350 Methods of Stratigraphy. — Winchell. 
metamorphic near the lines of igneous outburst.'"^ It is not 
difficult to mention in this enumeration of the characters of 
the Azoic of the south side of lake Superior, several important 
departures from the lithology of the Huronian of the typical 
region as described by Messrs. Logan and Murray, and as 
finally published by Logan in 1863. 
(a). In the t3''pical Huronian no gneiss is mentioned. 
(b). In the typical Huronian no serpentine is mentioned. 
(cj. In the typical Huronian the inclination of the beds is 
generally less than 50°, sometimes not over 10° or even 3°. 
(d). In the typical Huronitin there is not an absence of the 
sedimentary aspect, but its presence is one of its strong phys- 
ical features. 
(e). In the tj^pical Huronian the beds are not "much con- 
torted." They are faulted but the line of strike is persistent 
for long distances. 
The other characters enumerated pertain to the Huronian 
equally with the lower terranes, and can not be considered 
diagnostic of either, while the points of disagreement are so 
numerous, and so characteristic of the older formation that 
they warrant us in regarding the rocks exiiibiting them as 
non-Huronian. Indeed it becomes evident that Dr. Bigsby's 
Huronian was not Huronian at all. His comparisons, whether 
from America or from Norway, are very fair, but abundantly 
sufficient to show that he had in mind a series of strata that 
have been found to lie in all places where their superposition 
has been seen, in a relation of non-conformity with the typical 
Huronian. 
The principles of stratigraphy which have induced the pres- 
ent officers of the Canadian survey to embrace so wide a range 
of time, and so varied a lithology in the Huronian are diffi- 
cult to understand and express. The only justification for it, 
partial though it be, that I have been able to learn, consists 
in the partially incorrect mapping of the Huronian by Logan, 
Murray and Hunt.^ But as has been already remarked, those 
maps should be eorrected to agree with the descriptive text. 
^^ Report on the geology of the lake Superior land district. Part ii. 
p. 14. 
'^ It should be stated, howevor, that nearly all the geologists of Mich- 
igan and "Wisconsin have included the same wide range in the Huron- 
ian, in their official reports. Compare the reports of Brooks and 
Pumpelly, on the Geology df Michigan, and of Chamberlin, Irving, 
Sweet and Wright on the Geology of Wisconsin. 
