28 ROYAL SOCIETY OF CANADA 



Plate 8.) An analysis of the magnetite oceun-ing in the syenite peg- 

 matite at Craigmont. in the township of Eaglan, is given on page 72. 



Pynte. Pynliotite and Chalcopyritp. — All three of these minerals 

 have been found as constituents of the nepheline syenite. Pyrite is the 

 most common. Under the microscope it is occasionally present in small 

 well defined cubes, but usually it occurs in rounded or irregular grains. 



Graphite. — This mineral is not, so far as observed, a frequent or 

 an abundant constituent, but it has been noticed in the coarse phase of 

 the nepheline syenite exposed to the east of the York river in Dungannon 

 township. It occurs very pure, in small rounded shot-like forms con- 

 sisting of minute scales of the mineral arranged in a radiating or 

 plumose manner. In certain portions of the rock at this locality, gra- 

 phite in this fonn is quite abundantly distributed. It has been noticed 

 as an important and characteristic mineral in a certain variety of the 

 nepheline syenite of Siv:imalai m India, described by Holland, where it 

 constitutes 0.58 per cent of considerable masses of the rock.'' 



Holland explains its presence in this rock as due to its crystalliza- 

 tion from fusion, and regards it as a primary constituent and older 

 than the feldspar. This conclusion may be taken as applying also to 

 the graphite in the York river nepheline syenite. 



Description of the Several Occurrences. 



For purposes of description it will be most convenient to group the 

 several occurrences by townships, as follows: — 



I. The alkali syenites of the township of Lutterworth. 



II. The nepheline and associated alkali syenites of the township of 

 Monmouth. 



III. The nepheline and associated alkali syenites of the township of 

 Glamorgan. 



IV. The nepheline and associated alkali syenites of the townships of 

 Haroourt, Cardiff and Wollaston. 



V. The nepheline and associated alkali syenites of the township of 

 Methuen. 



VT. The nepheline and associated alkali syenites of the townships of 

 Faraday, Dungannon, Carlow and Monteagle. 



I. The All-ali Syenitea of the township of Lutterworth. — The 

 corundum-bearing syenite was discovered on lot 12, con. IV, in this 

 township, by ^Ir. Tett, when acting as assistant to W. A. Johnson, Esq., 

 of the Geological Survey of Canada, in the summer of 1905. This rock 

 is said to occupy an area from thirty to forty acres in extent and to cut 



' Mem. Geol. Surv. Ind., Vol. XXX. part 3, pp. 174 and 17j. 



