BY THE REV. J. E. TENISON-WOODS, P.G.S., F.L.S., &C. 1191 



supposed to be more the deep-seated portions of the fusion which at 

 the earth's surface produces basalts, lavas, and scoriae. That this is 

 very near the truth may be seen from certain sections in Northern 

 Europe whose upper portions have all the characters of volcanic 

 products but gradually merge into granite in the lower sections. 

 Hydrothermal action consequent upon pressure is the assigned 

 cause of all the phenomena, but this is of no moment in our 

 present inquiry. We may therefore conclude that there have been 

 volcanic products in connection with this range, which have now 

 disappeared or nearly disappeared. 



It must be borne in mind however, that these cannot be looked 

 for under the recent form of the volcanic series. Local rneta- 

 morphism has changed them. According to the researches of 

 Phillips and others, basalts, dolerites, &c, would be changed into 

 diorite, diabase, and other rocks, in which augite disappears, and 

 hornblende takes its place. Time and that constant interchange of 

 particles which takes place in even the most solid rocks would effect 

 these changes. 



Furthermore, even if there had been no erosion, we could not 

 expect to find these metamorphosed volcanic products widely distri- 

 buted. Probably they are only connected with those outlets where 

 the pressure was less, the gases and steam were able to expand, 

 and the chemical influence of oxidation felt. 



But nearly all of these products belonging as they did to the 

 upper portion of the granite have been swept away by erosion. 

 Yet not quite all. In the section of the Kuala Kangsa pass at 

 about 14 miles from Thaiping, there is a wide dyke which is 

 trappean. It has been much metamorphosed, and at present has 

 considerable resemblance to a porphyrinic rock. I have not 

 examined sections as yet, and therefore cannot give any further 

 information as to its character. This is the only dyke or rock of a 

 trappean character which I have seen in connection with the 

 granite, nor would this have been visible but for the cutting 

 connected with the road through the Pass at Gapis. 



It should be mentioned here that one of the greatest difficulties 

 experienced in exploring the geology of this country is the absence 



