MIXING DISTRICTS OF LOWER PERAK. 



Geological 

 description. 



Granitic 

 formation. 



Sedimentary 

 formation . 



JLime$tone. 



Before giving the particular mining features of these various 

 tin-fields, it is well to indicate first the geological outline of the 

 country. 



The geological conditions of this part of the State are more 

 varied than in the northern districts, and offer a greater diver- 

 sity of sedimentary formation. (See Section. ) 



The granite constitutes the foundation of the main ranges 

 and of the hills round which are distributed the different tin- 

 fields. 



It is met with in the Senggan range at Gunong Kledong, 

 Changkat Lahat, the Gopeng hills, Biijang Malacca, and 

 forms the basis of the Changkat Chumor and Janka, near 

 Tapa. 



Like in other parts of the country, the rock is highly por- 

 phyroid, composed of vitreous quartz, feldspar, mica and tour- 

 maline, in which are imbedded large crystals of feldspar. 



The decomposition of the granite by atmospheric agencies 

 has gradually denuded the large crystals, which are harder than 

 the feldspathic element in the paste, and left them projecting 

 from the surface, giving the rock a peculiar appearance. 



The amount of mica and tourmaline varies slightly in the 

 different localities, but without altering perceptibly the general 

 aspect. 



The sedimentary formation is represented by limestone, 

 white ferruginous clay, and talc-schist. 



The limestone is very abundant in the whole of the Kinta 

 region, and probably forms the basis of the alluvial deposit. 

 It is found at the foot of Changkat Lahat, between the latter 

 and Sungei Kinta. It has been greatly altered at the contact 

 with the neighbouring eruptive rock, and has taken a saccha- 

 roid aspect, being white and very crystalline. 



It is found again between Pengkalen Pegu and Pengkalen 

 Baru, where little peaks crop out of the alluvial soil, broken 

 up and highly decomposed at the surface, but offering no 

 longer the deep alterations noticed near the Senggan range. 



