Vol. 69.] GEOLOGICAL HISTORY OP THE MALAY PENINSULA. 351 



VIII. The Mesozoic Granite. 



All the granitic ranges of the Peninsula are, so far as is known, 

 remnants of approximately contemporaneous intrusions. The 

 available evidence points to the date of intrusion as having been at 

 some time after the Trias and before the Eocene, perhaps between 

 Inferior-Oolite and Cretaceous times. 1 Most of the granite contains 

 large porphyritic felspar-crystals, but some is non-porphyritic. 

 There is no reason to suppose that this difference marks any 

 important distinction with regard to the epoch of intrusion. 



The only other point in the petrology of the granite and asso- 

 ciated rocks to be noted here, is the fact that the Benom "Range 

 differs markedly from other granitic ranges in the. Peninsula. 

 In the Main Range, for instance, hornblende occurs sparingly, 

 sometimes in quantity; but, in the Benom Range, the rocks that 

 are known are mostly hornblende-granites and syenites. Ordinary 

 granite is known to occur, however. Porphyritic crystals of felspar 

 are found in the hornblende-granite, as in the granite of the other 

 ranges. 



IX. The Tertiary Coal Measures. 



The Tertiary Coal Measures were found in Selangor in 1908. 

 The credit of the discovery belongs to a Malay, who was prospecting 

 for tin-ore by means of shallow pits, and found instead a seam of 

 ■coal that proved later to be 40 feet thick. The Coal Measures 

 were mapped as well as circumstances allowed — they occur in the 

 ■densest virgin-jungle where there are no large streams, but plenty 

 Of swamp, — by the difference between the soil formed by the Coal 

 Measures and the soil formed by the quartzite and clay-slate on 

 which they lie. Put for an extension into swampy ground, where, 

 ■of course, geological mapping was impossible, prospecting work by 

 means of bores has shown that the limits of the Coal Measures thus 

 indicated were fairly correct. They cover about 2 square miles, 

 and are a remnant preserved on a low watershed from denudation. 

 The coal is of poor quality, being on the border-line of the coals and 

 lignites ; and, if the fixed carbon or calorific value be taken as the 

 basis of classification, it should be termed a ' lignite.' It might 

 equally well be termed 'pitch-coal' or 'sub-bituminous coal.' Some 

 •of the shales have been found to contain a small quantity of oil. 



A number of fossil leaves have been collected from the shales, 

 which Mr. H. IN". Ridley, F.R.S., kindly examined for me. Like 

 the flora of the Borneo Coal Measures, they resemble existing 

 jungle types. The only shells found so far are some crushed 

 specimens that are probably assignable to Helix. 



The evidence for the Coal Measures being Tertiary is that they 

 are unconformable on the greatly -disturbed quartzite and clay- 

 •slates ; also that they show no trace of alteration by the granite, 

 intrusions of which, with tin-ore, into the quartzites and clay-slates 



1 See Q. J. G. S. vol. lxvi (1910; p. 429. 



