proceedings: geological society 301 



and distribution of population were also among the subjects investigated. 

 The report was submitted to the President on January' 20, 1913, and has 

 since been published under the title, Railway Routes in Alaska: Docu- 

 ment No. 1346 H. R. 62d Cong., 2d Session, 172 pp., 1913. The maps 

 and profiles were submitted on March 1, 1913. These are now in print 

 as Part II of the report. 



Ralph W. Richards, Secretary. 



The 268th meeting was held on March 26, 1913, at tlie Cosmos Club. 

 At the session of the council preceding the open meeting the following 

 members were elected delegates to represent the Societj^ at the meeting 

 of the International Geological Congress at Toronto, August 7 to 12, 

 1913: — F. L. Ransome, David White, J. S. Diller, E. 0. Ulrich. 



The following informal communications were presented: A discovery 

 of gypsum and anhydrite in a drill hole at Centerville, Iowa: F. C. Greene. 



Niter near Melrose, Montana: Ralph W. Richards. Niter is found 

 as thin crusts on the surface of black limestone presumably of Devonian 

 age on Camp Creek about 3| miles northeast of ]\Ielrose; it is also dis- 

 seminated in veinlets to a less extent thru the rock. The purest salt 

 occurs as a snowy white to slightly yellow mass of needle-like crystals, 

 in the loose rock talus at the base of ledges. About 86 per cent of the 

 mass is soluble in water; the soluble portion has been analyzed by R. H. 

 Bailey and the following results obtained. 



Calcium sulfate 13.94 



Sodium sulfate 3.30 



Sodium chloride 20.42 



Sodium nitrate 21.77 



Potassium nitrate 39.48 



The nitrates make up about 61.25 per cent of the total water soluble 

 portion. An attempt was also made to determine the niter present in 

 the limestones; the water soluble portion was found to range from 1 to 

 5 per cent. 



regular program 



Quaternary problems of central Alaska: Henry M. Eakin. The pres- 

 ent drainage of Alaska is evident^ superimposed upon an older topog- 

 raphy whose drainage had little resemblance in arrangement to that of 

 today. This is shown by the topographic irregularities of the valleys 

 of the present master streams that were developed, in part at least, in 

 Quaternary time; in the irregular distribution of alluvial plains that 

 represent old erosional depressions; and in old valleys that are now 

 traversed by inadequate streams or are entirely abandoned. The 

 assumption of crustal movements to account for these features is pre- 

 cluded by the irregularities of the lowland basins; by the flood plains of 

 tributaries in reaches where the trunk stream has no flood plain, and in 

 the wide accordance in elevation of high terraces and silt deposits. 



The hypothesis advanced involves the ponding of water in the old 



