LAKE SUPERIOR FORMATIONS 69 
3. The Animikie, mainly a sedimentary series, but locally 
containing great series of volcanic rocks. 
4. The Upper Huronian, consisting mainly of sedimentary 
rocks. 
5. The Lower Huronian, consisting of green schists and 
included sediments. 
Besides these sedimentary series, the only proper factors in 
a time scale, there is an immense series of granites and gneisses 
largely of post-Upper Huronian age, which for convenience of 
reference have been given the old name Laurentian, a name 
applied to them when they were believed to represent the base- 
ment series. 
This succession is almost identical with that given by Van 
Hise on page 316. The difference between us is largely one of 
nomenclature. Van Hise writes (p. 317): 
These series are called Huronian because they are believed to be equiva- 
lent to the Upper Huronian and Lower Huronian of the original Huronian 
district north of Lake Huron. 
With this correlation I am not in accord. I believe the 
upper part of the original Huronian to be the equivalent of Van 
Hise’s Lower Huronian, and the original Lower Huronian to be 
included in his Archean. If this can be substantiated, I have no 
doubt Professor Van Hise will view my nomenclature favorably, 
for no one is more anxious than he to recognize the work of 
Logan and Murray, the founders of the Huronian. 
a”) 
In 1858 Logan gave the name ‘‘Huronian”’ to the copper- 
bearing rocks north of Lake Huron, the distribution of which 
was being worked out by his assistant, Murray. In 1863” he 
gave a summary of the previous annual reports, and this may be 
fairly taken as representing his mature views. Detailed sections 
are given from the Sudbury, Michipicoten, and Mississaga dis- 
tricts. The rocks are mainly sediments, but interstratified with 
them are beds of amygdaloidal greenstone. Intrusive green- 
stones and granites are also recognized. 
Two slate conglomerates were described separated by a 
t Rep. Geol. Sur., Can., 1857. 2 Geol. of Can., 1863, pp. 50-06. 
