AND GEOLOGY OF THE MALAY PENINSULA. 
129 
mountains which have been aw island (a Pinang on a smaller scale.) 
We will reserve a more particular account of the tidal action and 
modern alluvial formations at the extremity of the Peninsula, till we 
treat of the geology of Johore in detail, and before leaving the west¬ 
ern coast, mention some facts illustrative of the advance of the Su¬ 
matra coast, and corroborative of the view above taken respecting the 
shifting of the Straits from the Sumatra to the Peninsula side. It 
may be gathered from Mr. Anderson’s work* that the country, so far as 
observed by him in ascending the principal rivers from Deli to Sink, is 
of an uniform modern alluvial formation. The first layer consists of 
black mould, varying in thickness from 2 to 10 feet. The next layer 
is stiff white clay, 3 or 4 feet thick. The third or lowest is composed 
of sand and gravel, with fragments of granite intermixed. Near the 
lulls up the Assahan River, the highest layer is red earth, and this 
rests on mud and sand. Higher up, large masses of granite and 
light sandstone were found on the margin of the river. At Jambi, 
Lieutenant Crooke found the soil to be, 1st. a layer of rich vegeta¬ 
ble mould, 2nd. a layer of clay, 3rd, at the depth of 11 or 12 feet, a 
layer of peat, four feet in thickness “ containing trunks of trees of va¬ 
rious dimensions, the bark undecayed and the fibres of the wood re¬ 
taining much of their natural colour, strength and elasticity,” 4th. a 
layer of fine light coloured clay. Neither stone nor gravel were ob¬ 
served in the soil. But pebbles of quartz and fragments of ironstone 
are washed down by the river from the interior, and deposited on the 
sand bank.” 
Besides the great rivers, innumerable smaller ones traverse the 
country and are frequently united by channels. All the lower part 
of the country is subject to periodical inundations. Whether, since 
the deposit of the oldest layers of alluvium near the lulls, there has 
been any elevation of the land does not clearly appear. It is true 
that the largest part of the present surface of the alluvial country is 
considerably above the level of the sea, and there seems to he a gra¬ 
dual hut slight rise from the present coast to the hills. It does not 
however appear that this is greater than can he accounted for by the 
* See Anderson’s Mission to Sumatra throughout. 
