precipice. These small mines are rich enough to attract a few Malays and Chinese, who are the only inhabitants. The country is otherwise a dense jungle. The limestone is crystalline, without a trace of organism, though lines of stratification can still be traced. Tin is also found in the drift at the base of these hills, entangled as it is in the pinnacles and peaks of the underlying limestone.