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THE ROYAL SOCIETY OF CANADA 



Camptonite. Husereau Farm Near St. Benoit 



A very interesting exposure lies about half a mile east of the 

 intersection of the Ste. Sophie and Ste. Germaine Roads, about half 

 way between the Monastery of La Trappe and the village of St. 

 Benoit. This latter village is situated on the Canadian National 

 Railway between Montreal and Ottawa. This exposure is undoubtedly 

 related to the other basic intrusives described above, and is situated 

 on the farm belonging to one Husereau, and for want of a better name 

 will be referred to as the Husereau occurrence. 



This occurrence cuts the Grenville series on the north-west side 

 of a hill which rises about one hundred feet above the Ste. Sophie Road 

 to the west. The intrusive is roughly circular in outline and is about 

 250 yards in diameter. By far the largest part of the intrusive is 

 composed of a dark grey rock in which the most prominent feature 

 is irregular plates of mica which are in places a centimetre in diameter. 

 Small grains of colourless pyroxene can also be identified. 



Two other phases are present around the border of the principal 

 type. One is a light grey rock which appears to be composed almost 

 entirely of nepheline, and the other, which is apparently a transition 

 phase between the two, is a dark grey fine-grained rock with occasional 

 small plates of mica, which possesses no other features which are 

 distinguishable in the hand specimen. 



The mineralogical corriposition of the various phases of the 

 Husereau occurrence is shown below. 



a Abundant 



b Subordinate 



c Present 



