20 TIN MINING IN PERAK. 
over the Peninsula and some of the adjacent islands. The interval is so 
great that many thousands of feet of rock may have been deposited and 
slowly washed away again. However this may be, it is sufficient here 
to state that no traces of any such beds have yet been discovered in 
Perak, and so, from the mining point of view, their previous existence or 
non-existence is a matter of no moment. 
The period when the country assumed its present general configura- 
tion was, comparatively, quite recent. The eruption of the granite may 
very probably not have taken place at one time. There were most likely 
several successive eruptions, and between each the degradation of the 
granite itself and of the upturned edges of the beds of sedimentary rocks 
went on. All the present alluvial beds are of a date subsequent to the 
raising of the ranges of granitic hills, and if the suggestion already put 
forward, that the limestone was indurated by the molten trap-rock, is 
correct, then the eruption of the trap was anterior to the disturbance 
caused by the upheaval of the granitic. The peculiar forms of the edges 
of the limestone formation, the isolated position of small portions 
in places many miles from any other trace of it, and its fissured and 
shattered appearance, all seem to point to the conclusion that it was 
indurated prior to its being broken through by the granitic, and that 
the induration was uneven. According to this view the existing remains 
of the formation are those portions which in former times were sub- 
jected to the hardening action of the trap-rock, while all the un- 
hardened parts have been washed away. Some of the outliers may have 
been indurated by direct contact with the granite: in the hill known as 
Gunong Pondok there are several granite dykes traversing the crystalline 
limestone of which the hill is composed, and at the end of the hill next 
to the granite range the two rocks are in contact. This action could only 
have taken place to a limited extent at the edges of the formation, as in 
other situations there are thick intervening beds of the non-calcareous 
members of the series, widely separating the limestone from the granite. 
The taller hills are exclusively composed of granite, as are also some 
of the lower ones. The upturned Laurentian beds appear at the bases of 
the granitic ranges as spurs, or foot-hills, the limestone, in particular, 
forming most curious and picturesque hills, sometimes attaining a height 
of considerably over 2,000 feet. 
A suitably chosen section across the Kinta valley would give, 
starting from the Meru range:—granite, gneissic and schistose beds, 
clay-slates and sandstones, limestone, remains of trap, alluvium, lime- 
stone, clay-slates and sandstones, schistose and gneissic beds, and lastly 
the granite of the central range of the Peninsula. Sections in other valleys 
would not be so perfect, as the limestone particularly is very fragmentary. 
The ores of the following metals have been found in the different 
formations :— 
Granite .... Tin, lead, iron, arsenic, tungsten, titanium, 
¢ Tin, gold, lead, silver, iron, arsenic, copper, zinc, 
Laurentian : 
tungsten, manganese, bismuth. 
Quaternary .,. Tin, gold, copper, tungsten, iron, titanium. 
