proceedings: geological society 3t3 



at the time when the starch is decreasing most rapidly. A considerable 

 amount of water is absorljed in the hydrolysis of starch, and water is 

 produced by oxidation; the net result m.ay be either a loss or gain in free 

 water. About 2 per cent of the sugar is oxidized. 



Discussion. The change in flavor at the end of ripening was discussed 

 by Franklin, Gore and Chesnut. The point was brought out by 

 Sullivan, Franklin and Sosman that manganese dioxide, which is 

 present in banana peel, acts like a reducing agent or a catalyzer for 

 reduction. It was stated in reply to questions that bananas are usually 

 ripened off the trees. Means for accelerating or retarding ripening were 

 discussed by McBride, Franklin, Hillebrand and Gore. The latter 

 stated that experiments are planned on the effect of carbon dioxide 

 (asphyxiation) . 



Robert B. Sosman, Secretary. 



THE GEOLOGICAL SOCIETY OF WASHINGTON 



The 269th meeting was held on April 9, 1913, at the Cosmos Club. 

 In the open meeting E. 0. Ulrich spoke concerning the age of the Bays 

 sandstone of the Appalachian Valley. New fossils from the type local- 

 ity prove this exposure at least to be of Black River age. 



REGULAR program 



The mud lumps at the mouth of the Mississippi (illustrated) : E. W. 

 Shaw. The "Mud Lumps" are remarkable swellings of dark blue clay 

 in the shallow water at the mouths of the Mississippi. They commonly 

 form islands with a surface extent of an acre or more and a height of 

 5 or 6 feet. They have always been a serious obstacle to navigation 

 but with the exception of several papers written by Hilgard the pub- 

 lished literature concerning them seems meagre when we consider the 

 unusual and important character of the phenomenon. The present 

 paper is only a preliminary notice and a statement of working hypothe- 

 ses. The principal new hypothesis is that the delta is affected by a 

 bodily seaward fiowage and that the mud lumps are incidental to this 

 flowage. This involves the assumption that the outer beds are sandy 

 and comparatively rigid whereas Hilgard believes that just off shore 

 the deposit consists of very watery clay. He sets forth that a crust of 

 sand and silt are built out over this watery clay giving an unstable 

 condition and that wherever the crust is weak the sludge breaks up 

 thru, forming mud lumps. He also thinks that the mud springs which 

 are found on many lumps are vents for the fluid mud underneath. To 

 the present writer these seemed to be incidental to fissuring produced 

 by mud lump upheaval. 



A reconnaissance of the Arctic Slope of Alaska: E. de K. Leffingwell. 

 This area is bounded by the Canning River on the west and by the 

 Okpelak River on the east, and extends inland for about 80 miles. 

 Two provinces are recognized, the Arctic Mountains and the Arctic 



