SUGGESTIONS AS TO THE DESCRIPTION AND NAMING 
OF SEDIMENTARY ROCKS 
AG. cE DBE 
University of Colorado 
It seems unnecessary to apologize for suggestions as to describing 
and naming sedimentary rocks.* Shaw has recently said: 
The need of carefully recorded descriptions of the physical characteristics 
of ancient sediments is especially worthy of emphasis. .... Notwithstanding 
the fact that advances have been made, there is as yet no adequate systematic 
classification that is generally acceptable. There is not even a satisfactory 
nomenclature. 
To attempt a thoroughgoing logical classification of sedimentary 
rocks is beyond the scope of this article. Unless Grabau’s com- 
- pounding of prefixes into one dinosaurian term is deemed objection- 
able, his classification can scarcely be bettered. Here only two 
lines of suggestion are offered. One aims at systematizing field 
descriptions of rocks. The other deals with problems of nomen- 
clature which chiefly arose during the writer’s examination of three 
hundred specimens and eighty thin sections of the so-called ‘‘ Dead- 
wood” formation in the Bighorn Mountains, Wyoming. 
FIELD DESCRIPTION OF SEDIMENTARY ROCKS 
Lahee, in a warning against the padding of rock descriptions, 
remarks that every detail not germane to the immediate.purpose 
of a given report should be omitted.? Were reports used only by 
persons interested in such immediate purposes, the comment would 
hold good. But if one tries to discuss the conditions of sedimen- 
tation in any given region, he is either forced to personal reconnois- 
sance of adjacent regions or to dependence upon published reports of 
those regions. For such purposes the average descriptions of 
sediments are lamentably inadequate. Accordingly, there is here 
1 This article was written in April, 1920. 
2F. H. Lahee, Field Geology, p. 450. 
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