﻿314 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 25, 



and Besar (Rabbit and Coney I.), all of which appear to consist of 



sandstone and shale. 



In the next parallel to the east we find in Pulo Salu strata of clay- 

 stone and chert, highly indurated, crystalline, fissile, bluish, greenish, 

 and greyish ; soft clay ; quartz-veins ; quartzo-ferruginous walls ; a 

 subcrystalline grit of a granitiform aspect and in some places with a 

 greenish base ; — between Salu and P. Sudong, reefs of iron-rock* ; — 

 in P. Kapal, fine, purplish clay ; steatitic clay, indurated, white, with 

 seams and walls of iron-rock ; fine shale, indurated, purple ; — in 

 P. Piel Ayem, soap-stone of variable purity, indurated, coarsely foli- 

 ated ; hard steatite ; iron-rock in seams and veins ; the steatite at 

 some places containing iron-pyrites, and locally iron-masked and cel- 

 lular ; — in P. Blakang Padang, coarse conglomerate, some of the 

 pebbles of which are steatite, either pure or imbedding small quartz- 

 grains ; finer beds with much steatitic clay, generally of a light green- 

 ish colour, occasionally violet and red; broad beds of fine-grained 

 sandy marl. 



Returning to the north, we have in P. Marambong clay with quartz 

 and iron-rock remarkably developed ; — in the north-west division of 

 Singapore at TanjongGul, clay, fine (as at Marambong), with quartzo- 

 ferruginous walls ; at P. Sambulan and Tanjong Kling, clays traversed 

 by ferruginous andjaspideous walls; much laterite-gravel; — at P. Dam- 

 mar laterite soil, gravel, and fragments ; the coast of Singapore facing 

 it is lateritic ; on the west bank of the mouth of the Jurong clays and 

 sandy marl ; iron-rock swelling up through it in mam miliary and bo- 

 try oidal bosses ; ferruginous and jaspideous walls ; large laterite blocks 

 composed of small pebbles and fragments cemented together. 



Following this band of strata to the S.E., we observe in the Sikra 

 Islands clays chiefly, with ferruginous walls ; in Sikra Laut numerous 

 highly indurated, ramifying, mammillated, iron-walls ; radiating and 

 concentric laminae of colour ; thin beds of bluish-black and greenish 

 clays. These rocks are continued across to the Old Strait. In P. 

 Busong we find indurated sandstones and clays with irregular ferru- 

 ginous walls ; reticulations of quartz-veins ; much disturbance of stra- 

 tification ; — in P. Bukum, clay with indurated walls ; light-chocolate- 

 coloured clay ; laminae of colour ; — in P. Simakau and P. Siking, 

 iron-rock ; hard laterite ; — in P. Jong, clay, white with a faint green 

 tinge ; a few conglomerate-beds ; numerous iron-walls ; concentric 

 and radiating laminae of colour highly developed ; — in P. Sabaru 

 conglomerate, sandstone, clay ; numerous iron-dykes and laminae of 

 colour as in P. Jong. 



The next parallel is composed chiefly of sandstone and conglome- 

 rate, but with intervening beds of clay, mostly chocolate and purplish. 

 At particular places much iron-rock occurs, and ferruginous lamina- 

 tion is frequent, although not on the great scale of the Sabaru group. 

 The principal exhibition of this band is in the high range of hills on 



* This term is used for brevity in this general sketch. The most common form 

 is the hydrous peroxide of iron ; and the iron-rock throughout the district, I shall 

 afterwards show, is the common rock of each particular sifus disguised by a greater 

 or less injection of iron. 



