Maija J Raudsepp

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

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...

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 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...

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...

Bioneutralization of pH by microbial fermentation of added carbon substrates is a promising new method for remediation of the 1.7 GT/yr of alkaline mining tailings produced globally. Here, we present the first study to systematically compare and optimize the efficacy of microbial inocula of varying diversities, structures, and provenance and organi...

Deep, hot, and more alive than we thought Marine sediments represent a massive microbial ecosystem, but we still do not fully understand what factors shape and limit life underneath the seafloor. Analyzing samples from a subduction zone off the coast of Japan, Heuer et al. found that microbial life, in particular bacterial vegetative cells, decreas...

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...

Abstract The study investigates the in-situ strength of sediments across a plate boundary décollement using drilling parameters recorded when a 1180-m-deep borehole was established during International Ocean Discovery Program (IODP) Expedition 370, Temperature-Limit of the Deep Biosphere off Muroto (T-Limit). Information of the in-situ strength of...

Microbial community succession in tailings materials is poorly understood at present, and likely to be substantially different from similar processes in natural primary successional environments due to the unusual geochemical properties of tailings and the isolated design of tailings storage facilities. This is the first study to evaluate processes...

Microbial communities in decommissioned coal mines have the potential to promote methane generation. Here, two 1 m x 10 cm diameter column bioreactors designed to mimic an abandoned coal mine were monitored for a year, with zones of methanogenesis in the bottom, saturated waters and aerobic coal degradation and methane oxidation at the top. The res...

Full volume available at http://publications.iodp.org/proceedings/370/370title.html

In numerous global coal–bearing basins, methane, possessing a biogenic stable isotope composition, is spatially and temporally associated with groundwater recharge. However, beyond groundwater inoculating the subsurface with microorganisms, the biological mechanisms that control the distribution of biogenic methane are poorly understood. In this st...

International Ocean Discovery Program (IODP) Expedition 370 aimed to explore the limits of life in the deep subseafloor biosphere at a location where temperature increases with depth at an intermediate rate and exceeds the known temperature maximum of microbial life (~120°C) at the sediment/basement interface ~1.2 km below the seafloor. Drilling Si...

The microbial communities present in two underground coal mines in the Bowen Basin, Queensland, Australia, were investigated to deduce the effect of pumping and mining on subsurface methanogens and methanotrophs. The micro-organisms in pumped water from the actively mined areas, as well as, pre- and post-mining formation waters were analyzed using...

Biofilms coat the exterior of most water-exposed interfaces, from the surfaces of sediments and rocks to the interior walls of fluid transport systems and even medical and dental apparatus. Composed of a diverse assemblage of microbial species growing in a matrix of extracellular polymeric substances (EPS), biofilms are well-known for their ability...