748 EDWARD STEIDTMANN 



Basal complex 



Pre-Huronian — Batholithic intrusions, granites, etc. 

 Abitibi group 



Pontiac series — Sedimentary schists, iron formation, etc. 



Igneous intrusives — Chiefly basic 



Extrusives — Chiefly basic 

 Grenville series 



Crystalline limestone, etc. 



As in certain other recent papers by Wilson, he argues for a 

 local nomenclature of the pre-Cambrian and against extensive 

 correlations. 



Wilson^ reports that the succession of rocks underlying a part 

 of Amherst Township of Quebec about 60 miles northeast of Ottawa, 

 is as follows. 



Late pre-Cambrian — ^A single diabase dike 



Basal complex — 



Batholithic granite and syenite gneiss 



Buckingham series of intrusives — Gabbro, pyroxene, syenite, anorthosite 



Grenville series — ^Limestone, garnet, gneiss and quartzite 



Wilson^ reports on a geological reconnaissance of a part of 

 northwestern Quebec. The region includes a southern limestone 

 belt, Grenville series, a northern sedimentary and volcanic belt 

 (Abitibi group), and an intermediate belt of banded gneisses 

 largely igneous intrusives into the Abitib' group. The Abitibi 

 group includes schists, iron formations, and conglomerates which 

 have not been stratigraphically separated. 



Wilson^ concludes that the banded Laurentian gneisses are 

 mostly of igneous origin and owe their banding to differentiation 

 under deformative conditions, the latter causing fractures in the 

 crystallized portions which become filled with magma. 



' Morley E. Wilson, " Geology and Mineral Deposits of a Part of Amherst Town- 

 ship, Quebec." Canada Geol. Surv. Mem. No. 113 (1919), 54 pp., i map, 17 pis., 3 figs. 



^ Morley E. Wilson, "A Geological Reconnaissance from Lake Kipawa via Grand 

 Lake Victoria to Kawikawinika Island, Bell River, Quebec," Canada Geol. Surv. 

 Summ. Rept. igi2 (1914), pp. 315-36, fig. 



3 Morley E. Wilson, "The Banded Gneisses of the Laurentian Highlands of 

 Canada," Am. Jour. Sci., 4th Ser., Vol. XXXVI (1914), pp. 109-22. 



