THE POSSIBILITIES OF COOPERATION 401 



study of sediments and sedimentary deposits. This is of great 

 importance in connection with many aspects of geological his- 

 tory, and also because of its bearing on economic problems, 

 such as the origin and identification of deposits or accumula- 

 tions of coal, oil, gas, phosphates, sodium nitrate, clay, iron, 

 manganese, etc. 



The essential requirements are sufficient information on ( I ) 

 modern sediments and deposits, and (2) changes in sediments 

 after deposition and the causes of such changes. 



In the study of sediments now in process of formation it is 

 important to learn the mechanical state and shapes of particles 

 of different sizes, their mineralogical and chemical composition, 

 the arrangements of the material composing the deposit, the 

 source of the material, the transporting agencies, and the cause 

 of precipitation. Modern deposits must be studied in the scores 

 of forms in which they are laid down: in deserts and arid 

 regions and in humid climates, in the beds of great lakes, in 

 the track of glaciers, and in marine beds off the coast, in deltas 

 and bays, or on submarine plateaus, in lagoons, and on reefs 

 in subtropical and tropical waters. 



In much of this work chemical investigations are essential, 

 especially on the composition of the waters flowing into the 

 ocean, yielding data on the chemical degradation of the con- 

 tinent and the amount of soluble material discharged into the 

 sea. 



In undertaking this extensive investigation, which would 

 include the studies just cited and others on ancient deposits, the 

 following procedure is proposed: (i) To make a more com- 

 plete survey than has yet been made of the investigations that 

 are at present under way in the United States and Canada. 

 (2) To prepare, in the light of present geological knowledge, 

 a program for the investigations needed to supply an adequate 

 basis for interpreting sediments. As knowledge advances, the 

 program will have to be modified. (3) To canvass the field for 

 existing agencies that are suitable for prosecuting such investi- 

 gations. (4) To assign problems to those institutions or indi- 



