CLASSIFICATION OF DEPOSITS 



213 



the depth of water, and the nature of the organisms 

 living on the bottom and in the surface and subsurface 

 waters. After the detailed study of the marine 

 deposits collected by the " Challenger " and other deep- 

 sea expeditions, Murray and Renard proposed the 

 following classification : 



Deep-sea de- 

 posits beyond 

 100 fathoms 



Marine Deposits.* 



Red Clay 

 Radiolarian ooze 

 Diatom ooze 

 Globigerina ooze 

 Pteropod ooze 



Blue mud 

 Red mud 

 Green mud 

 Volcanic mud 

 Coral mud 



2. Shallow - water 



deposits, be- 

 tween low- 

 water mark and 

 100 fathoms 



3. Littoral deposits ' 



between high- 

 and low-water 

 marks 



Sands, gravels, 

 muds, etc. 



Sands, gravels, 

 muds, etc. 



A. Pelagic deposits 

 formed in deep 

 water removed 

 from land. 



B. Terrigenous de- 

 posits, formed 

 in deep and 

 shallow water 

 close to land- 



It has frequently been pointed out, even by the 

 authors themselves, that this classification is not 

 perfect, but no better has been as yet proposed. It is 



* Krummel has recently introduced the term " hemipelagic ' ' 

 for the deep-sea terrigenous deposits, and " eupelagic " for 

 the pelagic deposits in the above classification (" Handbuch 

 der Ozeanographie," vol. i., p. 205, Stuttgart, 1907). These 

 terms have, however, been employed already to express quite 

 other facts. 



