STUDIES FOR STUDENTS 421 



that many of the criteria for distinguishing various sorts of sedi- 

 ments are also applicable to rocks resulting from sediments after 

 cementation. 



The classification and lists of characters which follow are not 

 presented with the idea that they contain matter which is new, 

 but merely to bring together, in a way intended to be helpful, 

 certain things which have been well known to geologists. Much of 

 it has been pubHshed in one place and another in standard works, 

 and these sources have been drawn upon freely in the preparation 

 of the present paper. 



The various sorts of common sediments are as follows : 



Eolian 



Fluvial 



Pluvial 



Talus 



Glacial 



a) Till 



b) Fluvio-glacial deposits 

 Lacustrine 



a) Near-shore phase 

 h) Still-water phase 

 Marine 



a) Shallow-water deposits 



(i) Zone of major agitation 



(2) Zone of minor agitation 

 h) Deep-water deposits 



By pluvial deposits are meant those transported by rain water 

 or immediate run-off, without the agency of permanent streams. 

 Talus deposits are those whose constituents are rolled down steep 

 slopes by the action of gravity, not necessarily aided by water. 

 Near-shore lacustrine deposits are those laid in lakes between high- 

 water mark and the surf line. Shallow-water marine deposits are 

 those laid in the sea between high- water mark and the loo-fathom 

 hne, and deep-water deposits are laid in the deep sea beyond the 

 loo-fathom line. The shallow- water deposits of the sea have been 

 generally divided into {a) littoral deposits (those laid between 

 high- and low-water marks) and (&) non-littoral deposits (between 

 low- water mark and the loo-fathom line).^ For present purposes 



'See Murray, Report of the H.M.S. Challenger, Deep Sea Deposits, p. 186; and 

 Chamberlin and Salisbury, Geology, I, 368, 369, and 379. 



