276 J. W. GOLDTHWAIT GLACIATION IN THE WHITE MOUNTAINS 



ish schists and intrusives of the "Huronian" belt — a group of rocks which 

 are almost certainly absent from the district south and east of Bethlehem, 

 but are widely exposed to the north and west in the Dalton Eange and 

 Manns Hill. On the morainic country which forms the present drainage 

 divide south of Bethlehem Junction, near the Gale Eiver Forest Banger 

 Station — considered by Agassiz and Hitchcock to mark the confluence of 

 glaciers which moved northward from the Franconia Mountains — boul- 

 ders of porphyritic granite and granite gneiss are common. The presence 

 of both types of rock, in place, within the next few miles northwestward 

 makes it unnecessary to suppose that they came from the mountains on 

 the south. On the other hand, a quartz porphyry which is widely exposed 

 on the main north peaks of Mount Lafayette, at the head of the White 

 Cross Ravine, from which Agassiz's glacier was supposed to have come, 

 seems to be wholly absent from the drift at the north base of the moun- 

 tain, occurring only sparingly in small torrent-carried stones in the bed 

 of Lafayette Brook. There seems to be no logical ground for assigning a 

 northward movement of ice to this district, but ample reason to believe 

 that the movement was southward. 



ABSENCE OF CIRQUES AT THE SOURCE 



Finally, there remains the question whether evidence of a local glacier 

 occurs at the heads of the ravines on the northern slope of Mounts 

 Lafayette and Garfield. These mountains rise to altitudes of 5,269 and 

 4,519 feet respectively. To the south of Lafayette a long, rather straight 

 ridge is capped by the summits of Lincoln, Liberty, and Flume Moun- 

 tains. To the east of Garfield, the North and South Twin, Bond, and 

 Guyot offer additional areas for local snowfall (see plate 13). No detailed 

 contour map has ever been made of this portion of the mountains and no 

 reports of bowl-shaped ravines have appeared. I was prepared, however, 

 to find signs of glacial sculpture on the Franconia Mountains like the 

 cirques on the Mount Washington Bange. This expectation was not 

 fulfilled. The White Cross Ravine, at the head of Lafayette Brook, 

 identified by Hitchcock as the starting place of Agassiz's glacier, is a 

 characteristic torrent-carved valley of Preglacial date, V-shaped in sec- 

 tion, rather straight in trend, but with alternating spurs which a valley 

 glacier would have removed. Its middle course is narrow and steep- 

 sided and not at all troughlike; its head, while somewhat flaring, like a 

 funnel, is not bowl-shaped; although partly cliffed, it does not rise in a 

 semicircular headwall, and there is no hollowing out of the floor there, 

 as in Kings, Tuckermans, and other ravines on the Mount Washington 

 Range, If a local glacier ever formed in the White Cross Ravine, it was 



