236 proceedings: geological society 



THE GEOLOGICAL SOCIETY OF WASHINGTON 

 The 280th meeting was held at the Cosmos Club, February 25, 1914. 



REGULAR PROGRAM 



Some geologic features of the Eastport region, Maine (illustrated): 

 E. S. Bastin. No abstract. The paper was a part of the matter con- 

 tained in the United States Geological Survey's Eastport Folio, No. 

 192, now in press. 



A hypothesis for the origin of the carnotite deposits of Utah and Colorado 

 (illustrated): Frank L. Hess. The great bulk of the carnotite de- 

 posits of Utah and Colorado lie between the Rocky Mountains, the San 

 Rafael Swell, the Denver and Rio Grande Railroad and the Arizona 

 line, and are in crossbedded sandstones, which mostly seem to be of 

 McElmo (Jurassic) age, though part of the deposits may be in similar 

 sandstones of La Plata (lower Jurassic) age. 



The deposits contain besides carnotite, other oxidized vanadium 

 minerals, iron oxides, some copper carbonates and in places a chromium 

 mineral, and are invariably associated with fossil wood and reed-like 

 plants. The degree of decaj^ before fossilization seems to have had 

 much to do with the quantity of the minerals deposited and in places 

 logs are almost wholly replaced by carnotite and accompanying soft 

 minerals. On Red Creek in Brown's Park, Uinta County, Utah, carnotite 

 has formed in cracks adjacent to a copper bearing vein in Cambrian (?) 

 or pre-Cambrian (?) quartzite. At two other places veins carrying 

 smaller quantities of uranium and vanadium minerals have been found. 

 It is thought possible that the crossbedded sandstonesmay have been de- 

 posited in a very shallow inland sea with many islands and spits on which 

 lodged vegetable debris which had been washed from surrounding shores. 

 Also that sulphidic veins carrying uranium, vanadium, iron and chro- 

 mium minerals were eroded ; that sulphuric acid set free by the oxidation 

 of pyrite formed soluble sulphates of the other metals; that these were 

 carried into the sea and on coming into contact with the vegetation were, 

 in part at least, reduced to sulphides, though the uranium was possibly 

 reduced to an oxide, or to some combination with the vanadium. Upon 

 the raising, draining and oxidation of the rocks the minerals now found 

 were formed. 



Owing to his illness, Willis T. Lee did not deliver his paper, Bearing 

 of stratigraphy on the physiographic conditions of the Rocky Mountain 

 region during upper Cretaceous time (illustrated). 



The 281st meeting was held at the Cosmos Club, March 11, 1914. 



Under the head of Informal Communications F. C. Greene gave a 

 short discussion of the age of the loess of the Mississippi Valley, and 

 Frank L. Hess showed photographs of concretions in crossbedded La 

 Plata (?) sandstone on the northeast flank of the Henry Mountains, Utah. 

 The concretions follow both horizontal lines and the crossbedding 



