Sarah M. Hayes, Ph.D.
Sarah Hayes is a Research Chemist with the USGS Geology, Energy & Minerals (GEM) Science Center in Reston, VA.
Professional Experience
2016-present: U.S. Geological Survey Research Chemist
2012-2017: University of Alaska Fairbanks Assistant Professor of Chemistry
2010-2012: U.S. Geological Survey Mendenhall Postdoc
Education and Certifications
Ph.D. Soil and Water Science, 2010
M.A. Analytical Chemistry, 2005
B.A. Chemistry, 2003
Science and Products
Bulk Chemistry Data from Alaskan Stoker-Boiler Fly Ash
This dataset contains bulk chemical data for fly ash samples from the Atkinson Heat and Power Plant in Fairbanks, AK and National Institute for Standards and Technology (NIST) Standard Reference Materials (SRM) used for quality assurance and quality control.
Bulk Chemistry and X-ray Diffraction Results from Alaskan Stoker-Boiler Fly Ash
This data release contains the bulk chemistry and x-ray diffraction results of unreacted Alaskan stoker-boiler fly ash. X-ray diffraction results from the solid phase residuals of leaching experiments with the same fly ash are reported. The leaching experiments were performed with either 18 mega-ohm or simulated rainwater for up to 90 days and XRD was performed on solid phase residuals from sacr
X-ray Diffraction Results from Alaskan Stoker-Boiler Fly Ash
This dataset contains X-ray diffraction (XRD) results for coal samples from the Usibelli Coal Mine and fly ash samples from the Atkinson Heat and Power Plant in Fairbanks, AK. Additionally, X-ray diffraction results from the solid phase residuals of leaching experiments with the same fly ash are reported. The leaching experiments were performed with either 18 mgea-ohm or simulated rainwater for
Electron microprobe analyses of sphalerite from Central and East Tennessee mining districts, the Red Dog mining district (AK), and the Metaline mining district (WA)
Electron microprobe analyses of sphalerite (ZnS) were collected on samples from current or past mining operations in the USA with a specific focus on germanium (Ge), a byproduct critical mineral recovered from sphalerite. Data and methods reported are part of a research study published in the 'Related External Resources' section below.
Molecular-scale speciation of germanium and copper within sphalerite from Central Tennessee mining district (TN), Red Dog mining district (AK), and Metaline mining district (WA)
Oxidation state and bonding environment of Ge and Cu in ZnS and Zn mineral concentrates from a variety of sources [Central Tennessee mining district (TN), Metaline mining district, (WA), and Red Dog mine (AK)] were determined by linear combination fits from x-ray absorption spectroscopy (XAS) analysis. Sphalerites from the East Tennessee mining district contained Ge in concentrations that were too
Trace element composition and molecular-scale speciation characterization of sphalerite from Central and East Tennessee mining districts, Red Dog mining district (AK), and Metaline mining district (WA)
Germanium (Ge) is an element deemed critical globally, and used in electronics, communication, and defense applications. The supply of Ge is limited and as demand for it increases, its criticality increases. Germanium is exclusively recovered as a byproduct of either coal mining or zinc (Zn) mining, and the main mineral hosting Ge in Zn deposits is sphalerite (ZnS). However, the mechanisms of Ge e
Mineral abundances within bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Mineral abundances within bulk and size-fractionated mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S.A., were determined by Mineral Liberation Analysis (MLA) and X-Ray Diffraction (XRD). Data and methods reported are part of a research study published below in the 'Related External Resources' section.
Molecular speciation of Ge within sphalerite, hemimorphite, and quartz from mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Oxidation state and bonding environment of Ge in minerals within mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S. were determined by linear combination fits from x-ray absorption near edge spectroscopy (XANES) analysis. Ge content in quartz within these wastes was determined using XANES edge steps, and Ge content in sphalerite was compared using XANE
Elemental concentrations for bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Elemental concentrations for bulk and size-fractionated mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S. were determined after dissolution via acid digests or a sodium peroxide fusion. Elemental concentrations were determined for the leachate from a simulated rainwater leach of mine wastes. Data and methods reported are part of a research study publi
Electron microprobe analyses of sphalerite and hemimorphite from mine wastes from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Electron microprobe analyses of sphalerite (ZnS) and hemimorphite (Zn4Si2O7(OH)2·H2O) from sampled historical waste piles were conducted with a specific focus on germanium (Ge). In mine wastes at the Tar Creek Superfund Site, Oklahoma, USA, Ge is associated with ZnS (sphalerite) as expected, but weathering in the waste piles has led to a significant amount of Ge being incorporated into a zinc-sili
Editorial: Micro-to nano-analytical challenges towards trace element characterization of ore minerals: New perspectives and applications for sustainable georesources
No abstract available.
Authors
Manuel Keith, Sarah M. Hayes, C. L. Ciobanu, D. Fougerouse, M. Reich
A novel non-destructive workflow for examining germanium and co-substituents in ZnS
A suite of complementary techniques was used to examine germanium (Ge), a byproduct critical element, and co-substituent trace elements in ZnS and mine wastes from four mineral districts where germanium is, or has been, produced within the United States. This contribution establishes a comprehensive workflow for characterizing Ge and other trace elements, which captures the full heterogeneity of s
Authors
Sarah M. Hayes, Ryan J. McAleer, Nadine M. Piatak, Sarah Jane White, Robert R. Seal
Behavior of potentially toxic elements from stoker-boiler fly ash in Interior Alaska: Paired batch leaching and solid-phase characterization
Despite significant investigation of fly ash spills and mineralogical controls on the release of potentially toxic elements (PTEs) from fly ash, interactions with the surficial environment remain relatively poorly understood. We conducted 90-day batch leaching studies with paired analysis of supernatant and solid-phase mineralogy to assess the elemental release and transformation of fly ash upon r
Authors
Kyle P Milke, Kiana Mitchell, Sarah M. Hayes, Carlin J. Green, Jennifer Guerard
Germanium redistribution during weathering of Zn mine wastes: Implications for environmental mobility and recovery of a critical mineral
Germanium (Ge) is a metal used in emerging energy technologies, communications, and defense, and has been deemed critical by the United States due to its essential applications and scarce supply. Germanium is recovered as a byproduct of zinc (Zn) sulfides, and mining and processing of these materials lead to waste that could act both as a source of extractable Ge and a source for exposure to human
Authors
Sarah Jane White, Nadine M. Piatak, Ryan J. McAleer, Sarah M. Hayes, Robert R. Seal, Laurel A. Schaider, James P. Shine
Global tellurium supply potential from electrolytic copper refining
The transition towards renewable energy requires increasing quantities of nonfuel mineral commodities, including tellurium used in certain photovoltaics. While demand for tellurium may increase markedly, the potential to increase tellurium supply is not well-understood. In this analysis, we estimate the quantity of tellurium contained in anode slimes generated by electrolytic copper refining by co
Authors
Nedal T. Nassar, Haeyeon Kim, Max Frenzel, Michael S. Moats, Sarah M. Hayes
The role of hydrates, competing chemical constituents, and surface composition on CLNO2 formation
Atomic chlorine (Cl•) affects air quality and atmospheric oxidizing capacity. Nitryl chloride (ClNO2) – a common Cl• source–forms when chloride-containing aerosols react with dinitrogen pentoxide (N2O5). A recent study showed that saline lakebed (playa) dust is an inland source of particulate chloride (Cl–) that generates high ClNO2. However, the underlying physiochemical factors responsible for o
Authors
Haley M. Royer, Dhruv Mitroo, Sarah M. Hayes, Savannah Haas, Kerri A Pratt, Patricia Blackwelder, Thomas E. Gill, Cassandra J. Gaston
The effects of phosphatization on the mineral associations and speciation of Pb in ferromanganese crusts
The older layers of thick ferromanganese (FeMn) crusts from the central Pacific Ocean have undergone diagenetic phosphatization, during which carbonate fluorapatite (CFA) filled fractures and pore space and replaced carbonates. The effects of phosphatization on individual trace metal concentrations, speciation, and phase associations in FeMn crusts remain poorly understood yet may be important to
Authors
Kira Mizell, James R. Hein, Andrea Koschinsky, Sarah M. Hayes
Evaluating the utility of principal component analysis on EDS x-ray maps to determine bulk mineralogy
Due to advances in EDS technology, electron microscopy techniques have become an important tool to determine the relative abundance of mineral phases. However, few studies have directly compared EDS X‐ray mineralogy with traditional techniques for assessing bulk mineralogy and elemental composition. We show that analysing a limited area (~ 0.5–3.2 mm2) of fine‐grained metal extraction samples usin
Authors
Karen Spaleta, Sarah M. Hayes, Rainer Newberry, Nadine M. Piatak
Surficial geochemistry and bioaccessibility of tellurium in semi-arid mine tailings
Tellurium (Te) is a critical element due to its use in solar technology. However, some forms are highly toxic. Few studies have examined Te behavior in the surficial environment, thus little is known about its potential human and environmental health impacts. This study characterizes two physicochemically distinct Te-enriched mine tailings piles (big and flat tailings) deposited by historic gold
Authors
Sarah M. Hayes, Nicole A Ramos
Critical minerals: A review of elemental trends in comprehensive criticality studies
Mineral criticality is a subjective concept that has evolved throughout history. An abundance of literature on this topic has been published over the last decade, encompassing a variety of criteria and methodologies. To our knowledge, this work is the first large-scale effort to organize and analyze recent comprehensive criticality studies in order to determine if a consensus exists within the glo
Authors
Sarah M. Hayes, Erin A. McCullough
Non-USGS Publications**
Hayes, SM. 2018. Chapter 16: Engaging Early-Career Students in Research using a Tiered Mentoring Model. In: Best Practices for Supporting and Expanding Undergraduate Research in Chemistry. Gourley, B.; Jones, R., eds. ACS Publications: Washington, DC. pp 273-289. DOI: 10.1021/bk-2018-1275.ch016
Guerard, J. J.; Hayes, SM. 2018. Chapter 1: Introduction to Environmental Science of the Arctic: An Introductory, Lab-Based, Distance and On-Campus Course. In: Environmental Chemistry: Undergraduate & Graduate Classroom, Laboratory & Local Community Learning Experiences. Roberts-Kirchoff, E.; Benvenuto, M., eds. ACS Publications: Washington, DC. pp 1-19. DOI: 10.1021/bk-2018-1276.ch001
Emery, D.; Iceman, CR; Hayes, SM. 2018. Geographic variability of active ingredients in Spice within Alaska as an indicator of mechanisms of distribution and manufacture. Journal of Young Investigators. 34 (4), 11-20. doi: 10.22186/jyi.31.5.32-38
Knight, DC; Knight, NA; Chris R. Iceman, CR; Hayes, SM. 2017. Are Unpaved Road Dusts Near Fairbanks, Alaska a Health Concern? Examination of the Total and Bioaccessible Metal(loid)s. Journal of Young Investigators. 33 (1), 7-17. doi:10.22186/jyi.33.1.7-17
Root, RR; Hayes, SM; Hammond, C; Maier, RM; Chorover, J. 2015. Toxic metal(loid) speciation during weathering of iron sulfide mine tailings under semi-arid climate. Applied Geochemistry Special Issue to Honor the Geochemical Contributions of D. Kirk Nordstrom. 62, 131-149.
Hayes, SM; Root, RR; Perdrial, N; Maier, RM; Chorover, J. 2014. Surficial weathering of iron sulfide mine tailings under semi-arid climate. Geochimica et Cosmochimica Acta. 141, 240-257.
Hayes, SM; Webb, SM; Bargar, J; Chorover, J. 2012. Spectroscopic investigation of lead speciation in sulfate dominated arid mine tailings in Aravaipa Canyon, Arizona. Environmental Science and Technology. 46 (11), 5834-5841.
Hayes, SM; O’Day, PA; Webb, SM; Maier, RM; Chorover, J. 2011. Changes in zinc speciation with mine tailings acidification in a semi-arid weathering environment. Environmental Science and Technology. 45 (17), 7166-7172.
Hayes, SM. 2010. Effects of mineral weathering and plant roots on contaminant metal speciation and lability in arid lead-zinc sulfide mine tailings at the Klondyke Superfund Site, Graham County, AZ. Ph.D. Thesis, University of Arizona.
Hayes, SM; White, SA; Thompson, TL; Maier, RM; Chorover, J. 2009. Changes in lead and zinc lability during weathering-induced acidification of desert mine tailings: Coupling chemical and micro-scale analyses. Applied Geochemistry, 24, 2234-2245.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Data
Bulk Chemistry Data from Alaskan Stoker-Boiler Fly Ash
This dataset contains bulk chemical data for fly ash samples from the Atkinson Heat and Power Plant in Fairbanks, AK and National Institute for Standards and Technology (NIST) Standard Reference Materials (SRM) used for quality assurance and quality control.Bulk Chemistry and X-ray Diffraction Results from Alaskan Stoker-Boiler Fly Ash
This data release contains the bulk chemistry and x-ray diffraction results of unreacted Alaskan stoker-boiler fly ash. X-ray diffraction results from the solid phase residuals of leaching experiments with the same fly ash are reported. The leaching experiments were performed with either 18 mega-ohm or simulated rainwater for up to 90 days and XRD was performed on solid phase residuals from sacrX-ray Diffraction Results from Alaskan Stoker-Boiler Fly Ash
This dataset contains X-ray diffraction (XRD) results for coal samples from the Usibelli Coal Mine and fly ash samples from the Atkinson Heat and Power Plant in Fairbanks, AK. Additionally, X-ray diffraction results from the solid phase residuals of leaching experiments with the same fly ash are reported. The leaching experiments were performed with either 18 mgea-ohm or simulated rainwater forElectron microprobe analyses of sphalerite from Central and East Tennessee mining districts, the Red Dog mining district (AK), and the Metaline mining district (WA)
Electron microprobe analyses of sphalerite (ZnS) were collected on samples from current or past mining operations in the USA with a specific focus on germanium (Ge), a byproduct critical mineral recovered from sphalerite. Data and methods reported are part of a research study published in the 'Related External Resources' section below.Molecular-scale speciation of germanium and copper within sphalerite from Central Tennessee mining district (TN), Red Dog mining district (AK), and Metaline mining district (WA)
Oxidation state and bonding environment of Ge and Cu in ZnS and Zn mineral concentrates from a variety of sources [Central Tennessee mining district (TN), Metaline mining district, (WA), and Red Dog mine (AK)] were determined by linear combination fits from x-ray absorption spectroscopy (XAS) analysis. Sphalerites from the East Tennessee mining district contained Ge in concentrations that were tooTrace element composition and molecular-scale speciation characterization of sphalerite from Central and East Tennessee mining districts, Red Dog mining district (AK), and Metaline mining district (WA)
Germanium (Ge) is an element deemed critical globally, and used in electronics, communication, and defense applications. The supply of Ge is limited and as demand for it increases, its criticality increases. Germanium is exclusively recovered as a byproduct of either coal mining or zinc (Zn) mining, and the main mineral hosting Ge in Zn deposits is sphalerite (ZnS). However, the mechanisms of Ge eMineral abundances within bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Mineral abundances within bulk and size-fractionated mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S.A., were determined by Mineral Liberation Analysis (MLA) and X-Ray Diffraction (XRD). Data and methods reported are part of a research study published below in the 'Related External Resources' section.Molecular speciation of Ge within sphalerite, hemimorphite, and quartz from mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Oxidation state and bonding environment of Ge in minerals within mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S. were determined by linear combination fits from x-ray absorption near edge spectroscopy (XANES) analysis. Ge content in quartz within these wastes was determined using XANES edge steps, and Ge content in sphalerite was compared using XANEElemental concentrations for bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Elemental concentrations for bulk and size-fractionated mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S. were determined after dissolution via acid digests or a sodium peroxide fusion. Elemental concentrations were determined for the leachate from a simulated rainwater leach of mine wastes. Data and methods reported are part of a research study publiElectron microprobe analyses of sphalerite and hemimorphite from mine wastes from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Electron microprobe analyses of sphalerite (ZnS) and hemimorphite (Zn4Si2O7(OH)2·H2O) from sampled historical waste piles were conducted with a specific focus on germanium (Ge). In mine wastes at the Tar Creek Superfund Site, Oklahoma, USA, Ge is associated with ZnS (sphalerite) as expected, but weathering in the waste piles has led to a significant amount of Ge being incorporated into a zinc-sili - Publications
Editorial: Micro-to nano-analytical challenges towards trace element characterization of ore minerals: New perspectives and applications for sustainable georesources
No abstract available.AuthorsManuel Keith, Sarah M. Hayes, C. L. Ciobanu, D. Fougerouse, M. ReichA novel non-destructive workflow for examining germanium and co-substituents in ZnS
A suite of complementary techniques was used to examine germanium (Ge), a byproduct critical element, and co-substituent trace elements in ZnS and mine wastes from four mineral districts where germanium is, or has been, produced within the United States. This contribution establishes a comprehensive workflow for characterizing Ge and other trace elements, which captures the full heterogeneity of sAuthorsSarah M. Hayes, Ryan J. McAleer, Nadine M. Piatak, Sarah Jane White, Robert R. SealBehavior of potentially toxic elements from stoker-boiler fly ash in Interior Alaska: Paired batch leaching and solid-phase characterization
Despite significant investigation of fly ash spills and mineralogical controls on the release of potentially toxic elements (PTEs) from fly ash, interactions with the surficial environment remain relatively poorly understood. We conducted 90-day batch leaching studies with paired analysis of supernatant and solid-phase mineralogy to assess the elemental release and transformation of fly ash upon rAuthorsKyle P Milke, Kiana Mitchell, Sarah M. Hayes, Carlin J. Green, Jennifer GuerardGermanium redistribution during weathering of Zn mine wastes: Implications for environmental mobility and recovery of a critical mineral
Germanium (Ge) is a metal used in emerging energy technologies, communications, and defense, and has been deemed critical by the United States due to its essential applications and scarce supply. Germanium is recovered as a byproduct of zinc (Zn) sulfides, and mining and processing of these materials lead to waste that could act both as a source of extractable Ge and a source for exposure to humanAuthorsSarah Jane White, Nadine M. Piatak, Ryan J. McAleer, Sarah M. Hayes, Robert R. Seal, Laurel A. Schaider, James P. ShineGlobal tellurium supply potential from electrolytic copper refining
The transition towards renewable energy requires increasing quantities of nonfuel mineral commodities, including tellurium used in certain photovoltaics. While demand for tellurium may increase markedly, the potential to increase tellurium supply is not well-understood. In this analysis, we estimate the quantity of tellurium contained in anode slimes generated by electrolytic copper refining by coAuthorsNedal T. Nassar, Haeyeon Kim, Max Frenzel, Michael S. Moats, Sarah M. HayesThe role of hydrates, competing chemical constituents, and surface composition on CLNO2 formation
Atomic chlorine (Cl•) affects air quality and atmospheric oxidizing capacity. Nitryl chloride (ClNO2) – a common Cl• source–forms when chloride-containing aerosols react with dinitrogen pentoxide (N2O5). A recent study showed that saline lakebed (playa) dust is an inland source of particulate chloride (Cl–) that generates high ClNO2. However, the underlying physiochemical factors responsible for oAuthorsHaley M. Royer, Dhruv Mitroo, Sarah M. Hayes, Savannah Haas, Kerri A Pratt, Patricia Blackwelder, Thomas E. Gill, Cassandra J. GastonThe effects of phosphatization on the mineral associations and speciation of Pb in ferromanganese crusts
The older layers of thick ferromanganese (FeMn) crusts from the central Pacific Ocean have undergone diagenetic phosphatization, during which carbonate fluorapatite (CFA) filled fractures and pore space and replaced carbonates. The effects of phosphatization on individual trace metal concentrations, speciation, and phase associations in FeMn crusts remain poorly understood yet may be important toAuthorsKira Mizell, James R. Hein, Andrea Koschinsky, Sarah M. HayesEvaluating the utility of principal component analysis on EDS x-ray maps to determine bulk mineralogy
Due to advances in EDS technology, electron microscopy techniques have become an important tool to determine the relative abundance of mineral phases. However, few studies have directly compared EDS X‐ray mineralogy with traditional techniques for assessing bulk mineralogy and elemental composition. We show that analysing a limited area (~ 0.5–3.2 mm2) of fine‐grained metal extraction samples usinAuthorsKaren Spaleta, Sarah M. Hayes, Rainer Newberry, Nadine M. PiatakSurficial geochemistry and bioaccessibility of tellurium in semi-arid mine tailings
Tellurium (Te) is a critical element due to its use in solar technology. However, some forms are highly toxic. Few studies have examined Te behavior in the surficial environment, thus little is known about its potential human and environmental health impacts. This study characterizes two physicochemically distinct Te-enriched mine tailings piles (big and flat tailings) deposited by historic goldAuthorsSarah M. Hayes, Nicole A RamosCritical minerals: A review of elemental trends in comprehensive criticality studies
Mineral criticality is a subjective concept that has evolved throughout history. An abundance of literature on this topic has been published over the last decade, encompassing a variety of criteria and methodologies. To our knowledge, this work is the first large-scale effort to organize and analyze recent comprehensive criticality studies in order to determine if a consensus exists within the gloAuthorsSarah M. Hayes, Erin A. McCulloughNon-USGS Publications**
Hayes, SM. 2018. Chapter 16: Engaging Early-Career Students in Research using a Tiered Mentoring Model. In: Best Practices for Supporting and Expanding Undergraduate Research in Chemistry. Gourley, B.; Jones, R., eds. ACS Publications: Washington, DC. pp 273-289. DOI: 10.1021/bk-2018-1275.ch016Guerard, J. J.; Hayes, SM. 2018. Chapter 1: Introduction to Environmental Science of the Arctic: An Introductory, Lab-Based, Distance and On-Campus Course. In: Environmental Chemistry: Undergraduate & Graduate Classroom, Laboratory & Local Community Learning Experiences. Roberts-Kirchoff, E.; Benvenuto, M., eds. ACS Publications: Washington, DC. pp 1-19. DOI: 10.1021/bk-2018-1276.ch001Emery, D.; Iceman, CR; Hayes, SM. 2018. Geographic variability of active ingredients in Spice within Alaska as an indicator of mechanisms of distribution and manufacture. Journal of Young Investigators. 34 (4), 11-20. doi: 10.22186/jyi.31.5.32-38Knight, DC; Knight, NA; Chris R. Iceman, CR; Hayes, SM. 2017. Are Unpaved Road Dusts Near Fairbanks, Alaska a Health Concern? Examination of the Total and Bioaccessible Metal(loid)s. Journal of Young Investigators. 33 (1), 7-17. doi:10.22186/jyi.33.1.7-17
Root, RR; Hayes, SM; Hammond, C; Maier, RM; Chorover, J. 2015. Toxic metal(loid) speciation during weathering of iron sulfide mine tailings under semi-arid climate. Applied Geochemistry Special Issue to Honor the Geochemical Contributions of D. Kirk Nordstrom. 62, 131-149.Hayes, SM; Root, RR; Perdrial, N; Maier, RM; Chorover, J. 2014. Surficial weathering of iron sulfide mine tailings under semi-arid climate. Geochimica et Cosmochimica Acta. 141, 240-257.Hayes, SM; Webb, SM; Bargar, J; Chorover, J. 2012. Spectroscopic investigation of lead speciation in sulfate dominated arid mine tailings in Aravaipa Canyon, Arizona. Environmental Science and Technology. 46 (11), 5834-5841.Hayes, SM; O’Day, PA; Webb, SM; Maier, RM; Chorover, J. 2011. Changes in zinc speciation with mine tailings acidification in a semi-arid weathering environment. Environmental Science and Technology. 45 (17), 7166-7172.Hayes, SM. 2010. Effects of mineral weathering and plant roots on contaminant metal speciation and lability in arid lead-zinc sulfide mine tailings at the Klondyke Superfund Site, Graham County, AZ. Ph.D. Thesis, University of Arizona.Hayes, SM; White, SA; Thompson, TL; Maier, RM; Chorover, J. 2009. Changes in lead and zinc lability during weathering-induced acidification of desert mine tailings: Coupling chemical and micro-scale analyses. Applied Geochemistry, 24, 2234-2245.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.