ii6 



EJometres granodiorite, which extends up the valley for 

 about 10 miles (i 6 km.) to Five Mile creek. In 

 the granodiorite the valley is narrower and 

 more steep-sided, and the solid rocks are exposed 

 in many of the cliffs. After passing Five Mile 

 creek the granodiorite is again replaced by 

 Palaeoozic slates and limestones, the contact 

 zone of which is marked by a number of reddish 

 dykes of granite porphyry cutting the sedi- 

 mentary rocks. From this point onward to 

 Princeton the hills bordering the valley become 

 lower and more open, and soon after passing 

 Allison the railway crosses the Similkameen 

 river and enters the town of Princeton. 



136 m. Princeton — Altitude 2,120 ft. (646-15 m.). 



219 km. 



GEOLOGY OF THE REGION AROUND PRINCETON. 



GENERAL DESCRIPTION. 



Princeton is situated at the junction of the Similkameen 

 and Tulameen rivers, in a shallow depression in the 

 Interior Plateau region, which was formerly an Oligocene 

 lake basin. The region is characterized by comparatively 

 moderate relief, gently rounded hills and broad, open 

 valleys. It is sparsely forested, and in portions quite 

 open and grassy, so that it affords good grazing for horses 

 and cattle. 



The principal rocks of the region are flat lying sediments 

 of Oligocene age, resting on a basement of tilted Palaeozoic 

 rocks. They include sandstones, clays, shales, con- 

 glomerate, and coal seams, and contain a variety of fossil 

 plants, insects, and fish remains. These rocks are overlaid 

 by volcanic flows of andesite, basalt and fragmental 

 materials. 



The Palaeozoic rocks, to the south of the town of 

 Princeton, at Copper Mountain, contain low grade copper 

 deposits of considerable magnitude, which are now being 

 vigorously prospected. They carry chalcopyrite as the 

 principal copper mineral, and are either in the form of 

 contact metamorphic deposits situated in altered sedi- 

 mentary rocks at the contact of irruptive igneous bodies, or 



