Deux Rivieres
This is an area of fenitization similar to that in Springer Township 031-00-082).
Canadian occurrences of alkaline rocks have previously been listed and described in some detail in the monograph by Currie (1976a), although a significant number that have come to light since that publication will be found here. These new localities notably include extensive areas of peralkaline granites in Newfoundland, and of alkaline volcanics and intrusives in British Columbia, and it seems likely that many future discoveries will be concentrated in the latter area.
Many of the more northerly carbonatite occurrences are only poorly known and have not been dated. Although generally badly exposed, many have been drilled but rarely have findings been published. Many Canadian occurrences have been investigated for their economic potential (see, for instance, Ferguson, 1971) and important mining operations for nepheline syenite at Blue Mountain and Nb at St-Honore are taking place, with active exploration and appraisal for phosphate and vermiculite elsewhere. A number of occurrences in Ontario is described by Parsons (1961) and nearly 30 Ontario carbonatites have recently been re-investigated by R.P. Sage, although his internal reports were not available when the present accounts were compiled. K-Ar ages on numerous carbonatites in eastern Canada are given by Gittins et al.(1967) and of a broader range of alkaline rocks by Doig and Barton (1968). Rb-Sr ages and Sr isotopic ratios for many Ontario occurrences have been published by Bell et al. (1982).
This is an area of fenitization similar to that in Springer Township 031-00-082).
The nepheline syenite and syenite gneisses of Monmouth and Glamorgan Townships represent the most southwesterly extent of the Ontario nepheline syenite-syenite gneiss belt.
The area divides into the Haliburton-Hastings Highland complex of gneisses in the northwest and the Hastings basin of lower grade sedimentary rocks, principally limestones and pelitic schists and gneisses, in the southeast.
The nepheline syenites lying east and northeast of Bancroft in the townships of Dungannon and Monteagle are the most extensive of the southeast Ontario nepheline syenite-syenite gneiss belt. They include the Bancroft nepheline syenite (the East Road occurrence of Currie, 1976a, p.
In the townships of Dungannon and Monteagle a a narrow north- south-trending belt of nepheline gneisses follows the valley of the York River.
Situated mainly in Lyndoch Township, but extending eastwards into Griffith Township, the Wolfe Belt comprises a prominent east-west ridge of southward-dipping nepheline gneiss, nephelinized calc- silicate gneiss and metapyroxenite extending over some 6 km and with a maximum outcrop width of just
Northeastwards the Haliburton-Bancroft nepheline syenite and syenite gneiss belt continues to the Ottawa River but with only small, isolated occurrences of nepheline syenite in Denbigh, South Algoma, Sebastopol, Brougham and Admaston Townships (Hewitt, 1961, p. 102).
The Blue Mountain complex consists of a main mass 4x2.4 km from which extends a southwest-trending arm 6.4 km long and up to 0.4 km wide.
Located on the northern tip of Ellesmere Island, the Cape Richards intrusion is about 7x3 km but it is partly covered by ice, snowfields and scree. It is intruded into schists and marbles of Lower Palaeozoic age, or older.
The Freemans Cove suite consists of five agglomerate vents, about 75 dykes and small plugs, as well as several sills, within an area of 40x20 km at the southeast end of Bathurst Island. It is intrusive into Lower and Middle Devonian and Upper Cretaceous sedimentary rocks.