Open Access. Powered by Scholars. Published by Universities.®

Tectonics and Structure Commons™

Open Access. Powered by Scholars. Published by Universities.®

Western University

Articles 1 - 5 of 5

Full-Text Articles in Tectonics and Structure

Seismic Landslide Hazard Mapping For Greater Vancouver, British Columbia, Ali Fallah Yeznabad, Sheri E. Molnar, Hesham M. El Naggar Mar 2019

Seismic Landslide Hazard Mapping For Greater Vancouver, British Columbia, Ali Fallah Yeznabad, Sheri E. Molnar, Hesham M. El Naggar

Western Research Forum

The lower Mainland of southwest British Columbia (BC) hosts about 3.5 million people and significant infrastructures of national importance. Southwestern BC has the highest seismic risk in Canada with significant potential to cause earthquake-induced hazards including tsunamis, liquefaction and landslides. A Cascadia mega-thrust (MW 9) earthquake is predicted to generate $75 billion Canadian dollars in losses. This damage can be resulted from ground shaking or its secondary phenomena like landslides; ground shaking during earthquakes may trigger landslides that can damage or destroy buildings, bury roads and highways and kill and injure people. In Canada, during the past century and …

Go to article

Fluid-Present Anatexis Of Neoarchean Tonalite And Amphibolite In The Western Shandong Province, Chris Yakymchuk, Wenran Zhao, Yusheng Wan, Shoufa Lin, Fred Longstaffe Jan 2019

Fluid-Present Anatexis Of Neoarchean Tonalite And Amphibolite In The Western Shandong Province, Chris Yakymchuk, Wenran Zhao, Yusheng Wan, Shoufa Lin, Fred Longstaffe

Earth Sciences Publications

Metatonalite and amphibolite from the Taishan region of the Western Shandong Province in the North China Craton record c. 2.60 Ga fluid-present partial melting via the breakdown of biotite, plagioclase and quartz to produce peritectic hornblende and anatectic melt. Eight paired leucosome–melanosome samples from metatonalite and three paired samples from amphibolite were investigated to evaluate the composition of the melt. Hornblende, biotite and plagioclase in the leucosomes and hornblende and plagioclase in melanosomes from both rock types have similar compositions. Two leucosome samples from the metatonalite were influenced by the removal of heavy rare earth element-rich hornblende and the accumulation …

Go to article

An Overview Of Anorthosite-Bearing Layered Intrusions In The Archaean Craton Of Southern West Greenland And The Superior Province Of Canada: Implications For Archaean Tectonics And The Origin Of Megacrystic Plagioclase, Ali Polat, Fred J. Longstaffe, Robert Frei Jan 2018

An Overview Of Anorthosite-Bearing Layered Intrusions In The Archaean Craton Of Southern West Greenland And The Superior Province Of Canada: Implications For Archaean Tectonics And The Origin Of Megacrystic Plagioclase, Ali Polat, Fred J. Longstaffe, Robert Frei

Earth Sciences Publications

Anorthosite-bearing layered intrusions are unique to the Archaean rock record and are abundant in the Archaean craton of southern West Greenland and the Superior Province of Canada. These layered intrusions consist mainly of ultramafic rocks, gabbros, leucogabbros and anorthosites, and typically contain high-Ca (>An70) megacrystic (2–30 cm in diameter) plagioclase in anorthosite and leucogabbro units. They are spatially and temporally associated with basalt-dominated greenstone belts and are intruded by syn-to post-tectonic granitoid rocks. The layered intrusions, greenstone belts and granitoids all share the geochemical characteristics of Phanerozoic subduction zone magmas, suggesting that they formed mainly in a …

Go to article

Petrogenetic And Geodynamic Origin Of The Neoarchean Doré Lake Complex, Abitibi Subprovince, Superior Province, Canada, Ali Polat, Robert Frei, Fred J. Longstaffe, Ryan Woods Jan 2018

Petrogenetic And Geodynamic Origin Of The Neoarchean Doré Lake Complex, Abitibi Subprovince, Superior Province, Canada, Ali Polat, Robert Frei, Fred J. Longstaffe, Ryan Woods

Earth Sciences Publications

The Neoarchean (ca. 2728 Ma) anorthosite-bearing Doré Lake Complex in the northeastern Abitibi subprovince, Quebec, was emplaced into an association of intra-oceanic tholeiitic basalts and gabbros known as the Obatogamau Formation. The Obatogamau Formation constitutes the lower part of the Roy Group, which is composed of two cycles of tholeiitic-to-calc-alkaline volcanic and volcaniclastic rocks, siliciclastic and chemical sedimentary rocks, and layered mafic-to-ultramafic sills. In this study, we report major and trace element results, and Nd, Sr, Pb and O isotope data for anorthosites, leucogabbros, gabbros and mafic dykes from the Doré Lake Complex and spatially associated basalts and gabbros of …

Go to article

Petrology And Geochemistry Of The Tasse Mantle Xenoliths Of The Canadian Cordillera: A Record Of Archean To Quaternary Mantle Growth, Metasomatism, Removal, And Melting, Ali Polat, Robert Frei, Fred J. Longstaffe, Derek J. Thorkelson, Eyal Friedman Jan 2018

Petrology And Geochemistry Of The Tasse Mantle Xenoliths Of The Canadian Cordillera: A Record Of Archean To Quaternary Mantle Growth, Metasomatism, Removal, And Melting, Ali Polat, Robert Frei, Fred J. Longstaffe, Derek J. Thorkelson, Eyal Friedman

Earth Sciences Publications

Mantle xenoliths hosted by the Quaternary Tasse alkaline basalts in the Canadian Cordillera, southeastern British Columbia, are mostly spinel lherzolite originating from subcontinental lithospheric mantle. The xenoliths contain abundant feldspar veins, melt pockets and spongy clinopyroxene, recording extensive alkaline metasomatism and partial melting. Feldspar occurs as veins and interstitial crystal in melt pockets. Melt pockets occur mainly at triple junctions, along grain boundaries, and consist mainly of olivine, cpx, opx and spinel surrounded by interstitial feldspar. The Nd, Sr and Pb isotopic compositions of the xenoliths indicate that their sources are characterized by variable mixtures of depleted MORB mantle and …

Go to article