Chemical petrology, mineralogy and structure of the Tulameen complex, Princeton area, British Columbia.

• Main Author: Rublee, Vera Jacqueline.
• Other Authors: Lalonde, Andre
• Format: Others
• Published: University of Ottawa (Canada) 2009
• Subjects: Geology.
• Online Access: http://hdl.handle.net/10393/10315; http://dx.doi.org/10.20381/ruor-16770

The Tulameen complex is a structurally disrupted pluton made up of equal proportions of ultramafic and feldspathic rocks that outcrop for over 60 km$\sp2$ in southwestern British Columbia. Situated at the western margin of the Intermontane belt, the 14 km length of the Tulameen complex parallels the eastern boundary of the Eagle plutonic complex. Dunite, olivine and hornblende clinopyroxenite are the principle ultramafic rocks; wehrlite, olivine-hornblendite, magnetite clinopyroxenite and hornblendite are subordinate and are not mappable units. Feldspar-bearing rocks underlie the eastern half of the Tulameen complex and exhibit a progressive petrologic zonation from gabbro to syenogabbro and syenodiorite eastwards. Ductile shearing and brittle faulting of the Tulameen complex obscure the relationships between the various rock types, and the widespread faulted lithologic contacts attest that its present distribution does not represent its original entirety. The Tulameen complex is faulted against Late Triassic to Early Jurassic age lower greenschist grade metasedimentary and metavolcanic rocks of the Nicola Group to the east, and to the west by a one km wide belt of penetratively deformed schistose rocks, correlated with the Nicola Group. Contacts are northwest-striking mylonitic shear zones which extend beyond the ultramafic-syenodioritic body and envelope several smaller ultramafic bodies along the strike to the northwest and southeast of the Tulameen complex. The plutonic rocks become increasingly foliated and, in the case of feldspar-bearing rocks, intensely saussuritized adjacent to these high strain zones. The sense of shear along the northwest-trending ductile faults was determined to be dextral. (Abstract shortened by UMI.)