An Examination of the Overall Relationship between Spectral Reflectance and Chemical Composition of 58 Mine Tailings Samples

Spectral reflection curves from 58 mine tailings samples were grouped into 11 unique spectral categories using a cluster analysis technique. A good relationship was found between the spectral categories and Munsel colors (hue and value) but only 70% of all groups could be separated on the basis of a single chemical parameter (Fe). It appears that the overall chemistry has a profound influence on spectral reflection, with total Fe, Al, Si and C playing a dominant part. The parameter interactions are complex and this makes it difficult to predict chemical concentrations from spectral reflection values. Cluster analysis offers a means to predict several parameters and allows an examination of their interaction. However, the prediction accuracy of this technique needs to be improved

Speciation and solubility relationships of Al, Cu and Fe in solutions associated with sulfuric acid leached mine waste rock

Abstract Solutions from oxidized waste rock originating from an acid-leached waste dump were studied. The dissolution data suggest that after the majority of the soluble solid phases are removed, remaining solid phases continued to buffer the solutions in the acidic pH range. Incorporating the solution data into MINTEQA2 identified controls on the solubility of Al, Cu and Fe at pH values from about 2.5 to slightly over 5. Sulfate appears to play a significant role in the formation of solubility controlling solid phases for Al and Cu. This is not the case for Fe, and is suggested that Fe and Cu solubility may be controlled by cupric ferrite at low pH values

Integrating Science, Environment and Equity

Communication is the most important biological activity that allows species, including Homo sapiens, to survive. In our complex, and some might argue, “detached from nature” world, academic communication has not kept pace with population growth, affluence and technology. The human desire is for more but the Earth from a human dimension is finite. Human impacts on our natural environment are increasing in intensity, in geographic space and in ways that are not predicted. There is a recurring sentiment that we are heading for a place we do not want to go! Science education and effective communication provides a framework for informed debate to facilitate the emergence of shared, equitable values and governance policies that could change our future direction. We must understand what is natural science, how we interpret science and how we use science to sustain the human enterprise. Emergent technologies help in understanding science and through communication, its equitable applications. We need tomorrow’s thinking to solve today’s problems caused by yesterday’s actions.Land and Food Systems, Faculty ofUnreviewedFacult

Mine reclamation and sustainable development

Sustainable development has become a common phrase in today's language, much like the term ecology was in the 1960s. The concept of sustainable development appears to be simple, yet its definition as applied to real issues is elusive. The questions raised include: is mining sustainable? what is sustainable development with respect to mine reclamation? sustainable on regional or global dimensions? sustainable over what period of time? The concept of sustainable development as applied to mining must develop a meaningful working definition that incorporates non-renewable resource management within the economic realities of society and the desires of preservation and conservation. Much attention has been given to planning for exploration, pre-mining extraction and active mine operations, without concern of sustainable development or sustainability. Even less attention has been devoted to the concept of sustainability following the active phase of a mining operation. The additional question to be addressed is what does sustainability or sustainable development mean in the context of mine reclamation?Land and Food Systems, Faculty ofUnreviewedOthe

Research on tailings in British Columbia - U.B.C. experience

For the past several years the Department of Soil Science at the University of British Columbia has been involved in research related to vegetation of mine wastes. The general objective of the research program has been to characterize mine wastes, especially tailings, by physical, chemical, mineralogical and biological properties. In this manner, the research has been oriented towards understanding the inherent properties of mine wastes so that the materials may be transformed to a "soil" that will not only maintain vegetation but also sustain it, without the necessity of continuous management. During 1976-77 the Department of Soil Science, under the auspices of the British Columbia Department of Mines and Petroleum Resources has intensified its research on tailings. This research activity has been oriented towards a better understanding of the various types of tailings, their elemental composition, the elements they release upon weathering, growth limiting factors and vegetative success. The ultimate aim is to develop guidelines for the establishment of vegetation in the various biophysical regions of the province. It was also hoped that the mining industry would become involved in collecting the data, both environmental and laboratory, in order for them to develop their own expertise as well as help plan future reclamation programs. This integration of government, university and private sector has much to offer in terms of efficiency of utilization of resources, training and obtaining a base-line upon which British Columbia reclamation programs can be patterned.Land and Food Systems, Faculty ofUnreviewedOthe

Silicon isotopes record dissolution and re-precipitation of pedogenic clay minerals in a podzolic soil chronosequence

By providing the largest part of the reactive surface area of soils, secondary minerals play a major role in terrestrial biogeochemical processes. The understanding of the mechanisms governing neo(trans-)formation of pedogenic clay minerals in soils is therefore of the utmost importance to learn how soils evolve and impact the chemistry of elements in terrestrial environments. Soil-forming processes governing the evolution of secondary aluminosilicates in Podzols are however still not fully understood. The evolution of silicon (Si) isotope signature in the clay fraction of a podzolic soil chronosequence can provide new insight into these processes, enabling to trace the source of Si in secondary aluminosilicates during podzol-forming processes characterized by the mobilization, transport and precipitation of carbon, metals and Si. The Si isotope compositions in the clay fraction (comprised of primary and secondary minerals) document an increasing light 28Si enrichment and depletion with soil age, respectively in illuvial B horizons and eluvial E horizon. The mass balance approach demonstrates that secondary minerals in the topsoil eluvial E horizons are isotopically heavier with δ30Si values increasing from − 0.39 to + 0.64‰ in c.a. 200 years, while secondary minerals in the illuvial Bhs horizon are isotopically lighter (δ30Si = − 2.31‰), compared to the original “unweathered” secondary minerals in BC horizon (δ30Si = − 1.40‰). The evolution of Si isotope signatures is explained by the dissolution of pedogenic clay minerals in the topsoil, which is a source of light 28Si for the re-precipitation of new clay minerals in the subsoil. This provides consistent evidence that in strong weathering environment such as encountered in Podzols, Si released from secondary minerals is partially used to form “tertiary clay minerals” over very short time scales (ca. 300 years). Our dataset demonstrates the usefulness to measure Si isotope signatures in the clay fraction to discern clay mineral changes (e.g., neoformation versus solid state transformation) during soil evolution. This offers new opportunity to better understand clay mineral genesis under environmental changes, and the short-term impact of the dissolution and re-precipitation of pedogenic clay minerals on soil fertility, soil carbon budget and elemental cycles in soil–plant systems. </p

Tree diversity, site index, and carbon storage decrease with aridity in Douglas-fir forests in western Canada

Forests are important for biodiversity, timber production and carbon accumulation, but these ecosystem services may be impacted by climate change. Field data collected from individual forest types occurring across a climatic gradient can contribute to forecasting these consequences. We examined how changes in temperature, precipitation and aridity affect ecosystem services in 23 mature Douglas-fir (Pseudotsuga menziesii) forests in nine climatic regions across a 900 km gradient in British Columbia, Canada. Using Canadian National Forest Inventory methodology, we assessed richness and diversity of plant functional groups, site index, and above- and below-ground carbon stocks. As aridity increased, ecosystem-level tree species richness declined on average from four to one species, Douglas-fir site index declined from 30 to 15 m, and ecosystem carbon storage decreased from 565 to 222 Mg ha-1. Tree species richness was positively and herb species richness negatively correlated with carbon storage. Carbon storage by ecosystem compartment was largest in aboveground live tree biomass, declining in the following order: mineral soils > coarse woody debris and dead standing trees > forest floor > small and fine woody debris > understory plants. Mineral soil carbon at depths of 0-15 cm, 15-35 cm, and 35-55 cm increased with increasing mean annual precipitation and decreasing aridity. Our results indicate that as aridity increases and precipitation decreases, tree species richness, site index and carbon storage in existing Douglas-fir forests declines. However, assisted or natural migration of Douglas-fir into more humid regions could be associated with more diverse, productive, carbon-rich forests. This study informs carbon stock vulnerability and provides empirical data essential for carbon stock forecasts