﻿436 TOTJRMALINE-CORTJNDTJM ROCKS OF KINTA. [Allg. I9IO. 



In 1893 * Mr. Leonard Wray, in a note on black limestone at 

 Kamuning, said: — 



' In the schistose beds beneath the limestone, graphite has been found at 

 Batu Grajah.' 



A year later Mr. Wray gave a sketch of the geology of Perak, 2 

 saying :— 



' In some places, on the top of the limestone are small patches of heavy 

 black trap, often vesicular in texture. It is evidently now only a fragment 

 of what it once was, and is represented in many places by only a few scattered 

 fragments. . . .' 



M. Octave J. A. Collet, 3 in a publication the date of which is 

 unknown to me, mentioned (p. 79) schists and quartzites belonging 

 apparently to the Silurian and Devonian Systems, and (p. 80) 

 remarked on the possibility of the limestones being Carboniferous. 

 M. Collet also mentioned traps, trachytes, and basalts, but gave 

 no localities (p. 79). 



I do not propose to dwell on the statements of the above- 

 mentioned authors, except in so far as they affect the Kinta Valley ; 

 and that only for so long as is necessary to clear the ground 

 of any misunderstanding. The schists in the Kinta Valley are 

 above, and not beneath the limestone, as may be seen now in 

 many a section ; and there is no doubt, judging from my own 

 observations, and from a collection of ' trap-rocks ' in the Perak 

 Museum at Taiping, that the tourmaline-corundum rocks which 

 are the subject of this paper were mistaken for basalt. All these 

 rocks are fine-grained, and as the collector was not in the habit 

 of using a petrological microscope, he was, as perhaps many 

 another might have been under similar circumsta?ices, led astray 

 by a superficial resemblance that would have been seen to be 

 totally misleading if only a slice had been cut. 



II. Main Features of the Geology of the Kinta Valley. 



The structure of the Kinta Valley, which is now being mapped in 

 detail, is roughly illustrated by the accompanying section (p. 437). 

 On the east is the main granite range of the Malay Peninsula, rising 

 to over 7000 feet. On the west is the Kledang Range, also of 

 granite and also stanniferous, but rising to a much lower altitude. 

 The floor of the valley is of crystalline limestone squeezed into 

 sharp folds, and forming on the east a range of magnificent 

 limestone foothills below the granite range. On the west the 

 limestone is capped by small hills of schists and associated rocks, 

 which also form rolling ground in some places above the limestone 



1 ' Perak Museum Notes' No. 1, p. 29. 



2 Ibid. No. 4,,pp. 19-22. 



3 * L'Etain : Etude Miniere & Politique sur les Etats Fed£r£s Malais.' 

 JBrussels. 



