2007 : “Layered intrusions and regional geology of the Nootka Sound area, Vancouver Island, British Columbia”
– Summary of Activities 2007, Report 2008-1 p.35-46 (pdf, 14.1MB)
2006 : “Geology and Mineral Potential Update for the Muchalat-Hesquiat Region (NTS 092E, F, K, l), Vancouver Island”
– Geological Fieldwork 2006, Paper 2007-1 p.355-360 (pdf, 2.34MB)
2005 : “Update on the Mineral Deposit Potential of the Nootka Sound Region (NTS 092E), West Coast of Vancouver Island, British Columbia”
– Geological Fieldwork 2005, Paper 2006-1 p.323-330 (pdf, 7.4MB)
M.Sc. Thesis – Karin Fecova
Conuma River and Leagh Creek intrusive complexes: Windows into mid-crustal levels of the Jurassic Bonanza arc, Vancouver Island, British Columbia – Simon Fraser University, 2009 – Available digitally through Simon Fraser University (pdf, 18.0 MB)
Abstract: The Conuma River and Leagh Creek intrusive complexes are examples of mid-crustal portions of the Jurassic Bonanza island arc, located on Vancouver Island, British Columbia, Canada. The Conuma River locality exhibits layered intrusions, consisting of alternating hornblenditic and hornblende gabbroic cumulates, occurring with numerous, contemporaneous small volume mafic to intermediate intrusions in tonalitic rocks. The Leagh Creek intrusions exhibit extensive silicic and basaltic magma mingling. Both complexes are interpreted as products of multiple magma pulses into the solidifying host intrusions. Two new radiometric hornblende Ar-Ar ages suggest Early to Middle Jurassic ages for two intrusions from each of the complexes. Geochemical crystallization modeling shows a genetic link between the Conuma River cumulate hornblenditic and non-cumulate hornblende gabbroic intrusions via dominantly olivine fractionation. Conversely, most of the intrusions of both complexes cannot be related by simple crystallization modeling, suggesting a complex history, involving magma mingling and assimilation processes.
M.Sc. Thesis – S.J. Close
Geology and tectonics of the Nootka Island region, British Columbia – Simon Fraser University, 2006 – Available digitally through Simon Fraser University Library (pdf, 18.6MB)
Abstract: Nootka Island represents a portion of an accreted volcanoplutonic arc, on the western coast of Vancouver Island, British Columbia, of the Canadian Cordillera Insular Belt . This work provides a 1:110,000 scale geologic map and synthesises the regional tectonics. Two main protolith groups are evident on Nootka Island. Group 1 contains tholeiitic basalts that have within-plate / E-MORB element signatures. Limestones and siltstones comprise the intervening sedimentary strata. Group 2 comprises the youngest and consists of calc-alkaline, arc-like basalts, a plutonic suite, and minor hypabyssal bodies. Groups 1 and 2 resemble the Triassic Karmutsen and Jurassic Bonanza Formations. Plagioclase-hornblende thermometry and aluminium-in-hornblende barometry indicate metamorphism at up to 710o Celsius and 3.2 kbar of early Jurassic and older rocks. Whole rock argon dating of a basalt dyke post-deformation reveals crystallization ages of 168 Ma, and metamorphism at 158 Ma from an older Group 1 hyaloclastite.