Canadian Taconic Eruptives. — Winchell. 357 
between the eruptives north from the Vermont boundary and 
those of the upper Laurentian and the Norian. The Gren- 
ville series, with its crystalline limestones and anorthosytes, 
"the supposed upper Laurentian or Norian" and the "altered 
Quebec group" he correctly describes as of the same age as 
the "typical or original Huronian" or "probably Lower Cam- 
brian." In the introduction to his paper he intimates that the 
stratigraphy of the Laurentian rocks on the north side of the 
St. Lawrence valley "has a close connection" with that of the 
Quebec group. At that time that was a bold position to take, 
but many new facts that have been brought to light since, 
bearing on this problem, have gone toward a demonstration of 
its correctness. It matters not that the term Huronian has 
been largely extended since and geographically has rarel}^ been 
applied to these rocks by the Canadian survey, even under the 
sanction of Dr. Selw3'^n, nor that the Lower Cambrian age of 
the Norian and of its crj^stalline clastic rooks has not been ad- 
mitted by him,* because that extension of the Huronian has 
been an accidental after-thought and is not in keeping with 
the original descriptions, and because the Lower Cambrian age 
of the Norian has been accepted by an increasing number of 
later geologists who have examined their field relations. 
Dr. Selwyn describes two "groups" of rocks running north- 
ward from the Vermont boundary, one of which he calls the 
volcanic group ("group 2"), and one of crystalline schists 
("group 3"). In the light of present knowledge these seem to 
be identifiable with similar groups which occur in the Lake 
Superior region, viz: the Keweenawan and the Animikie or 
original Huronian. His "group 2" is thus described :f 
This ;L;i'(nii) embraces a j?real variety of crystalline, sub-crystalline and 
altered rocks, coarse, thick-bedded, feldspathic, chloritic, epidolic and 
quart/.ose sandstones, red, grey and greenish siliceous slates and 
argillites. great masses of dioritic, epidotic and seri)enlinous breccias 
and agglomerates, diorites, dolerites and amygdaloids. holding copper 
ore; serpentines, felsites and some fine-grained granitic and gneissic rocks 
also crystalline dolomites and calcites. Much of the division on the 
southeastern side of the axis, is locally made up of altered volcanic pro- 
ducts, both intrusive and interstratified, the latter being clearly of con 
temporaneous origin with the associated sandstones and slates. 
*Science, vol. i, p. 11, 1888. 
fGeol. Sur. Can., Rep. for 1877-1878, p. Af). 
