STRUCTURAL GEOLOGY OF BRITISH MALAYA 563 



already stated, granite connecting the two. In this granite there 

 are, in the neighborhood of Lenggong, about 30 miles north of 

 Kuala Kangsar, small hills of crystalline limestone surrounded by 

 the granite, which appear to be portions of the Carboniferous lime- 

 stone stoped away from the cover and prevented from sinking 

 farther by the viscosity of the magma. They contain secondary 

 minerals commonly found at such contacts. 



Farther to the south, in the Kinta District, mining operations 

 in the valley of a stream, the Johan, that rises in the Kledang range, 

 have revealed another island of limestone in the granite. 



The Kerbau Coulisse (No. 9) is the most arcuate of all those in 

 the Peninsula, a pronounced bend existing about half-way along 

 its course. The northern half is the higher, with several peaks 

 above 7,000 feet and along part of the northern half the descent is 

 steeper into Kelantan than into Perak. 



In the extreme north, in the neighborhood of Tomo, the details 

 of the coulisse are not yet accurately known, but south of Tomo 

 recent journeys have brought to light an interesting structural point. 

 On the map a sharp curve can be seen in the boundary between 

 Perak and Kelantan, about twenty miles south of Tomo. Here a 

 granite mountain, GunongNoring (6,194 ft.) visited in 1922 by Mr. 

 H. E. Savage, is, approximately, the end of the granite outcrop 

 along the watershed. A little north of Gunong Noring the granite 

 outcrop bifurcates, one fork passing through the headwaters of the 

 Perak River into Siamese territory between the Patani and Telubin 

 rivers, the other trending northeast. Part of the intervening 

 country is still unsurveyed, but it is behoved that the northeast 

 branch ends in hilly country east of Tomo. In between these two 

 forks of the granite ridge are altered sediments with small outcrops 

 of granite-aplite, hornblende-granite, and diorite, evidently apo- 

 physes from the main mass below the sediments. 



In both forks the granite is often gneissose owing to flow in the 

 magma. It is rich in biotite; and in the western fork I have 

 found a large outcrop crowded with Xenoliths of mica-schists, show- 

 ing that denudation has not removed much granite. 



The highest portion of the granite ridge in the Kerbau Coulisse 

 is in the neighborhood of the junction of the boundaries of Perak, 

 Kelantan, and Pahang. Here are three peaks of over seven 



