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are in fissures in both the igneous and sedimentary rocks. 

 The Oligocene rocks cover an area of about 40 square 

 miles (103 sq. km.) and contain a number of seams of coal, 

 ranging in thickness from a few feet up to 60 feet (18-29 ^^■)- 

 Some of the seams are being mined. The Oligocene also 

 includes important beds of clay which are utilized in the 

 manufacture of cement. 



PARTICULAR DESCRIPTION. 



The chief features of geological interest to be seen in the 

 vicinity of Princeton are the rocks of the Tertiary lake 

 basin, with the coal seams which are associated with them. 



In a low cliff within a few yards of the railway station 

 a good exposure of Oligocene sandstone is seen, The sand- 

 stone is a light coloured, coarse grained, feldspathic rock 

 dipping at a low angle towards the southwest. It shows 

 false bedding, and has been eroded by wind or water action 

 to form deep caves, the roof of the caves being a hard 

 compact bed of sandstone. 



On the east side of Similkameen river, at the end of the 

 traffic bridge, the outcrop of a coal seam is seen. The total 

 thickness of the seam is 25 feet (7-6 m.), but it contains 

 several small bands of clay. The associated rocks are 

 shale and sandstone. The coal dips S. 30° W. at an angle 

 of 12 degrees and is traversed by a few normal faults which 

 strike S. 45° W. The throw is usually only a few feet, the 

 downthrow being on the northwest side. The mineable 

 parts of the seam are a bench 7 feet (2 •13m.) to 10 feet. 

 (3-04 m.) thick in the upper half, and another bench 7 feet 

 (2-13 m.) thick in the lower half. Only the upper bench 

 is at present being worked. 



The coal is sub-bituminous, excellent for domestic use 

 and for the manufacture of gas. A sample of the seam 

 being mined gives the following proximate analysis: — 



Moisture 16-17 per cent. 



Volatile combustible matter. . .37-58 " 



Ash 4-58 " 



Fixed carbon 41 "67 " 



100-00 



