VALLEY OF THE PANNACK. 91 



stones, altered shales, and veins of the same feldspathic rock noticed 

 in the pass. The strata were inclined east by north, at an angle 

 of 70°. The ridge seems to run a little west of north, until it 

 disappears in the valley of the Snake River. Upon the summit 

 of this " divide" was found what was at first thought to be altered 

 coal, but upon farther examination it appeared to be an aluminous 

 rock, containing but a small trace of carbonate of lime. Its 

 colour was black, hardness greater than that of feldspar, and the 

 form a rhombic prism. The limestone was crystalline, and con- 

 tained numerous specimens of shells and corals, but in so altered 

 a state that it was impossible to determine them. 



The length of the fork of the Pannack which we descended is 

 sixteen miles. It pursues a westerly direction, until it joins the 

 main stream, which latter flows from the southward, through what 

 appeared to be a well-defined valley. The ground for a road is ex- 

 cellent, with only one or two exceptions, which are not of a serious 

 character. 



On descending the dividing ridge in which it heads, the rocks 

 were hidden by a black, rich soil; occasional boulders of granite 

 were seen on the surface, but no section could be obtained until 

 we came to a gorge about five miles down the valley. Here the 

 river cuts through a much lower ridge of hills, composed of lime- 

 stone, dipping to the east, at an angle of about 63° : below this the 

 stream has cut its bed through secondary hills formed of argilla- 

 ceous sandstone and clay, both of which are white, and mixed with 

 pieces of obsidian and occasional boulders of serpentine : still 

 lower down the valley, a section in a ravine to the right of the 

 road, discovered some rocks which might almost be considered 

 cretaceous ; alternating with white argillaceous sandstone, they con- 

 tained a considerable quantity of organic remains, principally 

 coral, but so much altered by heat that it was impossible to deter- 

 mine them with precision. The dip of these strata was about 10° 

 north-east. The be^S were covered by the remains of disaggre- 

 gated conglomerate, composed principally of porphyry and granite. 

 Proceeding down the stream, metamorphic sandstones, crystallized 

 almost to the whiteness of white quartz, were found, forming es- 

 carpments of the lower hills ; a short distance below this point, a 

 ridge of hills, composed of limestone, shales, and red sandstone, 

 extended across the valley ; they were all much inclined, with a 

 dip to the east. At this point, where the river cuts a passage 

 through this chain, a mass of feldspathic rock was seen. The dip 



