James Allen Aubut HBSc thesis abstract

Thesis Title: 
The Geology of the Southwest Margin of the Coldwell Complex
James Allen

Rocks of the Coldwell alkalic complex have intruded metasedimentary and metavolcanic rocks of the Schreiber-White Lake greenstone terrain.  The complex is believed to be the product of three intrusive magmatic episodes.  The oldest episode is characterized by gabbro and augite syenite and is exposed at the southwest margin of the complex.

The intrusion of the two units has produced a thermal metamorphic aureole that attains pyroxene hornfel facies at the contact with the gabbro.  The gabbro unit shows evidence of deformation resulting in cataclasis and recystallization of the feldspar.  This has produced a protoclastic to porphyroclastic texture.  The syenite is the later unit and has intruded the gabbro.

Within the two units is found a relatively complex suite of dyke rocks showing a complex intrusive history.  The most common dyke rock is lamprophyre.  This can be broken down into three types which represent approximately four periods of intrusion.  The youngest set is characterized by having "phenocrysts" of resorbed quartz.  The quartz may either represent high-pressure phenocrysts or xenocrysts.