This report supercedes U.S. Geological Survey Open-File Report 95-645A & B

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or

with the North American Stratigraphic Code. Any use of trade, firm, or product names is for descriptive purposes only

and does not imply endorsement by the U.S. Government.

U.S. Geological Survey, DFC, PO Box 25046, MS 973, Denver, CO, 80225 1

Wrangell-St. Elias National Park and Preserve, PO Box 439, Copper Center, AK, 99573

Corresponding authors’ email addresses: eppinger@usgs.gov, pbriggs@usgs.gov,

Geochemical Data for Environmental Studies of Mineral

Deposits at Nabesna, Kennecott, Orange Hill, Bond Creek,

Bremner, and Gold Hill, Wrangell-St. Elias National Park 

and Preserve, Alaska

by

R.G. Eppinger, P.H. Briggs, D. Rosenkrans, V. Ballestrazze, José Aldir,Z.A. Brown, J.G. Crock, W.M d'Angelo, 

M.W. Doughten, D.L. Fey, P.L. Hageman, R.T. Hopkins, R.J. Knight, M.J. Malcolm, J.B. McHugh, A.L. Meier, 

J.M. Motooka, R.M. O'Leary, B.H. Roushey, S.J. Sutley, P.M. Theodorakos, and S.A. Wilson

Open-File Report 99-342

1999

U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

1
2

TABLE OF CONTENTS

INTRODUCTION..................................................................................................................................................4

GENERAL GEOLOGY, DEPOSIT SETTING, AND MINING HISTORY.............................................................4

NABESNA................................................................................................................................................................4

KENNECOTT............................................................................................................................................................5

ORANGE HILL AND BOND CREEK.............................................................................................................................6

BREMNER ...............................................................................................................................................................6

GOLD HILL .............................................................................................................................................................7

METHODS OF STUDY.........................................................................................................................................7

SAMPLE MEDIA.......................................................................................................................................................7

SAMPLE COLLECTION AND PREPARATION.................................................................................................................8

Sediments .................................................................................................................................................8

Heavy Mineral Concentrates.....................................................................................................................9

Rocks........................................................................................................................................................9

Water........................................................................................................................................................9

Leached Samples ....................................................................................................................................10

Precipitates.............................................................................................................................................10

Willows...................................................................................................................................................10

ANALYTICAL TECHNIQUES ....................................................................................................................................10

Inductively Coupled Plasma-Atomic Emission Spectrometry....................................................................11

Ion Chromatography...............................................................................................................................11

Inductively Coupled Plasma-Mass Spectrometry......................................................................................12

Atomic Absorption Spectrophotometry.....................................................................................................12

Atomic Fluorescence...............................................................................................................................12

Ferrous Iron by Colorimetry ...................................................................................................................14

Alkalinity by Titration .............................................................................................................................12

Semiquantitative Emission Spectrography ...............................................................................................13

Which Technique Should I Use?..............................................................................................................13

DESCRIPTION OF DATA FILES........................................................................................................................13

FIELD NUMBERS....................................................................................................................................................13

GEOCHEMICAL ANALYSES.....................................................................................................................................14

DESCRIPTIONS OF TABLES AND FIELDS WITHIN TABLES ..........................................................................................14

Tables containing sample and site descriptive information.......................................................................14

Tables containing geochemical analyses..................................................................................................15

ACKNOWLEDGMENTS.....................................................................................................................................17

REFERENCES CITED.........................................................................................................................................17

LIST OF TABLES

Table 1. Elements determined and analytical methods used for all sample media collected .........................20

Table 2. Limits of determination for sediment and rock samples analyzed by 40-element inductively

coupled plasma-atomic emission spectrometry ..................................................................22

Table 3. Limits of determination for selected elements in sediment and rock samples...............................23

Table 4. Limits of determination for acidified water samples analyzed for selected elements by inductively

coupled plasma-atomic emission spectrometry...................................................................24

Table 5. Limits of determination for anions in water samples analyzed by ion chromatography....................25

Table 6. Limits of determination for water samples analyzed by 64-element inductively coupled plasmamass spectrometry (MW)...........................................................................................26

Table 7. Limits of determination for nonmagnetic heavy-mineral concentrate samples analyzed by

semiquantitative emission spectrography. ........................................................................27
3

LIST OF FIGURES

FILENAME

Figure 1. Locations of areas studied within Wrangell-St. Elias National Park and Preserve, Alaska. FIGURE1.PDF

Figure 2. Site locations for samples collected in the Nabesna mine area, Alaska. FIGURE2.PDF

Figure 3. Detailed site locations for samples collected around the Nabesna mill, Alaska.. FIGURE3.PDF

Figure 4. Site locations for samples collected in the Kennecott mine and mill areas, Alaska. FIGURE4.PDF

Figure 5. Site locations for samples collected in the Gold Hill area, Alaska. FIGURE5.PDF

Figure 6. Site locations for samples collected in the Orange Hill and Bond Creek areas, Alaska. FIGURE6.PDF

Figure 7. Site locations for samples collected in Bremner area, Alaska. FIGURE7.PDF
4

INTRODUCTION

Environmental geochemical investigations were carried out between 1994 and 1997 in Wrangell-St. Elias National

Park and Preserve (WRST), Alaska. Mineralized areas studied include the historic Nabesna gold mine/mill and surrounding

areas; the historic Kennecott copper mill area and nearby Bonanza, Erie, Glacier, and Jumbo mines; the historic mill and gold

mines in the Bremner district; the active gold placer mines at Gold Hill; and the unmined copper-molybdenum deposits at

Orange Hill and Bond Creek. The purpose of the study was to determine the extent of possible environmental hazards

associated with these mineralized areas and to establish background and baseline levels for selected elements. Thus,

concentrations of a large suite of trace elements were determined to assess metal loadings in the various sample media collected.

This report presents the methodology, analytical results, and sample descriptions for water, leachate, sediment, heavy-mineral

concentrate, rock, and vegetation (willow) samples collected during these geochemical investigations. An interpretive U.S.

Geological Survey Professional Paper incorporating these geochemical data will follow.

Analytical data for samples collected in 1994 at Nabesna and Kennecott were previously published in a U.S.

Geological Survey open-file report (Eppinger and others, 1995a and 1995b). An interpretive report on the 1994 data was also

published (Eppinger and others, 1997). The present report supercedes the older analytical data release, bringing all the data

from the entire study together in this single report. Also, sample locations are more accurate in the present report. The 1994

sample locations in the earlier report were determined by digitizing from 1:63,360-scale maps. These sites were re-occupied in

1996 and locations were refined using highly accurate military Global Positioning System (GPS) equipment (Rockwell

PLGR+96 units) and more detailed field maps provided by WRST.

The Nabesna gold mine is located in the south-central part of the Nabesna 1o X 3o quadrangle, along the northern edge

of WRST (fig. 1). Topography varies from relatively subdued near the confluence of Cabin and Jack Creeks (about 2800 ft/854

m in elevation), 4 miles (6.4 km) below the Nabesna mill, to the steep slopes and cliffs of White Mountain (about 6100 ft/1860

m) immediately to the west of the mill. The Nabesna and nearby Rambler mines are located on the eastern flank of White

Mountain. The area is accessible to four-wheel drive vehicles by an unimproved mine road at the end of the Nabesna road,

which branches off the Glenn Highway (Tok Cut-Off) at Slana.

The Kennecott mill and its associated copper deposits are located in the central part of the McCarthy 1o X 3o

quadrangle, surrounded by WRST. The Kennecott mill complex lies at the base of Bonanza Peak (6983 ft/2128 m), along the

margin of the Kennicott Glacier, at about 2000 ft (610 m) in elevation, while the mines which supplied the mill are located

several thousand feet higher on the steep slopes of Bonanza Peak. Access to the Kennecott mill and associated mines is via foot

or hired van from McCarthy. McCarthy is located at the end of the McCarthy road, which branches off the Edgerton Highway

at Chitina.

The Orange Hill deposit is located in the south-central part of the Nabesna 1o X 3o quadrangle, about 13 miles (21 km)

southeast of the Nabesna mine, near the foot of the Nabesna Glacier. The Bond Creek deposit is about 4 mi (6.4 km) east of

Orange Hill. Topography is subdued near the valley bottom at the base of Orange Hill (about 3000 ft/900 m in elevation), but

climbs steeply into rugged mountains rising over 8000 ft (2440 m) immediately east of Orange Hill and throughout the Bond

Creek area. The area is accessible only by bush plane to a remote airstrip at Orange Hill.

The Bremner mining district is located in the southwestern part of the McCarthy 1o X 3o quadrangle. Topography

varies from about 3500 ft (1070 m) in the valley of Golconda Creek, to over 6000 ft (1830 m) in the surrounding mountains. .

The area is accessible only by bush plane to a remote airstrip at Bremner.

Gold Hill is located in the Chisana mining district in the southeastern part of the Nabesna 1o X 3o quadrangle, about 6

mi (9.6 km) northeast of the remote rural community of Chisana. Topography in this relatively hilly area varies from about

4000 ft (1220 m) near the base of Gold Hill, to 5940 ft (1811 m) at the summit of Gold Hill. The area is accessible by foot from

Chisana, or by bush plane to a remote airstrip at Gold Hill.

GENERAL GEOLOGY, DEPOSIT SETTING, AND MINING HISTORY

Deposits at Nabesna, Kennecott, Gold Hill, Orange Hill, and Bond Creek are found within the allochthonous

Wrangellia terrane (Jones and others, 1977), one of the accretionary terranes that constitute the geology of southern Alaska.

Wrangellia originated at low paleo-latitudes in the proto-Pacific region and probably was sutured to southern Alaska in the Late

Cretaceous (Plafker and Berg, 1994). The Bremner district and surrounding Chugach Mountains are found within the Chugach

terrane, part of a large subduction-related accretionary complex. Accretion of the Chugach terrane to southern Alaska began in

the latest Triassic, but occurred mainly in latest Cretaceous to earliest Tertiary time. Subsequently, the Chugach terrane was

intruded by numerous Tertiary granitoid plutons (Plafker and others, 1994).

NABESNA

Rocks exposed near the Nabesna mine, are predominantly Upper Triassic limestone; lesser underlying Nikolai

Greenstone, an amygdaloidal subaerial basalt of Middle to Late Triassic age; and lesser overlying calcareous argillite and

siltstone of the Upper Jurassic and Lower Cretaceous Nutzotin Mountain Sequence (Moffit, 1943; Wayland, 1943; Lowe and

others, 1982; Newberry, 1986). The limestone, referred to as Chitistone Limestone by Wayland (1943), consists of about 366 m

of massive limestone, overlain by about 244 m of thin-bedded limestone (Wayland, 1943). It is intruded by Early Cretaceous

stocks and dikes of granodiorite and quartz diorite (Wayland, 1943; Lowe and others, 1982; Newberry, 1986; Weglarz, 1991)
5

that have K-Ar hornblende and biotite ages respectively of 109 and 114 Ma (Nokleberg and others, 1994). The Triassic to

Cretaceous rocks are overlain unconformably by andesitic and basaltic lavas of the Tertiary to Quaternary Wrangell Lava (Lowe

and others, 1982).

The intrusion of granodiorite into the carbonate sequence recrystallized some limestone and formed gold-bearing, ironrich skarn bodies. These skarns were exploited at the Nabesna and Rambler mines. Principal ore minerals were pyrite,

pyrrhotite, magnetite, and chalcopyrite, with minor galena, sphalerite, arsenopyrite, and stibnite. Gangue minerals included

garnet, wollastonite, vesuvianite, epidote, actinolite, hornblende, chlorite, scapolite, apatite, serpentine, and quartz (Wayland,

1943; Newberry, 1986; Weglarz, 1991). The main gold ores were pyrite veins along crosscutting fractures in limestone and

sulfide-silica-rich bodies (Nokleberg and others, 1994). Minor gold was produced from massive magnetite and pyrrhotite bodies

(Wayland, 1943). Total gold production is listed in Theodore and others (1991) as 0.08 million metric tons at 25 g/t Au.

Wayland (1943) also reports unquantified, but small, production of silver and copper. As noted by Newberry and others (1997),

classification of the deposits, based on production records, has been problematic. The Nabesna skarn deposit has been classified

as an iron skarn with byproduct gold (Theodore and others, 1991, table 3; Nokleberg and others, 1994), and as a gold-rich

copper skarn (Newberry and others, 1997). Similarly, the Rambler deposit has been classified as an iron skarn (Nokleberg and

others, 1994) and as a gold skarn (Newberry and others, 1997).

Gold was first panned at the foot of White Mountain in 1899 (Wayland, 1943). The earliest claims were located in the

Nabesna mine area between 1903 and 1905, and sporadic work continued into the 1920's. In 1929, the Nabesna Mining

Corporation was formed and mine development was accelerated (Hunt, 1996). By 1935, the operation was running year-round

and a stamp mill was processing 60 tons of ore per day. In the 1930s both mercury amalgamation and cyanide treatment were

attempted to recover gold (Holdsworth, 1937; Wayland, 1943). By 1940, the deposits at the Nabesna mine were exhausted.

However, the discovery in 1941 of a nearby gold-bearing pyrrhotite skarn body (probably the Rambler orebody) prompted

small-scale exploration and mining (Moffit, 1944). Sporadic exploration and drilling continued at Nabesna into the 1980's.

Presently, the mill and associated buildings are standing but in disrepair; a small amount of stockpiled ore remains near the old

tram; mine-waste rock remains near the mill and on slopes below caved adits high on White Mountain; and a thin (less than 1 m

thick) veneer of fine, pyrite-rich and iron-oxide-rich mill tailings is present over a several-thousand-square-meter area below the

mill.

KENNECOTT

Strata-bound copper deposits in the Kennecott area are found in the lower part of the Chitistone Limestone, near the

disconformable contact with the underlying Nikolai Greenstone. Basalt flows of the Nikolai Greenstone are mainly tholeiitic,

have a high background copper content of around 150 parts per million (ppm), and are more than 2,740 m thick in the Kennecott

region (MacKevett and others, 1997). The Chitistone Limestone grades upward into the Nizina Limestone. The carbonate rocks

represent a deepening-upward succession; the lower part of the Chitistone accumulated in an intertidal-supratidal, locally sabkha

setting; whereas the Nizina was deposited in a moderately deep water marine environment (MacKevett and others, 1997). In the

McCarthy quadrangle, the maximum thickness of the Chitistone Limestone is about 600 m and the maximum thickness of the

Nizina Limestone is about 500 m (MacKevett, 1978).

The Kennecott deposits were mined for their spectacularly high-grade copper ore, which locally exceeded 70 percent.

MacKevett and others (1997) suggest that the Kennecott deposits formed through the following sequence: (1) copper-enriched

Nikolai Greenstone was extruded during the Middle or Late Triassic; (2) carbonate sediments (Chitistone Limestone) were

deposited in a Late Triassic marine embayment on the Nikolai Greenstone; (3) sabkha-facies deposits, rich in sulfates and

organic matter, formed locally in the embayment and restricted circulation, leading to evaporation that resulted in brine

development; (4) karst features developed in exposed parts of the lower Chitistone Limestone following marine regression; (5)

the Chitistone was buried by as much as 3,050 m of marine limestone, black shale, and other sedimentary rocks of the Nizina

Limestone and the McCarthy, Nizina Mountain, and Root Glacier Formations; (6) the section was folded, faulted, and uplifted

during the Late Jurassic to Early Cretaceous; (7) uplift and folding provided hydrologic head that caused brine circulation and

leaching of copper from the Nikolai Greenstone; and (8) large orebodies formed in fissures and breccias in the lower Chitistone

Limestone when migrating copper-rich brines mixed with reduced fluids derived from gypsum-organic matter mixtures in the

sabkha horizons. The copper ore was mainly chalcocite and djurleite, with lesser chalcopyrite, bornite, covellite, digenite,

anilite, luzonite, idaite, malachite, azurite, chalcanthite, and orpiment (Bateman and McLaughlin, 1920; MacKevett and others,

1997). More than 535,000 metric tons of copper and several million ounces of silver were produced from 1911 to 1938, the

major period of mining activity (MacKevett and others, 1997). Average grade of the ore was about 13 percent.

Early Russian explorers reported implements of copper used by Copper River Indians at the mouth of the Copper River

(Douglass, 1964). Prospecting in the region in the late 1890's probably was stimulated by the Klondike gold rush. The first

Kennecott-type deposit was found by prospectors in 1900, who located extensive copper-stained outcrops crowning the Bonanza

deposit, high above the Kennicott Glacier (Douglass, 1964; Hunt, 1996). The other principal deposits were located within the

next few years. The first ore was shipped in 1911, but the peak of mining activity was from 1915 to 1929. Copper sulfide ore

was gravity-concentrated and shipped directly for processing in Washington. Copper was stripped from carbonate ore

(malachite and azurite) at the mill using a Kennecott-developed ammonia leach process, and then it was shipped for further

refining. The mines ceased production in 1938 because of low reserves, low copper prices, and labor problems (MacKevett and
6

others, 1997). Presently, the mill area remains intact, and carbonate-rich mine-waste rock remains below caved adits high above

the mill on Bonanza Ridge.

ORANGE HILL AND BOND CREEK

Rocks in the vicinity of the Orange Hill and Bond Creek porphyry copper-molybdenum deposits are composed

predominantly of a variety of intrusive rocks of the Cretaceous Nabesna batholith, a quartz diorite to granodiorite pluton dated at

105 Ma (Newberry and others, 1997). Less extensive are Pennsylvanian to Permian volcanic and volcaniclastic rocks; and

lesser Triassic Nikolai Greenstone. Volumetrically minor thin bodies of Permian limestone are present locally (Richter, 1973).

In both areas, quartz diorite and granodiorite of the Nabesna pluton are intruded by slightly younger hornblende-plagioclase

porphyry (Nokleberg and others, 1994; Richter, 1973). Limonite staining and hydrothermally altered rocks are extensive;

alteration mineral suites include biotite-quartz, quartz-sericite, and late-stage chlorite-sericite-epidote (Richter, 1973; Nokleberg

and others, 1987; Nokleberg and others, 1994). Hydrothermally altered rock occupies an area of 1 X 3 km at Orange Hill and 2

X 3 km at Bond Creek (Richter and others, 1975).

Mineralization consists of pyrite, chalcopyrite, and minor molybdenite in potassic and sericitic quartz veins and as

disseminations, commonly found along altered granite porphyry dikes (Richter and others, 1975; Nokleberg and others, 1994).

Magnetite and anhydrite are locally abundant. Associated with the porphyry deposits at Orange Hill are minor, gold-poor

skarns, found near limestone contacts. The skarn deposits consist of red, brown, and green garnet; vesuvianite; pyroxene;

epidote; diopside; wollastonite; hematite; magnetite; and the sulfides pyrite, chalcopyrite, bornite, covellite, massive pyrrhotite,

sphalerite, and minor molybdenite (Van Alstine and Black, 1946; Linn, 1973; Nokleberg and others, 1994; Newberry and others,

1997). The Orange Hill deposit contains 100 to 320 million tonnes grading 0.30 to 0.35 percent copper and 0.02 to 0.03 percent

molybdenum. The Bond Creek deposit contains an estimated 500 million tonnes grading 0.15 to 0.40 percent copper and 0.02

percent molybdenum (Young and others, 1997).

Neither Orange Hill nor Bond Creek have been mined, although both have been explored in the past and patented

mining claims are still held at Orange Hill. Early reports of ground staking at Orange Hill were for gold, although only

negligible quantities were found (Moffit and Knopf, 1910; Moffit, 1943). By the early 1930s, several copper lode claims were

held at Orange Hill and a few thousand feet of drill core had been obtained (Stewart, 1931; Van Alstine and Black, 1946).

Sporadic exploration in the 1960s and 1970s included mapping and drilling at Orange Hill (Linn, 1973) and Bond Creek

(Gillespie, 1970). Exploration activity ceased around 1980, when the areas were included in the newly established National

Park and Preserve. In 1996, only a few prospects, scattered drill core, and a cabin were evident at Orange Hill. Evidence of

exploration activity at Bond Creek in 1997 consisted of 3 small wooden drilling platforms and associated debris, all

subsequently removed by the NPS in 1998.

BREMNER

The most recent geologic maps of the Bremner area are the 1:250,000-scale reconnaissance maps of the McCarthy

quadrangle by MacKevett (1978) and Bering Glacier quadrangle by Plafker (unpublished mapping, 1998), the sources of the

following summary. Mountainous outcrop in the region around the Bremner gold deposits is predominantly the Cretaceous

Valdez Group, and intervening valleys are filled with unconsolidated Quaternary alluvial, colluvial, and glacial deposits. The

flysch deposits of the Valdez Group are at least several thousand meters thick and are composed interlayered metagraywacke

and argillite, and minor schist, slate, and phyllite. Rocks of the Valdez Group in the Bremner area are variably metamorphosed

to chlorite- or biotite-grade greenschist facies and have northwest-striking foliation and lineaments. The Valdez Group

represents turbidite deposits that formed extensive deep-sea fans. Hypabyssal, hornblende-rich, early to middle Tertiary

granodiorite and tonalite plutons, and dacite dikes and sills cut the Valdez Group. Large Tertiary intrusions cutting rocks of the

Valdez Group are found about 8 mi (13 km) northeast and 5 mi (8 km) south of the Bremner deposits. During our study of the

Bremner deposits, individual and swarms of granodiorite and dacite dikes were observed, all generally less than 2 m thick. We

also noted pervasive thin quartz and quartz-calcite veins and veinlets (metamorphic sweat veins?) cutting the Valdez Group

metasediments.

While gold can be panned from most streams in the area, paying placers were limited to (in order of increasing

importance) parts of the Bremner River, the Little Bremner River, and Golconda Creek (Moffit, 1914). The Golconda Creek

basin is where most placer and nearly all lode mining took place. Alluvial gravels along Golconda Creek were generally less

than 8 ft thick and were interpreted by Moffit as re-worked bench gravels. The fluvial re-working of the bench gravels reconcentrated the gold already disseminated within the bench deposits, making the deposits profitable (Moffit, 1914). Little lode

prospecting had been done along Golconda Creek prior to Moffit’s (1914) study, although he noted the presence of numerous

dikes and locally-mineralized calcite-bearing quartz veins. Moffit (1914) believed the placer gold was derived from the quartz

veins; subsequent discovery of gold-bearing quartz veins in the basin supports his theory. At the Lucky Girl mine (mislabeled

as the Yellowband mine on the USGS McCarthy A-7 quadrangle) we found a series of three adits following a northwesttrending, near vertical, pyrite-rich, banded, white quartz vein cutting slate. Brecciated portions of the vein are up to 2 m thick,

vuggy, and iron-oxide-rich. Ore at the adjacent mill site consisted of white quartz cobbles with sericite, chlorite, iron oxide as

clots and pseudomorphs after pyrite, calcite; and lesser galena, arsenopyrite, sphalerite, and free gold. At the Yellowband mine,

located about 4 km south of the Lucky Girl mine, we found a gold-bearing, pyritic, iron-stained quartz vein containing sparse

sericite and chlorite, and following a granodiorite dike swarm. Biotite in the granodiorite dikes has been altered to chlorite.

Vein quartz from the Sheriff mine, located about 3.2 km southeast of the Lucky Girl mine, contained iron-oxide clots, pyrite,
7

chlorite, sericite, free gold, calcite, and probably arsenopyrite. While production records from the Bremner district are scant,

MacKevett (1976) lists placer gold production at between 2000 and 3000 oz (56,700 and 85,000 g) and lode gold production at

about 750 oz (21,300 g).

The gold placers along the Little Bremner River were discovered in 1901 by two parties of prospectors and placer

claims were staked on Golconda Creek in that year (Moffit, 1914). Initial placer mining was by pick and hammer, but by 1911,

hydraulic giants were in use, with associated ditch lines and flumes (Moffit, 1914). By the early 1930s, both lode mine

development and placer prospecting were underway at Bremner, aided by construction of an airstrip in 1931 (Stewart, 1933).

Placer activity was apparently much-reduced from that reported by Moffit (1914), consisting of prospecting at the mouth of

Standard Creek and on Golconda Creek over a 2.5 mi stretch both above and below Standard Creek (Stewart, 1933). Lodes at

the Lucky Girl, Yellowband, and Sheriff were apparently being exploited, and a small mill utilizing mercury amalgamation was

constructed at the Lucky Girl mine. Mining activities at Bremner ceased during World War II and never resumed (Hunt, 1996).

Presently, the mill and mine buildings have collapsed, but several cabins remain standing. Mill tailings and mine waste piles are

evident at the lode mines. However, only scattered hand-stacked piles of boulders remain along Golconda Creek as evidence of

the earlier frenzied placer activities.

GOLD HILL

The following description of the geology of the Gold Hill area is extracted from Richter and Jones (1973). Bedrock in

the Gold Hill area is predominantly marine and subaerial volcanic and volcaniclastic rocks of the Lower Cretaceous Chisana

Formation. The 10,000-ft thick Chisana Formation consists of andesitic volcanic flows; volcanic conglomerate; tuffs;

fragmental volcanic units (probably lahars and avalanche deposits); volcanic sandstone and siltstone; and, in the lower part of

the section, thin lenses of marine argillite, graywacke, pebble conglomerate and tuffaceous mudstone. Jurassic to Cretaceous

argillite and mudstone deposits are found locally. North of Gold Hill are extensive deposits of rhythmically interbedded Jurassic

deposits of graywacke, siltstone, and argillite. Small bodies and dikes of Tertiary to Cretaceous andesite porphyry and

porphyritic diorite are scattered throughout the placered area. A large intrusion of pyroxene-diorite monzonite is exposed just

west of Gold Hill. Quaternary to Tertiary unconsolidated gravels and isolated patches of Wrangell Lava are present locally.

Most of the bedrock around Gold Hill is concealed by Quaternary glacial gravel and sand deposits, fluvioglacial (?) deposits,

solifluction deposits, and alluvial deposits.

The productive placer gravels are Tertiary, lying near or on volcanic and sedimentary rocks of the Chisana Formation

(Richter and Matson, 1972). All placer mines in the district are found in an area 5 mi (8 km) in diameter, centered on Gold Hill,

and include Bonanza Creek and its tributaries, Gold Run Creek, and Big Eldorado Creek (Capps, 1915; Moffit, 1943). Other

heavy minerals found in the placer deposits include native copper, native silver, galena, cinnabar, and molybdenite (Nokleberg

and others, 1987). Total gold production from the placers is about 1.4 million grams (Nokleberg and others, 1987). Scattered

about Gold Hill are pyritic, iron-oxide stained outcrops of andesite (?) and a few prospects that explore gold- and silver-bearing

base metal lodes. Several areas of iron-oxide-stained, sulfate-bearing, altered bedrock are found near the junction of Bonanza

and Chathenda Creeks (Richter and others, 1975). One of the lodes visited in this study, on N.P. Nelson Hill, is a galenasphalerite-chalcopyrite-calcite-quartz vein breccia containing malachite and limonite. The vuggy vein cuts feldspar-andesite

porphyry. Other small gold-bearing veins of similar character are described briefly by Capps (1915), Stewart (1931), Moffit

(1943), and Richter and others (1975). There is no reported production from the lode deposits. Capps (1915) believed that the

gold-bearing lodes were the source of the placer gold deposits. The placer deposits produced about 50,000 oz (1.4 million g) of

gold (Nokleberg and others, 1987).

Placer gold was discovered at Gold Hill in May of 1913, resulting in initial claims on Bonanza Creek, where 200 oz of

gold was recovered in two days (Bleakley, 1996). A gold rush ensued. Several thousand stampeders were in the Chisana

district by October, 1913, when Chisana City was founded, and all available sites had been claimed by July, 1914. However, the

boom was short-lived, the district was in decline by 1915, and by 1920 only eight mines remained, employing less than 20 men

(Bleakley, 1996; Hunt, 1996). Small-scale placer mining has been fairly continuous in the district since then and continues into

the present on unpatented claims located prior to formation of the National Park and Preserve in 1980. Currently, a few

scattered cabins are occupied sporadically during summer months, when small-scale sluicing activities take place.

METHODS OF STUDY

SAMPLE MEDIA

Geochemical sample media include rock, mine waste, mill tailings, stream-sediment, heavy-mineral-concentrate, water,

precipitates, and (at Nabesna only) willow samples. Rock samples were collected generally as composite chip samples from

outcrop, alluvium, mine, and mill tailings. Several mine waste, mill tailings and mineralized bedrock samples were collected for

leaching, using a synthetic meteoric water leach test. The stream-sediment and heavy-mineral-concentrate samples were

collected at mined and unmined areas to provide geochemical information about drainage basins proximal and distal to mine

areas.

The chemical composition of a stream-sediment sample is controlled primarily by the major geologic units within the

drainage basin and to a lesser degree by metal-scavenging materials such as amorphous iron- and manganese oxides, clays, and

organic matter. Minor elemental constituents within the stream sediment, such as elements related to mineral deposits within the
8

drainage basin, may be detected in the sediment analysis, but commonly have a small overall influence on the sample because of

dilution by barren material.

Since elements related to mineral deposits are commonly found in heavy minerals, heavy-mineral-concentrate samples

from stream sediment were also collected. Heavy-mineral concentrates provide chemical information about ore-related and

rock-forming dense minerals, and permit chemical determination of some elements not easily detected in stream-sediment

samples. Further, microscopic identification of nonmagnetic minerals in heavy-mineral-concentrate samples may provide

additional useful mineralogical information.

Water samples were collected from available natural water sources, principally from flowing streams, but also from

seeps, springs, and ponds. Mineral deposits rich in sulfide minerals, solid waste from mine dumps and mill tailings derived

from such deposits, and sulfide-rich rocks of non-economic significance are possible sources of acid and metal loading in the

environment. The water samples provide data reflecting the effects of mining on the environment and data indicating water

quality associated with undeveloped mineralized areas.

Precipitate samples were collected from a few sites at Nabesna and Orange Hill. These were collected as flocs

precipitating from metalliferous waters.

Reconnaissance willow samples were collected at and below the Nabesna mill site. The willows were collected to test

whether the plants had taken up metals related to the mineral extraction activities.

SAMPLE COLLECTION AND PREPARATION

A count of the various types of samples collected from each area studied is listed in the table below. In the table, “site

dupes” and “anal. dupes” refer to sample quality control site duplicates (collected in the field) and analytical duplicates (split

from sample in the laboratory), respectively. Sample sites maps are provided in figure 2 (Nabesna mine area), figure 3 (Nabesna

mill area), figure 4 (Kennecott), figure 5 (Gold Hill), figure 6 (Orange Hill and Bond Creek), and figure 7 (Bremner).

Total Nabesna Kennecott Gold Hill Orange

Hill

Bond

Creek

Bremner

Water 101 51 11 15 7 8 9

 Site dupes 10 4 2 1 1 1 1

 Anal. dupes 1 1

Sediment 70 22 11 15 6 8 8

 Site dupes 93 2 1 1 1 1

 Anal. dupes 1 1

Leach 18 12 2 1 3

 Anal. dupes 31 1 1

Rock 56 24 10 7 3 7 5

Anal. dupes 21 1

Concentrate 51 11 7 14 5 5 9

Anal. dupes 1 1

Precipitate 72 5

Willow 32 32

Sediments

Each stream-sediment sample consisted of alluvium from the active stream channel, composited by collecting sediment

increments from several places at the sample site, generally along a 30-ft (10-m) stretch of the channel. In order to improve

sample representativity, an attempt was made to collect 20 to 30 increments at each site. However, at some sites sparse

distribution of available sediment reduced the number of increments to less than 10. The sediment was sieved on site with a 10

mesh (2 mm) stainless steel screen. A 2-lb (1-kg) sample of minus-10 mesh sediment was collected in a cloth bag and air-dried.

Sediment samples were predominantly from stream alluvium, but a few were collected from ponds and springs. Sediments were

also collected from just below mill tailings and mine waste piles. These were composited in a similar manner as described

above

In the laboratory, sediment samples were air-dried and sieved at 80 mesh (0.177 mm), following the method of Peacock

and others (1996). The coarse fraction was disgarded. The fine sediment fractions from samples collected during the initial year

of study (1994) were further sieved into two fractions: minus-80 mesh to plus-200 mesh (0.074 mm), and minus-200 mesh.

The two sieve fractions were chosen to assess variation of metal content with sediment particle size. This variation was found to

be minimal, so in the subsequent years of sample collection, the minus-80 mesh sample was analyzed in toto. The fine sediment

fractions were pulverized to a fine flour consistency (minus-100 mesh/0.149 mm), with clean quartz sand pulverized between

each sample to reduce risk of cross-contamination. For each sample, an approximate 6.5-oz (185-g) portion was saved for

chemical analyses; any remaining material was subsequently archived. Sediment sieve size and sources are listed in the

sediment data file.
9

Heavy Mineral Concentrates

Most panned concentrate samples were collected from the same active alluvium as sediment samples. Some samples

were also collected from mill tailings and mine waste. Alluvial samples were collected from around boulders and in coarse

gravels. The pan concentrate samples were not composited as the stream sediment samples were, but were collected as grab

samples in areas where heavy minerals tend to accumulate. A 14-inch stainless steel gold pan was filled with stream sediment

sieved to minus-10 mesh (2 mm) with a stainless steel screen, resulting in approximately 16 lb (7.2 kg) of material. This sieved

alluvium was panned at the site when running water was available, or collected in a cloth bag for later panning. The alluvium

was panned until most of the less-dense minerals (primarily quartz and feldspar), organic materials, and clays were removed.

Generally, one to three percent of the original sample remained after panning. The panned sample was bagged, air-dried, and

saved for further laboratory preparation.

In the laboratory, panned concentrate samples were sieved to minus-20 mesh (0.84 mm), and then gravity separated

using bromoform (specific gravity about 2.85) to remove remaining light minerals, primarily quartz and feldspar. The resultant

heavy-mineral-concentrate sample was separated into magnetic, weakly magnetic, and nonmagnetic fractions using a modified

Frantz Isodynamic Separator (Taylor and Theodorakos, 1996a). The magnetic fraction was extracted at a setting of 0.25 ampere

and contains primarily magnetite and ilmenite. The weakly magnetic fraction was extracted at a setting of 1.75 ampere and

consists largely of ferromagnesian silicates and iron oxides. The remaining nonmagnetic fraction may contain many ore-related

minerals including sulfide minerals, gold and other native metals, and some accessory oxides and silicates. The nonmagnetic

heavy-mineral-concentrate samples were split using a Jones splitter. One split was hand ground with an agate mortar and pestle

for chemical analysis and the other split was used for microscopic mineralogical analysis. Clean quartz sand was hand ground

between samples to clean the mortar and pestle, thereby reducing the risk of cross-contamination between samples.

Rocks

Mineralized and unmineralized rock samples were collected from outcrop, mine waste, mill tailings, and alluvium.

Rock samples were typically composite chip samples collected at the sites. Single grab samples were collected where

compositing was not possible. Rock descriptions were recorded in field notes and later entered into the rock data file.

In the laboratory, rock samples were coarsely crushed to pea-sized pieces and then split with a Jones splitter, generally

following the procedure of Taylor and Theodorados (1996b). For each sample, an approximate 6.5 oz (185 g) portion was

pulverized and saved for chemical analysis and subsequent archival of any remaining material. Clean quartz rock and sand was

crushed and pulverized, respectively, between samples to reduce the risk of cross-contamination between samples.

Water

A 1-liter polypropylene bottle was used for collecting water for sampling. The bottle was rinsed prior to sample

collection. While rigorous width- and depth-integrated sampling protocol was not followed, an attempt at collecting integrated

samples was made by collecting at intervals across the entire width of the stream or spring. When possible, we collected below

riffles--natural zones of mixing. The filled 1-liter bottles were capped and shaken prior to collecting sub-samples from them.

Sub-samples were collected in polypropylene bottles rinsed on site with unfiltered water for unfiltered water samples and with

filtered water for filtered samples. Bottles for acidified samples were pre-rinsed in the laboratory with a 10 percent nitric acid

solution. In all cases, care was taken at each site to minimize contamination by rinsing bottles and equipment; and by using

new, unpowdered vinyl gloves, disposable equipment (filters, syringes, etc.), and plastic sheets to cover work areas.

A variety of water samples was collected from the areas studied, and the kinds of water samples collected evolved over

the years as the study progressed. During the first year (1994) three sub-samples were collected: (1) an unacidified, filtered raw

water sample for anion analysis, (2) an acidified, unfiltered sample for trace and major cation analysis of both dissolved and

suspended species, (3) an acidified, filtered sample for trace and major cation analysis of dissolved species. The unacidified

samples were kept cool on ice or permafrost in the field and in a refrigerator in the laboratory prior to analysis. Samples were

filtered with sterile 0.45-micron disposable filters and acidified to pH < 2 with ultra-pure, concentrated nitric acid to prevent

precipitation of metals and bacterial growth.

Additional water samples collected in 1996 and 1997 include water for ferrous iron content, water for mercury content,

and (in 1997 only) water for measuring alkalinity in the laboratory. The ferrous iron water samples were filtered as described

above; collected in opaque, dark brown polypropylene bottles to prevent light penetration; and acidified with ultra-pure,

concentrated hydrochloric acid to pH < 2. The mercury water samples were filtered as described above; collected in acid-rinsed

glass bottles with Teflon lids; and preserved with potassium dichromate/nitric acid. The waters for laboratory-determined total

alkalinity analysis were collected at sites where water pH was > 4.5, as unfiltered, unacidified samples, and were kept cool as

described above. The 1997 laboratory alkalinity analyses provide a means to assess quality of companion alkalinity analyses

collected on site throughout the study, as described below. In general, the agreement between the two alkalinity methods was

found to be good.

 Other water data collected and recorded on-site include temperature, pH, conductivity, dissolved oxygen content, an

estimate of the water flow rate, total acidity, and total alkalinity. Conductivity and pH were collected with Orion meters

calibrated with standards at each site prior to sample measurement. For pH, two calibration buffer standards that bracketed the

sample’s pH were used. Dissolved oxygen content was determined using a field-portable CHEMetrics brand colorimetric test

kit. Total acidity measurements were collected in 1997 only, using a field-portable Hach titration kit, and titrating to the

phenolphthalein endpoint. Only waters with pH values below 7.0 were tested for acidity, which is a measure of total base-
10

neutralizing capacity of the water, reported in ppm as CaCO3. On-site total alkalinity measurements were collected from 1994

through 1997 at each water sample site where pH was > 4.5, using a field-portable CHEMetrics titration kit. Alkalinity is a

measure of total acid-neutralizing capacity of water and is reported in ppm as CaCO3.

Leached Samples

Samples were collected from mine waste, mill tailings, and outcrop for a synthetic meteoric water leachability test.

Samples were collected by scraping material from the upper 1 inch (2.5 cm) of the surface layer and filling a large canvas bag

with approximately 2 lb (1 kg) of material. Samples were composited by collecting several increments from several places at

the sample site. For better sample representativity, an attempt was made to collect 20 to 30 increments at each site. Four

deviations from this sample collection methodology were made at Nabesna (sites 6NA031-6NA034), where mill tailings core

samples rather than surficial samples were composited. Unsieved leach samples were saved for further preparation in the

laboratory.

Laboratory preparation for the samples, described briefly below, followed a modification of the EPA Synthetic

Precipitation Leaching Procedure 1312 (Environmental Protection Agency, 1994). This method is used to determine mobility of

inorganic analytes present in samples of soils, wastes, and waste waters. The composited, solid, dry sample was passed through

a 9.5 mm (0.375 mesh) sieve. Water used for leaching was organic-free, deionized water, acidified with sulfuric acid/nitric acid

(60/40 weight percent mixture) to a pH of 4.20 ± 0.05, the pH recommended in the procedure for waste materials. Using a ratio

of 20:1 water to sample, 1 liter of acidified, deionized water (temperature, 23( C) was added to 50 g of sample in a rinsed

polypropylene bottle. The mixture was rotated at 30 ± 2 rpm for 18 ± 2 hours. Blank samples using the acidified, deionized

water were included for each batch of samples leached. Following rotation, measurements for pH, conductivity, temperature,

oxygen content, and alkalinity were collected on the leachates. Our modification to the EPA 1312 procedure was done at the

filtering stage. Rather than filtering the entire 1-liter leachate through a stainless steel positive pressure filtration unit, we

filtered only the amount of sample required for analysis, using sterile 0.45-micron disposable filters. Following filtration,

leachates were acidified with ultra-pure, concentrated nitric acid. Prior to leaching, splits of the solid phases of the samples

were saved for analysis, permitting comparison of metal contents in the total sample (hereafter referred to as leach solid phase)

with those in the leacheable portion (hereafter referred to as leachate).

Precipitates

A few precipitate samples were collected at Nabesna and Orange Hill. These samples are flocs precipitating out of

metalliferous waters onto the underlying substrates. The samples were composited from wet areas on alluvium or mill tailings

and placed in sealed plastic bags. In the laboratory the precipitates were dried, hand-ground with a mortar and pestle, and then

split for chemical and mineralogical analysis by X-ray diffraction. Clean quartz sand was hand ground between samples to clean

the mortar and pestle, thereby reducing the risk of cross-contamination between samples.

Willows

All willow samples were collected from Nabesna on August 13, 1997. Samples of two willow species, Salix Alaxensis

and Salix Glauca, were collected by compositing leaves from new-growth (1997) stems. At each sample site, samples from

approximately five willow bushes of a single species within a 30 ft (9 m) radius were composited and placed in a tightly woven,

breathable, 5.5 in by 10.5 in Hubco bag. If both willow species were present at a given site, Salix Glauca was the species

collected. Samples were collected at numerous points on the Nabesna mill tailings, on a traverse about 3000 ft (910 m)

downstream of the mill tailings, and on a traverse about 4400 ft (1340 m) lateral to the mill tailings.

In the laboratory, each willow sample was placed in a plastic colander and washed, first under tap water, then under deionized water (Peacock, 1996). Next, the samples were dried in a drying oven, and weighed. Then the samples were ashed, and

the ash was weighed and saved for analysis. The weight percent ash was calculated from the sample and ash weights (Peacock,

1996). Analyses of willow samples are reported on a dry-weight basis.

ANALYTICAL TECHNIQUES

A large number of chemical elements were determined, using a variety of quantitative and semi-quantitative analytical

techniques. Table 1 shows the various elements determined and analytical methods used for each of the sample media collected

in the study. A brief description and published references for each analytical method is given below. Descriptions and quality

assurance/quality control (QA/QC) protocol for most of the analytical methods used in this study are found in Arbogast (1996).

U.S. Geological Survey laboratories analyzed all water samples. Solid samples were analyzed by both U.S. Geological Survey

laboratories and by a contractor, XRAL Laboratories, Inc., as indicated in the data files.

Throughout the study, QA/QC concerns were addressed through the use of internal reference standards, field blanks,

sample site duplicates, and analytical duplicates. QA/QC samples comprised 19 percent of the total number of samples

analyzed. Reference standards were interspersed with batches of samples and the analyses of the reference standards were

checked to assure that reported values were within ± 20 percent of the accepted values. About 5 percent of the QA/QC samples

were reference standards. Water samples included field blanks of de-ionized water, used to check for contamination from

sampling equipment and preservatives. Field blanks were collected following the same procedures as those used for normal

water samples. Field blanks comprised about 6 percent of the total number of water samples. Sediment and water sample site

duplicates were collected randomly and comprise about 6 percent of the total number of samples. The site duplicates were

collected following the same procedures as those used for normal water and sediment samples. Analytical duplicates for the
11

various sample media comprise about 2 percent of the total. Only the sample site duplicates are retained in the published data

files.

In the data files for the various sample media, discrepancies in element concentration for the same sample determined

by different analytical methods (for example, gold) may be attributable to the particulate nature of certain elements, different

sample weights used, different dissolution and extraction procedures, and to instrumental bias. For gold in particular, the atomic

absorption spectrophotometric (AAS) analytical method provides the most statistically representative results, due to the larger

sample weight analyzed; a 10-gram sample weight is used for the AAS analysis, whereas a 10-milligram sample weight is used

in the emission spectrographic technique.

For simplicity, reporting units for all sample media are percent (%), parts per million (ppm), or parts per billion (ppb).

Water sample analyses, which are commonly reported in the literature as milligrams per liter or micrograms per liter, are given

here as ppm or ppb, respectively.

Inductively Coupled Plasma-Atomic Emission Spectrometry

Three ICP-AES methods were used in the study for multi-element analyses: (1) a 40-element total digestion method

(designated "ET" in table 1 and in the data files) for sediments, rocks, precipitates, leach solid phases, and willows (willow

analyses are dry weight); (2) a 10-element, partial-extraction method (designated "EP" in table 1 and in the data files) for

sediments, rocks, and leach solid phases; and (3) a trace- and major-element scan for acidified water and leachates (designated

"EW" in table 1 and in the data files.

In the first multi-element method, 40-element ICP-AES, samples were digested and analyzed following the procedure

of Briggs (1996). Samples were digested using a mixture of hydrochloric, nitric, perchloric, and hydrofluoric acids, and the

solutions were heated at 110( C until dry. Additional perchloric acid and water were added to the residue and the mixture was

then taken to dryness at 150( C. Aqua regia and dilute nitric acid were added to the residue to bring the solution to a final

volume, the solution was heated at 95( C for an hour, and then, after cooling, the sample was aspirated into the argon plasma

and element concentrations were determined simultaneously with a multi-channel ICP-AES instrument. Limits of determination

for 40-element ICP-AES are shown in table 2.

In the second multi-element method, concentrations of Ag, As, Au, Bi, Cd, Cu, Mo, Pb, Sb, and Zn were determined on

samples by a 10-element ICP-AES partial extraction procedure developed by Motooka (1996). Samples were decomposed with

concentrated hydrochloric acid and hydrogen peroxide in a hot-water bath. Metals were extracted in diisobutyl ketone

(DIBK)/Aliquat 336 in the presence of ascorbic acid and potassium iodide. The DIBK/Aliquat 336 phase was then aspirated

directly into the argon plasma and element concentrations were determined simultaneously with a multi-channel ICP-AES

instrument. Mineralized rock samples with high copper content (above 10,000 ppm) required dilution for the 10-element ICPAES method because of copper interferences on other elements. Thus, the ICP-AES partial extraction (EP) trace-element

analyses for mineralized rocks with high copper content (principally those from mines or prospects) are qualitative estimates and

should be used cautiously. Limits of determination for 10-element ICP-AES are shown in table 3.

In the third multi-element method, acidified water samples were analyzed for major (Al, Ca, Fe, K, Mg, Na, and Si)

and selected trace elements following the ICP-AES method of Briggs and Fey (1996). Water samples collected in 1994 were

preconcentrated by a factor of 20 to 1 by evaporation at 100( C and subsequent dissolution the residue in nitric acid. The

residue solutions were then aspirated into the plasma and element concentrations were determined by ICP-AES. The

preconcentration step was used when specific conductivities for the water samples were less than 2000 microsiemens/cm; water

samples with conductivities greater than 2000 microsiemens/cm were not preconcentrated and were analyzed directly by ICPAES, using a modification of the method by Lichte and others (1987) (Paul H. Briggs, personal communication, 1995).

Beginning in 1995, the preconcentration step was eliminated for water samples because a new instrument with better dynamic

range was used. Limits of determination for the multi-element ICP-AES method for water samples are shown in table 4.

A separate ICP-AES method was used to determine tungsten in sediment and rock samples collected in 1994 only, the

ion-exchange separation ICP-AES method developed by Doughten and Aruscavage (1996). The samples were decomposed

with nitric, hydrofluoric, and hydrochloric acids and then evaporated to dryness. The residue was dissolved in hydrochloric acid

and this solution was passed through an ion-exchange column, where the chloride form of tungsten was adsorbed onto the resin.

Tungsten was eluted from the resin, dissolved in hydrochloric acid, and determined by ICP-AES. This method is designated IE

in table 1 and in the data files. Limits of determination for tungsten in sediment and rock samples are shown in table 3.

Tungsten was not determined on samples collected after 1994.

Ion Chromatography

The anions Cl-

, F-, NO3

-

, and SO4

2-were determined sequentially by ion chromatography on unfiltered, unacidified water

samples following a modification (d'Angelo and Ficklin, 1996) of the procedure of Fishman and Pyen (1979). The raw water

samples were kept cool from the time of collection until they were analyzed. The samples were injected into a chromatograph

where ions of interest separate along an ion exchange separator column at different rates, depending on the affinity of each

species for the ion-exchange resin. Samples then passed into a flow-through conductivity cell where the anions were detected

and their peak heights were recorded. Unknown samples were compared with peak heights of reference standards to determine

sample concentrations. This method is designated IC in table 1 and in the data files. Limits of determination for anions in raw

water samples are shown in table 5.
12

Inductively Coupled Plasma-Mass Spectrometry

Acidified-filtered and acidified-unfiltered waters, and water from the synthetic meteoric water leach test were analyzed

to determine 64 elements by ICP-MS using a method developed by the U.S. Geological Survey (A.L. Meier, personal commun.,

1995; Meier and others, 1994). This method is designated MW in table 1 and in the data files. The method is used to determine

over 60 elements directly in the water sample without the need for preconcentration or dilution. Element detection limits are in

the sub-part-per-billion range and the working linear range is six orders of magnitude or more. By using derived response

curves, percent of ionization, and natural isotopic abundances, estimates of concentrations for the elements can be determined in

samples without the need of a calibration standard for every element. The method is most useful for trace elements in the partsper-billion range; analyses for major elements in the parts-per-million range are less accurate and ICP-AES data should be used.

Limits of determination for 64 elements by ICP-MS are shown in table 6. Limits vary because a newer ICP-MS instrument with

improved sensitivity was acquired during the life of the study.

Atomic Absorption Spectrophotometry

Various atomic absorption spectrophotometric (AAS) methods were used for determining selected elements in

sediment, rock, and water samples. These methods are described individually below. Determination limits for these techniques

are given in table 3.

Concentrations of thallium in the sediment and rock samples were determined by the AAS technique of O'Leary

(1996). The samples were digested using hydrofluoric acid, sulfuric acid, hydrochloric acid, and hydrogen peroxide. Thallium

was extracted into a solution of 10 % Aliquat 336 and MIBK (methyl isobutyl ketone) in the presence of potassium iodide and

ascorbic acid and determined by flame AAS. This method is designated AA in table 1 and in the data files. Sediment and rock

samples for gold analysis were digested using a hydrobromic acid-bromine digestion, an MIBK extraction, and then gold was

determined on the solutions by flame AAS . However, samples with gold concentrations of less than 0.050 ppm were

subsequently analyzed by graphite-furnace AAS, which has a 0.002 ppm lower determination limit for gold (O'Leary and Meier

(1996). The gold determinations are designated GF in table 1 and in the data files.

Mercury was measured in sediment, rock, and water samples using the cold-vapor AAS technique of O'Leary and

others (1996). The sediment and rock samples were decomposed with nitric acid and sodium dichromate. Preserved water

samples were analyzed directly. Mercury (II) was reduced in the solutions to elemental mercury gas with hydroxylamine

hydrochloride and stannous chloride in a continuous flow system, releasing mercury into the quartz cell of an atomic absorption

spectrophotometer where the mercury concentration was determined. This method is designated CV in table 1 and in the data

files.

Sediment and rock samples were analyzed for arsenic, antimony, and selenium using a continuous-flow

hydride generation AAS (Hageman and Welsch, 1996). The samples were digested using concentrated nitric, perchloric,

sulfuric, and hydrofluoric acids; hydrochloric acid was added to form Se (IV), necessary for determination by hydride

generation. A mixture of hydrochloric acid, sodium borohydride, and sodium hydroxide was added to produce selenium

hydride. The selenium hydride gas was then stripped off the liquid using a phase separator and transported with inert gas to the

atomizer of the atomic absorption spectrophotometer where selenium concentration was determined. A similar procedure was

used for arsenic and antimony. This method is designated HY in table 1 and in the data files. Some of the samples were not

analyzed for arsenic by the HY technique because of high arsenic concentrations beyond the working range of the method (for

these, arsenic was determined by ICP-AES methods), because of elemental interferences in certain mineralized rock samples, or

because of insufficient sample remaining following analyses by other methods (the HY method was the last method used).

Atomic Fluorescence

Water samples analyzed for mercury by cold-vapor atomic absorption were all found to contain concentrations less

than the analytical detection limit of 0.1 parts per billion (ppb). Therefore, the water samples were analyzed by atomic

fluorescence, which has limits of detection of 0.01 parts per billion (J. Crock, personal communication, 1998). For this method,

mercury (II) was reduced as described above for the cold-vapor atomic absorption, and then was released into an atomic

fluorescence detector, where the mercury concentration was determined. This method is designated AF in table 1 and in the data

files. Limits of determination are shown in table 3.

Ferrous Iron by Colorimetry

Ferrous iron was determined by colorimetry, using a microprocessor-controlled, single beam Hach spectrophotometer.

Samples were introduced into an AccuVac Ampul and mixed quickly. Phenanthroline in the ampul reacts with ferrous iron in

the sample to form an orange color in proportion to the ferrous iron concentration. Ferric iron does not react. The ampul was

then placed into the spectrophotometer and concentration was measured. For concentrations higher than 3 ppm, solutions were

diluted and re-analyzed. Limits of determination are shown in table 3.

Alkalinity by Titration

On-site alkalinity tests were done on all samples collected throughout the study, using a field-portable CHEMetrics

titration kit. For comparison, water samples were also collected in 1997 for laboratory alkalinity determination. For the

laboratory alkalinity, an Orion 960 Autochemistry System was used for endpoint titration analysis. The titrant was added to 50

ml of sample until a pH of 4.5 was achieved. Alkalinity was then calculated and reported in units of ppm as CaCO3. Limits of

determination are shown in table 3.
13

Semiquantitative Emission Spectrography

The minus-20-mesh nonmagnetic heavy-mineral-concentrate samples were analyzed by a direct-current arc,

semiquantitative emission spectrographic (SES) technique and 37 major, minor, and trace elements were determined (Adrian

and others, 1996). Spectrographic results were determined by visually comparing spectra derived from the sample and recorded

on photographic film against spectra obtained from laboratory reference standards. Standard concentrations are geometrically

spaced over any given order of magnitude as follows: 100, 50, 20, 10, 5, 2 etc. Samples whose concentrations were estimated to

fall between those values were assigned values of 70, 30, 15, 7, 3, 1.5 etc. The precision of this analytical technique is

approximately ± one reporting interval at the 83 percent confidence level and ± two reporting intervals at the 96 percent

confidence level (Motooka and Grimes, 1976). Elements determined by SES are Ag, As, Au, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu,

Fe, Ga, Ge, La, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Pd, Pt, Sb, Sc, Sn, Sr, Th, Ti, V, W, Y, Zn, and Zr. This method is designated

ES in table 1 and in the data files. Limits of determination for elements determined by SES are listed in table 7.

Which Technique Should I Use?

In some sample media, the same elements were determined by more than one analytical technique (Table 1). This

section is provided as guidance for those instances where multiple values are listed for a given element in a sample.

Filtered/acidified and unfiltered acidified water samples and leachate water samples were analyzed by both ICP-MS and ICPAES. In general, the ICP-AES method is more quantitative and data from this method is preferred over ICP-MS in those

instances where values are given by both methods. This is particularly true for the major elements Al, Ca, Fe, K, Mg, Na, and

Si, where concentrations commonly exceeded the dynamic range of the ICP-MS instrument. Similarly, SO4

2- values determined

by ion chromatography are preferred over those determined by ICP-MS. For solid sample media, gold analyses by graphite

furnace atomic absorption are in all cases preferred over gold values reported by ICP-AES methods. As described above, high

copper content (above 10,000 ppm) in solid samples can cause interferences on other elements (Ag, As, Au, Bi, Cd, Mo, Pb, Sb,

and Zn) in the 10-element, partial extraction ICP-AES method. In these instances, the total extraction ICP-AES method is

preferred for these elements.

DESCRIPTION OF DATA FILES

The analytical data files are provided in two formats, as a Microsoft Access 97 database and as separate Lotus .WK1

files. The data in the Access database are arranged as a series of tables and associated queries, and follow Access naming

conventions. The tables and brief descriptions follow below. For those not using Microsoft Access 97, the tables are saved as

separate .WK1 files with the same name and fields. The following abbreviations are used in the tables: FeOx, iron oxide;

MnOx, manganese oxide; XRD, X-ray diffraction; GX, sample collected for geochemical analysis; HS, hand sample collected

for reference.

FIELD NUMBERS

The field number coding scheme is as follows: The first number indicates the year the sample was collected, i.e., 4

indicates 1994, 6 indicates 1996, and 7 indicates 1997. The next two letters indicate samples from the Nabesna (NA), Kennecott

(KE), Orange Hill (OR), Bond Creek (BC), Bremner (BR), or Gold Hill (GH). The next 3 digits indicate the sample site

number. The above three parameters comprise the Site ID. Following the 3-digit number are suffixes indicating sample media

type and, if applicable, QA/QC samples. The Site ID and media suffix together comprise the sample field number. These

suffixes evolved from the initial 1994 season to the latter seasons, as indicated below:

Media Suffix Year

Rock R all

(R1, R2, R3, etc., indicate multiple rock samples from the site)

Stream sediment S, sieve size minus-80 mesh 1996, 1997

S1, sieve size minus-200 mesh 1994

S2, sieve size minus-80 to plus-200 mesh 1994

Heavy-mineral concentrate C all

Sample for leaching varies: L. R, or T all

Vegetation sample V all

Filtered/unacidified water W1 1994

FU 1996, 1997

Unfiltered/acidified water W 1994

RA 1996, 1997

Filtered/acidified water W3 1994

FA 1996, 1997

Water for mercury analysis HG 1996, 1997

Water for ferrous iron analysis FE 1996, 1997

Water for laboratory alkalinity analysis ALK 1996, 1997
14

For QA/QC samples, a “D” suffix immediately following the 3-digit number indicates a sample site duplicate. These suffixes

precede the sample media type suffix. Thus, field number 4NA021S1 indicates a 1994 minus-200-mesh stream sediment from

Nabesna site 021, while field number 4NA0212DS1 indicates a site duplicate of the same.

GEOCHEMICAL ANALYSES

All geochemical data are given in the following format. Field identifiers consist of a single line. The first one or two

letters give the chemical element symbol, then units of measurement, and finally a code for the analytical method used for the

element in that particular column. These three items are separated by underscores. Element symbols and associated names are

shown in table 1. Units of measurement are: PPM, parts per million; PPB, parts per billion; and PCT, percent. The analytical

methods and associated code letters are:

AA atomic absorption spectrophotometry

AF atomic fluorescence for mercury

CV cold-vapor atomic absorption spectrophotometry for mercury

CO colorimetric method for ferrous iron

EP inductively coupled plasma-atomic emission spectrometry (partial extraction)

ET inductively coupled plasma-atomic emission spectrometry (total digestion)

ES semiquantitative emission spectrography

EW inductively coupled plasma-atomic emission spectrometry (water samples)

GF graphite-furnace atomic absorption spectrophotometry

HY hydride generation atomic absorption spectrophotometry

IC ion chromatography

IE ion exchange inductively coupled plasma-atomic emission spectrometry

MW inductively coupled plasma-mass spectrometry (water samples)

For example, As_PPM_ET indicates arsenic, in parts per million, determined by total digestion inductively coupled plasmaatomic emission spectrometry. For the geochemical data, the symbol "<" indicates that an element was not observed at the

lower limit of determination shown. A ">" indicates that an element was detected but in concentration above the upper limit of

determination shown. An H indicates that the sample was not analyzed because of an elemental interference. A blank entry

indicates that the sample was not analyzed for that particular element.

DESCRIPTIONS OF TABLES AND FIELDS WITHIN TABLES

Below are brief descriptions of the various tables and fields contained within the tables. First are tables containing

sample and site descriptive information, next are tables containing chemical analyses. Fields common to all or most tables are

listed together. Fields unique to specific tables are listed below those tables.

Tables containing sample and site descriptive information

Table Contents

TblSampleLog table of all sample sites and the various sample media collected at each site

Fields:

Site_ID site identifier

Field_No_Root field number root (= site identifier with applicable QA/QC coding)

Water_RA unfiltered, acidified water

Water_FA filtered, acidified water

Water_FU filtered, unacidified water

Water_FE filtered, acidified water for Fe2+ analysis

Water_HG filtered, preserved water for Hg analysis

Water_ALK unfiltered, unacidified water for laboratory alkalinity analysis

Sediment sediment sample

Concentrate heavy-mineral concentrate sample

Rock rock sample

Leach sample collected for leaching

Precipitate precipitate sample

Vegetation vegetation (willow) sample

Notes additional notes on samples collected

Table Contents

TblSampleSiteInfo information related to the sample site

Fields:

Site_ID site identifier

NPS_ID WRST geologist site identifier
15

Latitude latitude in decimal degrees

Longitude longitude in decimal degrees

LatD latitude, degrees

LatM latitude, minutes

LatS latitude, decimal seconds

LonD longitude, degrees

LonM longitude, minutes

LonS longitude, decimal seconds

XYError_m location error in meters, as determined by GPS instrument

Datum datum used for coordinate determination

Coordinate_Source how coordinates were obtained

Date_Coll date of sample collection at site

Time_Coll time of sample collection at site

Location brief description of sample location

1X3_Quadrangle 1° X 3° quadrangle

Bedrock_Geology bedrock geology at the site

Additional_Info additional site-related information

Table Contents

TblWaterSiteInfo information related to water sample sites

Fields:

Site_ID site identifier

Field_No_Root field number root (= site identifier with applicable QA/QC coding)

QA/QC_Info information on QA/QC samples

Temp_C water temperature at collection site, degrees Celsius

Estimated_Flow_L/MIN estimated water flow in liters per minute

pH water pH at collection site

Conductivity_uS/CM water conductivity at collection site, microsiemens/centimeter

Dissolved_O2_PPM dissolved oxygen in water at collection site

Alkalinity_Site_PPM water alkalinity at collection site, as parts per million CaCO3

Acidity_PPM water acidity at collection site, as parts per million CaCO3

Table Contents

TblLeachInfo information related to samples leached following modification of EPA 1312 method

Fields:

Site_ID site identifier

Field_No sample field number

Source source of sample (mine waste, mill tailings, outcrop, etc.)

Leach_Sample_Desc descriptive information for sample collected for leaching

XRD_Leach_Major minerals identified by X-ray diffraction, >20 %

XRD_Leach_Minor minerals identified by X-ray diffraction, 5 % to 20 %

XRD_Leach_Trace minerals identified by X-ray diffraction, less than 5 %

pH_Final final pH of leachate at time of collection

T_C_Final temperature of leachate at time of collection

Conductivity_uS/CM_Final conductivity of leachate at time of collection, microsiemens per

centimeter

Alkalinity_PPM_Final alkalinity of leachate at time of collection, as parts per million CaCO3

Date_Leach_Done date that leach was completed

Time_Leach_Done time that leach was completed

Tables containing geochemical analyses

The following fields are common to all or most tables containing geochemical analyses:

Site_ID site identifier; for example 6BC009 (this field is common to ALL tables)

Field_No_Root field number root; this is the site identifier with applicable QA/QC suffix; for example 6BC009D

Field_No sample field number; this is the site identifier with applicable QA/QC suffix and sample media suffix;

for example 6BC009DFA

Lab_No sample laboratory-assigned number

Job_No job number for job in which sample was analyzed
16

Lab analytical laboratory (USGS = U.S. Geological Survey laboratory; XRAL = XRAL, Inc. contract

laboratory)

Sample_Description description of prepared sample for analysis

QA/QC_Info quality assurance/quality control sample information

For the following tables, geochemical analyses follow the common fields described above.

TblWaterDataAnions anion analyses, filtered/unacidified water samples

TblWaterDataCationsFAacidified/filtered cation analyses, filtered/acidified water samples

TblWaterDataCationsRAacidified/NOTfiltered cation analyses, unfiltered/acidified water samples

TblWaterDataFe2+ Fe2+ analyses, filtered/acidified water samples

TblWaterDataHg Hg analyses, filtered/preserved water samples

TblLeachSolidData solid-phase analyses of splits of samples collected for leaching

TblLeachDataAnions anion analyses for samples leached following modification of EPA 1312

method

TblLeachDataCations cation analyses for samples leached following modification of EPA 1312

method

The following fields are unique to specific tables:

Table Contents

TblConcentrateData heavy-mineral concentrate descriptive and analytical data

Fields:

Field_Mineralogy_Exam on-site hand lens examination of panned concentrate

Sieve_Size sample sieve size as prepared in laboratory

Character character of sample: single grab or composite of several increments

Source sample collected from outcrop, float, alluvium, etc.

Geochemical analyses follow at this point.

Table Contents

TblPrecipitateData precipitate descriptive and analytical data

Fields:

XRD_Info minerals in sample identified by X-ray diffraction

Character character of sample: single grab or composite of several increments

Source sample collected from outcrop, float, alluvium, etc.

Geochemical analyses follow at this point.

Table Contents

TblRockData rock descriptive and analytical data

Fields:

XRD_Info minerals in sample identified by X-ray diffraction

Near_Mine yes/no: Was sample site near or distal from mine or prospect?

Character character of sample: single grab or composite of several increments

Source sample collected from outcrop, float, alluvium, etc.

Geochemical analyses follow at this point.

Table Contents

TblSedimentData sediment descriptive and analytical data

Fields:

Sieve_Size sample sieve size as prepared in laboratory

Character character of sample: single grab or composite of several increments

Source sample collected from outcrop, float, alluvium, etc.

Increm/Reach_m format: X or X/Y, where X is number of sample increments collected and

Y is length of sampled reach in meters

Geol_Info_Alluvium geologic description of alluvium at sample site

Geochemical analyses follow at this point.

Table Contents

TblWaterDataAlkalin laboratory-determined alkalinity for water samples

Fields:

Alkalinity_Lab_PPM_TI total alkalinity, as parts per million CaCO3
17

Analytical_Note note from analyst

Table Contents

TblWillowData willow descriptive and dry-weight analytical data

Fields:

Species species of willow sample analyzed

Geochemical analyses follow at this point.

ACKNOWLEDGMENTS

We would like to thank the Wrangell-St. Elias National Park and Preserve staff for logistical help. James Harrower of

the Great Kennicott Land Co. and Kirk Stanley, owner of the Nabesna mine, are thanked for allowing access to their properties.

David Firewick and Craig Motooka of the U.S. Geological Survey are thanked for their laboratory sample preparation.

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20

Table 1.--Elements determined and analytical methods used for all sample media collected. [MW, water by inductively

coupled plasma-mass spectrometry; EW, water by inductively coupled plasma-atomic emission spectrometry; ET, solid

by total-extraction inductively coupled plasma-atomic emission spectrometry; EP, solid by partial-extraction inductively

coupled plasma-atomic emission spectrometry; HY, hydride generation atomic absorption; GF, graphite-furnace atomic

absorption; CV, cold-vapor atomic absorption; AF, atomic fluorescence; AA, atomic absorption; IE, specific-ionelectrode atomic absorption; ES, semiquantitative emission spectrography; IC, ion chromatography; CO, colorimetry; 1,

water, acidified-filtered and acidified-unfiltered samples; 2, water, unacidified-unfiltered samples; 3, water leaches,

acidified-filtered and acidified-unfiltered samples; 4, sediment samples; 5, rock samples; 6, nonmagnetic, heavy-mineralconcentrate samples; 7, precipitate samples; 8, willow samples.

ELEMENT MW EW ET EP HY GF CV AF AA IE ES IC CO

Ag, silver 1,3 3 4,5,7,8 4,5 6

Al, aluminum 1,3 1,3 4,5,7,8

As, arsenic 1,3 3 4,5,7,8 4,5 4,5,8 6

Au, gold 1,3 4,5,7,8 4,5 4,5 6

B, boron 1,3 6

Ba, barium 1,3 1,3 4,5,7,8 6

Be, beryllium 1,3 1,3 4,5,7,8 6

Bi, bismuth 1,3 4,5,7,8 4,5 6

Ca, calcium 1,3 1,3 4,5,7,8 6

Cd, cadmium 1,3 1,3 4,5,7,8 4,5 6

Ce, cerium 1,3 4,5,7,8

Cl-, chloride 2

Co, cobalt 1,3 1,3 4,5,7,8 6

Cr, chromium 1,3 1,3 4,5,7,8 6

Cs, cesium 1,3

Cu, copper 1,3 1,3 4,5,7,8 4,5 6

Dy, dysprosium 1,3

Er, erbium 1,3

Eu, europium 1,3 4,5,7,8

Fe, iron 1,3 1,3 4,5,7,8 6

Fe2+, ferrous iron 1

F-, fluoride 2

Ga, gallium 1,3 4,5,7,8 6

Gd, gadolinium 1,3

Ge, germanium 1,3 6

Hf, hafnium 1,3

Hg, mercury 1,4,5,8 1

Ho, holmium 1,3 4,5,7,8

In, indium 1,3

Ir, iridium 1

K, potassium 1,3 1,3 4,5,7,8

La, lanthanum 1,3 4,5,7,8 6

Li, lithium 1,3 1,3 4,5,7,8

Lu, lutetium 1

Mg, magnesium 1,3 1,3 4,5,7,8 6

Mn, manganese 1,3 1,3 4,5,7,8 6

Mo, molybdenum 1,3 1,3 4,5,7,8 4,5 6

Na, sodium 1,3 1,3 4,5,7,8 6

Nb, niobium 1,3 4,5,7,8 6

Nd, neodymium 1,3 4,5,7,8

Ni, nickel 1,3 1,3 4,5,7,8 6

NO3

-

, nitrate 2

P, phosphorous 1,3 4,5,7,8 6

Pb, lead 1,3 1,3 4,5,7,8 4,5 6

Pd, palladium 1 6

Pr, praseodymium 1,3

Pt, platinum 1 6

Rb, rubidium 1,3

Re, rhenium 1,3

Rh, rhodium 1
21

Ru, ruthenium 1

Sb, antimony 1,3 3 4,5 4,5 6

Sc, scandium 1,3 4,5,7,8 6

Se, selenium 1,3 4,5

Si, silicon 1,3 1,3

Sm, samarium 1,3

Sn, tin 1,3 3 4,5,7,8 6

SO4

2-, sulfate 2

Sr, strontium 1,3 1,3 4,5,7,8 6

Ta, tantalum 1,3 4,5,7,8

Tb, terbium 1,3

Te, tellurium 1,3

Th, thorium 1,3 4,5,7,8 6

Ti, titanium 1,3 1,3 4,5,7,8 6

Tl, thallium 1,3 4,5

Tm, thulium 1,3

U, uranium 1,3 4,5,7,8

V, vanadium 1,3 1,3 4,5,7,8 6

W, tungsten 1,3 4,5 6

Y, yttrium 1,3 4,5,7,8 6

Yb, ytterbium 1,3 4,5,7,8

Zn, zinc 1,3 1,3 4,5,7,8 4,5 6

Zr, zirconium 1,3 6
22

Table 2.--Limits of determination for sediment, rock, precipitate, leach solid phase, and willow samples analyzed by 40-

element inductively coupled plasma-atomic emission spectrometry, total extraction (ET). [Element names are shown in

Table 1]

Sediments, Rocks, Precipitates, Leach

Solid Phases

Willows1

Element Lower Determination

Limit

Upper Determination

Limit

Lower Determination

Limit

Upper Determination

Limit

Percent

Al 0.005 50 0.0009 50

Ca 0.005 50 0.0009 50

Fe 0.02 25 0.0009 25

K 0.01 50 0.0018 50

Mg 0.005 5 0.0009 5

Na 0.006 50 0.0009 50

P 0.005 50 0.0009 50

Ti 0.005 25 0.0009 25

Parts Per Million

Ag 2 10,000 0.3 10,000

As 10 50,000 2 50,000

Au 8 50,000 2 50,000

Ba 1 35,000 0.2 35,000

Be 1 5,000 0.2 5,000

Bi 10 50,000 2 50,000

Cd 2 25,000 0.3 25,000

Ce 5 50,000 0.7 50,000

Co 2 25,000 0.2 25,000

Cr 2 50,000 0.2 50,000

Cu 2 15,000 0.2 15,000

Eu 2 5,000 0.3 5,000

Ga 4 50,000 0.7 50,000

Ho 4 5,000 0.7 5,000

La 2 50,000 0.3 50,000

Li 2 50,000 0.3 50,000

Mn 4 50,000 0.7 50,000

Mo 2 50,000 0.3 50,000

Nb 4 50,000 0.7 50,000

Nd 9 50,000 0.7 50,000

Ni 3 50,000 0.3 50,000

Pb 4 50,000 0.7 50,000

Sc 2 50,000 0.3 50,000

Sn 5 50,000 0.8 50,000

Sr 2 15,000 0.3 15,000

Ta 40 50,000 7 50,000

Th 6 50,000 0.7 50,000

U 100 100,000 20 100,000

V 2 30,000 0.3 30,000

Y 2 25,000 0.3 25,000

Yb 1 5,000 0.2 5,000

Zn 2 15,000 0.3 15,000

1 Lower determination limits for willow samples are lower than those for other media because the willow samples were

weighed and ashed prior to analysis—essentially a preconcentration step. The values were then converted back to a wholesample basis, resulting in lower determination limits.
23

Table 3.--Limits of determination for selected elements in sediment, rock, leach solid phase, willow, and water samples.

[Element names are shown in Table 1; values for solids are in parts per million; values for water samples are as

indicated; EP, partial extraction 10-element inductively coupled plasma-atomic emission spectrometry; ; GF, graphitefurnace atomic absorption spectrophotometry; CV, cold-vapor atomic absorption spectrophotometry; AF, atomic

fluorescence, HY, hydride generation atomic absorption spectrophotometry; AA, atomic absorption spectrophotometry;

IE, ion exchange separation inductively coupled plasma-atomic emission spectrometry; CO, colorimetry; ppm. [parts

per million; ppb, parts per billion]

Sediments, Rocks, Leach Solid Phases, and

Willows, values in parts per million

Water, values as indicated

Element Method Lower Determination

Limit1 Upper DeterminationLimit1 Lower DeterminationLimit1 Upper DeterminationLimit1

Ag EP 0.08 400

As EP 1 6,000

Au EP 0.1 1,500

Bi EP 1 6,000

Cd EP 0.05 500

Cu EP 0.05 500

Mo EP 0.1 900

Pb EP 1 6,000

Sb EP 1 6,000

Zn EP 0.05 500

Au GF 0.002 0.05

Hg CV 0.02 1.8 0.1 ppb none2

Hg AF 0.01 ppb none2

As HY 0.6 20

Sb HY 0.6 20

Se HY 0.2 4

Tl AA 0.1 10

W IE 1 200

Fe2+ CO 0.01 ppm none2

1

 Limits of determination shown here are nominal and limits may vary in the data files. The variability in limits of

determination is due to variable sample weight used, dilution of the sample solution, instrumental interference correction, and

slight changes in methodology over time.

2 Samples with high concentrations were diluted and re-analyzed.
24

Table 4.--Limits of determination for acidified water and leachate samples analyzed for 24 elements by inductively

coupled plasma-atomic emission spectrometry (EW). [Element names are shown in Table 1; see text for discussion of

preconcentration]

No Preconcentration Preconcentrated

Element Lower Determination

Limit

Upper Determination

Limit

Lower Determination

Limit

Upper Determination

Limit

Parts Per Million

Al 0.1 1,000 0.025 1,000

Ca 1 1,000 0.05 1,000

Fe 0.1 1,000 0.025 1,000

K 1 1,000 0.05 1,000

Mg 1 1,000 0.05 1,000

Na 1 1,000 0.05 1,000

P 0.05 1,000 0.025 1,000

Si 1 1,000 0.05 1,000

Parts Per Billion

Ba 5 10,000 1 10,000

Be 10 10,000 1 10,000

B 10 10,000 2.5 10,000

Cd 10 10,000 1 10,000

Cr 10 10,000 2 10,000

Co 10 10,000 2 10,000

Cu 10 10,000 4 10,000

Pb 50 10,000 5 10,000

Li 10 10,000 5 10,000

Mn 10 10,000 2 10,000

Mo 20 10,000 4 10,000

Ni 10 10,000 4 10,000

Sr 1 10,000 1 10,000

Ti 50 10,000 10 10,000

V 10 10,000 2 10,000

Zn 10 10,000 2 10,000
25

Table 5.--Limits of determination for anions in water samples determined by ion chromotography. [Element names are

shown in Table 1]

Anion Lower

Determination Limit

Upper

Determination

Limit1

Parts Per Million

Cl- 0.1 4

F- 0.05 2

NO3

- 0.5 10

SO4

2- 0.5 20

1 Samples containing concentrations greater than the upper limits of determination listed here required dilution.
26

Table 6.--Limits of determination for water samples analyzed by 64-element inductively coupled plasma-mass

spectrometry (MW). [Element names are shown in Table 1]

Element Lower Determination

Limit1 Element Lower DeterminationLimit1

Parts per million (ppm) Parts per billion (ppb)

Ca 0.05 Li 0.10

Mg 0.01 Mn 0.01

Na 0.01 Mo 0.02

Si 0.25 Nb 0.02

Parts per billion (ppb) Nd 0.01

Ag 0.01 Ni 0.10

Al 0.01 Pb 0.05

As 0.20 Pr 0.01

Au 0.01 Rb 0.01

Ba 0.02 Re 0.02

Be 0.05 Sb 0.02

Bi 0.01 Sc 0.10

Cd 0.02 Se 0.20

Ce 0.01 Sm 0.01

Co 0.02 Sn 0.05

Cr 1.00 Sr 0.02

Cs 0.01 Ta 0.02

Cu 0.50 Tb 0.005

Dy 0.005 Te 0.10

Er 0.005 Th 0.01

Eu 0.005 Ti 0.10

Fe 10.00 Tl 0.05

Ga 0.02 Tm 0.005

Gd 0.005 U 0.01

Ge 0.02 V 0.10

Hf 0.05 W 0.02

Ho 0.005 Y 0.01

In 0.01 Yb 0.01

K 0.30 Zn 0.50

La 0.01 Zr 0.05

1

 Limits of determination shown here are nominal and limits may vary in the data files. The variability in limits of

determination is due to variable sample weight used, dilution of the sample solution, instrumental interference correction, slight

changes in methodology over time, and acquisition of a newer, more sensitive instrument during the life of this study. Upper

limits of determination are not shown because samples with high concentrations were diluted and re-analyzed.
27

Table 7.--Limits of determination for nonmagnetic heavy-mineral concentrate samples analyzed by semiquantitative

emission spectrography. [Element names are shown in Table 1]

Element Lower Determination

Limit

Upper Determination

Limit

Element Lower Determination

Limit

Upper Determination

Limit

Percent Parts Per Million

Ca 0.1 50 Ge 20 200

Fe 0.1 50 La 100 2,000

Mg 0.05 20 Mn 20 10,000

Na 0.5 10 Mo 10 5,000

P 0.5 20 Nb 50 5,000

Ti 0.005 2 Ni 10 10,000

Parts Per Million Pb 20 50,000

Ag 1 10,000 Pd 10 2,000

As 500 20,000 Pt 50 2,000

Au 20 1,000 Sb 200 20,000

B 20 5,000 Sc 10 200

Ba 50 10,000 Sn 20 2,000

Be 2 2,000 Sr 200 10,000

Bi 20 2,000 Th 200 5,000

Cd 50 1,000 V 20 20,000

Co 20 5,000 W 50 20,000

Cr 20 10,000 Y 20 5,000

Cu 10 50,000 Zn 500 20,000

Ga 10 10,000 Zr 20 2,000