170 ALASKA AND ITS MINERAL RESOURCES 



Pelly all the way up to Hoole river. Just below the mouth of 

 the McMillan the river has cut a canyon through gray granite 

 hills, below which are dark crystalline schists with east-west 

 strike and northerly dip, associated with which are alternating 

 marbles and chloritic schists, probably of the Fortymile series. 

 Granite occurs again near the junction with the Lewes. Of the 

 valley of the McMillan nothing was known. The Pelly above 

 the detour or bend had a similar series of quartzite schists, with 

 interbedded limestones on the north, while the Glenlyon hills to 

 the south were of granites. Above these are sandstones sup- 

 posed to belong to the coal-bearing series and dipping 45° S. 

 Still higher up in Hoole canyon are marbles again, associated 

 with schists and volcanic rocks, possibly of the Rampart series. 

 Still further northeast, in the middle canyon of the Frances 

 river, Dawson found marbles again, while in the Tootsha range 

 to the east were seen granites and schists with abundant quartz 

 veins. 



All along the summit of the Coast range the prevailing rocks 

 are granites, cut by later porphyr}^ dikes. They form a belt 20 

 to 80 miles wide, and are generally of the hornblende or intru- 

 sive t}rpe. On the Dyea and Skagway trails they extend down 

 on the northeast side to the mid-length of Lake Bennett. In 

 the range of hills between Miles canyon and the Teslin river are 

 diabasic or dark eruptive rocks and limestones, which may be- 

 long to the Rampart series, though Dawson considers the lime- 

 stones to be probably Carboniferous. 



Along the region of Rink and Five Finger rapids, below the 

 Big Salmon, are infolded masses of Cretaceous rocks (Kenai?) 

 with conglomerate at the base, overlain in places by lavas. Be- 

 low these are greenish eruptive rocks, and then near the mouth 

 of the Pelly is granite again, succeeded below the Pelly by basalt 

 flows. Twenty-five miles below the Pelly granitic rocks again 

 appear, and are succeeded by crystalline schists of various kinds, 

 which constitute the prevailing rock down nearly to Fortymile. 



COAL AND LIGNITE 



Coastal Region 



The coal of Alaska so far examined, whether in the interior or 

 on the seacoast south of Bering strait, is of Eocene or early Ter- 

 tiary age and belongs without exception to varieties of lignite, 

 brown coal, or glance coal. North of Bering strait, in the vicin- 



