PRE-CAMBRIAN LITERATURE OF NORTH AMERICA 657 



Quirke' maps the Espaiiola area representing the eastward 

 extension of the original Huronian. His classification of the pre- 

 Cambrian follows. 



Great unconformity 

 Huronian 



Keweenawan — Diabase injection 

 Igneous contact 

 Cobalt series 



Gowganda formation— Massive slate 



Conglomerate member 400 feet 



Graywacke slate 400 feet 



Bedded conglomerate 650 feet 



Unconformity 

 Bruce series 



Serpent quartzite 8,000 ( ?) feet 



Espanola group 



Espanola limestone 25 feet 



Espanola gray^^acke 280 feet 



Bruce limestone 1^0 feet 



Slight unconformity 



Mississagi quartzite 4000 feet 



Great unconformity 

 Pre-Huronian 



Granite intrusions 

 Igneous contact 



Basic intrusions 

 Igneous contact 



Schistified sediments 



Large-scale maps were made by Stansfield^ of certain mica, 

 apatite deposits in the townships of Hull and Buckingham of 

 Ottawa Valley. The pre-Cambrian rocks underlying this area 

 comprise : 



Igneous intrusives 



c) Trap dykes 



b) Gabbro and pegmatites of the mineral deposits 



a) Older pegmatite veins 

 GrenviUe series 

 Ottawa gneiss 



The Ottawa gneiss includes granite and syenite gneiss, crystal- 

 line limestones, quartzites, garnet-gneisses, sillimanite gneisses, 



'Terence T. Quirke, "Espanola District, Ontario," Canada Geol. Surv. Mem. 

 No. 102 (191 7), 75 pp. 6 pis., 8 figs., map. 



= John Stansfield, "Certain Mica, Graphite, and Apatite Deposits of the Ottawa 

 Valley," etc., Canada Geol. Siirv. Siimm. Rept. igii (1912), pp. 280-85. 



