Paragenesis, geochemistry and metallogeny of the Dublin Gulch intrusion-related Au deposit, Yukon Territory, Canada

This study concerns the Dublin Gulch intrusion-related gold system, Yukon Territory, Canada. Located 85 km, north northwest of the town of Mayo, YT, the property hosts a 3.3 M oz Au deposit associated with a mid-Cretaceous pluton. A detailed, 8 stage, hydrothermal paragenesis has been constructed for the deposit. At least two discrete fluids are responsible for sulfide mineralization at Dublin Gulch. The latter of the two hydrothermal fluids is responsible for the majority of Au endowment on the property. Geochemical signatures of mineralization support this finding, displaying distinct populations of arsenopyrite compositions and sulfur isotopes for each fluid. Lead isotopes from sulfosalts associated with the second fluid suggest hydrothermal scavenging from country rocks. Geochronology and petrogenetic studies show that a short lived intrusive event c. 93-94 Ma took place at Dublin Gulch and that the main Au mineralising fluid may be linked to a yet unseen intrusion at depth.

Effects of introduced moose (Alces alces) on vegetation composition, nutrient dynamics, and decomposition rates in boreal forest ecosystems in Newfoundland, Canada

Globally, consumers affect ecosystem processes including nutrient dynamics. Herbivores have been known to slow nutrient flow in boreal forest ecosystems. I examined the effects of introduced moose on disturbed forests of Newfoundland, Canada by conducting a field experiment during August - November 2014 in 20 paired moose exclosure-control plots. I tested whether moose browsing directly and indirectly affected forests by measuring plant species composition, litter quality and quantity, soil quality, and decomposition rates in areas moose exclosure-control plots. I analyzed moose effects using linear mixed effects models and found evidence indicating that moose reduce plant height and litter biomass affecting the availability of carbon, nitrogen, and phosphorus. However, plant diversity, soil quality, and litter decomposition did not differ between moose exclosures and controls. Moose in Newfoundland directly influence plant regeneration and litter biomass while indirect effects on soil ecosystems may be limited by time, disturbance, and climate.

Mineralogy, mineral chemistry, and genesis of precious metal-bearing volcanogenic massive sulfide deposits in the Newfoundland Appalachians, Canada: the Ming deposit as example

The Ming deposit, Newfoundland Appalachians, is a metamorphosed (upper greenschist to lower amphibolite facies), Cambro-Ordovician, bimodalmafic volcanogenic massive sulfide (VMS) deposit that consists of several, spatially-associated, elongated orebodies composed of stratabound semimassive to massive sulfides and/or discordant sulfide stringers in a rhyodacitic footwall. Copper is the main commodity; however, the deposit contains precious metal-bearing zones with elevated Au grades. In this study, field observations, microscopy, and micro-analytical tools including electron microprobe, laser ablation inductively coupled plasma mass spectrometry, and secondary ion mass spectrometry were used to constrain the relative timing of precious metal emplacement, the physico-chemical conditions of hydrothermal fluid precipitation, and the sources of sulfur, precious metals, semi-metals and metals. The ore mineral assemblage is complex and indicates an intermediate sulfidation state. Pyrite and chalcopyrite are the dominant ore minerals with minor sphalerite and pyrrhotite, and trace galena, arsenopyrite and cubanite. Additional trace phases include tellurides, NiSb phases, sulfosalts, electrum, AgHg±Au alloys, and oxides. Silver phases and precious metals occur predominantly in semi-massive and massive sulfides as free grains, and as grains spatially associated with arsenopyrite and/or sulfosalts. Precious metal phases occurring between recrystallized pyrite and within cataclastic pyrite are rare. Hence, the complex ore assemblage and textures strongly suggest syngenetic precious metal emplacement, whereas metamorphism and deformation only internally and locally remobilized precious metal phases. The ore assemblage formed from reduced, acidic hydrothermal fluids over a range of temperatures (≈350 to below 260ºC). The abundance of telluride and Ag-bearing tetrahedrite, however, varies strongly between the different orebodies indicating variable ƒTe₂, ƒSe₂, mBi, and mSb within the hydrothermal fluids. The variations in the concentrations of semi-metals and metals (As, Bi, Hg, Sb, Se, Te), as well as Au and Ag, were due to variations in temperature but also to a likely contribution of magmatic fluids into the VMS hydrothermal system from presumably different geothermal reservoirs. Sulfur isotope studies indicate at least two sulfur sources: sulfur from thermochemically-reduced seawater sulfate and igneous sulfur. The source of igneous sulfur is the igneous footwall, direct magmatic fluid/volatiles, or both. Upper greenschist to lower amphibolite metamorphic conditions and deformation had no significant effect on the sulfur isotope composition of the sulfides at the Ming deposit.

Student Independent Projects Environmental Studies 2011: Creating Federal Policies to Support Environmental Education in Canada.

Environmental Education is an essential component of childhood education and can play a vital role in the development of positive environmental attitudes, community involvement and environmental awareness. One of the main challenges faced by Canadian educators is the lack of support and funding to fully engage and participate in Environmental Education programs that are locally available. To better understand the viewpoint and challenges of educators and Environmental Education programs, this paper includes an interview series with three Environmental Education leaders, followed by a discussion section on significant commonalities. Through the research of peer-reviewed literature, federal documents, and environmental networks, this research paper aims to interpret the development and challenges of K-12 environmental education in North America as well as to review the established programs, networks, and resources availble to Canadian educators.