348 ME. J". B. SCRIVENOE ON THE [JuilC I9I3,. 



The eastern coast also is low-lying, but more sandy than the west,, 

 and from it, too, isolated hills spring up like islands. 



In the Straits of Malacca there are a few rocky islands, distinct 

 from the large mangrove-covered islands such as those that fringe- 

 parts of the coast of Perak and Selangor. In the China Sea 

 numerous rocky islands, of which Tiuman is the largest, lie close- 

 to the coast. 



III. Brief Sketch of the Geology oe the Peninsula. 



Anyone who has read some of the earlier works on the tin- 

 fields of the Peninsula would naturally conclude that the superficial 

 recent deposits are of great importance. This, however, is not the- 

 case, owing to the fact that the Peninsula is now experiencing a 

 long-continued period of uplift, which has prevented any great 

 accumulations of alluvium in the valleys. Weathered rocks in 

 situ, soft granitic rocks rich in kaolin, and Palseozoic clays have- 

 been described erroneously as alluvium, and we can confine our 

 attention almost entirely to the solid geology of the country. A. 

 brief sketch of this now will make subsequent sections more easily 

 understood. 



The oldest-known rocks in situ are a calcareous series, named 

 provisionally the Kaub Series, with which is associated in Pahang 

 the Pahang Volcanic Series, partly contemporaneous with the 

 Eaub Series, but continuing into later times. The Eaub Series, 

 forms a large part of the lower-lying land of the Peninsula, where 

 the rivers have cut down to it through superincumbent rocks. A 

 series of radiolarian cherts and fine-textured shales is believed to 

 be a phase of the Eaub Series. 



Unconformable to the Eaub Series is a great development of 

 littoral rocks — quartzite, conglomerate, shale, clay-slates, and 

 phyllites formed by metamorphism of the shales. Some rocks 

 of the Pahang Volcanic Series are contemporaneous with part of 

 them. In the Kinta district of Perak, and in other localities, at 

 the base of these littoral rocks is a considerable thickness (about 

 200 feet where best preserved) of stanniferous clays with boulders,, 

 believed to be of glacial origin. The quartzites, etc. form a large- 

 part of the hilly country of the Peninsula, and they, together 

 with the glacial clays, will be referred to collectively as the- 

 Gondwana rocks. 



Intrusive into the Eaub Series and the Gondwana rocks is the 

 granite of the ranges enumerated above, with other associated 

 plutonic rocks. 



No granite in situ in the Peninsula is known to be older than 

 the Eaub Series and the Gondwana rocks; but in the glacial clays,, 

 the tuffs of the Pahang Volcanic Series, and the conglomerate 

 of the Gondwana rocks, there is evidence of a much older granite 

 that was stanniferous like the younger granite. The granite that 

 is older than the Eaub Series, etc., and not yet known in situ, is 

 referred to as the Palaeozoic Granite; the younger granite- 

 is referred to as the Mesozoic Granite. 



