123 



gravels contain both gold and platinum, the proportion 

 varying in different streams and in different parts of the 

 same stream. This proportion of gold to platinum varies 

 in the streams mentioned from 4 to i to i to i . The source 

 of the platinum has definitely been traced to the elongated 

 peridotite stock which crosses Tulameen river at Eagle 

 creek and extends south-easterly from there to the head 

 of Newton creek. 



The mining of the platinum placers, which began in 

 1885, has up to now usually been carried on only by 

 individual miners with the ordinary methods that such 

 men use. Attempts have, however, been made at Eagle 

 creek. Slate creek, and Granite creek to mine by hydraulic 

 methods, but none of these have been very successful. 

 Old working may be seen at several points on Tulameen 

 river between Slate creek and Eagle creek. 



The total amount of platinum obtained from the gravels 

 has been variously estimated at 12,000 to 20,000 ounces. 

 The present output, however, is only a few ounces annually. 



DIAMONDS. 



The diamond bearing rocks are most conveniently seen 

 on the Tulameen river at the mouth of Eagle creek, 8 

 miles (12 -8 km.) west of Tulameen village. The river 

 at this point cuts a valley nearly 3,000 feet (914-4 m.) 

 deep, through the middle of a large stock composed of 

 peridotite, pyroxenite and gabbro, which is intrusive in 

 Triassic sediments and volcanics. A vertical section 

 through the stock, given in the accompanying diagram, 

 illustrates the relations of the various rocks to each other. 

 The centre of the stock is composed of peridotite, and this 

 is surrounded on all sides by a border of pyroxenite into 

 which the peridotite passes by a gradual change in com- 

 position, the olivine of the one rock being replaced by the 

 pyroxene of the other. Outside the pyroxenite is a thin 

 border of gabbro, which in places passes into an augite syen- 

 ite. The syenite however also occurs in intrusive relation 

 to the pyroxenite. It seems clear that the three rocks were 

 originally present in one common magma, which, in the 

 course of injection into the overlying rocks and while 

 gradually cooling, differentiated into three distinct types, 

 the most basic in the central part and the most acid on the 

 outside. 



