2 1 4 RECENT P UBLICA TIONS 



as well as the Grenville series in eastern Ontario and Quebec, probably 

 the equivalents in age of the western Huronian, show similar curving 

 bands and eruptive contacts of the underlying Laurentian, as described 

 by Adams, Barlow, and Ells ; and the same is true, in part at least, 

 of Labrador, as described by Lowe. 



On the other hand, the Huronian regions in the United States 

 south of Lake Superior, and also in New Brunswick, present a basal 

 conglomerate resting unconformably on the Laurentian, according to 

 Van Hise and Dawson. It may be that in the latter cases the thick- 

 ness of sediments was not great enough to depress the Laurentian 

 floor to the level of fusion or plasticity; or that the Huronian, as 

 recognized in these regions, is really younger and overlies the 

 upturned edges of the rocks described as Huronian in the northern 

 Archaean. Some remarks in Van Hise's pre-Cambrian geology seem 

 to suggest this. 



It is likely that eruptive contacts of batholitic masses with over- 

 lying rocks exist under every great mountain chain ; though the 

 " Fundamental Complex " thus arising is disclosed only in the more 

 ancient and therefore more deeply eroded mountain systems. Some- 

 thing like this has been shown to exist in British Columbia by Daw- 

 son, but of Jurassic age. Under the later mountain systems, however, 

 the arching of anticlinal folds probably aided the uprising of the 

 plastic base ; and we may suppose that the core of granite and gneiss 

 forms long belts rather than approximately round batholites. 



The term Laurentian has been used in the paper to include gran- 

 ites and gneisses of later age than the Ontarian or Huronian rocks, 

 following the custom of the Canadian geologists who have worked in 

 western Ontario. As this use differs from Logan's original definition, 

 it might be better to substitute another name, unless it shall appear 

 that the relation described above is universal in North America, and 

 that the supposed Huronian found to rest uncomformably on the 

 Laurentian is really of later age than the true Huronian. 



RECENT PUBLICATIONS. 



— -Adams, Frank D. Nodular Granite from Pine Lake, Ontario. Bul- 

 letin Geological Society of America, Vol. IX, pp. 163-172, PI. 11, 

 February 1898. 



— Andersson, Frithiof. Uber die Ouartare Lagerserie des Ristinge Klint 

 Auf Langeland eine Biologisch-Stratigraphische Studie. Upsala, 1897. 



