Bingham Canyon Research Articles

Investigating the Spatial Patterns of Heavy Metals in Topsoil and Asthma in the Western Salt Lake Valley, Utah

Mining activities, particularly in large excavations like the Bingham Canyon Copper Mine in Utah, have been increasingly linked to respiratory conditions due to heavy-metal-enriched waste and dust. Operating continuously since 1906, the Bingham Canyon Copper Mine contributes 4.4% of the Salt Lake Valley PM2.5 pollution. However, the extent of its contributions to larger-sized particulate matter (PM10) dust, soil and water contamination, and human health impacts is largely unknown. Aerosol optical depth data from Sentinel-2 imagery revealed discernible dust clouds downwind of the mine and smelter on non-prevailing-wind days, suggesting potential heavy metal dispersion from this fugitive dust and subsequent deposition to nearby surface soils. Our analysis of topsoils from across the western Salt Lake Valley found mean arsenic, copper, lead, and zinc concentrations to be well above global background concentrations. Also, the minimum values for arsenic and maximum values for lead were well above the US EPA regional screening levels for residential soils. Thus, arsenic is the metal of greatest concern for impacts on human health. Elevated concentrations of all metals were most notable near the mine, smelter, and tailings pond. Our study linked these elevated heavy metal levels to regional asthma outcomes through cluster analysis and distance-related comparison tests. Significant clusters of high asthma rates were observed in regions with elevated topsoil heavy metal concentrations, impacting both low- and high-income neighborhoods. The findings of this preliminary study suggest that the mine, smelter, and recent construction activities, especially on lands reclaimed from former tailings ponds, could be contributing to atmospheric dust containing high levels of heavy metals and exacerbating asthma outcomes for residents. However, the methods used in the study with aggregated health outcome data cannot determine causal links between the heavy metal contents of soil and health outcomes; they can only point to potential links and a need for further investigation. Such further investigation should involve individual-level data and control for potential confounding factors, such as socioeconomic status, access to healthcare, and lifestyle factors, to isolate the effect of metal exposures on asthma outcomes. This study focused on atmospheric deposition as a source of heavy metal enrichment of topsoil. However, future research is also essential to assess levels of heavy metals in subsoil parent materials and local surface and groundwaters to be able to assess the links between the sources or methods of soil contamination and health outcomes.

Environmental Impacts of the Bingham Canyon Mine

Mining and extraction have spurred economic growth in recent years but have also led to ecological damage. This research explores the environmental impacts of the Bingham Mine, in Utah, USA, by processing remote sensing satellite data to portray changes in the surrounding environment. The method utilizes the NDVI to visualize changes in vegetation cover. This research found that the Bingham Mine’s mining activities have significantly impacted the surrounding environment, necessitating a collective effort for restoration. Pollution mitigation and active restoration efforts are proposed solutions. Revegetation may involve assessing suitable plant species, soil remediation, and establishing native or non-invasive vegetation to support future ecological communities. The local Utah government should prioritize monitoring the mine’s operations to ensure compliance with environmental regulations, including proper waste disposal, wastewater treatment, and pollution reduction. This paper seeks to highlight the lesser-known impacts of mining activities, and then suggest possible solutions to achieve more sustainable means of extraction.

Thinking Like a Copper Mine: An Ecological Approach to Corporate Ethos and Prosōpon

ABSTRACT This essay uses Aldo Leopold’s essay “Thinking Like a Mountain” as a heuristic for analyzing the rhetorical processes of erasure that have created one of the largest open pit copper mines on the planet: The Bingham Canyon Mine (BCM). Contributing to studies of corporate rhetoric, persona criticism, and nonhuman agencies, I argue that the BCM, and its corporate owner Rio Tinto, is characteristic of Being-in-the-Anthropocene and informs rhetoricians about our extra-human ethos, or manner of dwelling, as an entwinement with corporate actors. Taking Rio Tinto as a synecdoche for corporate personhood and persona (prosōpon), I make the case for an ecological approach to corporate disclosedness that accounts for the earthly resources of corporate rhetorical invention (e.g., copper). Through the later work of Martin Heidegger, I show how the BCM has become a standing reserve within a corporate world picture that is rhetorically apparent in the rhetorical architecture of Salt Lake City, Utah.

Unexpected Landscapes. Wastelands as ‘buffer zones’ for the future

Mining operations at Bingham Canyon Mine, Utah, 2009 by Arbyreed. License: CC BY-NC-SA 2.0 Land worldwide is deeply marked by human activity, which became heavier, harder, more wasteful, and permanent after the industrial revolution. The landscapes of the Anthropocene encompass riddled proving ground and test sites, nuclear wastelands, immense open-pit mines, contaminated lands, disappearing bodies of water, boundless landfills, and discarded territories. These grounds are the landscapes of growth, production, and destruction: the sceneries where the show of quarrying, discharge, stockpile, abandonment, drainage, and burial is staged. However, this rush to exhaustion is giving shape to the landscape of tomorrow: the examination of unforeseen uses and values attributed in the current age to some of these ‘sceneries of consumption’ – the Bingham Canyon Mine near Salt Lake City; the former Fresh Kills landfill in New York; the decommissioned Templehof Airport in Berlin– suggest they may play unpredictable cultural and strategic roles in the next future.

Metal(loid) Deportment in Sulfides from the High-Grade Core of the Bingham Canyon Porphyry Cu-Mo-Au Deposit, Utah

Abstract Porphyry deposits supply the bulk of the world’s Cu and Mo and significant amounts of Au, as well as other minor and trace metal(loid)s, including Ag, Re, Te, Pd, Se, Bi, Zn, and Pb. Porphyry deposits are gaining in importance as a source of critical raw materials with the increasing global demand for these commodities. To date, minor and trace metal(loid)s are still commonly recovered as by-products from porphyry ores without prior characterization of their host mineralogy that could inform more efficient processing and improved recoveries. We report a comprehensive metal(loid) deportment study on a complete vein paragenetic series in samples from the northwestern high-grade zone of the Bingham Canyon Cu-Mo-Au porphyry deposit, Utah. The polyphase Bingham stock comprises an early premineralization equigranular monzonite phase that was intruded by a series of five successive, ore-related porphyry intrusions. Veins with hypogene Cu-(Fe) sulfide assemblages from all five porphyry intrusions were characterized for their trace metal(loid) contents by laser ablation-inductively coupled-mass spectrometry (LA-ICP-MS). It was found that bornite and digenite contain elevated Bi, Ag, Te, and Se relative to chalcopyrite, whereas the latter contains elevated concentrations of Co, Ga, and In. A stepwise decline in sulfide abundance occurs over the porphyry intrusion sequence and is more pronounced in digenite and bornite than in chalcopyrite. The related diminishing concentration per rock volume (inventory) of Bi, Ag, Te, and Se in the youngest porphyry dikes could have been caused in part by a geochemical change in the mineralizing fluid supply across successive intrusive-hydrothermal cycles. Element mapping of exsolved digenite within bornite revealed characterstic partitioning of metal(loid)s between bornite and digenite; most notably Ag, but also Te and Au are enriched in digenite relative to enclosing bornite. Bornite domains within these composite grains reveal complex zonation of Sn, In, and Bi, which are attributed to stress-induced diffusion within bornite, resulting from the digenite exsolution process. The selective partitioning of metal(loid)s between bornite and digenite is likely a common feature in many porphyry Cu deposits, given the fundamental mineralogical characteristics of these two sulfides. Our results contribute to an improved understanding of the distribution (from mineral to deposit scale) of critical trace metal(loid)s in porphyry deposits, particularly those containing exsolved digenite. This knowledge can be applied to determine more accurately the value of ore resources, to improve geometallurgical models and by-product recoveries, and to help limit the environmental effects of metal(loid) dispersion.

Polygamous Family Life and Geographic Isolation: The Poetry of Esther Ann Birch Bennion

Polygamous Family Life and Geographic Isolation: The Poetry of Esther Ann Birch Bennion

Industrial Pioneerism in the Beehive State: Rio Tinto and the Corporate Persona

Contributing to organizational rhetoric, environmental communication, and persona criticism, this paper offers the corporate persona as a heuristic for mapping the rhetorical forces of corporate rhetors in a networked era of rhetoric and subjectivity. Giving the rhetor presence where there is absence, the corporate persona is a single image of a multiple subject implied by discursive and extra-discursive networks. I show how mining giant Rio Tinto Kennecott (RTK), which owns the Bingham Canyon Copper Mine outside of Salt Lake City, uses places, spaces, and objects—including a visitor’s center, a suburban community, a soccer stadium, and a natural history museum—to create a pioneer persona that is tied to cultural memories of the Utah Deseret. RTK’s persona is illustrative of how corporations are networked subjects that can adapt their very selfhoods to meet different exigencies while evading singular responsibilities.

Stress Perturbations From Hydrological and Industrial Loads and Seismicity in the Salt Lake City Region

AbstractThe interconnection between anthropogenic and natural surface loads and seismicity continues to be poorly understood. The metropolitan Salt Lake City in Utah hosts various industrial, hydrological, and tectonic processes, including the Bingham Canyon mine and its associated tailings facility, precipitation and water storage at the surface and in aquifers, as well as the seismically active Wasatch Fault Zone. The March 18, 2020 M5.7 Magna earthquake occurred east of a mine tailings impoundment that receives ∼60 million tons/yr of ore waste products since the early 1900s. Here we investigate the spatiotemporal elastic stress changes due to anthropogenic mass transfer and natural hydrological loading and unloading. Two local earthquake clusters host persistent microseismicity and the 2020 M5.7 Magna earthquake sequence. The amplitude and sign of the computed Coulomb stress changes at seismogenic depths strongly vary with the receiver fault geometry, the frictional coefficient, and the location, and can reach tens of kPa and ∼1 kPa/yr due to the tailings loads, a substantial fraction of background tectonic loading. The long‐term and seasonal stress changes from regional hydrological processes are only up to a few kPa. A lack of statistically significant seasonality in seismicity across Utah suggests a weak control by cyclic hydrological loads. Explicit knowledge of the fault architecture is essential to allow for seismic hazard assessment considering external stress loading.

The Role of Satellite InSAR for Landslide Forecasting: Limitations and Openings

The paper explores the potential of the satellite advanced differential synthetic aperture radar interferometry (A-DInSAR) technique for the identification of impending slope failure. The advantages and limitations of satellite InSAR in monitoring pre-failure landslide behaviour are addressed in five different case histories back-analysed using data acquired by different satellite missions: Montescaglioso landslide (2013, Italy), Scillato landslide (2015, Italy), Bingham Canyon Mine landslide (2013, UT, USA), Big Sur landslide (2017, CA, USA) and Xinmo landslide (2017, China). This paper aimed at providing a contribution to improve the knowledge within the subject area of landslide forecasting using monitoring data, in particular exploring the suitability of satellite InSAR for spatial and temporal prediction of large landslides. The study confirmed that satellite InSAR can be successful in the early detection of slopes prone to collapse; its limitations due to phase aliasing and low sampling frequency are also underlined. According to the results, we propose a novel landslide predictability classification discerning five different levels of predictability by satellite InSAR. Finally, the big step forward made for landslide forecasting applications since the beginning of the first SAR systems (ERS and Envisat) is shown, highlighting that future perspectives are encouraging thanks to the expected improvement of upcoming satellite missions that could highly increase the capability to monitor landslides’ pre-failure behaviour.

Petrochronology of hydrothermal rutile in mineralized porphyry Cu systems

Hydrothermally formed rutile is a common mineral in porphyry Cu (-Au-Mo) deposits and has the potential to provide versatile information about the physical-chemical conditions and timing of mineralization. In this study, we investigated the trace element composition and U-Pb dates of hydrothermal rutile by LA-ICP-MS together with its petrographic context, in four well-studied porphyry systems: Batu Hijau (Indonesia), Bingham Canyon (USA), El Salvador (Chile) and Northparkes (Australia). A similar sequence of rutile generations occupying comparable textural positions was found to be common to all investigated deposits. We particularly focused on the most common rutile generation that is formed by the breakdown of biotite and temporally closely associated with mineralization as demonstrated by intergrowth relationships between individual, blocky rutile grains and Cu-Fe sulfides as well as cathodoluminescence imaging of mineralized quartz veins. Compositionally, rutile shows large trace element variations within and among the porphyry deposits, indicating that the compositions of both the local host rock and the fluid phase influence that of hydrothermal rutile. In comparison with non-hydrothermal rutile of various petrogenetic origins, rutile from porphyry Cu deposits show characteristic differences regarding their Sn, W, Si and Fe concentrations, indicating that rutile might be used to fingerprint porphyry-style mineralization. Due to its temporal link to Cu mineralization, texturally controlled in-situ U-Pb dating of blocky rutile grains by LA-ICP-MS provides the possibility to directly determine the absolute timing of Cu mineralization. Despite variable incorporation of initial Pb in the investigated hydrothermal rutile, we obtained robust lower intercept U-Pb dates that overlap within uncertainty with previously obtained mineralization ages for all four deposits, including those based on high-precision (ID-TIMS) zircon dating of bracketing porphyry intrusions. This demonstrates that rutile can be used to accurately predict the age of porphyry Cu deposit formation and with a precision better than 1.5% relative for deposits older than ca. 10 million years.

Assessment of the Available Historic RADARSAT-2 Synthetic Aperture Radar Data Prior to the Manefay Slide at the Bingham Canyon Mine Using Modern InSAR Techniques

Assessment of the Available Historic RADARSAT-2 Synthetic Aperture Radar Data Prior to the Manefay Slide at the Bingham Canyon Mine Using Modern InSAR Techniques

Copper-mineralised porphyries sample the evolution of a large-volume silicic magma reservoir from rapid assembly to solidification

Volatile-rich intermediate to silicic magmatic systems can feed devastating volcanic eruptions but also generate valuable magmatic-hydrothermal ore deposits that supply most of the world's copper. Understanding the geometry, dynamics and timescales of these magmatic systems is critical in developing models for predicting the occurrence of ore deposits and future large volcanic eruptions. Here, we use zircon petrochronology from an equigranular monzonite and successively emplaced porphyry dykes to reconstruct the time – temperature – composition evolution of the magma that sourced the giant Cu-Mo-Au deposit at Bingham Canyon (USA). Combining high-precision CA-ID-TIMS geochronology with in-situ trace element analyses by LA-ICP-MS shows the intra-grain, inter-sample and temporal geochemical changes recording the evolution of the magmatic system over 817 ± 62 kyr. Systematic variation of zircon chemistry with time indicates crystallisation from a coherent magma reservoir. After reservoir assembly its thermal and chemical state was controlled by protracted monotonous crystallisation over ∼650 kyr with rapid cooling over the first 200 kyr followed by a longer period approaching the granite solidus. Porphyry Cu-Au ore formation occurred after the early drop in magma temperature that resulted in large-scale fluid saturation and expulsion into the sub-volcanic environment but main Mo-mineralisation occurred after protracted low-temperature magma storage and the emplacement of the last porphyry. Zircons do not quantify the depth of this reservoir but integrating independent geophysical evidence with 2-D thermal modelling indicates that the time – temperature evolution recorded by the zircons is consistent with rapid incremental assembly of this large pluton (magma emplacement rate ≳ 0.0065 km3/yr) by initially zircon-undersaturated monzonitic magma into pre-heated upper crust. Our results indicate that massive fluid expulsion from rapidly-formed, large magma reservoirs containing mobile but mushy magma (>40 wt.% melt) can occur in the upper crust, favouring the formation of giant porphyry copper deposits.

Nature and Origin of Zoned Polymetallic (Pb-Zn-Cu-Ag-Au) Veins from the Bingham Canyon Porphyry Cu-Au-Mo Deposit, Utah

Abstract Polymetallic veins (Pb-Zn-Cu-Ag-Au) at the world-class Bingham Canyon, Utah, porphyry Cu-Au-Mo deposit have long been recognized, but poorly understood. They are laterally zoned outward from the center of the porphyry deposit transitioning from Fe-Cu to Pb-Zn-Cu-Ag-Au mineralization. Physical and chemical characterization of these polymetallic veins provide insight into the origin, timing, and controls of ore deposition. These sheared, sulfide-rich, NE/SW- trending veins are dominated by pyrite and multiple generations of quartz, with lesser amounts of other sulfide and gangue minerals. Gold (0.27–4.61 ppm) provides the most value to the ore, though the veins contain substantial Cu and Ag as well. Host rocks include Eocene monzonite and Paleozoic limestone and quartzite—all of which can contain economic ore lodes. Associated alteration is predominantly sericitic and argillic, with mineralization in wall rocks restricted to 1.5 m from the vein margins. Mineral assemblages vary with distance from the center of the main porphyry Cu-Au-Mo deposit and the modal abundances are dependent on the host rock. The appearance of both galena and sphalerite (and tennantite to an extent) occur along a boundary that creates a halo around the center of the associated porphyry deposit. This is accompanied by a shift in metal ratios and an increased concentration of chalcophile trace elements in sulfides from the polymetallic veins as determined by electron microprobe analyses (EMPA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Significant hosts of Ag include galena and tennantite, and Cu is hosted primarily in chalcopyrite, tennantite, and sphalerite. The main host of Au could not be determined, but Au could be focused along fractures or hosted in inclusions found in pyrite. The δ34S values of vein pyrite have a narrow range (2.3–3.4‰) suggestive of a magmatic source, whereas δ18O of quartz is more variable (11.5–14.0‰). These values are similar to several other polymetallic vein deposits associated with porphyry Cu deposits. This can be explained by fractionation of magmatic fluids at lower temperatures (350°–250°C) and/or mixing with exchanged 18O-rich meteoric water. Ore grades (Cu, Ag, Au) improve with distance from the center of the porphyry deposit; however, this is accompanied by higher concentrations of deleterious elements (e.g., Pb, As, Bi) for downstream processing. These polymetallic veins were created sequentially throughout the formation of the deposit. Initial joints in the sedimentary rocks probably formed as a result of emplacement of a barren equigranular monzonite intrusion, with continued dilation and propagation in all host rocks with each subsequent intrusion. The northeast orientation of the joints was controlled by the regional stress field, which is more apparent distal to the center of the Bingham deposit. Vein mineralization appears to postdate all intrusions and the porphyry Cu-Au mineralization; however, it may be related to the late fluids responsible for Mo mineralization in the main porphyry orebody that followed intrusion of the quartz latite porphyry. Quartz-sericite-pyrite mineralization associated with the veins precedes galena-sphalerite-pyrite mineralization. This was followed by late precipitation of chalcopyrite and tennantite and late normal faulting.

Tele-production of miningscapes in the open-pit era: The case of low-grade copper, Bingham Canyon, US and Chuquicamata, Chile (1903–1923)

In 1906, the Guggenheim Exploration Company (GUGGENEX), financed the low-grade copper project that Daniel Cowen Jackling had started three years earlier at Bingham Canyon (Utah, US). With GUGGENEX's investment, the exploitation of copper entered into the open-pit mining era. Nine years later, the Guggenheims applied the industrial experience acquired in Bingham Canyon in the opening of the Chuquicamata Mine (northern Chile). In both cases, all the crucial decisions about the mining were made in Manhattan, New York, while the local territories faced these projects' outcomes. From a geohistorical standpoint, and through the analysis of several archives, in this paper, we explore how the extractive territories associated with these mines were remotely produced, transformed, and redefined; becoming “teleconnected miningscapes”. We aimed to visualize how the cross-sector partnership between large economic groups—GUGGENEX—and scientific personalities was essential in the emergence of open-pit copper mining. We argue that the miningscapes produced in Bingham Canyon and Chuquicamata mines are an entanglement of scientific discourses, research (geology and metallurgy), materialities (capital and technology), human bodies (workers) and nature (copper porphyries, water, air, etc.) that were unevenly and remotely produced from the headquarters of GUGGENEX.

Analyzing high-frequency seismic signals generated during a landslide using source discrepancies between two landslides

High-frequency seismic signals are generated during landslides and can be analyzed to obtain detailed information regarding landslide dynamics. However, a better understanding of the physical process that produces such high-frequency signals is required. The two massive landslides that occurred on April 11, 2013 in the Bingham Canyon Mine pit (Utah, USA) generated low- and high-frequency seismic signals. Using the low-frequency signals, we inverted the force-time functions of the two events and estimated their dynamics. We used the signals generated by the two events and filtered in three frequency bands to obtain the source discrepancies between the two events. By analyzing these source discrepancies, we found that the low- and medium-frequency signals were generated due to the bulk movement of sliding material. Furthermore, the medium-frequency signals contained information regarding small-particle impacts along the sliding path. The high-frequency (1–3 Hz) signals are controlled by small-scale process of sliding materials, and are sum of stochastic phenomena. This clarification of the source of the high-frequency signals is expected to improve the analyses of seismic signals generated during landslides.

Back-Analysis of the Bingham Canyon South Wall: A Quasi-static Complex Slope Movement Mechanism

A 610-m-high portion of the South Wall of the Bingham Canyon open pit has experienced slow-moving slope deformations several times during spring melt until the movement was stabilized approximately 7 years ago. To develop and optimize life of mine slope designs, an understanding of the mechanism(s) and associated material strength parameters, was required. A back-analysis and calibration of the strength parameters for the salient rock mass and structural features was undertaken. The back-analysis consisted of understanding the conditions and trigger for the slope movement and adjusting strength parameters to match available monitoring data (time-domain reflectometer cables, inclinometers, interferometric radar data, etc.). The trigger for the movement was attributed to the spring high-perched water levels in the upper part of the wall. A FLAC3D model was built to back-analyze and capture the complex behavior of the slope during the high deformation period (August 2011). The back-analysis was consistent with the conceptual model and indicated that the slide was composed of mixed mechanisms, namely, a structurally controlled mechanism for the upper wall and a rock mass controlled mechanism for the lower wall (toe). The analysis supported by a converging FLAC3D model, were used to guide mining engineers in developing robust pit design in the South Wall. Today, the O-Slide instability is being fully managed by rigorous monitoring, implementation of a toe buttress, successful dewatering efforts, and unloading of the movement mass as another slice of mining advances down the South Wall.

Life and Labor among the Immigrants of Bingham Canyon

Life and Labor among the Immigrants of Bingham Canyon

Innovative Rockfall Solutions Based on Calibration and Field Testing

Rockfall hazards are ubiquitous in mining environments making their control critical for safe mining operations. The complex processes involved in rockfall events necessitate a probabilistic modeling approach with well-calibrated material properties. The controls designed to mitigate rockfall hazards need to be reliable, efficient, and safe to deploy to meet the constraints present at an active mine. This paper presents an innovative solution to rockfall at Rio Tinto’s Bingham Canyon Mine. The solution incorporates the site-specific calibration and creation of a predictive rockfall model with the design, field testing, implementation, and monitoring of the rockfall controls.

Cargo Porphyry Cu-Au Deposit – Where is the High Grade Core?

The Cargo Copper-Gold Porphyry deposit lies within the world class porphyry belt of the Ordovician Macquarie volcanic arc. It is one of several porphyry complexes in the Lachlan Orogen including Cadia Valley (42.8 MOz Au), Northparkes, Cowal and Copper Hill.The Cargo Porphyry Intrusive Complex is a calc-alkaline suite of late Ordovician age (467 Ma) intrusives comprising quartz monzodiorite and diorite intruded by coeval andesitic and trachy-andesitic volcanics. The most prominent NW trending structural zone is characterised by areas of strong silicification, pyritisation and tectonic brecciation together with stockwork and sheeted quartz veining. It is up to 300 m wide bounded on the southern side by a major 60o SW dipping normal fault and on the Northern side by 75o SW dipping shear zones.Mineralization and alteration is zoned from a western core of fracture controlled, potassic altered porphyry (Cu-Mo-Au) to a peripheral zone of phyllic altered gold rich quartz-sulphide veining up to 200 m wide, surrounded by an outer propylitic zinc rich halo.The peripheral zone of Cargo contains gold rich sheeted quartz veins which hosted 14 small gold workings in the late 1800’s. Two lode systems, Dalcoath and Spur, have JORC inferred resource of 4 Mt @ 1.19g/t gold for 154,000 Oz Au.A classically zoned porphyry Cargo’s geochemical footprint is comparable in size to the famous Bingham Canyon and the Bougainville Panguna deposits despite the fact that Cargo’s porphyry deposits’ western half has been faulted away.

Assessing Thallium Elemental Systematics and Isotope Ratio Variations in Porphyry Ore Systems: A Case Study of the Bingham Canyon District

The Bingham Canyon porphyry deposit is one of the world’s largest Cu-Mo-Au resources. Elevated concentrations of thallium (Tl) compared to average continental crust have been found in some brecciated and igneous samples in this area, which likely result from mobilization of Tl by relatively low temperature hydrothermal fluids. The Tl-enrichment at Bingham Canyon therefore provides an opportunity to investigate if Tl isotope ratios reflect hydrothermal enrichment and whether there are systematic Tl isotope fractionations that could provide an exploration tool. We present a reconnaissance study of nineteen samples spanning a range of lithologies from the Bingham district which were analysed for their Tl content and Tl isotope ratios, reported as parts per ten thousand (ε205Tl) relative to the NIST SRM997 international standard. The range of ε205Tl reported in this study (−16.4 to +7.2) is the largest observed in a hydrothermal ore deposit to date. Unbrecciated samples collected relatively proximal to the Bingham Canyon porphyry system have ε205Tl of −4.2 to +0.9, similar to observations in a previous study of porphyry deposits. This relatively narrow range suggests that high-temperature (>300 °C) hydrothermal alteration does not result in significant Tl isotope fractionation. However, two samples ~3–4 km away from Bingham Canyon have higher ε205Tl values (+1.3 and +7.2), and samples from more distal (~7 km) disseminated gold deposits at Melco and Barneys Canyon display an even wider range in ε205Tl (−16.4 to +6.0). The observation of large positive and negative excursions in ε205Tl relative to the mantle value (ε205Tl = −2.0 ± 1.0) contrasts with previous investigations of hydrothermal systems. Samples displaying the most extreme positive and negative ε205Tl values also contain elevated concentrations of Tl-Sb-As. Furthermore, with the exception of one sample, all of the Tl isotopic anomalies occur in hydrothermal breccia samples. This suggests that ε205Tl excursions are most extreme during the migration of low-temperature hydrothermal fluids potentially related to sediment-hosted gold mineralization. Future investigation to determine the host phase(s) for Tl in breccias displaying both chalcophile element enrichment and ε205Tl excursions can potentially provide new information about hydrothermal fluid composition and could be used to locate sites for future porphyry exploration.