TITLES AND ABSTRACTS OF PAPERS 87 



GLACIAL LAKE MISSOULA 

 BY B. W. STONE 



{Abstract) 



A large and irregular ice-dammed lake which filled a great part of the 

 drainage basin of Clark Ford, in western Montana, was named and described 

 by J. T. Pardee in 1910. His observations were mainly in the Bitterroot Val- 

 ley. This paper gave evidence of the extent of Lake Missoula in Flathead. 

 Indian reservation, together With a description of an abandoned course of 

 Flathead River. The large arm of Lake Missoula River which lay in the 

 Flathead reservation was connected through its life with the arm in Bitter- 

 root Valley by way of Missoula River Canyon near Paradise, and at its high- 

 est stage by a col at Evaro, 10 miles west of Missoula. The Northern Pacific 

 Railway enters the reservation through this col. The greatest depth of the 

 lake within the reservation was 1,500 feet at Perma and 1,300 feet in the 

 vicinity of Flathead Lake. Lake-cut benches are common throughout the 

 reservation. Sediment was deposited to a depth of more than 200 feet. 

 Granite boulders indicate floating icebergs. 



Previous to glaciation Flathead River flowed west 10 miles from the present 

 position of the Big Arm of Flathead Lake, then south through Little Bitter- 

 root Valley. This course was barred by a terminal moraine, and the present 

 stream cuts through a moraine at the lower end of the lake and reaches its 

 former course 20 miles south of the moraine. 



Presented in abstract from notes. 



PHTSIOGRAPHIG RELATIONS OF SERPENTINE, WITH SPECIAL REFERENCE TO 

 THE SERPENTINE STOCK OF STATEN ISLAND, NEW YORK 



BY WILLIAM OTIS CROSBY 



{Abstract) 



The serpentine stock of Staten Island holds the formal relation of a monad- 

 nock to the Cretaceous peneplain, here buried beneath the coastal plain sedi- 

 ments. That it is a true residuary relief or erosion remnant is shown to be 

 extremely improbable. Likewise mechanical (fracture and slip) faulting does 

 not afford an adequate explanation. But this, it is believed, is found in the 

 generally accepted view that this great body of essentially structureless ser- 

 pentine has originated in the progressive, downward alteration of a stock of 

 some massive, basic, magnesian, igneous rock, such as peridotite. Of this 

 alteration hydration, with the resultant great expansion, is here the most 

 important phase ; and the expansion, which may amount to 40 per cent, must 

 take place. mainly upward or in the direction to give it the maximum topo- 

 graphic value. We have here a species of chemical as distinguished from 

 mechanical faulting, and a new physiographic type, a variety of auto-relief 

 not heretofore clearly recognized. Comparison with the spine or obelisk 

 (pel^lith) of Mont Pele is suggested, and this comparison suggests the name 

 9tatenUth for the new type, which is further shown to include other than 



