1881.] 
121 
[Wadsworth. 
THE APPROPRIATION OF THE NAME LAURENTIAN BY 
THE CANADIAN GEOLOGISTS. 
BY M. E. WADSWORTH. 
(ABSTRACT.) 
The name Laurentian was given by Mr. Edward Desor in 1850 
to some marine deposits in Maine, on the St. Lawrence River, and 
Lakes Champlain and Ontario. Mr. Desor’s paper was first read 
before this Society and published in the Proceedings (III, 357- 
358). With this application the term Laurentian was quite fre- 
quently employed by Mr. Desor (Proc. Bost. Soc. Nat. His., 1851, 
IV, 29, 33; Bull. Soc. Geol. France, 1851 (2), VIII, 420-423; IX, 
94-96; Am. Jour. Sci., 1852 (2), XIV, 49-59); and it seems to 
have passed into current use amongst geologists, especially between 
1850 and 1857. In 1854 Sir William Logan appropriated the 
name to designate the Canadian rocks which he had heretofore 
called the “ Metamorphic Series.” Logan’s action appears to have 
been unjustifiable and needless. Needless, because the rocks to 
which he gave the name Laurentian were the equivalents of the 
Azoic of Foster and Whitney. It is to be remembered that the 
term Huronian was not employed until 1855, and this formation 
was for many years thereafter regarded as Paleozoic. Unjustifi- 
able, because the name Laurentian was in current use for a differ- 
ent formation ; to which another name had to be given later on on 
account of Logan’s action, thus further complicating the synonymy. 
Unjustifiable, because Logan knew of Desor’s application of the term 
and had employed it in the same manner himself (Report of Pro- 
gress Geol. Survey, Canada, 1850-51, p. 8). The complications grow- 
ing out of the deprivation of Desor by Logan of the credit belonging 
to the former are, first, the use of the name Laurentian in geolog- 
ical literature with two different meanings ; secondly, the naming of 
Desor’s Laurentian, Champlain, by Prof. C. H. Hitchcock, and thus 
giving the term Champlain two distinct significations in geologi- 
cal literature. 
So far as the writer is aware, but one American geologist has 
ever protested against the injustice done Desor by the Canadian 
geologists (Amer. Jour. Sci. 1857 (2), XXIII, 305-314). 
