Geoscience BC

Iron-rich minerals, such as hematite (α-Fe2O3), are prominent constituents of the Martiansurface; theyare considered to be potential indicators of past aqueous activityand habitability. This study investigated the interaction betweenthe extremophilic black fungus Rhinocladiella similis LaBioMMi 1217 and hematite under simulated laboratory conditionson Mars, focusing on redox-mediated dissolution processes, metabolicadaptations, and biosignature formation. The fungus was cultivatedwith powdered and polished hematite substrates, and mineral alterationwas monitored through physicochemical measurements and scanning electronmicroscopy (SEM). Genome mining was performed to identify and mapgenes involved in iron metabolism. The metabolic profile of the fungusunder hematite treatment was assessed via untargeted metabolomics.Over 15 days, the cultures exhibited marked acidification (pH decreasedfrom 7.0 to 4.7) and a 10-fold increase in the dissolved Fe2+ ion concentration (26–270 mg/L), indicating metabolicallydriven iron reduction. SEM revealed surface etching and localizedroughening consistent with microbially induced weathering, whereasthese changes were absent in the abiotic controls. Genes linked tosiderophore biosynthesis (sidA, sidC, sidD, sidF, sidH, sidI, and sidL) and reductiveiron assimilation (FET3, FTR1, and FRE1) were identified. Untargeted metabolomics confirmedthe secretion of organic acids, iron-chelating siderophores (e.g.,ferrichrome C), and redox-active aromatic compounds in the presenceof hematite, supporting a multifaceted strategy that combines acidification,chelation, and redox mediation. Collectively, these results show thatthe fungus actively promotes hematite dissolution through organicmolecule-mediated mechanisms. Such interactions hold astrobiologicalrelevance, as fungal modification of hematite might lead to the productionof diagnostic chemical and mineralogical biosignatures, informingfuture life-detection strategies on Mars.

Abstract Basin morphometry can strongly affect lake-internal processes relevant for productivity, such as turbulent mixing, photosynthetic energy acquisition, sedimentation, and nutrient recycling. Yet, in both empirical and theoretical studies of whole-lake primary production, lake morphometry is often simplified to a single 1-dimensional measure – lake mean depth. Using the conceptual, process-based model ‘Lake2D’, we addressed the question: To what extent can pelagic and benthic producer dynamics, integrated over a lake basin, be captured by approaches that use mean depth as the only morphometrical variable? We created two models of algal biomass dynamics in a radially symmetric, cone-shaped lake – one preserving the lake’s vertical and radial dimensions and one preserving only the lake’s mean depth – and compared model predictions of algal biomass dynamics across a wide range of lake sizes, mixing conditions, water transparency, and nutrient content. Our analyses reveal that model predictions differ substantially but predictably in much of the investigated parameter space, and identifies the light environment set by lake depth, water clarity and pelagic nutrients, but also lake area, as main drivers of the differences. Most commonly, the model based on mean depth underestimates benthic algal biomass and overestimates pelagic algal biomass, the net effect on total biomass being a 5-50% underestimate in shallow lakes and a 5-20% overestimate in many deeper lakes. Since gross primary production (GPP) in our model scales with algal biomass, we believe that global estimates of lake GPP should be corrected for the systematic errors inflicted by the prevailing 1-dimensional approaches.

The presence of heavy metal Cr(VI) in water indicates environmental pollution. Heavy metal Cr(VI) that exceeds the standard can be harmful to health because it is toxic and carcinogenic. Activated carbon can be used as a heavy metal adsorbent. Modification of activated carbon using nitric acid can increase metal adsorption capacity. Therefore, this study aims to determine the kinetic of hexavalent chromium (Cr(VI)) removal by corn cob-based activated carbon modified with nitric acid. The modified activated carbon was characterized by Boehm titration and FTIR spectrophotometer. The adsorption capacity was identified in various parameters, involving the initial concentration of Cr(VI), pH value, contact time, and concentration of the adsorbent to obtain the optimal Cr(VI) removal efficiency value. The most optimal Cr(VI) adsorption was obtained at an activated carbon dosage of 3 g/L, pH value of 1, contact time of 140 minutes, and 100 mg/l Cr(VI) concentration. Based on adsorption kinetics data, the pseudo-second-order equation was obtained (R2 =0.994). The adsorption phenomenon followed the Langmuir isotherm model (R2 = 0.998) with an optimum adsorption capacity of 28.32 mg/g. Corn cob-activated carbon modified with nitric acid has many acidic groups that act as effective active sites for reducing Cr(VI) from water.

Carbon storage via shallow CO2 injection and mineralization in subsurface geologic formations has been demonstrated at the kilotonne scale in basalt (e.g., Hellisheidi, Iceland) but not in ultramafic rock. This type of storage dissolves CO2 in water that is then injected underground into shallow rock formations from 300-2000 m depth, where it reacts and forms permanent carbonate minerals. This project assesses the potential for CO2 injection into serpentinite, specifically within British Columbia, Canada.Site selection included multi-criteria index overlay analysis for logistical factors (e.g. water, electricity, access) and evaluation of geological data to prioritize which sites contain 1 km2 mapped voluminous serpentinite. Of the 746 mapped ultramafic formations, 84 formations within 21 areas meet threshold criteria, and of these, three stand out with clearly higher potential. These are 1) the Shulaps complex, 2) the Coquihalla serpentine belt, and 3) the Tulameen intrusion, all in southwest British Columbia. These areas have in common that they are close to infrastructure, are located in regions with higher annual temperatures, and have known geological and geophysical characteristics indicative of serpentinite. The Shulaps and Coquihalla are mantle massifs and mainly composed of serpentinized harzburgite, and Tulameen is an Alaskan-type ultramafic intrusion with a serpentinized dunite core.Six different carbon storage potential estimates using volume limitations, dissolution, and reactivity rates from experiments, and natural analogues are shown for the three potential sites, for Shulaps 141.2-18,682 MtCO2, for Coquihalla 9.416-1,245 MtCO2, and for Tulameen 2.825-373.6 MtCO2. Fieldwork observations and preliminary results show, as expected, heterogeneity of protoliths, serpentinization extent, and fracture density between the areas. Coquihalla was selected for a proposed pilot injection study because of its high serpentinization extent (>90%, suggesting high reactivity), continuous high fracture density (suggesting adequate injectivity), site accessibility through existing road systems, and proximity to electricity.An additional aspect of project development is engagement with local communities. All three of the top-ranked sites fall within traditional lands of First Nations peoples, and we conducted early engagement with 22 First Nations or alliances. The priorities for engagement were to inform people about the project and its implications, get consent for fieldwork, have a discussion, and start relationship building.

Key Messages: (1) Intertidal polygonal tepee structures can be found around the entire Arabian Peninsula. (2) Diagenesis is initiated with microbially mediated cementation. (3) Potential link between polygonal tepee structures and polygonal reefs.

An understanding of catchment-scale processes and sediment dynamics is crucial for the informed and sustainable development of mountain communities. Given the steep topography, glacier retreat, and intensifying weather patterns due to climate change, many mountain towns face heightened vulnerability to geohazards. Studies show that as glaciers retreat, paraglacial processes typically lead to elevated sediment yields, exacerbating existing hazards. However, postglacial landscapes are dynamic, complex, and heterogeneous systems shaped by a variety of processes, and no two systems are the same. The efficiency in which glacial sediments are reworked and transported to and through river systems (connectivity) varies over time and space. In this study, we investigate the link between landscape history, sediment (dis)connectivity, and postglacial sediment dynamics in a glacierized, mountainous catchment in Southern British Columbia. We begin by mapping the geomorphology, identifying sediment sources, storage landforms and transfer processes. Subsequently we employ morphometric analysis and landform mapping paired with age estimates, to quantify sediment yield. These results are compared to historical channel changes and estimates of structural connectivity to better understand the variation in postglacial sediment dynamics. By integrating diverse datasets and methodologies, we are able to estimate the variability in sediment yield and changing relative contributions of sediment sources at a range of spatial and temporal scales. Preliminary results of this work shed light on and underscore the need for additional studies that investigate long-term (e.g., postglacial) changes in sediment connectivity. Such research can inform decision-making in landscapes that are rapidly changing and experiencing deglaciation.