100 ABSTRACTS 



of clay, sand and coarse gravel, together with widely distributed 

 lignite beds. The character and extent of the glaciation of the Puget 

 Sound region are indicated in these deposits, and it is found that the 

 principal flow of ice was rather from the north than from the moun- 

 tains on the southeast. Two problems are presented by the phenom- 

 ena : (i) The sequence of glacial advance and retreat and the extent 

 and duration of climatic changes indicated by the presence of lignites ; 

 (2) the bearing of the peculiar conditions of glacial development upon 

 the physiography of the sound. Either the deeper valleys of the 

 sound have been eroded during a period of high level from the once 

 more extensive sheets of drift or, as suggested by Russell, the chan- 

 nels represent the beds repeatedly occupied by glaciers which in their 

 advance and retreat built up the plateau-like eminences of the region, 

 probably upon the divides of the preexisting topography. The past 

 condition of Puget Sound under confluent glaciation is probably now 

 represented by the Malaspina glacier and its attendant phenomena. 



The Leucite Hills, Wyoming. By J. F. Kemp. 



The paper opened with a brief statement of our earlier knowledge 

 of the distribution of leucite, and of the special interest that attaches 

 to it. Outside of the European mainland localities were cited on the 

 Lipari Islands, the Cape Verde Islands in Asia Minor, Siberia, Java, 

 New South Wales, Kilima-Njaro, Argentina, Brazil, New Jersey, 

 Arkansas, Lower California, Yellowstone Park, Montana, and British 

 Columbia. The presence of the rich alkaline magmas from Montana 

 to the Mexican line, and in or near the eastern Rocky Mountains, 

 was commented on. The previous observations of Zirkel on the rock 

 of the Leucite Hills were briefly summarized so as to show that the 

 only minerals observed by him in the very limited materials gathered 

 by the geologists of the fortieth parallel were leucite in great abun- 

 dance, small prisms of augite, biotite, apatite, and magnetite, and that 

 the remarkable absence of feldspar, haliyne, and nepheline, was a cause 

 of surprise to him^. The geographical situation of the Leucite Hills 

 and their areal distribution was then shown by lantern slides. There 

 are three mesas or buttes in the main group, of which the southern, or 

 Leucite Hills proper, is the largest. Orenda Butte, two or three miles 

 north, is next, and Black Rock Butte, five miles northeast, is the 

 smallest of all. The two former consist of several lava sheets resting 

 on Laramie sandstones. From them arise cones 300 feet and less in 



