﻿1851.] 



LOGAN — GEOLOGY OF SINGAPORE. 



333 



where too wet and sour to make a fertile soil. Rice is grown on 

 some patches of it. The bluish sea-mud contains good ingredients, 

 but clay is in excess, and the animal matter appears to assist in ren- 

 dering it hard and untractable when it is not saturated with water. 

 Even for such a soil nature has provided plants useful to man, for the 

 betel-nut and some of the indigenous fruit-trees grow well in it with 

 little cultivation. Although there are cultivated plants adapted for 

 every kind of soil in the District, and it has indigenous tribes who 

 can live exclusively on its yams, sago, fish, and wild animals, it is 

 incapable of feeding a population of the more civilized races ; and the 

 latter must always be dependent on other countries for the great 

 necessary of life, viz. rice. 



The rocks which are used for economical purposes are not nume- 

 rous. The only edible one is the fine clay called ampo, which is 

 made into thin cakes, smoked, and kept for use. 



The plutonic rocks, and the indurated sandstones and conglome- 

 rates, are used .for the foundations of houses. Lateritic stones are 

 sometimes used by the Malays as pedestals for the posts on which 

 their small houses rest. Granite is used for steps, milestones, tomb- 

 stones, &c. Of the blue alluvial clays the bricks and tiles are made, 

 of which the town of Singapore is built. The fine kaolin which 

 abounds has been found the best adapted of any in India for the manu- 

 facture of porcelain, but no manufactory has ever been established*. 



IV. Traces of the Geological History of the District. 



Having thus given a general description of the actual constituents 

 and arrangement of the rocks of the district, we have next to inquire 

 whether they preserve any evidences of its past geological history, 

 and I think the following conclusions may be safely adopted. 



1. Ceasing for a moment to view the district as isolated, it is 

 established that it is a portion of the zone of elevation extending from 

 the Himalayas (or their vicinity) to Banka, or rather to the granite 

 patch in Java ; approximately parallel to the plutonic zones of Bur- 

 mah, Siam, Cambodia, and Anam, which seem to terminate in Borneo, 

 and surrounded by the great volcanic band of the Indian Archipelago, 

 the most active western portion of which, Sumatra, is semi-plutonic, 

 and is parallel and adjacent to the Malay Peninsula ; separated from 

 it only by the broad and shallow submarine valley of the Straits of 

 Malacca f. 



2. The sedimentary strata of the district were deposited prior to 

 the elevation of the Malay Peninsula, and therefore prior, probably, 

 to the elevation of the whole south-eastern region of Asia. 



3. They were formed from the abrasion of a tract composed 

 chiefly of clays, and probably partially elevated above the level of the 

 sea, or at least so near its surface as to be subject to strong currents. 

 These appear to have prevailed along some of its wasting shores in 



* See Dr. O'Shaughnessy's Report of Experiments made by him for Government, 

 f See * The Physical Geography and Geology of the Malay Peninsula/' Journ. 

 Ind. Arch. vol. ii. p. 89-93. 



