Structural study of the auriferous Santoy shear zone, northeastern Glennie domain, Saskatchewan

The study area lies within the Pine Lake Greenstone belt of the Glennie domain, 125 km northeast of LaRonge, SK. The Santoy shear zone hosts the Santoy 7, Santoy 8/8 East, and “Santoy Gap” gold deposits. This shear zone was studied using a structural and geochronological (ID-TIMS) approach in order to decipher its complex relationship with plutonism, deformation, alteration, and gold mineralization. Surface and subsurface mapping reveals that the Santoy shear zone, and deposits therein, show a clear structural relationship with the Carruthers Lake synform. The Santoy 7, Santoy “Gap”, and Santoy 8 deposits lie along the western limb of this structure while Santoy 8 East has been re-oriented by north-trending, 45°-plunging, S folds. The development of a splay off the D3 Tabbernor fault, located approximately 8 km east of the deposits, influenced the localization of strain along the western limb of the Carruthers Lake synform. This strain localization, in tandem with elevated fluid pressures, emplaced auriferous fault-fill quartz veins along ore zone parallel dykes during D3 dextral-reverse oblique slip movement. The age of the Lizard Lake pluton (1874.6 ± 2.9 Ma) and the ore zone adjacent hanging wall dyke (1874.6 ± 1.9 Ma) serves as a maximum mineralization age for these deposits. Structural relationships suggest that the Packman Lake pluton acted as a buttress during D3 deformation and produced a compressional jog in the Santoy shear zone that may have increased fracture density and fluid flow during mineralization. The age of this intrusion (1807 ± 7 Ma) serves as a maximum age for the development of this flexure. Gold mineralization at Santoy is closely associated with a calc-silicate alteration assemblage. This assemblage formed synchronously with the main stage mineralization event. Titanite and zircon within this assemblage was dated to 1755.5 ± 8.4 Ma (titanite) and 1754.0 ± 1.8 Ma (zircon) indicating syn-D3 deposit formation. A beryliferous pegmatite dyke that displays an F3 axial planar cleavage and crosscuts the auriferous ore lens at Santoy 8A has an age of 1736.1 ± 1.9 Ma. This age represents a minimum mineralization age for this system and a minimum age for regional D3 deformation in the Glennie domain.

Name thesis:degree_name

Master of Science (MSc)

Level thesis:degree_level

Master's

Discipline thesis:degree_discipline

Geology

Grantor dc:publisher

Faculty of Graduate Studies and Research, University of Regina

Year dc:date.issued

2016

Author dc:creator

• Wood, Chase Robertson

Advisor dc:contributor.advisor

• Bethune, Kathryn

Committee members dc:contributor.committeemember

• Raharimahefa, Tsilavo
• Chi, Guoxiang

Language dc:language.iso

en

DOI

https://doi.org/10.82465/3672

OAI identifier oai:identifier

oai:uregina.scholaris.ca:10294/7672