Sasha Wilson

University of Alberta | UAlberta · Department of Earth and Atmospheric Sciences

Amorphous carbonates are increasingly recognized as important precursors in biomineralization and abiotic carbonate precipitation at ambient temperatures. Understanding the conditions and factors that influence the stability of amorphous Ca-, Ca−Mg-, and Mg-carbonates (ACC, ACMC, and AMC) is essential for understanding how organisms control biomine...

Carbon neutral or negative mining can potentially be achieved by integrating carbon mineralization processes into the mine design, operations, and closure plans. Brucite [Mg(OH)2] is a highly reactive mineral present in some ultramafic mine tailings with the potential to be rapidly carbonated and can contain significant amounts of ferrous iron [Fe(...

The Cracked Mountain edifice is a basaltic subglacial volcano (i.e. tuya) situated in southwest British Columbia, Canada. The edifice is dominated by subaqueously deposited, massive to poorly stratified, variably palagonitized lapilli tuffs intruded by syn-eruptive dikes and lobes of peperitic pillow-lavas (15–20 vol.%); minor stacks of pillow-lava...

Geochemical carbon dioxide removal (CDR) technologies capture and store carbon dioxide (CO2) from the atmosphere using alkaline materials that are rich in calcium (Ca) and magnesium (Mg). Alkaline materials include natural rocks such as basalt, industrial by-products such as steel slag, or artificially generated and industrially produced materials...

In this contribution, we evaluate the applicability of short-wave infrared spectroscopy to characterizing mineral assemblages in palagonitized glaciovolcanic edifices at Cracked Mountain, a basaltic volcano within the Garibaldi Volcanic Belt, and Kima Kho, a basaltic tuya within the Northern Cordilleran Volcanic Province. Second-order evaluation of...

Jarosite and related subgroup minerals are of high importance in mineral processing, as sources and sinks for metals and acidity in the environment, and they have the potential to preserve elemental and isotopic biomarkers relevant to the search for life in the solar system. The crystal structures and chemistry of jarosite minerals affect their sta...

Jezero Crater on Mars is a paleolacustrine environment where Mg-carbonates may host evidence of ancient life. To elucidate the environmental and mineralogical controls on biosignature preservation, we examined samples from five terrestrial analogs: Lake Salda (Turkey), Lake Alchichica (Mexico), Qinghai-Tibetan Plateau (China), Mg-carbonate playas (...

Alkaline lakes have some of the most unique and diverse known mineral assemblages as a result of their very high pH and dissolved inorganic carbon concentrations. In these closed-basin systems, aqueous geochemistry and mineralogy are intimately linked, whereby the removal of elements through mineral precipitation controls the lake water geochemistr...

Among the ex-situ carbon capture and sequestration (CCS) techniques that have been developed to mitigate the damages of anthropogenic climate change, Enhanced Rock Weathering (ERW) is recently gaining traction. It is the spreading of finely ground silicate rock in agricultural settings to increase soil alkalinity and form secondary (pedogenic) carb...

Transformations between clay minerals, such as smectites or serpentines, and carbonate minerals play an important role in regulating Earth's climate. Both types of minerals have also preserved fossil, isotopic and molecular records of Earth's biosphere throughout geological time. There is an old and intimate connection between magnesium-rich clay m...

Mineral carbonation of alkaline mine residues is a carbon dioxide removal (CDR) strategy that can be employed by the mining industry. Here, we describe the mineralogy and reactivity of processed kimberlites and kimberlite ore from Venetia (South Africa) and Gahcho Kué (Canada) diamond mines, which are smectite-rich (2.3–44.1 wt.%). Whereas, serpent...

Mineral carbonation is a Carbon Capture Utilization and Storage (CCUS) technique that can be used to remove or divert carbon dioxide (CO2) from the atmosphere and store it in carbonate minerals. Hydraulic fracturing flowback and produced water (FPW) is Ca- and Mg-rich wastewater generated by the petroleum industry that can be used to sequester CO2...

Flowback and produced water (FPW) generated by hydraulic fracturing operations is highly saline and contains elevated concentration of ions including calcium and magnesium. Here, we investigate the use of FPW as a source of calcium and magnesium for carbon dioxide (CO2) capture and storage in carbonate minerals. We performed pH titration experiment...

The Coorong Lakes, South Australia, are one of the models for unravelling the ‘Dolomite Problem’. Critically, today only a few modern environments remain where large quantities of very high magnesium calcite (Ca0.5Mg0.5CO3) (also described as protodolomite or disordered dolomite) and magnesite (MgCO3) precipitate. Previously conducted laboratory st...

Meteorites that fall to Earth quickly become contaminated with terrestrial microorganisms. These meteorites are out of chemical equilibrium in the environments where they fall, and equilibration promotes formation of low-temperature alteration minerals that can entomb contaminant microorganisms and thus preserve them as microfossils. Given the well...

The combination of hydraulic fracturing with horizontal drilling has revolutionized oil and gas production. However, most of our understanding of the subsurface mechanisms and chemical interactions that occur during the process come from analyses of flowback and produced water (FPW). While the chemical composition of FPW can provide some informatio...

Enhanced rock weathering (ERW) sequesters CO2 via solubility and mineral trapping and can be implemented by the mining industry to reduce their net greenhouse gas emissions. Kimberlite residues from Venetia Diamond Mine in South Africa, as well as powdered forsterite, serpentinite, wollastonite skarn, and 10 wt.% brucite mixed with quartz sand, wer...

Tellurium (Te) is a Critical Mineral and its biogeochemical behaviour has mostly been interpreted from laboratory-based studies rather than direct field observations, due to the scarcity of Te in the environment. The historic mining district of Moctezuma, Sonora, Mexico, hosts the only Au mine worldwide where native tellurium is the main ore minera...

There is increasing evidence that the surface materials on Europa are influenced by endogenic and exogenic processes and chemistry. To explore how this may drive the diversity of resultant minerals on the surface of Europa, this study has explored a number of samples within the MgSO4−H2SO4−H2O ternary with synchrotron X-ray powder diffraction acros...

In this study we present the first Mg isotope data that record the fate of Mg during mineralisation of atmospheric CO2 in ultramafic mine tailings. At the Woodsreef Asbestos Mine, New South Wales, Australia, weathering of ultramafic mine waste sequesters significant amounts of CO2 in hydromagnesite [Mg5(CO3)4(OH)2·4H2O]. Mineralisation of CO2 in ab...

Recent experimental studies have demonstrated that clay minerals (e.g., kaolinite, illite, and montmorillonite) have higher affinities for some trace elements under acidic versus alkaline conditions. This suggests that clays might be important vectors in the transport of trace elements from sites of acidic chemical weathering on land to marine depo...

Mineralogically complex feedstocks, including kimberlite, serpentinite, and wollastonite skarns, have vast capacities to sequester carbon dioxide (CO2) through enhanced rock weathering and CO2 mineralization. However, only a small reactive fraction of these feedstocks will be accessible for carbon dioxide removal at Earth’s surface conditions. We h...

Melting of the Greenland Ice Sheet is a leading cause of land-ice mass loss and cryosphere-attributed sea level rise. Blooms of pigmented glacier ice algae lower ice albedo and accelerate surface melting in the ice sheet’s southwest sector. Although glacier ice algae cause up to 13% of the surface melting in this region, the controls on bloom devel...

Mineral distributions can be determined in drill core samples from a Carlin-type gold deposit, using micro-X-ray fluorescence (µXRF) raster data. Micro-XRF data were collected using a Bruker Tornado µXRF scanner on split drill core samples (~25 × 8 cm) with data collected at a spatial resolution of ~100 µm. Bruker AMICS software was used to identif...

Bioturbating organisms contribute significantly to elemental cycling in sediments through burrowing, grazing, organic matter and altering porewater chemical conditions. In the process, organisms are known to produce copious amounts of faecal material at high rates, sometimes in excess of 1 000 000 kg/day in a 1 km² area (Swinbanks, 1981; Pearson &...

Carbonation of ultramafic mine tailings has the potential to offset greenhouse gas emissions from mining by trapping CO2 within the crystal structures of Mg-carbonate minerals and hydrotalcite supergroup minerals, which form as weathering products in tailings storage facilities. Here, we present a detailed geochemical and mineralogical assessment o...

Accelerated carbonation of ultramafic mine tailings has the potential to offset CO2 emissions produced by mining ores from Cu-Ni-platinum group element, podiform chromite, diamondiferous kimberlite, and historical chrysotile deposits. Treatments such as acid leaching, reaction of tailings with elevated concentrations of gaseous CO2, and optimizatio...

Mineral carbonation is a negative emissions technology for capturing CO2 in carbonate minerals. Previous studies have demonstrated that accelerated production and carbonation of brucite [Mg(OH)2] from synthetic saline water can be used to store atmospheric CO2 in hydrated Mg- carbonate minerals [1,2]. In this study, we use hydraulic fracturing flow...

The advent of microfluidics has revolutionized the way we understand how microorganisms propagate through microporous spaces. Here, we apply this understanding to the study of how endolithic environmental microorganisms colonize the interiors of sterile rock. The substrates used for our study are stony meteorites from the Nullarbor Plain, Australia...

Jarosite is a common mineral in acidic, sulfate-rich environments where it is critical in regulating the acidity of aquatic systems and the mobility of trace elements and potential contaminants. This research aims to understand jarosite formation and recrystallization in these environments by examining the stable iron isotope geochemistry of jarosi...

Mineral carbonation is one of the promising methods for CO2 sequestration and is part of a strategy for mining companies to offset their greenhouse gas emissions [1]. In this study, we investigated the reactivity of kimberlite ore and processed kimberlite (tailings) from the Venetia and Voorspoed diamond mines (South Africa). Processed kimberlites...

NASA's strategy in exploring Mars has been to follow the water, because water is essential for life, and it has been found that there are many locations where there was once liquid water on the surface. Now perhaps, to narrow down the search for life on a barren basalt‐dominated surface, there needs to be a refocusing to a strategy of “follow the n...

The hydromagnesite–magnesite playas near Atlin, British Columba, Canada are unique Mg-carbonate depositional environments that have formed at Earth's surface since the end of the last deglaciation. This study elucidates the mechanisms, pathways, and rates of magnesite (MgCO 3 ) formation in these near-surface environments, which are challenging to...

High temperature gas–solid reactions interactions are ubiquitous in and on the Earth and other planetary bodies (Fig. 1). In these natural systems, gases are elusive. Like a hurricane’s wind that leaves a path of destruction but no trace of wind after the event, the gas that initiated a gas–solid reaction may be conspicuously absent. Because gases...

High temperature gas–solid reactions interactions are ubiquitous in and on the Earth and other planetary bodies (Fig. 1). In these natural systems, gases are elusive. Like a hurricane’s wind that leaves a path of destruction but no trace of wind after the event, the gas that initiated a gas–solid reaction may be conspicuously absent. Because gases...

Goethite (α-FeOOH) is a source and sink for trace elements in surficial environments. Its elemental and isotopic composition may be perturbed during recrystallization, particularly when accelerated by aqueous Fe(II), but the factors that control such reactivity and the extent to which it occurs are poorly understood. Here we react goethite samples...

Carbon mineralisation of ultramafic mine tailings can reduce net emissions of anthropogenic carbon dioxide by reacting Mg-silicate and hydroxide minerals with atmospheric CO2 to produce carbonate minerals. We investigate the controls on carbonate mineral formation at the derelict Woodsreef chrysotile mine (New South Wales, Australia). Quantitative...

The carbonation of ultramafic rocks, including tailings from ultramafic-hosted ore deposits, can be used to remove CO2 from the atmosphere and store it safely within minerals over geologic time scales. Quantitative X-ray diffraction (XRD) using the Rietveld method can be employed to estimate the amount of carbon sequestered by carbonate minerals...

The world's major source of iron ore is hosted in Precambrian banded iron formations. These chemical (meta-) sedimentary rocks are composed of alternating laminae of iron oxide minerals and chert. Despite the economic significance of high-grade iron ore deposits, controversy persists after decades of research on how banded iron formations became up...

Recent exploratory field mapping of marine sedimentary sequences in the Koushk Mine locality in the Bafq region of Central Iran, and on the northern slopes of the Elborz Mountains south of the Caspian Sea, has yielded large, complex body and trace fossils of Neoproterozoic–early Cambrian age. The recovered specimens resemble the previously document...

Organic matter is increasingly shown to influence the mobility of uranium (U) in the environment. The mobility of U likely depends on whether the organic matter is in dissolved or solid form, with the latter able to retard U mobility. In this work, column experiments were used to reveal that solid organic matter, in the form of well characterized t...

De Beers kimberlite mine operations in South Africa (Venetia and Voorspoed) and Canada (Gahcho Kué, Victor, and Snap Lake) have the potential to sequester carbon dioxide (CO2) through weathering of kimberlite mine tailings, which can store carbon in secondary carbonate minerals (mineral carbonation). Carbonation of ca. 4.7 to 24.0 wt% (average = 13...

Mineral carbonation in ultramafic mine tailings is generally accepted to be a safe and long term means of trapping and storing CO2 within the structures of minerals, but it poses the risk of releasing potentially hazardous metal contaminants from mineral wastes into the environment. Stockpiles of reactive, finely pulverised ultramafic mine tailings...

Precambrian banded iron formations record the composition of Earth’s atmosphere and hydrosphere during the global rise of oxygen. It has been suggested that the banded texture of these rocks points to fluctuations in ocean chemistry although this remains a subject of debate. Here we show, by petrographic and electron microscopy of Palaeoproterozoic...

Vickers-Rich, P., Soleimani, S., Farjandi, F., Zand, M., Linnemann, U., Hofmann, M., Wilson, S.A., Cas, R. & Rich, T.H. November, 2017. A preliminary report on new Ediacaran fossils from Iran. Alcheringa XX, xxx-xxx. ISSN xxxx-xxxx. Recent exploratory field mapping of marine sedimentary sequences in the Koushk Mine locality of the Bafq region in Ce...

The rare earth elements (REE) are a group of 17 metals that include the lanthanides, Sc and Y, which are critical for many modern technologies including consumer electronics, medicine and communication. One of the major controls on the concentrations of the REE in regolith material (including soils) is the abundance of these elements in the parent...

A microbial mineral carbonation trial was conducted at the Woodsreef Asbestos Mine (NSW, Australia) to test cyanobacteria-accelerated Mg-carbonate mineral precipitation in mine tailings. The experiment aimed to produce a carbonate crust on the tailings pile surface using atmospheric carbon dioxide and magnesium from serpentine minerals (asbestiform...

Unambiguous identification of biosignatures on Mars requires access to well-characterized, long-lasting geochemical standards at the planet’s surface that can be modified by theoretical martian life. Ordinary chondrites, which are ancient meteorites that commonly fall to the surface of Mars and Earth, have well-characterized, narrow ranges in trace...