55 



and micaceous limestone — treated by the mill 

 is, however, brought from near Maynooth. 



344-57 m. Monmouth Road. Alt., 1,181 ft. (360 m.j. 



554-7 km. 



347-87 m. Toryhill. Alt., 1,147 ft. (349-6 m.). 



560 km. 



The Nepheline Syenite-Granite Intrusion in the 

 Central Part of the Township of Monmouth. 



In the vicinity of Tory-hill there is a large and very 

 interesting occurrence of nepheline syenite, which is found 

 as a border or marginal phase of a body of pegmatitic 

 granite running through the centre of the Township of 

 Monmouth in a direction about N. 30 E. for about six 

 miles (9-6 m.). This granite mass has a maximum width 

 of a little over one mile. The border of nepheline-syenite 

 is from one-eighth to half-a-mile (200 to 800 m.) in width. 

 The whole occurs as an intrusion into the white crystalline 

 limestones of the Grenville series. 



The granite is pink or red in colour and is usually of 

 medium grain. It frequently shows the rapid variation in 

 size of grain common in pegmatite. At the north-eastern 

 end of the mass it is distinctly foliated. Further to the 

 south this foliation becomes less distinct, but the rock 

 presents a streaked appearance. 



The feldspars present are albite, microperthite, ortho- 

 clase and microcline, the two first mentioned minerals 

 predominating. The ferromagnesian constituents are 

 present only in very small amount and consist of biotite 

 and two varieties of hornblende. 



The granite is nowhere rich in quartz, although in the 

 north-eastern part of the mass this mineral is present in 

 considerable amount. To the south-east this mineral 

 decreases in amount and the rock assumes a syenitic 

 facies. 



This syenite is red in colour and is composed almost 

 exclusively of feldspar, which is for the most part micro- 

 perthite, the iron-magnesia constituents occurring in 

 occasional dashes with rudely parallel arrangement. It 

 differs from the granite not only in the fact that no quartz 

 is visible in the thin sections but also in that hornblende is 



