5 CGB 5 – Lake Joseph Road (South of Highway 141)

Heidi Daxberger; Phillip Ruscica; and Sheila Ballantyne

GPS Coordinates (45°14’15.76″N , 79°48’21.21″W)

Parking: Park along the shoulder of the road.

The Lake Joseph Road site consists of an about 30 m long outcrop that is located along the Lake Joseph Road (South of HW 141), at the intersection of and south of Clear Lake Road.

The outcrop was split into two sections shown on the map above.

Click here to open the bedrock geology legend on the OGS website

Section 1 - North

The digital 3D model of the Joseph Road Outcrop shows the Northern Section of the road cut. Here you can investigate the well developed foliation of the gneissic rocks as well as metre-scale boudinage of metamorphosed mafic intrusions. Furthermore, stretching and partial rotation of Potassium Feldspars (felsic bands) due to shearing can be seen.


Section 2 - Center 

The second 3D model shown here represents the centre portion of the road outcrop. Here you can see an about 15 cm large porphyroclast of potassium feldspar that shows a bit of a sigmoidal shape. Wet conditions lower the visibility of the otherwise well developed gneissic banding.


In the following slide show you can view outcrop and close-up images of the Joseph Road outcrop.

Thin Sections of Hand Samples

The following google slide show shows whole slide images of the CGB 5 hand samples in thin section.



Additionally, higher magnification close up views are provided below for both thin sections VLS-21-63A and VLS-21-63B in form of 360 rotation videos.


Plain Polarized Light (PPL) view of sample VLS-21-63A.


Crossed Polarized Light (XPL) view of sample VLS-21-63A.


The following two thin section videos are of slide 63B, these show the view perpendicular to foliation of sample VLS-21-63.



Plain Polarized Light (PPL) view of sample VLS-21-63.


Crossed Polarized Light (XPL) view of sample VLS-21-63.


Additional photographs, detailed descriptions, and high resolution images of thin sections are available to post-secondary instructors. Please email virtual.petrology.network@utoronto.ca

All comments, questions, and concerns are always welcome at this email address.


Go to the next chapter: CGB 6 – Salt Dock!


Atlas of the Central Gneiss Belt Bedrock Geology in Southern Ontario: LiDAR-Derived Digital Outcrops, 3D Hand Samples, Petrography, and Geochemistry Copyright © 2022 by Heidi Daxberger; Phillip Ruscica; and Sheila Ballantyne is licensed under a Ontario Commons License – No Derivatives, except where otherwise noted.

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