Geological Society. 753 



Malay Peninsula that has beon gathered during the course of 

 economic work since 1903. 



The main points are as follows : — 



During the Mesozoic Era earth-movements took place in a part 

 of the crust which is now the site of the, Malay Peninsula. 

 These movements resulted in the formation of two large anticlinal 

 folds. The folding admitted of the intrusion of two masses of 

 granite, and the intrusion was accompanied by faulting of the 

 rocks in the folds,, and by ' magmatic stoping' on a large scale. 



The rocks affected by the folding are the Raub Series of cal- 

 careous rocks, and the Malayan Gondwana rocks, resting un con- 

 formably on the Eaub Series, and in many places faulted down 

 against that series. 



The palaeontological evidence afforded by small collections from 

 the Haub Series cannot be reconciled with the field evidence. No 

 fixed horizon has been discovered in these rocks, which may be 

 either Carboniferous or Permo-Carboniferous. Associated with the 

 Eaub Series are volcanic rocks, which are evidence of contem- 

 poraneous submarine eruptions. The eruptions continued into 

 later times. 



At the base of the Gondwana rocks are glacial deposits that may 

 be referred to the same horizon as the late Palaeozoic glacial deposits 

 of Peninsular India, the Salt Range, Australia, and South Africa, 

 but this horizon cannot be defined exactly in the terms of the 

 European sequence. Its presence shows that the Raub Series must 

 be older than the Productus Beds of the Salt Range, or equivalent 

 to the shales below the boulder-bed in the trans-Indus section of 

 the Salt Range. 



The glacial deposits are succeeded by littoral deposits, and far to 

 the east of the glacial deposits a Rhaetic horizon has been described 

 in them by Mr. R. B. Newton, and named by him the Myophorian 

 Sandstone. To account for the apparent discrepancy in age 

 between the climatic horizon afforded by the glacial deposits and 

 the Myophorian Sandstone, an hypothesis has been adopted to the 

 effect that the Malayan Gondwana rocks were deposited on the 

 Gondwanaland coast-line as it moved slowly eastwards, probably 

 with many checks and oscillations. 



The glacial deposits show that this portion of the Gondwanaland 

 coast contained stanniferous granite and also much corundum. 

 This granite is called ' the Palaeozoic Granite,'' as distinguished from 

 * the Mesozoic Granite ' : it is not known in situ. The glacial 

 deposits are, therefore, part of a Palaeozoic tin-field, now being 

 worked at the same time as the stanniferous deposits derived from 

 the Mesozoic Granite. 



Denudation has brought to light the two great anticlinal folds 

 and the granite masses upon which they now rest. On the west is 

 the Main Range Anticline, on the east the Benom Anticline. The 

 eastern limb of the former and the western limb of the latter meet 

 in the Main Range Foothills. The eastern limb of the Benom Anti- 

 cline is formed by the main Gondwana outcrop, which includes the 

 highest peak in the Peninsula (Gunong Tahan, altitude 7188 feet). 



