Page:The Journal of geology (IA journalofgeology21894univers).pdf/128

Lawson,^[1] in 1893, on lithological grounds suggests the following hypothetical correlation of certain rocks of Western Ontario and Minnesota, Eastern Ontario and Quebec:

	Western Ontario and Minnesota.			Eastern Ontario.	Quebec.
In order of superposition.	Ontarian system.			Hastings series.	Grenville series.
	Laurentian system.			Ottawa gneiss.	Ottawa gneiss.
	Carltonian-Anorthosites of Minnesota.				Norian.
In order of chronological sequence; an irruptive rock being of later age than the formations which it invades.	Carltonian-Anorthosites of Minnesota.				Norian.
	Laurentian system.	${\displaystyle \scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \ \end{matrix}}\right.}}$	Batholitic granites and gneisses.	Ottawa gneiss.	Ottawa gneiss.
	Ontarian system.			Hastings series.	Grenville series.

Comments.—It seems to the reviewer that such lithological correlations between rocks in different and widely separated geological provinces have no value. The reasons for this belief cannot be here stated, but they have been published in Bull. No. 86, U. S. Geol. Survey.

Barlow^[2] describes the Laurentian granites and gneisses as intrusive in the Huronian rocks north of Lake Huron. The localities described are Killarney Village; Beaver, Fox, Balsam, Three Mile, Brush, Camp, Crooked, Johnny, Panache, Wavy, Chief's, Daisy, Baby and Alice lakes; Goshen, Broder and Dell townships; Wahnapital river; Cartier and Straight Lake Stations; and two islands near Thessalon. As evidence of the eruptive nature of the Laurentian gneiss in the Huronian sediments are cited the diverse stratigraphic relations of the rocks along their line of junction; the invariable alteration of the sedimentary rocks along the contact line; the inclusion of angular fragments, clearly referable to the adjacent sedimentary strata in the gneiss; the occurrence of gneissic intrusions and apophyses of pegmatite, occurring in or lam-