133 
ANI> GEOLOGY OF THE MALAY PENINSULA. 
pared with that of heavy waves or breakers, there are localities in 
which they appear to exert a large influence in the abrasion of points, 
and accumulation of alluvium. The Strait of Singapore afford ma¬ 
ny evidences of this. It is formed by a submarine valley cutting 1 
across the Peninsular range. The projecting- belts of hills and their 
strata are consequently transverse to the direction of the currents. 
Wherever exposed, they are seen to be rapidly wasting. The hori¬ 
zontal strata of the Siglap and Tanah Mera hills, having in great 
measure escaped the platonic influence, yield rapidly, and have fur¬ 
nished materials for the sandy plains which stretch between and on 
either side of them, and the sand bank which fronts them. The se¬ 
dimentary ranges to the west of Singapore plain, which have been 
variously indurated, charged with iron, and highly inclined, have op¬ 
posed greater resistance to the sea; but the quantity of soft clays and 
shales which they contain has facilitated its action, and long ribs and 
ledges of ironmaskcd rock, stretching across the banks, mark at once 
how difficultly destmctable they are in themselves, and how unavail¬ 
ing they have proved to save the hills which they bound together. 
At one place the sea has cut through some highly indurated strata 
and divided an island (Blakang Matf) in two, and, a strong cur¬ 
rent rushing through this narrow gateway into New Harbour, its old 
circuitous route around the northern end of the island has gradually 
been filled up with mud, and the detached northern half thus united 
to Singapore. The islands in the Strait are all greatly abraded. 
The plain of Singapore affords a good illustration of the mode in 
which the alluvial tracts of the Peninsula have been formed. Origi¬ 
nally a bay, with numerous creeks penetrating between the hill ranges 
which form its boundaries and receiving the streams from the short 
ravines at their summits, these creeks have been gradually convert¬ 
ed into vallies, and the hay into a plain. Several ancient sandy 
beaches have been preserved, rising above the clayey plain to heights 
which measure the .difference between the ordinary high water level, 
or that to which the sea can deposit mud, and the levels to which 
waves of different force can roll up sand on beaches and banks. The 
different directions in which these pertnatangs run, with reference 
