Article
Geochemistry & Geophysics
S. E. Grasby, J. B. Percival, I Bilot, O. H. Ardakani, I. R. Smith, J. Galloway, M. Bringue, T. McLoughlin-Coleman
Summary: Research on the Smoking Hills in Arctic Canada has revealed striking similarities to Mars, with abundant jarosite-rich deposits and sulfate minerals formed through oxidative weathering. The formation of the Smoking Hills is mainly attributed to auto-combustion of pyritic mudstones due to oxidative weathering, generating high temperatures and sulfur minerals. Therefore, the study suggests that the deposition of metal sulfates on Mars may indicate a more habitable environment than previously thought.
Article
Energy & Fuels
Lihui Liu, Qinfu Liu, Shuai Zhang, Yakui Li, Longtao Yang
Summary: Pyrite, a common and important mineral in coal and coal gangue, undergoes thermal transformation during combustion, impacting the environment and coal utilization. This study reveals that during coal gangue combustion, pyrite transforms into hematite and releases SO2 gas.
Article
Geosciences, Multidisciplinary
Leo Aimar, Emanuelle Frery, Julian Strand, Charles Heath, Shahbaz Khan, Isabelle Moretti, Cindy Ong
Summary: This study uncovers a potential hydrogen system in the Grass Patch area of Western Australia and highlights the differences between the hydrogen seeps and salt lakes in terms of their geological characteristics and gas measurements. The research suggests the need for long-term monitoring of surface features to better understand the evolution and variability of gas mix seepage and its relationship with bacterial activity or geogenic hydrogen sources.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Geosciences, Multidisciplinary
G. J. Retallack
Summary: Ferruginous biofilms are a form of preservation that can retain detailed imprints of venation in fossil leaves even in coarse sandstone. These biofilms, created by filamentous iron-oxidizing bacteria, exhibit distinctive felted textures and are observed in Ediacaran vendobionts. This study finds no evidence for a uniquely Ediacaran style of fossil preservation, suggesting that various preservation methods were used for Ediacaran fossils.
Article
Geochemistry & Geophysics
David Wacey, Kate Eiloart, Martin Saunders
Summary: The study reports on hematite-mineralised examples of Gunflint organisms, documenting subtle variations in iron oxide mineralisation styles using different microscopy techniques. The findings suggest that iron oxide mineralisation was a taphonomic rather than primary metabolic process, impacting the preservation of microfossils and the modification of fossilised organisms' morphology.
Article
Engineering, Chemical
Rahul Ram, Liam Morrisroe, Barbara Etschmann, James Vaughan, Joel Brugger
Summary: This study investigates the adsorption of lead on various common minerals, revealing the partitioning behavior between solids and the aqueous phase under different conditions. Different minerals show distinct affinity for lead adsorption, influenced by solution pH and lead concentration.
MINERALS ENGINEERING
(2021)
Article
Geosciences, Multidisciplinary
Chamindra L. Vithana, Prashani A. K. Ulapane, Rohana Chandrajith, Leigh A. Sullivan, Jochen Bundschuh, Nadia Toppler, Nicholas J. Ward, Atula Senaratne
Summary: The Muthurajawela Marsh in Sri Lanka is a critically important coastal wetland ecosystem that contains acid sulfate (AS) soil materials. However, due to development activities in the surrounding areas, there is a risk of exposure of the AS soils in the marsh. The study found that all sites lacked inherent buffering capacity, which could lead to the release of acidity and potential impact on the marsh ecosystem.
Article
Geochemistry & Geophysics
M. Chen, I. H. Campbell, J. N. Avila, W. Tian, P. C. Hayman, R. A. F. Cas, T. R. Ireland
Summary: This study presents in-situ multiple sulfur isotope analyses of pyrites from deep marine sediments in the Kalgoorlie-Kambalda area of Western Australia. The results reveal different sulfur isotope compositions in different sediment types, providing important insights into the ancient oceanic environment of the region.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Thermodynamics
Lihui Liu, Qinfu Liu, Kenan Zhang, Shuai Zhang, Kuo Li, Jintao Li, Gaoyu Peng
Summary: Pyrite in coal gangue can be decomposed into pyrrhotite when heated in an inert atmosphere. Pyrites with different morphologies and structures exhibit distinct thermal behavior. When heated in an air atmosphere, pyrites can be oxidized to nano-hematite.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Astronomy & Astrophysics
Pengfei Zuo, Jiangtao Sun, Xuefei Liu, Jinhua Hao, Deshun Zheng, Yu Li
Summary: Jamsite is a common sulfate mineral on Mars, with limited exposures in ancient sedimentary rocks on Earth, hindering our understanding of its genesis and analogues on Mars. A study of sulfates- and sulfides-enriched black shales in early Cambrian rocks in China identified two types of jarosite, with type II likely forming earlier than type I. Energy-dispersive X-ray spectrometry analysis revealed different atomic ratios of Fe/Al in the two jarosite types.
Article
Geochemistry & Geophysics
A. Moreras-Marti, M. Fox-Powell, E. Stueeken, T. Di Rocco, T. Galloway, G. R. Osinski, C. R. Cousins, A. L. Zerkle
Summary: In this study, sediment samples from sulfur-rich environments in Iceland and Canada were analyzed for quadruple sulfur isotope values, revealing different microbial sulfur cycling processes between the sites. The results suggest the potential for quadruple sulfur isotope values to serve as biosignatures for life in sulfur-rich Martian environments. The contrasting physical and chemical characteristics of the sites support different microbial sulfur cycling processes, with implications for targeting sites for future missions to Mars.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geosciences, Multidisciplinary
J. Olsthoorn, E. W. Tedford, G. A. Lawrence
Summary: This study visualizes the salt finger formation under ice in lakes through laboratory experiments, showing that while these fingers can be detected in camera recordings, they are nearly absent in temperature records. The research quantifies the velocity of salt-plumes, measures the increase in bottom salinity, and suggests that salinity is often distributed evenly with depth. By comparing salt fluxes, it is concluded that favorable conditions for salt fingering exist in most seasonally ice-covered lakes.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Vitor R. Barrote, Svetlana G. Tessalina, Neal J. McNaughton, Noreen J. Evans, Steven P. Hollis, Bradley J. McDonald
Summary: The Nimbus Ag-Zn(-Au) deposit is a hybrid VHMS deposit with epithermal characteristics formed under shallow water conditions in the Yilgarn Craton. The mineralization is hosted by a bimodal volcanic rock succession overlain by a polymict conglomerate with enriched sedimentary intervals. Trace element analysis in sedimentary pyrite suggests the potential for developing it as an exploration tool for similar ore deposits.
MINERALIUM DEPOSITA
(2021)
Article
Multidisciplinary Sciences
Josefin Martell, Carl Alwmark, Luke Daly, Stephen Hall, Sanna Alwmark, Robin Woracek, Johan Hektor, Lukas Helfen, Alessandro Tengattini, Martin Lee
Summary: This study explores the three-dimensional distribution of hydrous phases within the nakhlite meteorite and reveals that the alteration is localized and of short duration. This implies that habitable environments could not have been sustained on Mars during the Amazonian period.
Review
Geochemistry & Geophysics
Zhaoxia Jiang, Qingsong Liu, Andrew P. Roberts, Mark J. Dekkers, Vidal Barron, Jose Torrent, Sanzhong Li
Summary: Hematite is a common canted antiferromagnetic mineral with a reddish color. Its identification and quantification can be conveniently achieved through magnetic and color properties. Understanding hematite's characteristics and content is crucial for studies of the iron cycle, paleoenvironmental evolution, and research on Mars. However, previous research mainly focuses on stoichiometric hematite, neglecting the effects of cation substitution. Remagnetization is another complex problem associated with hematite. Recognizing the properties of cation-substituted hematite and understanding remagnetization mechanisms are important for identifying and interpreting the magnetic signals carried by hematite.
REVIEWS OF GEOPHYSICS
(2022)
Review
Biology
Eric Alexander Runge, Muammar Mansor, Andreas Kappler, Jan-Peter Duda
Summary: Deep-sea hydrothermal systems are important for the emergence of life, but the distribution and diversity of microbial communities in ancient systems are still unclear. Understanding the formation and preservation of microbial biosignatures in these systems is challenging and requires multidisciplinary studies.
Article
Biotechnology & Applied Microbiology
Jianrong Huang, Adrian Mellage, Julian Pavon Garcia, David Gloeckler, Susanne Mahler, Martin Elsner, Natalia Jakus, Muammar Mansor, Hongchen Jiang, Andreas Kappler
Summary: Autotrophic nitrate-reducing Fe(II)-oxidizing microorganisms play a crucial role in carbon, iron, and nitrogen cycles. The study showed that the distribution of electrons from Fe(II) oxidation to either CO2 fixation or nitrate reduction deviated from the theoretical value. N2O was the main denitrification product. Furthermore, the Fe/N ratios influenced the distribution of electrons and the degree of cell-mineral interactions.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Engineering, Environmental
Guoqiang Zhao, Mengxi Tan, Binbin Wu, Xiaoshan Zheng, Ruoxuan Xiong, Baoliang Chen, Andreas Kappler, Chiheng Chu
Summary: Tidal-induced redox oscillations can activate thermodynamically stable iron minerals into a metastable phase for enhanced ROS production.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Geochemistry & Geophysics
Qian Zheng, Shuxin Tu, Yiwen Chen, Hongjun Zhang, William Hartley, Bangjiao Ye, Lu Ren, Juan Xiong, Wenfeng Tan, Andreas Kappler, Jingtao Hou
Summary: This study investigates the adsorption behavior of As(III) and As(V) on ferrihydrite. The results show that ferrihydrite has a higher affinity for As(III) and contains abundant micropores that contribute to the immobilization of As(III).
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Environmental Sciences
Timm Bayer, Elizabeth J. Tomaszewski, Casey Bryce, Andreas Kappler, James M. Byrne
Summary: In this study, a chemostat was used to investigate the autotrophic nitrate-reducing Fe(II)-oxidizing culture KS over 24 days. The results showed that the Fe(II) oxidation rate was highest in the chemostat, but the extent of oxidation was similar to the other experimental setups. Short-range ordered Fe(III) phases and goethite were detected in the chemostat. The study revealed the importance of reactive nitrogen intermediates on Fe(II) oxidation, mineral formation, and cell-mineral interactions under continuous conditions.
ENVIRONMENTAL MICROBIOLOGY REPORTS
(2023)
Article
Multidisciplinary Sciences
Jannik Martens, Carsten W. Mueller, Prachi Joshi, Christoph Rosinger, Markus Maisch, Andreas Kappler, Michael Bonkowski, Georg Schwamborn, Lutz Schirrmeister, Janet Rethemeyer
Summary: In Siberian permafrost sediments deposited during the Pleistocene, the presence of reactive iron leads to the mineral-bound organic carbon, which reduces microbial CO2 production after thawing. Rapid thaw of ice-rich Pleistocene-age permafrost can expose a large pool of organic matter to microbial degradation and greenhouse gas emissions, but protective physico-chemical mechanisms may restrict microbial accessibility and reduce decomposition, influenced by changing environmental conditions during sediment deposition. Study of different organic matter fractions in Siberian permafrost deposited during colder and warmer periods reveals that carbon preservation in mineral-associated organic matter is enhanced by reactive iron minerals, while warmer and wetter conditions reduce organic matter stabilization and increase CO2 production. The stability and bioavailability of Pleistocene-age permafrost carbon are important for predicting future climate-carbon feedback.
NATURE COMMUNICATIONS
(2023)
Article
Engineering, Environmental
Yuge Bai, Tianran Sun, Muammar Mansor, Prachi Joshi, Yiling Zhuang, Stefan B. Haderlein, Stefan Fischer, Kurt O. Konhauser, Daniel S. Alessi, Andreas Kappler
Summary: In this study, the roles of dissolved organic matter (DOM) and organo-mineral associations (OMAs) in electron transfer were investigated during microbial Fe-(III)-mineral reduction. Only when both DOM and OMAs were present, significant electron transfer occurred. The proportion of DOM and OMAs showed a positive correlation with the extent of Fe-(III) mineral reduction, but the variation in DOM proportion had a stronger effect on the reduction compared to OMAs. These findings provide new insights into how organic carbon facilitates iron transformation and the associated biogeochemical cycling of nutrients and contaminants in forest soil systems.
ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS
(2023)
Article
Engineering, Environmental
Dandan Chen, Kuan Cheng, Tongxu Liu, Guojun Chen, Andreas Kappler, Xiaomin Li, Raymond Jianxiong Zeng, Yang Yang, Fujun Yue, Shiwen Hu, Fang Cao, Fangbai Li
Summary: This study demonstrates that dual N-O isotopes and kinetic modeling can be used to distinguish biological and chemical processes during microbially mediated NRFO. The main nitrate reductase in Acidovorax sp. strain BoFeN1 was found to be membrane-bound dissimilatory nitrate reductase (Nar). N-O isotopes can be used to differentiate between chemical and biological reactions, and chemodenitrification plays a more important role than biological reactions during the coupled process.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Juan Liu, Yongjin Xiang, Yiwen Chen, Hongjun Zhang, Bangjiao Ye, Lu Ren, Wenfeng Tan, Andreas Kappler, Jingtao Hou
Summary: This study synthesized hematite samples with tunable oxygen vacancy defect (OVD) concentrations and investigated their effects on arsenate adsorption. The results revealed that oxygen vacancy was the primary defect type on the hematite surface. Quantitative relationships between OVD concentration and enhanced arsenate adsorption were established. NH3-DRIFT analysis and DFT calculations demonstrated the beneficial role of OVDs in improving adsorption strength and promoting arsenate immobilization.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Zhao-Feng Yuan, Yujie Zhou, Zheng Chen, Tong Zhang, Andreas Kappler, Williamson Gustave, Xianjin Tang, Jianming Xu
Summary: A new sustainable method using man-made aerenchymatous tissues (MAT) to increase soil redox potential (Eh) and reduce arsenic accumulation in rice paddies has been proposed and verified.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Bobo Xing, Nigel J. D. Graham, Binghao Zhao, Xian Li, Youneng Tang, Andreas Kappler, Hailiang Dong, Mari Winkler, Wenzheng Yu
Summary: Biomineralization occurring in the bacterial periplasmic space enhances electron transfer. Denitrification-driven Fe(II) oxidation plays a crucial role in connecting iron and nitrogen cycling in the environment. This study investigated the pathways and effects of iron entering the periplasmic space of the denitrifier Pseudomonas sp. JM-7, providing insights into the microbial metabolism and electron transfer in relation to iron presence.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Astronomy & Astrophysics
Matthew J. Roche, Mark G. Fox-Powell, Rachael E. Hamp, James M. Byrne
Summary: Recent studies have explored the metabolic pathways in Enceladus' ocean, suggesting the existence of methane generation driven by hydrothermal activity. This study investigates whether microbial iron reduction could occur in the ocean, and demonstrates the possibility of biogeochemical iron cycling in Enceladus' ocean.
INTERNATIONAL JOURNAL OF ASTROBIOLOGY
(2023)
Review
Microbiology
Laurent Philippot, Claire Chenu, Andreas Kappler, Matthias C. Rillig, Noah Fierer
Summary: Considerable progress has been made in recent years in determining the soil properties that influence the structure of the soil microbiome. However, the effects of microorganisms on their soil habitat have received less attention. Microorganisms not only contribute to nutrient cycling and organic matter transformations, but also alter the soil habitat through various mechanisms. Understanding the interactions between microorganisms and soil properties can have significant ecological implications.
NATURE REVIEWS MICROBIOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Timm Bayer, Ran Wei, Andreas Kappler, James M. Byrne
Summary: The adsorption capacity and overall efficiency of mixed-valent magnetite nanoparticles (MNPs) for heavy metal pollutants are influenced by their redox state and surface charge, which are affected by microbial redox cycling of iron (Fe) in magnetite and changes in pH. Microbial modification of MNPs has an important impact on the adsorption of Cu2+ and Cd2+, and a change in stoichiometry of the MNPs can have a greater influence than a change of pH.
ACS EARTH AND SPACE CHEMISTRY
(2023)