The Pike Lake Pluton - A Layered Syenite Intrusion in Lanark County - Part 2

In my July 17, 2017 blog posting I mentioned that Jean Dugas, in his 1952 doctoral thesis, had described  a syenite intrusion falling between Black Lake and Pike Lake, which he named the Black Lake body, but which is now known The Pike Lake Pluton.  I also mentioned that in the text of his thesis Dugas (1952) had remarked on the good bedding within the syenite body and included a spectacular photo of bedding in the syenite body (his photo number  54 at page 159 of his thesis).   Dugas placed the outcrop shown in  photo number 54 in Lot 24, Concession VI of North Burgess township.   Locating that outcrop is problematic as his Black Lake syenite body (the Pike Lake pluton) does not appear to outcrop in Lot 24 of Concession VI. Specifically, the map included with his thesis, and Wilson and Dugas’ (1961) map 1089A issued by the GSC, which replicates the map in the thesis, do not show the syenite body as outcropping on Lot 24 of Concession VI.

This past summer I visited friends who have a home on Black Lake and took the opportunity to visit a few of the outcrops of the syenite body that are visible on Google Earth. The outcrops are just to the north of Black Lake Road and about 400 meters west of  Pike Lake Route 16, and fall in Lot 23 very close to the southern  boundary of concession VII.   As such the outcrops are very close to Lot 24 of Concession VI.  The following photographs show layering, but are not close to the spectacular laying shown in Jean Dugas’ photograph.

The ruler in the photos is one meter (39 inches) long.

Christopher Brett
Ottawa

References

Dugas, Jean, 1952,
 Geology of the Perth map area, Lanark and Leeds Counties, Ontario; Ph. D., McGill, 189 pages, four  maps.    [ Map 1089A  replicates a map that is part of the  thesis.]
http://www.collectionscanada.gc.ca/obj/thesescanada/vol2/QMM/TC-QMM-124004.pdf
http://digitool.library.mcgill.ca/thesisfile124004.pdf

Wilson, Morley E. and  Dugas, Jean,  1961,
Map 1089A, Geology, Perth, Lanark and Leeds Counties, Ontario, Geological Survey of Canada; Geology by Morley E. Wilson, 1930 and Jean Dugas, 1949; Descriptive notes by Jean Dugas.
https://doi.org/10.4095/107951