AND GEOLOGY OF THE MALAY PENINSULA. 97 
fitude of scattered rents, the rupture would be across the direction 
of tension, or parallel to the sides of the zone. It is not to be sup¬ 
posed that in nature anything so simple as an intumescence uniform 
in length and breadth could occur, and the irregularities in the boun¬ 
daries of the zone, and in the direction of the tension in different la¬ 
titudes must have been considerable. Nevertheless we find that the 
evidences of the mode of action preserved in the remaining sedimen¬ 
tary rocks corroborate, in the most striking manner, the deductions 
that might have been made from a theory based simply on the gene¬ 
ral direction of the zone. The broken edges of the uplifted strata 
exhibit in their strike, wherever they have been examined, a near ap¬ 
proximation to the direction of the zone. Ranges of plutonic and 
sedimentary rocks and the vallxes between them, in most cases, pur¬ 
sue a similar direction. Having ascertained this to be the case on 
the eastern and western coasts of Jchore, Pahang and Salangor, 
and having minutely verified it over nearly the whole of Singapore 
and the adjacent islands, we are justified in concluding that the 
same facts will be found repeated throughout the rest of the Pe¬ 
ninsula, where we know that the leading plutonic phenomena are, 
In other respects, similar to those of the southern region. Here we 
are everywhere reminded of the mode in which the Peninsula rose. 
¥ 
If the strata are not visible, we may often trace the Peninsular di¬ 
rection in the junction between the greyish, yellowish or light reddish 
sandy soils and the strongly marked reddish and light chocolate clays. 
And where these well contrasted colours are wanting, the general 
ranges of the principal vallies, and hilly ridges, fui nish a similar in¬ 
dication. Even the fissures in the protruding granitic blocks tell the 
same history. 
But the plutonic intumescence has left other evidences besides 
ruptured and upraised strata, of its presence beneath those parts of 
the zone where it has not reached the present surface. Even at a 
distance of many miles from the nearest visible plutonic rocks, the 
exhalations from the subjacent intumescent mass have risen into the 
strata in innumerable ramifying walls, veins, and irregular patches, 
producing the various forms of siliceous, and ferro-siliceous, lateritic 
