298 proceedings: geological society 



parallel Ijut not on one plane indicate quiet bodies of water into wliich 

 sand was blown. 



14. Clay galls: Clay galls are a characteristic product of a sandy 

 region with temporary bodies of water. 



15. Pore space, or packing: The Catahoula sandstone appears loosely 

 packed. The evidence is still very uncertain, but this seems to corre- 

 spond rather with beach and dune sands. 



16. Fossil evidence: The plants which are (according to E. W. Berry) 

 nutmeg, date palm, and palm (unidentified) indicate a tropical coast. 

 Bones of camel and rhinoceros, found near by in the same formation, 

 also indicate a warm climate. 



Conclusion: The weight of evidence is for an arid, tropical, sandy 

 region with permanent or temporary bodies of water. 



The 'probable mode of origin of the Lewis overthrust: M. R. Campbell. 

 No abstract. 



Auriferous pocket deposits of the Klamath Mountains, California: 

 H. G. Ferguson. No abstract. 



The 284th meeting was held at the Cosmos Club, April 22, 1914. 



INFORMAL COMMUNICATIONS 



Origin and mode of formation of magmatic gases: Stanislas Meunier, 

 read by C. N. Fenner. (See this Journal, 4: 213. May 4, 1914.) 



So-called waterlaid loess of the central United States: E. W. Shaw. 

 Photographs and specimens of stratified loess from southwestern Ken- 

 tucky and Yazoo City and Edwards, Mississippi, were exhibited. 

 Much of the stratified loess which has been reported appears to be some 

 other material, though some of it has been derived by wash from nearby 

 outcrops of loess. For example, the stratified loess reported from south- 

 western Indiana appeared to the speaker to consist of a stream terrace 

 deposit, some windblown sand and some true unstratified loess. How- 

 ever, true loess is, in rare instances, really stratified. The stratifica- 

 tion is of a somewhat peculiar type, apparently not involving variations 

 in size of grain. The bedding planes are parallel to the top and base 

 of the deposits and are marked b}^ very thin dark bands which seem to 

 consist of carbonaceous material and are probably the remains of layers 

 of vegetable material, perhaps forest litter developed at times when loess 

 deposition was interrupted, or at least unusually slow. The facts 

 that the stratification does not involve sorting of the component grains, 

 and that it is not horizontal, but parallel to the present and pre-loess 

 'surfaces, seems to indicate that even where stratified the loess is not a 

 water-laid deposit. Indeed, it seems surprising that the loess, if wind 

 deposited, does not show more general stratification of this nature be- 

 cause of the annual fall of forest leaves, and other interruptions in 

 deposition. 



regular PROGRAM 



The characteristics of the Mississippi delta in the light of some obser- 

 vations on Old World deltas: E. W. Shaw. Certain phenomena, par- 



