Prepared in cooperation with the Bureau of Land Management

Review of Samples of Tailings, Soils, and Stream 

Sediments Adjacent to and Downstream from the Ruth 

Mine, Inyo County, California

By James J. Rytuba, Christopher S. Kim, and Daniel N. Goldstein

Open-File Report 2011-1105

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2011

For more information on the USGS—the Federal source for science about the Earth,

its natural and living resources, natural hazards, and the environment:

World Wide Web: http://www.usgs.gov

Telephone: 1-888-ASK-USGS

Suggested citation:

Rytuba, J.J., Kim, C.S. and Goldstein, D.N., 2011, Review of samples of tailings, soils and stream sediment adjacent 

to and downstream from the Ruth Mine, Inyo County, California: U.S. Geological Survey Open-File Report 2011-1105, 

38 p. [ht tp://pubs.usgs.gov/of/2011/1105/].

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. 

Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted material contained within this report.
iii

Contents

Abbreviations, definitions, and datum used .................................................................................................................... v

Introduction.................................................................................................................................................................... 1

Background and Objectives ....................................................................................................................................... 1

Mining History and Geology....................................................................................................................................... 2

Sample Locations and Methods .................................................................................................................................... 2

Sample Locations and Conditions.............................................................................................................................. 2

Field Sampling Methods............................................................................................................................................. 2

Tailings, Soils and Sediments ................................................................................................................................ 2

Analytical Methods......................................................................................................................................................... 3

Soils and Tailings....................................................................................................................................................... 3

Extended X-ray Absorption Fine Structure (EXAFS) Spectroscopy ........................................................................... 3

Results........................................................................................................................................................................... 4

Tailings and Waste Rock at the Ruth Mine ................................................................................................................ 4

Speciation of Arsenic in Tailings ................................................................................................................................ 5

Conclusions................................................................................................................................................................... 5

Acknowledgments ......................................................................................................................................................... 6

References Cited........................................................................................................................................................... 7

Figures

1. Location map of the Ruth gold mine in the western Mojave Desert. Gold mines are shown by yellow 

squares and mercury (Hg) mines are shown by red squares...................................................................................19

2. Generalized geologic map showing location of volcanic fields and associated Au-Ag deposits, including 

the Ruth Mine Au deposit in the western part of the Mojave desert, Inyo County, California...................................20

3. Overview of the Ruth Gold Mine and mill site, Inyo County, California. ...................................................................21

4. Soil sample sites noted by a BK prefix were collected adjacent to the Ruth Mine to assess contamination

of soils by the Ruth tailings ......................................................................................................................................22

5. Central part of Homewood Canyon downstream from the Ruth Mine......................................................................23

6. Mine and mill workings at the Ruth Mine and tailings piles that are being eroded into the unnamed wash in 

Homewood Canyon. ................................................................................................................................................24

7. Mine building maintained and used by visitors to the Ruth Mine and recreation area with picnic tables..................25

8. Central part of dry wash in Homewood Canyon with tailings exposed in bank eroded from old road and 

deposited on the north (left) side of the wash (brown sediment)..............................................................................26

9. Tailings used in construction of the old road in the central part of Homewood Canyon...........................................27

10. Tailings in bank deposits in the wash located in the lower part of Homewood Canyon, sample site T11 

shown in figure 3......................................................................................................................................................28

11. Enrichment of As in surface background soil sample as compared to subsurface soil at the same sample 

sites in the Ruth mine area. .....................................................................................................................................29

12. Arsenic concentrations from stream sediment collected in the center of the active channel of the dry 

wash passing through Homewood Canyon in the Ruth Mine area ..........................................................................30

13. Distribution of mass in 8 size fractions of tailings produced by dry sieving, Ruth Mine area. ...............................31
iv

14. Concentration of As in tailings increases with decreasing grain size to the S8 size fraction, Ruth Mine, 

Inyo County, California. ...........................................................................................................................................32

15. Box plot of As concentration in tailings at the Ruth Mine, sediment and pre-mining sediment downstream 

from the mine, and surface soil, 0-2 inch depth, and subsurface soil, 2-6 inch depth in the area of the Ruth 

Mine.........................................................................................................................................................................33

16. EXAFS raw spectra (black) and linear combination fits (red) for size fractions of the RMS03C sample, 

specifically the A, S5, B, S7, and C, S9 size fractions .............................................................................................34

17. Micro x-ray fluorescence intensity maps of As (A ) and Fe (B) in tailings from the Ruth Mine, and a tricolor fluorescence map (C) showing relative concentrations of As, Ca, and Fe ......................................................35

18. Correlation plot of As and Fe shows three distinct populations (A ) numbered 1-3 based on X-ray 

fluorescence analysis of the S7 size fraction of the Ruth Mine tailings (B). Each of the three populations 

map to different As-enriched locations with variable As:Fe ratios (C, D, and E, representing populations 1, 

2, and 3, respectively)..............................................................................................................................................36

19. Arsenic-Iron correlations for four different size fractions of Ruth Mine tailings. A , S5 (250 μm–500 μm), 

B, S6 (125 μm–250 μm), C, S7 (75 μm–125 μm), and D, S8 (45 μm–75 μm). .....................................................37

20. Color contour map of As concentration in stream sediment and soil samples from the NURE sample set...........38

Tables

1. Sample locations and notes from Ruth Mine, Inyo County, California. ...................................................................... 9

2. CHEMEX data for background soils, tailings, and sediment from the Ruth Mine site. ............................................12

3. Concentration of elements in sieved size fractions of tailings sample from Ruth Mine. ..........................................15

4. Enrichment of As and Zn in surface-soil samples compared to subsurface concentrations at Ruth Mine, 

Inyo County, California. ...........................................................................................................................................17

5. Arsenic speciation determined by EXAFS spectroscopy for selected grain size fractions of Ruth Mine 

tailings. ....................................................................................................................................................................18
v

Abbreviations, definitions, and datum used

Vertical and horizontal coordinate information is referenced to the North American Datum of 1927 (NAD 27 CONUS).

As, generic shorthand for arsenic; does not denote speciation.

DOC, dissolved organic carbon

DOM, dissolved organic matter

EE/CA, Engineering evaluation/cost analysis for “non-time-critical removal actions,” as defined by the U.S. Environmental 

Protection Agency’s Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).

EXAFS, Extended X-ray Absorption Fine Structure Spectroscopy

Hg, generic shorthand for mercury; does not denote speciation.

HgT,

Hg

total mercury (inorganic plus organic).

F,

MMHg, monomethyl mercury, methylmercury, and monomethylmercury (CH

total mercury (inorganic plus organic) in a filtered sample (either 0.1 m or 0.45 m, as specified in the text).

3Hg+

ng/kg, nanogram per kilogram, equivalent to one (1) part per trillion.

) 

ng/L, nanogram per liter, approximately equivalent to one (1) part per trillion.

ppm, parts per million, equivalent to mg/kg or μg/g.

SC, specific (electrical) conductivity, reported in units of millisiemens per centimeter (mS/cm).
Review of Samples of Tailings, Soils, and Stream 

Sediments Adjacent to and Downstream from the 

Ruth Mine, Inyo County, California

By James J. Rytuba1, Christopher S. Kim2, and Daniel N. Goldstein1

Introduction

Background and Objectives

The Ruth Mine and mill are located in the western Mojave Desert in Inyo County, 

California (fig. 1). The mill processed gold-silver (Au-Ag) ores mined from the Ruth AuAg deposit, which is adjacent to the mill site. The Ruth Au-Ag deposit is hosted in 

Mesozoic intrusive rocks and is similar to other Au-Ag deposits in the western Mojave 

Desert that are associated with Miocene volcanic centers that formed on a basement of 

Mesozoic granitic rocks (Bateman, 1907; Gardner, 1954; Rytuba, 1996). The volcanic 

rocks consist of silicic domes and associated flows, pyroclastic rocks, and subvolcanic 

intrusions (fig. 2) that were emplaced into Mesozoic silicic intrusive rocks (Troxel and 

Morton, 1962). The Ruth Mine is on Federal land managed by the U.S. Bureau of Land 

Management (BLM). Tailings from the mine have been eroded and transported 

downstream into Homewood Canyon and then into Searles Valley (figs. 3, 4, 5, and 6). 

The BLM provided recreational facilities at the mine site for day-use hikers and restored 

and maintained the original mine buildings in collaboration with local citizen groups for 

use by visitors (fig. 7). The BLM requested that the U.S. Geological Survey (USGS), in 

collaboration with Chapman University, measure arsenic (As) and other geochemical 

constituents in soils and tailings at the mine site and in stream sediments downstream 

from the mine in Homewood Canyon and in Searles Valley (fig. 3). The request was 

made because initial sampling of the site by BLM staff indicated high concentrations of 

As in tailings and soils adjacent to the Ruth Mine.

This report summarizes data obtained from field sampling of mine tailings and 

soils adjacent to the Ruth Mine and stream sediments downstream from the mine on June 

7, 2009. Our results permit a preliminary assessment of the sources of As and associated 

chemical constituents that could potentially impact humans and biota. 

1

U.S. Geological Survey, Menlo Park, Calif.

2

Chapman University, Orange, Calif.
2

Mining History and Geology

The following history of the Ruth Mine is summarized from Julihn and Horton 

(1937) and Briggs (2007). 

The Ruth Mine is in the Sherman Mining District, 12 miles north of Trona in 

Homewood Canyon, on the east side of the Argus Range (coordinates: 35°, 53’, 26.24” 

N, 117°, 24’, 32.18” W). Doug Graham and Smiley Jones discovered gold in the Canyon 

in 1899, and shortly after identifying the source, the Graham-Jones mine was formed. 

The mine operated under control of Jones and Graham until 1937 when they leased the 

mine to the Burton brothers. The Burton brothers renamed the mine the Ruth Mine in 

1937 and upgraded the equipment to produce 70 tons of ore per day. Equipment included 

a 40-ton vat leaching cyanide mill. Nearby mines, including the Davenport Mine, also 

owned by the Burtons, transported ore to the Ruth Mill for processing. The mine 

operated until WWII when order L-208 shut down all gold mining in California. The 

camp became a ghost town nearly overnight. 

The Ruth Mine is in an unnamed ephemeral drainage in the Argus Range. 

Tailings from the mine have migrated downstream toward Searles Valley, to the 

northeast, during episodes of heavy rainfall. The area, located in the Basin and Range 

province, consists of short mountain ranges generally trending north-south, separated by 

valleys filled with quaternary deposits (Stoffer, 2004). Ore at the Ruth Mine consists of 

free gold associated with pyrite in iron-stained quartz stringers in a fissure in quartz 

monzonite bedrock. Bedrock of the surrounding area mostly is Mesozoic granite, with 

some Paleozoic marine sedimentary rocks and Pliocene and Pleistocene basalts and 

pyroclastic rocks. Quaternary alluvium covers much of the area of Homewood Canyon. 

Sample Locations and Methods

Sample Locations and Conditions

Samples were collected to assess the concentration of As and associated elements 

in tailings and soils at the Ruth Mine and in stream sediments downstream from the mine. 

Sample site locations and description are listed in table 1 and are shown in figures 3, 4, 

and 5. 

Field Sampling Methods

Tailings, Soils and Sediments

Samples consisting of 100 to 500 g of mine tailings and soils were collected from 

the area of the Ruth Mine and stream sediments with the prefix S were collected from the 

unnamed drainage in Homewood Canyon (fig. 3). At each soil-sample site, a surface-soil 

sample, from the 0-2-inch depth interval labeled with suffix “0”, and a subsurface-soil 

sample, from the depth interval 2-6 inches, labeled with suffix “1”, was taken in order to 

assess the possible contamination of surface soils from wind- and water-transported 

tailings derived from the Ruth Mine (table 1, fig. 4). In Homewood Canyon, stream 

sediments downstream from the Ruth Mine were collected from the active channel at the 

surface, and at some sites, subsurface sediment was collected. Test pit samples within the 
3

drainage in Homewood Canyon were dug to assess the depth of contaminated sediment 

within the active channel and have a TP prefix (table 1, figs. 4 and 5). Samples of 

tailings, soil, and sediments were stored and shipped in Ziploc®

One sample of tailings from the tailings pile was weighed and then sieved into 10 

size fractions to evaluate the concentration of As as a function of grain size. The sample 

passed through a series of 10 stainless steel, 13-inch sieves featuring increasingly finer 

meshes, with the aid of a Ro-Tap Testing Sieve Shaker Model B from Tyler Industrial 

Products. The sample was agitated for a period of 30 minutes to insure effective size 

separation, resulting in 8 distinct size fractions (table 3); no significant amount of 

material was observed to pass through the 8th-10th sieves (≤45 μm). Splits of 5-10 g 

from the initial bulk sample and from each fraction size weighing >5 g were analyzed 

using inductively coupled plasma-mass spectrometry (ICP-MS). 

 bags at ambient 

temperature.

Analytical Methods

Soils and Tailings

Multielement analyses for all dry soils and tailings were done in the laboratories 

of ALS Chemex. Bulk samples were ground in a zirconia ring mill and subjected to a 

near-total four-acid digestion. Elements, other than Hg, were determined by ICP–MS. 

Mercury was determined by cold vapor atomic absorption spectroscopy (CVAAS) 

following methods similar to those described by Crock (1996) and O’Leary and others 

(1996). Results of chemical analyses are listed in table 2.

Extended X-ray Absorption Fine-Structure (EXAFS) Spectroscopy

Bulk As K-edge EXAFS spectroscopic analysis was done at the Stanford 

Synchrotron Radiation Lightsource (SSRL) at room temperature, in fluorescence mode, 

with a Lytle detector (for high-concentration samples; [As]T>1,000 ppm) or a Ge 30-

element detector (for low-concentration samples; [As]T

EXAFS spectra were averaged, background-subtracted and fitted over a k-range 

of 2-10 Å

<1,000 ppm). The speciation of 

As in the tailings sample was then determined by comparison of its EXAFS spectrum 

with those from an As model compound EXAFS library of 16 homogeneous As(III) and 

As(V) phases including crystalline, amorphous, and sorbed compounds collected in 

transmission mode. Each model EXAFS spectrum, reflecting the distinct structural 

arrangement of arsenic in that particular sample, is unique and can, therefore, be utilized 

as a component phase in combination with other model spectra to characterize a 

heterogeneous, natural, As-bearing sample. The EXAFS spectra of the mine-waste 

samples were analyzed using a linear least-squares fitting method that has been employed 

in a wide range of environmental systems (Foster and others, 1998; Paktunc and others, 

2004) to deconvolute the composite spectrum of the natural sample into the sum of its 

individual As-bearing components. 

-1 using the SixPack software program (Webb, 2005). Each model compound 

was first applied individually, with the compound yielding the best fit (that is, the lowest 

reduced χ2

 value, an indicator of the quality of fit) selected as the first component for 

subsequent fits. Additional model compound spectra were then individually combined 
4

with the first component to generate two-component fits, repeating the process until no 

more significant contributors, that is, those representing ≥10 percent of the total fit, could 

be added that caused the reduced χ2

 value to decline by ≥10 percent. The final fit, 

providing both the identification of the relevant arsenic species and their percent 

contributions to the fit, represents the EXAFS-determined As speciation of that sample. 

This method, while providing a direct, nondestructive route to characterizing As 

speciation, is limited to the spectra in one’s model compound database, has detection 

limits of ~100 ppm [As]T

Results

 and is considered to have errors of ±10 percent in the final 

quantitative phase determinations (Wang and Mulligan, 2008; Kim and others, 2000). 

Tailings and Waste Rock at the Ruth Mine

Tailings present in the two piles at the Ruth Mine have high concentrations of As 

(1,300 to 3,880 ppm) based on samples collected by the BLM staff (U.S. Bureau of Land 

Management, 2008). The tailings, located on the banks of the drainage in Homewood 

Canyon, have been eroded and have migrated downstream (fig. 6). In addition, tailings 

were removed from the mine area to construct the dirt road in Homewood Canyon that 

provided access to the mine, as well as other dirt roads adjacent to the mine. The dirt 

road in Homewood Canyon subsequently was paved and then abandoned when a new 

paved road was constructed. Segments of the old road remain in the central and lower 

part of the canyon (fig. 5, road samples T3-8 and T10, T12, and T13). Locally, the 

pavement has disintegrated and exposed the tailings, which are being eroded and released 

into the drainage in Homewood Canyon (figs. 8 and 9). The As concentration of tailings 

in the road is variable, with the highest concentration recorded at 1,990 ppm (table 2, 

samples T3-T13). The dirt roads, which are adjacent to the mine area at the BLM 

recreation site, also are composed of tailings, with As concentrations up to 2,570 ppm 

(table 2, fig. 4, samples T1 and T2). 

The results of the grain-size analysis of one tailings sample are listed in table 3 

(sample RMS03C). No tailings were present in the size fractions smaller than 45 μm, and 

most of the mass of the tailings was present in the largest grain-size fraction, S1, that 

contains particles larger than 2,830 μm (fig. 13). The As concentration in the bulk sample 

was 2,230 ppm. The As concentration in the largest grain-size fraction was 2,280 ppm, 

and As concentration increased with decreasing grain size, reaching a maximum 

concentration of 3,270 ppm in the smallest size fraction, 45 μm - 75 μm (fig. 14). 

Tailings from the Ruth Mine have been released into the drainage in Homewood 

Canyon, and then into Searles Valley, for a distance of about 6 km (fig. 3). Upstream 

from the mine area, the concentration of As in stream sediment is 10 ppm, comparable to 

the As concentrations in premining sediment (13 to 23 ppm) exposed in the stream bank 

(table 2, samples B1-B3). Sediment in the active channel of the drainage has the highest 

As concentration, more than 300 ppm, adjacent to the tailings piles (fig. 12, samples S2 

and S3). The As concentration in sediment decreases downstream from the mine site and 

ranges from 40 to 65 ppm in the central part of Homewood Canyon (fig. 12, samples S8-

12). In the lower part of Homewood Canyon, the As concentration decreases to 

background levels of 9 ppm (figs. 10 and 12, sample S15). The As concentration ranges 
5

from 6 to 16 ppm in the drainages within the northern part of Searles Valley, and these 

values are similar to regional background levels (figs. 3 and 12, samples S16-22). 

Sediment samples were collected from test pits dug within the active channel to 

assess the depth of contaminated sediment present. Test pits 1, 2, and 4 showed 

consistent, elevated As concentrations throughout the depth sampled, indicating that Ascontaminated sediment is present to a minimum depth of 18 inches (table 2). In test pit 3, 

the As concentration decreased to background levels below a depth of 6 inches. 

Samples of soils were taken along two parallel transects from the tailings piles to 

the BLM recreational picnic site located west of the mine (fig. 4). A surface sample and 

subsurface sample of soil was taken at each sample site to assess the level of 

contamination in surface soils from wind- and water-transported tailings. Both surface 

and subsurface soils have elevated As concentrations adjacent to the tailings piles 

(samples BK1, 2, and 3), indicating that tailings have contaminated the soils to a depth 

greater than 6 inches. Samples further from the tailings pile have background levels of As 

in the subsoil but are enriched in As in the surface soils, with enrichment ranging from 

186 percent to 271 percent of As in the subsurface soil sample (table 4, fig. 11). Soil 

samples taken adjacent to dirt roads composed of tailings have high concentrations of As 

in both surface and subsurface samples (samples BK 5, 7, and 10; fig. 4). This indicates 

that tailings eroded from the roads in the picnic area have contaminated the soil to a depth 

greater than 6 inches.

The concentration of As in tailings, sediment, and soil samples is summarized by 

box plots in figure 15. The concentration of As is highest in mine tailings (14–2,570 

ppm), and lowest in pre-mining sediment (<20 ppm). The As concentrations are higher 

in surface soils compared to subsurface soils, indicating wind and fluvial transport of 

particulate As has resulted in significant As enrichment in surface-soils and stream 

sediment in the active stream channel in Homewood Canyon (table 4, figs. 11 and 12). 

Speciation of Arsenic in Tailings

Fits of the As EXAFS spectra collected from different size fractions (S5, S7, and 

S9, the last of which yielded sufficient quantities of material for EXAFS but not ICP-MS 

analysis) of the size-separated tailings sample are shown in figure 16, with quantitative 

fits provided in table 4. Linear fitting of the EXAFS data indicates that Ca- (and Fe-) 

bearing As phases dominate, specifically the related minerals arseniosiderite,

Ca2Fe3+

3O2(AsO4)3·3(H2O) and yukonite, Ca3Fe3+(AsO4)2(OH)3·5H2O in addition to 

Ca-arsenate, Ca3(AsO4)2

Micro X-ray fluorescence maps of As and Fe in particles of the S7 (75-125 μm) 

tailings-size fraction indicates that Fe is associated with only some of the As phases, but 

. Arsenic sorbed to goethite also is present in two of the three 

samples. The presence of As sorbed to goethite in Ruth mine wastes previously was 

reported by Paktunc and others (2004). These findings are consistent with the relatively 

high levels of Ca (>3.84 percent) and Fe (>3.15 percent) in the selected size fractions as 

shown in table 3 (notably, both As, Ca, and Fe concentrations increase with decreasing 

particle size). Based on EXAFS analyses of other mine sites, sorption of As on Fe phases 

is common; however arseniosiderite has only recently been reported in tailings from AuAg ore deposits in the Mojave Desert. In the Randsburg district, arseniosiderite is present 

as a primary As phase in the Au-Ag ores, and as a secondary As phase in the tailings 

(Rytuba and others, 2007). 
6

most of the observed As-enriched particles are not associated with high concentrations of 

Fe (fig. 17a-b). This suggests that there are multiple As phases present that contain 

variable amounts of Fe (fig. 17). A correlation plot, which plots the relative As and Fe 

fluorescence of every pixel in the map, reveals roughly three populations of pixels, two of 

which feature relatively high but separate As:Fe ratios, and one with a very low As:Fe 

ratio (fig. 18). Based on the EXAFS linear combination fitting results, the former 

populations likely correspond to As mineral phases, such as arseniosiderite and yukonite, 

while the latter likely represents iron oxides with low concentrations of sorbed As. 

Correlation plots showing the relative As and Fe fluorescence in four grain-size fractions, 

S5 (250–500 μm), S6 (125–250 μm), S7 (75–125 μm) and S8 (45–75 μm) indicate that 

distribution of As phases is somewhat dependent on grain size (fig. 19). For example, in 

grain size fractions S5 and S6, the phase characterized by a high As:Fe ratio is absent. 

This indicates that As speciation varies with grain size and that the finer grain-size 

fractions have more As phases. 

Conclusions

Mine tailings present in two piles at the Ruth Mine have very high concentrations 

of As, compared to EPA guidelines. The As concentration in tailings is a function of 

grain size and increases with decreasing grain size, reaching a maximum concentration in 

the smallest measurable size fraction representing particles between 45-75 μm in 

diameter. The tailings piles are on the banks of an unnamed drainage in Homewood 

Canyon and have been eroded and released into the drainage and migrated downstream. 

Arsenic-contaminated sediment is present in the active channel of the drainage from the 

mine site to the central part of the canyon. At the mouth of the Homewood Canyon and 

in Searles Valley, As concentration in sediment within the drainage channel decreases to 

background levels. Tailings with high As concentration are present in the abandoned road 

in Homewood Canyon, which was constructed from tailings and subsequently paved. 

The road is disintegrating and releasing As-enriched tailings into the drainage within 

Homewood Canyon. 

Two transects of soil samples collected in the mine area indicate that tailings 

eroded from the tailings piles and dirt roads have contaminated the surface soils, with the 

surface soil containing as much as 280 percent more As, compared to the subsurface soil. 

Concentrations of As in the surface-soil range from 13 to 5,396 ppm. Where surface soils 

are highly contaminated with As near the tailings piles and dirt roads, As concentrations 

are elevated in both surface and subsurface soils. The enrichment factor of 2,100 percent 

(site BK5) is anomalous. Other soil samples indicate a local enrichment factor closer to 

200 percent (fig. 11). A consistent enrichment of surface soils of more than 200 percent 

occurs in the soil-sample transect nearest the mine site (table 4). 

Three discrete As phases have been identified using EXAFS spectroscopy in the 

tailings: arseniosiderite, yukonite, and Ca-arsenate; these phases are likely to have a high 

As:Fe ratio in corresponding micro-X-ray fluorescence correlation plots and appear to be 

more dominant in the smallest grain-size fractions (45–125 μm). Arsenic also exists as a 

surface-sorbed phase to goethite, but if present at expectedly low concentrations it should 

yield a low As:Fe ratio in the same correlation plots.

Arsenic concentrations detected in sediments and soils from this study suggest the 

tailings and other mine wastes have the potential to be a significant source of As 
7

contamination to the immediate surroundings. Enrichment factors ranging from 1 to 21 

times higher As concentrations in surface soils relative to subsurface soils indicate that 

wind and local fluvial transport of As-enriched tailings has occurred. The fine-grained 

tailings are more amenable to transport and have higher As concentrations because As 

increases with decreasing grain size of the tailings. 

The observed elevated concentrations of As present in tailings and soils adjacent 

to the Ruth Mine site are similar to observations at other mined areas in the western 

Mojave Desert where As-enriched tailings and soils are present. Hydrothermal systems 

associated with emplacement of Miocene volcanic centers have mobilized As, and 

subsequently concentrated it, in and adjacent to Au-Ag deposits. Erosion of As-enriched, 

altered material has resulted in large areas with anomalously high As in sediment and 

soils (fig. 20). The As concentration map shown in figure 20 is constructed from samples 

that originally were collected during the National Uranium Resource Evaluation (NURE) 

Hydrogeochemical and Stream Sediment Reconnaissance program in the 1970s; the 

samples were subsequently reanalyzed by the USGS (Smith, 1999). At mines and mine 

site areas in the western Mojave Desert, such as those near the Ruth Mine, processing of 

Au-Ag ores has contributed to exceptionally high As concentrations in tailings, 

sediments, and soils that have migrated from the mine site by means of both wind and 

fluvial processes. This has resulted in contamination of sediments and surface soils with 

As at levels that are of potential environmental concern to both humans and biota. 

Acknowledgments

The authors thank the BLM for providing funding for this work. Thanks also to 

Chapman University Environmental Geochemistry Laboratory group members Jessey 

Francies, Kayleigh Hyde, Kevin Meston, and Suzie Shdo for assistance with field 

sampling.

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Smith, S.M., 1999, National Geochemical Database: U.S. Geological Survey Open-File 

Report 97-492. 

Stoffer, Philip, 2004, Desert landforms and surface processes in the Mojave National 

Preserve and vicinity: U.S. Geological Survey Open-File Report 2004-1007, last 

accessed Feb. 2011 at http://pubs.usgs.gov/of/2004/1007/. 

Troxel, B.W., and Morton, P.K., 1962, Mines and mineral resources of Kern County, 

California: California Division of Mines and Geology, County Report 1, p. 120-

124. 

Tucker, W.B., 1923, Kern County, Mojave mining district: California Division of Mines 

and Geology. County Report 1, p. 43-45. 

Tucker, W.B., and Sampson, R.J., 1933, Kern County, Mojave mining district: California 

Division of Mines and Geology. County Report 31, p. 465-485. 

U.S. Bureau of Land Management, 2008. Draft Removal Site Inspection—Ruth Mine: 

Denver, Colo., National Operations Center. 

Wang, S.L.; Mulligan, C.N., 2008, Speciation and surface structure of inorganic arsenic 

in solid phases—A review: Environment International, v. 34, no. 6, p. 867-87. 

Webb, S.M., 2005, SIXpack—a graphical user interface for XAS analysis using 

IFEFFIT. Physica Scripta, T115, p. 1011-1014. 
9

Table 1. Sample locations and notes from Ruth Mine, Inyo County, California.

Field Latitude Longitude Sampling

number date Notes

 Background

09RU-BK1-0 35.89071 117.40958 This background sampling is closest to the tailings

09RU-BK1-1 35.89071 117.40958 Mostly tailings, still very reddish in color

09-RU-BK2-0 35.89056 117.40946

09-RU-BK2-1 35.89056 117.40946

09RU-BK3-0 35.89071 117.40958 Soil not as red 

09RU-BK3-1 35.89071 117.40958

09-RU-BK4-0 35.89044 117.40993

09-RU-BK4-1 35.89044 117.40993

09RU-BK5-0 35.8905 117.41062 Sample taken near the parking lot

09RU-BK5-1 35.8905 117.41062

09-RU-BK6-0 35.89023 117.41035

09-RU-BK6-1 35.89023 117.41035

09RU-BK7-0 35.89024 117.41108 Near road - Very red & rocky

09RU-BK7-1 35.89024 117.41108

09-RU-BK8-0 35.89009 117.41077 Located about 10 ft from clear tailing contaminated soil

09-RU-BK8-1 35.89009 117.41077 Run-off from the road. About 20 ft from campsite

09RU-BK9-0 35.89 117.41152 Between road and campground

09RU-BK9-1 35.89 117.41152

09-RU-BK10-0 35.89001 117.4122 At foot of hiking trail

09-RU-BK10-1 35.89001 117.4122

 Sediment

09RUS1 35.89105 117.41061

09RU-S2 35.8913 117.40928 Taken from right under the main tailings pile

09RUS3 35.89205 117.41061

09RU-S4 35.89309 117.40726 Downstream from tailings

09RUS5 35.89426 117.407

09RU-S6 35.89548 117.40619 Downstream from tailings

09RUS7 35.89635 117.40514

09RU-S8 35.89934 117.38968

09RU-S9 35.90007 117.39098

09RUS10 35.89984 117.39238
10

Table 1. Sample locations and notes from Ruth Mine, Inyo County, California—Continued.

Field Latitude Longitude Sampling

Number Date Notes

09RUS11 35.89886 117.39309

09RUS12 35.89837 117.39427

09RUS15 35.89333 117.35651

09RUS16 35.90593 117.33018

09RUS17 35.87787 117.31702

09RUS18 35.88579 117.34871

09RUS19 35.87909 117.34594

09RUS20 35.8711 117.33955

09RUS21 35.85772 117.32724

09RUS22 35.828 117.31705

 Sediment Depth Profile

09RU-TP1-0 35.90012 117.39125 Very rocky consistency - looked slightly damp as we got deeper

09RU-TP1-6 35.90012 117.39125 Large rocks kept us from going any farther. (Light breeze)

09RU-TP1-12 35.90012 117.39125

09RU-TP2-00 35.89963 117.3904

09RU-TP2-06 35.89963 117.3904 Mixed sediment. Could only dig to about 14 inches

09RU-TP2-12 35.89963 117.3904

09RU-TP3-0 35.90031 117.39174

09RU-TP3-6 35.90031 117.39174

09RU-TP3-12 35.90031 117.39174 Samples were taken from an embankment on an incline

09RU-TP3-18 35.90031 117.39174

09RU-TP4-00 35.8931 117.40721

09RU-TP4-06 35.8931 117.40721

09RU-TP4-12 35.8931 117.40721

 Tailings

09-RU-T1 35.89006 117.41087 Tailings used for road material. Adjacent to table. Sloping downward

09-RU-T2 35.89027 117.41104 Base of side road that leads to picnic area. Intersection with main road

09RU-T3 35.90042 117.39143 Base of bank at where erosion is bringing road metal/tailings into wash

09RU-T4 35.90051 117.39156 Top of bank cut near side road, below boulder. Largely tailings

09RU-T5 35.90055 117.39155 On side road where erosion is exposing tailings used for base of trail

09RU-T6 35.8997 117.3933 Samples collected near old road

09RU-T7 35.89932 117.39389 Had to break up some of the asphalt to get to the samples
11

Table 1. Sample locations and notes from Ruth Mine, Inyo County, California—Continued.

Field Latitude Longitude Sampling

Number Date Notes

09RU-T8 35.89909 117.39469

09RU-T9 35.9002 117.39257

09RUT10 35.89415 117.37652

09RUT11 35.8936 117.37616

09RUT12 35.89431 117.37773

09RUT13 35.89443 117.37848

09RUB3 35.89296 117.40733
12

Table 2. CHEMEX data for background soils, tailings, and sediment from the Ruth Mine site. 

[ppm: parts per million; %: percent]

Sample Ag Al As Ba Ca Co Cr Cu Fe K Mg Mn Na

ppm % ppm ppm % ppm ppm ppm % % % ppm %

Background

09RU-BK1-0 0.3 0.69 1,230 230 2.17 9 23 31 2.51 0.29 0.38 578 0.03

09RU-BK1-1 0.2 1.11 1,140 260 1.81 11 12 36 3.01 0.42 0.58 652 0.04

09RU-BK2-0 0.3 0.68 1,325 290 2.95 11 10 27 2.82 0.3 0.38 675 0.03

09RU-BK2-1 0.3 1.1 507 230 1.58 10 27 32 2.76 0.3 0.66 514 0.06

09RU-BK3-0 0.2 1.39 289 230 1.25 10 13 31 2.81 0.4 0.73 526 0.07

09RU-BK3-1 0.2 1.49 197 220 1.03 11 13 35 2.9 0.4 0.8 524 0.07

09RU-BK4-0 0.2 1.41 18 190 1.13 10 19 36 3.51 0.3 0.73 439 0.08

09RU-BK4-1 0.2 1.55 9 220 1.32 11 15 38 3.76 0.25 0.8 478 0.09

09RU-BK5-0 0.2 1.17 536 210 1.32 11 19 31 2.84 0.28 0.68 553 0.05

09RU-BK5-1 0.2 1.44 246 170 1.04 11 26 33 2.88 0.31 0.86 571 0.05

09RU-BK6-0 0.2 1.95 25 200 0.94 13 29 47 3.32 0.46 1.17 600 0.08

09RU-BK6-1 0.2 1.88 11 210 1.09 12 20 43 3.22 0.48 1.11 597 0.07

09RU-BK7-0 0.2 0.72 2,160 270 2.2 11 17 31 2.77 0.32 0.28 732 0.02

09RU-BK7-1 0.4 0.59 2,900 300 2.69 12 11 33 2.97 0.31 0.21 879 0.02

09RU-BK8-0 0.2 1.83 76 170 1.15 13 22 40 3.09 0.39 1.11 651 0.04

09RU-BK8-1 0.2 1.9 28 170 1.13 12 25 39 3.08 0.39 1.09 640 0.05

09RU-BK9-0 0.2 1.44 13 140 0.52 9 18 21 2.04 0.4 0.65 577 0.05

09RU-BK9-1 0.2 1.5 7 140 0.53 9 18 22 2.07 0.4 0.68 571 0.05

09RU-BK10-0 0.4 0.62 1,485 330 2.82 11 19 61 2.37 0.29 0.28 678 0.02

09RU-BK10-1 0.2 1.14 683 220 1.52 10 13 38 2.23 0.35 0.5 606 0.04

Tailings

09RU-T1 0.4 0.47 2,570 430 2.96 14 5 50 2.89 0.31 0.18 885 0.01

09RU-T2 0.3 0.6 2,570 320 2.85 13 12 31 2.93 0.32 0.22 913 0.02

09RU- T3 0.2 0.65 1,990 360 3.3 12 10 38 2.78 0.33 0.3 813 0.03

09RU- T4 0.2 0.63 2,170 340 3.61 12 13 30 2.71 0.35 0.21 851 0.03

09RU- T5 0.2 0.66 1,500 290 2.49 9 10 18 2.36 0.3 0.22 712 0.03

09RU- T6 0.2 1.43 109 200 1.09 8 12 24 2.55 0.38 0.65 486 0.06

09RU- T7 0.2 1.07 372 170 1.02 7 11 17 2.5 0.35 0.43 472 0.05

09RU- T8 0.2 1.23 577 250 1.23 10 13 23 3.45 0.4 0.55 588 0.05

09RU- T9 0.2 0.86 683 250 1.97 8 10 17 2.34 0.31 0.35 573 0.03

09RU- T10 0.2 0.92 1,490 260 2.39 12 7 36 3.37 0.39 0.34 681 0.05

09RU- T11 0.2 1.15 14 130 0.5 6 12 16 2.37 0.21 0.38 313 0.05

09RU- T12 0.2 1.12 939 300 2.13 10 11 26 2.7 0.45 0.54 678 0.05

09RU- T13 0.2 0.72 1,760 320 2.63 10 11 33 2.67 0.34 0.28 715 0.03

09RU-B1 0.2 1.84 16 280 1.17 9 20 25 2.36 0.73 0.89 784 0.08

09RU-B2 0.2 1.24 13 210 0.87 6 15 14 1.85 0.4 0.51 520 0.05

09RU-B3 0.2 0.7 23 130 0.55 5 11 16 2.17 0.18 0.33 411 0.04

Not detected (detection limit): B (10 ppm), Be (0.5 ppm) , Bi (2 ppm), Cd (0.5 ppm), Ga (10 ppm), Hg (1 ppm), 

La (20 ppm), Mo (1 ppm), Th (20 ppm), Tl (10 ppm), U (10 ppm), W (10 ppm)
13

Table 2. CHEMEX data for background soils, tailings, and sediment from the Ruth Mine site—Continued.

Sample Ni P Pb S Sb Sc Sr Ti V Zn

ppm ppm ppm % ppm ppm ppm % ppm ppm

Background

09RU-BK1-0 7 1,410 57 0.03 14 4 89 0.03 42 316

09RU-BK1-1 8 1,150 8 0.01 12 5 76 0.07 63 142

09RU-Bk2-0 8 1,050 32 0.03 11 4 69 0.03 43 126

09RU-BK2-1 9 1,120 29 0.02 5 4 62 0.08 62 110

09RU-BK3-0 8 1,080 12 0.01 4 4 56 0.11 68 74

09RU-BK3-1 8 1,190 22 0.01 2 4 56 0.13 77 72

09RU-BK4-0 6 1,110 2 0.01 2 4 60 0.13 100 48

09RU-BK4-1 7 1,060 3 0.01 2 4 73 0.13 108 47

09RU-BK5-0 10 1,100 12 0.01 8 4 53 0.07 63 73

09RU-BK5-1 11 1,200 8 0.01 3 4 52 0.1 68 64

09RU-BK6-0 14 1,270 10 0.01 2 6 62 0.17 93 69

09RU-BK6-1 11 1,250 5 0.01 2 5 59 0.16 89 59

09RU-BK7-0 7 870 17 0.01 21 5 53 0.02 34 131

09RU-BK7-1 7 820 11 0.01 25 5 61 0.01 32 121

09RU-BK8-0 14 1,210 11 0.01 2 5 52 0.14 78 82

09RU-BK8-1 12 1,160 4 0.01 2 5 50 0.13 77 61

09RU-BK9-0 11 780 6 0.01 2 3 43 0.12 42 48

09RU-BK9-1 11 780 6 0.01 2 3 46 0.13 43 48

09RU-BK10-0 9 580 20 0.01 31 4 57 0.01 36 151

09RU-BK10-1 10 660 10 0.01 15 4 51 0.06 39 97

Tailings

09RU-T1 7 730 11 0.02 37 5 69 0.01 31 101

09RU-T2 8 820 13 0.01 24 5 59 0.01 32 103

09RU- T3 12 780 11 0.03 27 5 70 0.01 38 200

09RU- T4 14 680 12 0.03 27 5 66 0.01 41 258

09RU- T5 11 650 10 0.02 17 4 52 0.01 32 217

09RU- T6 7 930 5 0.01 2 4 51 0.1 58 47

09RU- T7 7 770 9 0.01 5 3 48 0.07 52 56

09RU- T8 9 970 11 0.02 7 4 51 0.08 78 95

09RU- T9 8 660 51 0.01 9 3 52 0.04 39 77

09RU- T10 7 880 9 0.02 19 5 63 0.04 63 127

09RU- T11 5 520 4 0.01 2 3 39 0.07 59 28

09RU- T12 10 940 7 0.02 11 4 58 0.07 54 156

09RU- T13 11 760 10 0.03 24 4 55 0.01 40 202

09RU-B1 15 810 9 0.01 2 4 56 0.1 40 62

09RU-B2 10 550 6 0.01 2 2 39 0.07 30 38

09RU-B3 3 480 3 0.01 2 2 32 0.07 51 27
14

Table 2. CHEMEX data for background soils, tailings, and sediment from the Ruth Mine site—Continued.

Ag Al As Ba Ca Co Cr Cu Fe K Mg Mn Na

ppm % ppm ppm % ppm ppm ppm % % % ppm %

Sediment

09RU-S1 0.2 0.55 10 90 0.26 4 9 8 3.09 0.19 0.16 481 0.07

09RU-S2 0.2 0.54 310 120 0.82 6 8 12 1.8 0.19 0.2 328 0.04

09RU-S3 0.2 0.92 333 210 1.45 10 16 21 4.12 0.3 0.44 565 0.05

09RU-S4 0.2 1.09 12 140 0.62 6 9 14 1.98 0.35 0.44 376 0.1

09RU-S5 0.2 0.69 284 170 1.19 7 6 14 1.7 0.25 0.31 461 0.04

09RU-S6 0.2 1.06 19 140 0.7 8 11 17 2.54 0.32 0.51 429 0.06

09RU-S7 0.2 0.88 200 170 1.04 6 7 14 1.7 0.31 0.35 437 0.06

09RU-S8 0.2 0.52 40 80 0.43 4 7 8 1.24 0.15 0.2 194 0.05

09RU-S9 0.2 0.84 52 150 0.66 10 22 18 5.17 0.26 0.41 406 0.05

09RU-S10 0.2 0.77 41 100 0.59 7 18 15 4.16 0.18 0.26 262 0.08

09RU-S11 0.2 0.54 39 90 0.45 4 5 9 1.42 0.17 0.23 225 0.04

09RU-S12 0.2 1.01 66 150 0.75 8 10 17 2.38 0.31 0.47 431 0.06

09RU-S15 0.2 0.57 9 80 0.37 3 6 9 1.27 0.17 0.17 195 0.05

09RU-S16 0.2 0.73 13 110 0.5 5 9 13 1.93 0.22 0.35 297 0.05

09RU-S17 0.2 0.62 9 100 0.6 5 7 11 1.6 0.19 0.32 280 0.04

09RU-S18 0.2 0.84 6 110 0.44 6 11 15 2.45 0.23 0.36 313 0.07

09RU-S19 0.2 0.63 10 90 0.41 6 13 13 2.62 0.16 0.32 274 0.04

09RU-S20 0.2 0.69 7 100 0.42 4 6 12 1.34 0.2 0.31 236 0.06

09RU-S21 0.2 1.03 11 110 0.91 5 10 16 1.94 0.26 0.53 376 0.06

09RU-S22 0.2 0.72 16 100 0.85 4 9 12 1.65 0.2 0.41 280 0.05

Sample Ni P Pb S Sb Sc Sr Ti V Zn

ppm ppm ppm % ppm ppm ppm % ppm ppm

09RU-S1 3 310 5 0.01 2 1 25 0.07 65 18

09RU-S2 4 370 5 0.01 4 2 31 0.04 36 35

09RU-S3 8 800 7 0.01 3 3 46 0.10 102 60

09RU-S4 6 520 5 0.01 2 3 45 0.11 41 35

09RU-S5 5 460 5 0.01 4 2 36 0.06 30 46

09RU-S6 7 620 6 0.01 2 3 42 0.12 59 39

09RU-S7 5 460 5 0.01 3 3 42 0.07 31 44

09RU-S8 2 370 3 0.01 2 1 27 0.04 26 17

09RU-S9 8 630 5 0.01 2 3 37 0.11 153 36

09RU-S10 6 460 7 0.01 2 2 46 0.09 137 20

09RU-S11 3 350 3 0.01 2 1 26 0.05 30 20

09RU-S12 7 590 6 0.01 2 3 43 0.11 54 41

09RU-S15 3 320 7 0.01 2 1 30 0.04 24 17

09RU-S16 5 530 4 0.01 2 2 31 0.07 43 29

09RU-S17 4 490 3 0.01 2 2 40 0.07 36 24

09RU-S18 5 550 9 0.01 2 2 37 0.08 60 27

09RU-S19 5 530 2 0.01 2 2 29 0.07 71 21

09RU-S20 3 460 3 0.01 2 2 35 0.06 29 20

09RU-S21 5 480 5 0.01 2 2 66 0.08 41 31

09RU-S22 4 600 5 0.01 2 2 76 0.07 38 27
15

Table 3. Concentration of elements in sieved size fractions of tailings sample from Ruth Mine. 

[ppm: parts per million; %: percent]

Sample Size Hg Ag Al As Ba Be Bi Ca Cd Ce Co Cr Cs Cu Fe

ppm ppm % ppm ppm ppm ppm % ppm ppm ppm ppm ppm ppm %

Sample RMS03C

RMS03C-S1 > 2,830 μm 0.56 0.23 5.55 2,280 500 0.84 0.06 2.35 0.12 35.7 9.4 26 2.64 16.5 2.66

RMS03C-S2 2,830 μm -1,700 μm 0.65 0.24 5.42 2,200 520 0.94 0.1 2.42 0.13 33.9 9.8 23 2.98 16.4 2.75

RMS03C-S3 1,700 μm -1,000 μm 0.69 0.24 5.71 2,340 460 0.84 0.05 2.51 0.15 35.4 10.1 22 3.01 19.2 2.77

RMS03C-S4 1,000 μm -500 μm 0.03 0.23 5.77 2,290 550 0.95 0.07 2.79 0.16 31.9 11 22 3.3 17.1 2.84

RMS03C-S5 500 μm -250 μm 0.9 0.22 6.73 2,720 680 1.01 0.06 3.84 0.19 35.6 14.5 22 4.2 20.8 3.15

RMS03C-S6 250 μm - 125 μm 1.29 0.23 6.7 2,860 810 1.15 0.08 4.38 0.22 36.8 16.9 23 4.48 24.9 3.24

RMS03C-S7 125 μm - 75 μm 1.08 0.22 6.82 3,050 890 1.15 0.08 4.91 0.23 43.7 18.9 26 4.91 29.3 3.62

RMS03C-S8 75 μm -45 μm 1.25 0.22 6.64 3,270 910 1.15 0.1 5.2 0.26 44.6 19.5 28 5.11 32.4 3.73

RMS03C-Bulk 0.79 0.24 6.09 2,230 530 0.99 0.07 3.17 0.18 36.8 12.7 25 3.51 17.1 2.74

Sample Size Ga Ge Hf In K La Li Mg Mn Mo Na Nb Ni P Pb

Sample RMS03C ppm ppm ppm ppm % ppm ppm % ppm ppm % ppm ppm ppm ppm

RMS03C-S1 > 2,830 μm 12.15 0.1 0.6 0.036 2.45 18.8 16.1 0.33 492 4.08 0.06 4.9 12.5 510 8.8

RMS03C-S2 2,830 μm -1,700 μm 13 0.08 0.7 0.038 2.49 16.8 15 0.27 495 2.04 0.05 5.4 11.5 470 8.8

RMS03C-S3 1,700 μm -1,000 μm 13 0.08 0.6 0.039 2.59 18.3 13.8 0.28 527 1.86 0.05 5.9 11.1 490 9.1

RMS03C-S4 1,000 μm -500 μm 13.7 0.09 0.6 0.039 2.74 15.8 13 0.28 605 2.01 0.06 6 10.9 440 9.2

RMS03C-S5 500 μm -250 μm 15.95 0.09 0.7 0.046 3.25 18.1 13.2 0.31 841 2.23 0.07 6.8 13.1 480 11

RMS03C-S6 250 μm - 125 μm 16.55 0.09 0.7 0.043 3.32 18.1 12.7 0.31 985 2.53 0.07 7 14.1 510 12.5

RMS03C-S7 125 μm - 75 μm 17 0.11 0.7 0.046 3.29 22.1 13.1 0.32 1130 2.9 0.07 7.4 16.6 590 14.3

RMS03C-S8 75 μm -45 μm 16.6 0.11 0.7 0.049 3.2 22.7 12.6 0.32 1170 3.18 0.07 7.3 17.4 630 15.5

RMS03C-Bulk 14.15 0.08 0.6 0.037 2.76 19.3 14.5 0.3 630 2.05 0.06 5.8 12.6 500 10.2

Sample Size Rb S Sb Sc Se Sn Sr Ta Te Th Ti Tl U V W

Sample RMS03C ppm % ppm ppm ppm ppm ppm ppm ppm ppm % ppm ppm ppm ppm

RMS03C-S1 > 2,830 μm 84.7 0.07 48.2 8.3 2 0.7 88.9 0.28 0.08 2.9 0.205 0.4 6.4 88 3.5

RMS03C-S2 2,830 μm -1,700 μm 84.3 0.03 44.6 8.2 1 0.9 80.2 0.31 0.09 3.3 0.198 0.44 5 85 3.6

RMS03C-S3 1,700 μm -1,000 μm 85.9 0.03 47.2 8.2 1 0.8 82.8 0.33 0.1 3.2 0.217 0.42 5 86 3.9

RMS03C-S4 1,000 μm -500 μm 82.6 0.03 44.6 7.6 2 0.9 83.7 0.37 0.1 3 0.209 0.44 4.9 87 4.1

RMS03C-S5 500 μm -250 μm 96.2 0.03 47.6 8.7 2 0.9 101.5 0.4 0.09 3.4 0.233 0.54 5.9 101 4.5

RMS03C-S6 250 μm - 125 μm 94.8 0.04 48.9 9 2 1 113.5 0.41 0.11 3.5 0.23 0.53 6.3 104 4.7

RMS03C-S7 125 μm - 75 μm 100.5 0.04 50.4 9.6 2 1.2 119.5 0.41 0.11 4.1 0.237 0.55 7 106 4.9

RMS03C-S8 75 μm -45 μm 98 0.03 51.4 9.9 2 1.2 135.5 0.4 0.13 4.3 0.24 0.57 7.7 106 5.4

RMS03C-Bulk 93 0.04 45.5 8.6 2 0.9 92.5 0.32 0.1 3.3 0.207 0.47 5.5 89 3.9
16

Table 3. Concentration of elements in sieved size fractions of tailings sample from Ruth Mine—Continued.

Sample Size Y Zn Zr

ppm ppm ppm

Sample RMS03C

RMS03C-S1 > 2,830 μm 6.1 127 17.4

RMS03C-S2 2,830 μm -1,700 μm 6.2 142 16.9

RMS03C-S3 1,700 μm -1,000 μm 6.1 154 15.9

RMS03C-S4 1,000 μm -500 μm 5.6 176 16

RMS03C-S5 500 μm -250 μm 6.3 251 16.2

RMS03C-S6 250 μm - 125 μm 6.7 290 16.3

RMS03C-S7 125 μm - 75 μm 7.7 326 19.1

RMS03C-S8 75 μm -45 μm 8.4 365 19.4

RMS03C-Bulk 6.1 179 15.8
17

Table 4. Enrichment of As and Zn in surface-soil samples compared to subsurface concentrations at Ruth Mine, Inyo County, 

California.

Field As ppm As ppm Percent As in surface Zn ppm Zn ppm Percent Zn in surface

Number Surface Subsurface soil compared Surface Subsurface soil compared 

Soil 0-2 inches Soil 2-4 inches to subsurface soil Soil 0-2 inches Soil 2-4 inches to subsurface soil

09RU-BK1 1,230 1,140 108 316 142 223

09RU-BK2 1,325 507 261 126 110 115

09RU-BK3 289 197 147 74 72 103

09RU-BK4 18 9 200 48 47 102

09RU-BK5 5396 246 2193 73 64 114

09RU-BK6 25 11 227 69 59 117

09RU-BK7 2,160 2,190 99 131 121 108

09RU-BK8 76 28 271 82 61 134

09RU-BK9 13 7 186 48 48 100

09RU-BK10 1,485 683 217 151 97 156
18

Table 5. Arsenic speciation determined by EXAFS spectroscopy for selected grain size fractions of Ruth Mine tailings.

Sample name Size Range [As] (ppm) As Speciation Red. χ2

Arseniosiderite Yukonite As(V)-goethite Ca-arsenate

RMS03C_S5 250-500 μm 2,720 65 % 53 % 1.092

RMS03C_S7 75-125 μm 3,050 39 % 46 % 39 % 0.888

RMS03C_S9 32-45 μm N/A 56 % 55 % 0.943
19

Figure 1. Location map of the Ruth gold mine in the western Mojave Desert. Gold mines are shown by yellow 

squares and mercury (Hg) mines are shown by red squares.
20

Figure 2. Generalized geologic map showing location of volcanic fields and associated Au-Ag deposits, including the Ruth Mine Au deposit in the 

western part of the Mojave desert, Inyo County, California.
21

Figure 3. Overview of the Ruth Gold Mine and mill site, Inyo County, California. Sediment samples were taken at sites (yellow dots) in the dry wash in 

Homewood Canyon and the northern part Searles Valley to assess the migration of tailings downstream from the mine site. Sample IDs for the sample 

locations on the left-hand side of the image are provided in figures 4 and 5.
22

Figure 4. Soil sample sites noted by a BK prefix were collected adjacent to the Ruth Mine to assess contamination of soils by the Ruth tailings. Tailings 

were used for road constructions and samples noted by a T prefix are of tailings present in the roads. Samples of stream sediment, noted by an S 

prefix, were collected to assess migration of tailings downstream from the mine site. 
23

Figure 5. Central part of Homewood Canyon downstream from the Ruth Mine. Sediment sample sites in the dry wash have a prefix S and test pit 

samples within the wash to assess the depth of contaminated sediment have a TP prefix. Tailings used in the construction of the old Homewood 

Canyon road were sampled where they are being eroded from the road at sites noted with a T prefix.
24

Figure 6. Mine and mill workings at the Ruth Mine and tailings piles that are being eroded into the unnamed wash in Homewood Canyon.
25

Figure 7. Mine building maintained and used by visitors to the Ruth Mine and recreation area with picnic tables (area to right of buildings).
26

Figure 8. Central part of dry wash in Homewood Canyon with tailings exposed in bank eroded from old road and deposited on the north (left) side of the 

wash (brown sediment).
27

Figure 9. Tailings used in construction of the old road in the central part of Homewood Canyon. Sample sites T5 –T9 shown in figure 5. 
28

Figure 10. Tailings in bank deposits in the wash located in the lower part of Homewood Canyon, sample site T11 shown in figure 3.
29

Figure 11. Enrichment of As in surface background soil sample as compared to subsurface soil at the same sample sites in the Ruth mine area. 
30

Figure 12. Arsenic concentrations from stream sediment collected in the center of the active channel of the dry wash passing through Homewood Canyon 

in the Ruth Mine area. See figures 3-5 for sample locations. Sample are arranged in order of increasing distance from the tailings pile, but the 

distance between sample locations is not to scale.
31

Figure 13. Distribution of mass in 8 size fractions of tailings produced by dry sieving, Ruth Mine area. No appreciable quantities of tailings were present in 

the size fractions less than 45 μm (size fractions S9-S11). 
32

Figure 14. Concentration of As in tailings increases with decreasing grain size to the S8 size fraction, Ruth Mine, Inyo County, California.
33

Figure 15. Box plot of As concentration in tailings at the Ruth Mine, sediment and pre-mining 

sediment downstream from the mine, and surface soil, 0-2 inch depth, and subsurface soil, 2-6 

inch depth in the area of the Ruth Mine. 
34

Figure 16. EXAFS raw spectra (black) and linear combination fits (red) for size fractions of the 

RMS03C sample, specifically the A, S5, B, S7, and C, S9 size fractions. See table 4 for 

quantitative fitting results.
35

Figure 17. Micro x-ray fluorescence intensity maps of As (A) and Fe (B) in tailings from the Ruth Mine, and a tri-color fluorescence map (C) showing 

relative concentrations of As, Ca, and Fe. Fe is shown in red, Ca in blue, and As in green, according to the legend (D). Scale bar in all maps is 

100 μm.
36

Figure 18. Correlation plot of As and Fe shows three distinct populations (A) numbered 1-3 based on X-ray fluorescence analysis of the S7 size 

fraction of the Ruth Mine tailings (B). Each of the three populations map to different As-enriched locations with variable As:Fe ratios (C, D, and 

E, representing populations 1, 2, and 3, respectively). 
37

Figure 19. Arsenic-Iron correlations for four different size fractions of Ruth Mine tailings. A, S5 (250 μm–500 μm), B, S6 (125 μm–250 μm), C, S7 

(75 μm–125 μm), and D, S8 (45 μm–75 μm).
38

Figure 20. Color contour map of As concentration in stream sediment and soil samples from the 

NURE sample set. The Ruth Mine, located to the north of the pictured area in fig. 20, is linked, 

both in historic mining activity and fundamental geology, to the mines shown in this study area.