TY - JOUR
T1 - Tellurium biogeochemical transformation and cycling in a metalliferous semi-arid environment
AU - Missen, Owen P.
AU - Etschmann, Barbara
AU - Mills, Stuart J.
AU - Sanyal, Santonu K.
AU - Ram, Rahul
AU - Shuster, Jeremiah
AU - Rea, Maria A.D.
AU - Raudsepp, Maija J.
AU - Fang, Xi Ya
AU - Lausberg, Ella R.
AU - Melchiorre, Erik
AU - Dodsworth, Jeremy
AU - Liu, Yang
AU - Wilson, Siobhan A.
AU - Brugger, Joël
N1 - Funding Information:
We thank Associate Editor Prof. Georges Calas and Executive Editor Prof. Jeffrey G. Catalano for handling our manuscript, and three anonymous reviewers for their detailed, insightful comments. The authors acknowledge support funding provided to OPM by an Australian Government Research Training Program (RTP) Scholarship, a Monash Graduate Excellence Scholarship (MGES) and a Monash–Museums Victoria Scholarship (Robert Blackwood). Further financial support for this work was provided by The Ian Potter Foundation (grant ‘tracking tellurium’ to SJM) and the ARC Research Hub on Australian Copper–Uranium (project number: IH130200033), funded by the Australian Research Council, BHP Olympic Dam and the South Australian Department of State Development. This research used equipment funded by Australian Research Council grant LE0882821.
Funding Information:
We thank Associate Editor Prof. Georges Calas and Executive Editor Prof. Jeffrey G. Catalano for handling our manuscript, and three anonymous reviewers for their detailed, insightful comments. The authors acknowledge support funding provided to OPM by an Australian Government Research Training Program (RTP) Scholarship, a Monash Graduate Excellence Scholarship (MGES) and a Monash?Museums Victoria Scholarship (Robert Blackwood). Further financial support for this work was provided by The Ian Potter Foundation (grant ?tracking tellurium? to SJM) and the ARC Research Hub on Australian Copper?Uranium (project number: IH130200033), funded by the Australian Research Council, BHP Olympic Dam and the South Australian Department of State Development. This research used equipment funded by Australian Research Council grant LE0882821. There is a long list of people to thank for their assistance at various stages of this study, named in approximate chronological order: Stefan Ansermet (Mus?e Cantonal de G?ologie, Lausanne, Switzerland; field support); A/Prof Frank Reith (University of Adelaide; inspiring work in gold biogeochemistry); Mike Rumsey and Dr Jens Najorka (Natural History Museum, London; SEM and PXRD); the Wilson lab for hosting OPM and Jie (Rachel) Cheng (University of Alberta; DNA extraction); the Melchiorre & Dodsworth labs and Dr. Becky Talyn (CSUSB; DNA extraction); Junnel Alegado (Monash University; expert sample preparation); the Monash Isotopia laboratory and Dr Massimo Raveggi (Monash University; LA?ICPMS); Australian Laboratory Services Hermosillo (ALS), in particular Milka Galindo and Gabriela Montano; the Australian Genome Research Foundation, in particular Anna Ikonomopoulos and Wei Lu; and the Monash Centre for Electron Microscopy.
Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2022/3/15
Y1 - 2022/3/15
N2 - 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 mineral (Bambolla mine). In contrast to Bambolla, the nearby San Miguel mine features a typical epithermal-style assemblage of silver sulfides, selenides, and tellurides; this dichotomy provides comparative sites to study environmental Te mobility during weathering as a function of source composition (same host rock and climate). This study characterised the regolith geochemistry, mineralogy and microbial diversity around these two Te-enriched sites. Scanning electron microscopy of fresh mineral surfaces from the weathering zone suggests that Te was released to the environment through oxidative dissolution of primary Te minerals, especially native tellurium at Bambolla. Micron-scale gold grains (<100 μm) in regolith samples have morphologies consistent with the dealloying of the gold telluride calaverite (AuTe2). Secondary Te minerals observed in situ include abundant tellurite (TeO2) and highly Te-enriched Fe (hydr)oxides, which may contain up to 20 mole% Te substitution for Fe. The presence of residual organic material in association with embedded secondary nano-minerals suggests that Te (bio)transformation processes were likely associated with weathering. In particular, carbon-rich globules on the surface of millimetre-sized grains of native tellurium contain abundant Te nanoparticles, suggestive of bioreduction. DNA extraction and sequencing of the bacterial 16S rRNA gene revealed that the Te-enriched (up to 1750 ppm) regolith proximal to the Te-rich veins hosted microbial communities with varying composition but similar overall diversity compared to regolith collected from distal locations (more than 50 m from the mineralised veins). Of the detected bacterial Amplicon Sequence Variants (ASVs) from Te-rich regolith which could play an active role in Te (bio)transformation processes, representatives from the phyla Proteobacteria, Actinobacteria and Acidobacteria were the most abundant, followed by Firmicutes, candidate phylum WPS-2, Chloroflexi, Planctomycetes and Patescibacteria. This study provides the first evidence that Te undergoes dynamic cycling in the environment, with nanoscale chemical and structural changes governing the biogeochemical behaviour of Te on the macroscale. In doing so, this work provides important information on the underlying controls for Te mobility in both environmental settings, such as Te-rich rock outcrops and anthropogenic settings, such as Te-containing solar panel stockpiles.
AB - 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 mineral (Bambolla mine). In contrast to Bambolla, the nearby San Miguel mine features a typical epithermal-style assemblage of silver sulfides, selenides, and tellurides; this dichotomy provides comparative sites to study environmental Te mobility during weathering as a function of source composition (same host rock and climate). This study characterised the regolith geochemistry, mineralogy and microbial diversity around these two Te-enriched sites. Scanning electron microscopy of fresh mineral surfaces from the weathering zone suggests that Te was released to the environment through oxidative dissolution of primary Te minerals, especially native tellurium at Bambolla. Micron-scale gold grains (<100 μm) in regolith samples have morphologies consistent with the dealloying of the gold telluride calaverite (AuTe2). Secondary Te minerals observed in situ include abundant tellurite (TeO2) and highly Te-enriched Fe (hydr)oxides, which may contain up to 20 mole% Te substitution for Fe. The presence of residual organic material in association with embedded secondary nano-minerals suggests that Te (bio)transformation processes were likely associated with weathering. In particular, carbon-rich globules on the surface of millimetre-sized grains of native tellurium contain abundant Te nanoparticles, suggestive of bioreduction. DNA extraction and sequencing of the bacterial 16S rRNA gene revealed that the Te-enriched (up to 1750 ppm) regolith proximal to the Te-rich veins hosted microbial communities with varying composition but similar overall diversity compared to regolith collected from distal locations (more than 50 m from the mineralised veins). Of the detected bacterial Amplicon Sequence Variants (ASVs) from Te-rich regolith which could play an active role in Te (bio)transformation processes, representatives from the phyla Proteobacteria, Actinobacteria and Acidobacteria were the most abundant, followed by Firmicutes, candidate phylum WPS-2, Chloroflexi, Planctomycetes and Patescibacteria. This study provides the first evidence that Te undergoes dynamic cycling in the environment, with nanoscale chemical and structural changes governing the biogeochemical behaviour of Te on the macroscale. In doing so, this work provides important information on the underlying controls for Te mobility in both environmental settings, such as Te-rich rock outcrops and anthropogenic settings, such as Te-containing solar panel stockpiles.
KW - Biogeochemistry
KW - Mineral transformations
KW - Moctezuma, Sonora, Mexico
KW - Nanoparticles
KW - Tellurium
UR - https://www.scopus.com/pages/publications/85123623329
U2 - 10.1016/j.gca.2021.12.024
DO - 10.1016/j.gca.2021.12.024
M3 - Article
AN - SCOPUS:85123623329
SN - 0016-7037
VL - 321
SP - 265
EP - 292
JO - Geochimica et Cosmochimica Acta
JF - Geochimica et Cosmochimica Acta
ER -
SDG 13 Climate Action