64 The American Geologist. January, it<94 
molten condition subsequent to the deposition and lithification of the 
Huronian sediments. The Huronian system, therefore, is regarded as 
the oldest of sedimentary origin known in that region; and it is 
supposed to have been laid down on a firm floor of rock analogous to 
granite. Fusion, irruptive flow, and reerystallization of this granitic 
floor are thought to have produced the Laurentian gneiss, whose par- 
allel foliation of the component minerals and alternation of coarse and 
fine bands are believed to be magmatic flow structure. Fragments of 
the Huronian rocks are inclosed in the gneiss, and the latter sends out 
coarsely crystalline seams, which are interstratified with the Huronian 
beds, and dike-like apophyses which cut these beds transversely. 
The Archean rocks west of lake Superior. By William Henry 
Chatterton Smith. Bulletin, G. S. A., vol. iv, pp. 333-348, August 4, 
1893. We read this able essay with deep regret that its author was not 
spared for further work. His death occurred soon after the society's 
last winter meeting, for whose success he had been very active as sec- 
retary of the local committee. The essay treats of the part of the Do- 
minion of Canada from the Lake of the Woods eastward to the Thunder 
Bay district north of Lake Superior, and from the international 
boundary north to the Canadian Pacific railway. The lower Archean 
or Laurentian rocks are granitoid and gneissic. occupying more than 
half of the country as large rounded or ovoid areas, like those mapped 
by Hitchcock in New Hampshire, by Barlow north of lake Huron, and 
by Lawson in western portions of this district. Surrounding and gen- 
erally dipping away from the nuclear granitic areas, the upper Archean 
rocks constitute an irregular network and comprise in ascending order 
the Coutchiching and Keewatin series of Lawson, the former consisting 
of gneisses and mica schists, and the latter of plutonic, volcanic and 
pyroclastic rocks. Since the accumulation of the upper Archean 
series, the basal granites and gneiss have been molten and their con- 
tacts with the overlying rocks are nearly everywhere distinctly irrup- 
tive. In its present condition and relationship, therefore, the so-called 
Laurentian system in this part of Canada is held to be of post-Kee- 
watin age, as was first announced by Lawson. Richly gold-bearing 
quartz veins are found in the Keewatin rocks of the Lake of the Woods; 
and nickeliferous diorite has been recently discovered near the mouth 
of this lake. 
Bulletin of the Geological Society of America. Proceedings of the 
Fifth Annual Meeting, held at Ottawa, Canada. December 2s, 29 and 
::n. 1892. H. L. Fairchild, Secretary; Joseph Stanley-Brown, Editor. 
Vol. iv, pp. i-xi, 371-458; Sept. 23, 1893. 
Between the brochure last noticed and this final part of the vol- 
ume are two papers: The Laurentian of the Ottawa district (pp. 349 
360), by R. W. Ells; and Height of the Bay of Fundy coast in the Gla- 
cial period relative to sea-level, as evidenced by Marine Fossils in the 
Boulder-clay at St. John, New Brunswick (pp. 3(51-370), by Robert 
Chalmers. Somewhat full outlines of each were presented in the Am. 
Geologist for last February and March. 
