362 The American Geologist. June, 1895 
Bell considered the eruptive sills that appear interstratified 
with the slates as surface trap flows, cotemporary with the 
sedimentary depositions, and the whole of Permian or Trias- 
sic age. Sir W, E. Logan, however, in a note in the same vol- 
ume, shows satisfactorily that these beds cannot be other than 
as usually believed, i. e., Cambrian. Mr. E. D.Ingall called at- 
tention to the intrusive character of some of these diabase 
sheets, and Lawson affirms as a general proposition that there 
are no contemporaneous volcanic rocks in the Animikie group, 
but that all the sheets are of the nature of laccolitic sills. So 
far as the region examined by Lawson is concerned it may be 
accepted as a correct statement of the relations of these igne- 
ous rocks. But when it is remembered that these laccolites of 
the Thunder Bay district are both numerous and thick, and 
that they can be only the offshoots from some central area, 
far or near, where this intrusion must have had its source 
and greatest activity, it is very reasonable to expect both 
greater disturbances of the same strata and traces of volcanic 
debris in the rocks of the age at which the disturbance took 
place. That the eruptives of the northwest coast of lake Su- 
perior cannot all be assigned to a single epoch of disturbance is 
made evident by the researches of Lawson. That some were 
as earl}^ as the lower part of the Animikie there is still reason 
to believe. This will appear in a subsequent paper. 
There are Taconic sedimentary rocks much further west, 
even on the eastern slopes of the Rocky mountains, as first 
brought to light by Dr. Rominger.* The same fact had been 
discovered earlier, though apparently not yet published, by 
Mr. R. G. McConnell, of the Canadian Geological Survey. 
There is a vast thickness here of Taconic slates and quartz- 
ytes, Olenellvs having been found at an estimated thickness 
of 8,000 feet above the base, but no igneous rocks have been 
reported. 
If a rapid glance now be given at the facts recited concern- 
ing the existence of Taconic eruptives in Canadian territory, 
it becomes apparent that a similar and cotemporary history 
*Cari, Rominoer, Descriptinn of Primordial fossils from Mt. Steplieii, 
N. W. Territory of Cainubi, Proc. Acad. Nat. Sci.Phila., 1887. Reviewed 
by Mr. C. D. Walcott, Am. .Tour. Sci., Sept., 1888. See also Rominger, 
Am. (Jeologist, vol. ii, p. 35G, 1888: R. G. McConnell. Am. (Jkologist, 
vol. Ill, p. 22, 1889; Rep. Pro-?. Can. Geol. Sur., 188G. Report D [1887]. 
