184/.] including Notices of Sumatra, the Malay Peninsula, fyc. 553 



Sumatra and not with the mountain chain of the Peninsula. If this 

 -view shall be found to he borne out by further observations, we must 

 conceive that the old granite mountain chain of the Peninsula (which, as 

 is shown in the paper before mentioned, terminates apparently between 

 Parcelar Point and Pulo Varela, although a few minor groups exist in the 

 interior to the southward) had its extremity in this direction washed by 

 the sea. The region below which operated the expansive volcanic fluids 

 or gases whose effects we are considering, extended from Sumatra to the 

 Peninsula, and probably a little to the westward of the one and consi- 

 derably to the eastward of the other, for the whole vast platform or 

 partially emerging and partially subsiding continent that rises out of the 

 depths of the Indian ocean and stretches eastward far into the Pacific, 

 rests on one region of connected though shifting subterranean excitement. 

 The line of most intense force would be the ordinary one, the volcanic 

 chain of Sumatra. Thence the waves of the volcanic sea would travel in 

 parallel lines to the north-eastward, causing a tension of the region and 

 a tendency to split in the direction of those lines. That portion of the 

 region intermediate between the western and eastern mountain chains 

 which had not been disturbed and fractured during the process of elevation 

 like that from which the chains were obtruded, or of which the fractures 

 had not reached the surface, would offer most insistence. But on 

 arriving at the western limit of the old fractures caused during the ele- 

 vation of the Malayan chain, the space so fractured would yield in vari- 

 ous points of weakness. The old fractures at the southern extremity 

 of the chain would, by the tension, be prolonged in the same direction, 

 that is to the S. E., and cross fractures being established and the vol- 



sula. The central mountains are chiefly plutonic and volcanic. The granite or sienite 

 of the southern regions would appear from Marsden's slight notice to resemble that of 

 Singapore. The lower tracts of the west coast as described by him possess a remarkable 

 resemblance in their general configuration to the surface of Singapore. Like the latter, 

 they consist of rounded elevations of no great height, separated by winding flat swamps 

 penetrating for miles between them. The hills " not unfrequently exhibit the appearance 

 of an amphitheatre." A co-incidence in a configuration so uncommon when other analo- 

 gies are also considered, can hardly be viewed as accidental. The soil he describes as a 

 stiff reddish clay. The rock exposed in sea cliffs and in some place? at the bottoms of 

 rivers is a species of clay called by the natives nappal, which is common inSingapore. 

 The country between the mountains and the eastern coast ot Sumatra is little known, but 

 what information has been obtained respecting its geological features 1 have collected in 

 the paper before alluded to. 



4 c 2 



