Vol. 68.'] THE GOPENa BEDS OP KINTA. 143 



portion is composed of clayey beds that I propose to call pro- 

 visionally the Gropeng Beds, and they cannot, I think, be better 

 described in a few words than by saying that they strongly resemble 

 drift, composed of till and boulder-clays. The lowland on the 

 north, and the floor of the Pulai hollow, are an extension of part 

 of the Gopeng Beds, the remainder, together with the phyllites 

 and quartzites, having been denuded away by the River Tekka. 

 Underneath this extension, and at no great depth, is a limestone 

 floor. On the north-west the cap of Gopeng Beds is broken by the 

 Sungei'Eaia, which has cut down to the limestone ; and on the south 

 the same conditions obtain in the lowland as on the north, but the 

 extension of the Gopeng Beds is not so marked. 



The development of alluvium in this area is small, and, so far as 

 concerns this paper, unimportant. 



The following is the sequence of the rocks of the Gopeng 

 neighbourhood in point of age : — 



Youngest : The Mesozoic granite and its modification, 

 and the associated veins. 

 The phyllites and quartzites. 

 The Gopeng Beds. 

 Oldest: The crystalline limestone. 



(1) The Crystalline Limestone. 



The crystalline limestone is part of the great limestone formation 

 of Kiuta that forms the floor of the valley, and there can be 

 little doubt that it is of the same age as the limestone on the 

 other side of the main range in Pahang, where fossil remains point 

 to a Carboniferous or Permo-Carboniferous age. The crystalline 

 structure is due to regional metamorphism, and the bedding, where 

 visible, generally is highly inclined or vertical. In colour the 

 limestone is white or grey, and the grains of calcite may reach a 

 considerable size. 



Where the limestone forms hills, the sides are always steep, and 

 generally take the shape of precipitous cliff's, the most notable of 

 which is on the east side of Gunong Tempurong, where there is a 

 sheer precipice about 800 feet high (see fig. 2, p. 144). The surface of 

 the limestone under the Gopeng Beds is always irregular, and consists 

 of numerous sharp pinnacles and troughs that are often capped by- 

 iron and manganese oxides. There is no reason to suppose that this 

 irregularity represents an old land-surface : for the presence of the 

 cap of iron oxides supports the view that the pinnacles and troughs 

 are due to solution of the limestone by ground water operating 

 underneath the covering of Gopeng Beds, and carrying iron in a 

 soluble form. 



No trace of organisms has been found in the limestone in the 

 Gopeng area, so far as I am aware. The junction with the 

 intrusive granite is sharply marked. 



