Proposed Title 1: - Queen's University

hornblende-feldspar gneiss showing Hbl 1 and Kfs 1 porphyroclasts. E: Field photo of the
mylonitized metavolcano-sedimentary rocks of the melanocratic metagranitoid unit. F:
Microphotograph of the mylonitized metavolcano-sedimentary rocks showing a mylonitic
fabric that consists of flattened and preferentially oriented trails of Bt 1 , Chl 1 , Src 1 ,
dynamically recrystallized Qtz 1 and rotated Kfs 1 porphyroclasts. G: Field photo of the
mylonitized quartz-feldspar rocks showing rotated δ- and σ-type winged Kfs 1 porphyroclasts.
H: Microphotograph of the mylonitized quartz-feldspar rocks showing σ-Kfs 1 , recrystallized
Qtz 1 and Src 1 . Pen indicates north. Bt: biotite, Chl: chlorite, Kfs: potassium feldspar, Hbl:
hornblende, Py: Pyrite, Qtz: quartz, Src: sericite.
2.4.1.2. Structural and metamorphic relationships in the Main Ore shear zone
The Main Ore shear zone records a complex history of ductile, brittle-ductile and
brittle deformation. The shear zone strikes N240 o and is steeply southeast dipping at the
surface (75 o to 85 o ) but becomes shallow at depth (30 o to 40 o ) (Fig. 2.3B). Southeast of the
shear zone, cataclasite and ultracataclasite dominate the hanging wall. The intensity of the
cataclasitic deformation increases from southeast to northwest toward the ductile shear
zone where the footwall is mylonite-dominated and overprinted by a mélange of
cataclasite, breccias and veins that host the uranium mineralization (Fig. 2.3B).
The ductile component of the shear zone defines the oldest deformation observed.
The shear zone displays a southeast dipping foliation and northeast trending elongation
lineation (Fig. 2.3) defined by elongate Kfs 1 feldspars and recrystallized Qtz 1 quartz (Fig.
2.4F). The mylonitic fabric is heterogeneously developed due to contrasting rheology of
the melanocratic metagranitoid rocks. The strain is more localized into relatively weak
rock types such as the metavolcano-sedimentary rocks (Fig. 2.4E), which have a mylonitic
fabric and foliation consisting of preferentially oriented trails of Bt 1 biotite, Chl 1 chlorite,
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