U.S. Department of the Interior

U.S. Geological Survey

U.S. Geological Survey Professional Paper 1619

Environmental Geochemical Studies of Selected

Mineral Deposits in Wrangell–St. Elias

National Park and Preserve, Alaska

Prepared in cooperation with the

National Park Service,

Wrangell–St. Elias

National Park and Preserve, Alaska
Cover photographs. Lower right: Altered bedrock in the Orange Hill area, Alaska. Orange, 

red, and yellow hues are principally the result of oxidation of pyrite, resulting in iron oxide and 

soluble sulfate minerals. Left: USGS scientist getting pH reading from acidic, metalliferous 

water derived from seasonal snow melt draining the Nabesna mill tailings. Upper right: 

Naturally acidic, metalliferous stream water draining altered bedrock in the Orange Hill area, 

Alaska. Note rock hammer in stream for scale.
Environmental Geochemical Studies of

Selected Mineral Deposits in Wrangell–

St. Elias National Park and Preserve, Alaska

By Robert G. Eppinger, Paul H. Briggs, Danny Rosenkrans, and Vanessa Ballestrazze

U.S. Geological Survey Professional Paper 1619

U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with the

National Park Service,

Wrangell–St. Elias National Park and Preserve, Alaska
U.S. Department of the Interior

Bruce Babbitt, Secretary

U.S. Geological Survey

Charles G. Groat, Director

For sale by U.S. Geological Survey, Information Services

Box 25286, Federal Center

Denver, CO 80225

This publication is also available online at:

http://greenwood.cr.usgs.gov/pub/ppapers/p1619/

Any use of trade, product, or firm names in this publication

is for descriptive purposes only and

does not imply endorsement by the U.S. Government

Library of Congress Cataloging-in-Publication Data

Environmental geochemical studies of selected mineral deposits in Wrangell–St. Elias

National Park and Preserve, Alaska / by Robert G. Eppinger ... [et al.].

p. cm.—(U.S. Geological Survey professional paper ; 1619)

Includes bibliographical references.

1. Environmental geochemistry—Alaska—Wrangell–Saint Elias National Park and

Preserve. 2. Ore deposits—Alaska—Wrangell–Saint Elias National Park and Preserve. I.

Eppinger, R.G. II. Series.

QE516.4 .E57 2000

551.9’09798’3—dc21 99–046702
III

Contents

Abstract ......................................................................................................................................... 1

Introduction .................................................................................................................................. 2

Acknowledgments ....................................................................................................................... 4

Methods ........................................................................................................................................ 5

Kennecott ...................................................................................................................................... 7

Geology, Deposit Setting, and Mining History............................................................ 7

Results of Study .............................................................................................................. 9

Interpretation .................................................................................................................. 9

Bremner ......................................................................................................................................... 11

Geology, Deposit Setting, and Mining History............................................................ 11

Results of Study .............................................................................................................. 11

Interpretation .................................................................................................................. 12

Gold Hill ......................................................................................................................................... 15

Geology, Deposit Setting, and Mining History............................................................ 15

Results of Study .............................................................................................................. 18

Interpretation .................................................................................................................. 19

Orange Hill and Bond Creek ....................................................................................................... 23

Geology, Deposit Setting, and Mining History............................................................ 23

Results of Study .............................................................................................................. 24

Interpretation .................................................................................................................. 24

Nabesna ........................................................................................................................................ 25

Geology, Deposit Setting, and Mining History............................................................ 25

Results of Study .............................................................................................................. 27

Interpretation .................................................................................................................. 30

Discussion...................................................................................................................................... 32

Conclusions ................................................................................................................................... 34

References Cited .......................................................................................................................... 35

Appendix. Basic Statistics for Sediments, Rocks, Alluvial Heavy-Mineral

Concentrates, and Leachates for Samples from All Areas Studied in

Wrangell–St. Elias National Park and Preserve, Alaska................................................. 37

Figures

1. Map showing locations of areas studied in Wrangell–St. Elias National Park

and Preserve, Alaska....................................................................................................... 3

2. Photographs showing present-day setting of areas studied in Wrangell–

St. Elias National Park and Preserve, Alaska .............................................................. 4
IV

3–7. Maps showing generalized geology and site locations for samples collected in: 

3. Kennecott mine area............................................................................................. 8

4. Bremner area ........................................................................................................ 10

5. Gold Hill mine area ................................................................................................ 12

6. Orange Hill and Bond Creek areas .................................................................... 14

7. Nabesna mine area .............................................................................................. 16

8–12. Piper diagrams and box and whisker diagrams showing, respectively: 

8. Major and trace ion composition, and summary statistics for

selected ions and field parameters, in 13 water samples from

Kennecott area ...................................................................................................... 18

9. Major and trace ion composition, and summary statistics for

selected ions and field parameters, in 10 water samples from

Bremner area ......................................................................................................... 20

10. Major and trace ion composition, and summary statistics for

selected ions and field parameters, in 16 water samples from

Gold Hill area.......................................................................................................... 22

11. Major and trace ion composition, and summary statistics for

selected ions and field parameters, in 17 water samples from

Orange Hill and Bond Creek areas ..................................................................... 26

12. Major and trace ion composition, and summary statistics for

selected ions and field parameters, in 55 water samples from

Nabesna area......................................................................................................... 28

13. Sketch map and distribution of arsenic and manganese in water along

Cabin Creek above, on, and below Nabesna mill tailings piles............................... 31

14. Ficklin diagrams of pH versus dissolved metal content in water samples

collected from Nabesna, Orange Hill and Bond Creek, Kennecott,

Bremner, and Gold Hill ................................................................................................... 33

Tables

1. Sample media collected at study areas in Wrangell–St. Elias National Park

and Preserve, Alaska ....................................................................................................... 5

2. Elements determined, analytical methods, and collection/preparation

procedures used ............................................................................................................... 6
1

Environmental Geochemical Studies of

Selected Mineral Deposits in Wrangell–St. Elias 

National Park and Preserve, Alaska

By Robert G. Eppinger,1 Paul H. Briggs, Danny Rosenkrans,2 and Vanessa Ballestrazze

Abstract

Environmental geochemical investigations took place in 

Wrangell–St. Elias National Park and Preserve (WRST), Alaska, 

between 1994 and 1997. Areas studied include the historic 

Kennecott stratabound copper mines and mill area; the historic 

mines and mill in the Bremner district, where gold was produced from polymetallic veins; the sporadically active gold 

placer mines at Gold Hill; the undisturbed, unmined porphyry 

copper-molybdenum deposits at Orange Hill and Bond Creek; 

and the historic mines and mill at Nabesna, where gold-bearing 

iron skarn deposits were exploited. The cooperative study 

between the U.S. Geological Survey and the National Park 

Service focused on identifying and characterizing geochemical 

signatures associated with these mineralized areas. Sample 

media included surface water, bedload sediment, rock, mine 

waste, and mill tailings samples.

Predominant influences on the variation in water and sediment chemistry are the deposit type and local geology. At Kennecott surface waters are near neutral in pH and of the calciumbicarbonate type. Most waters have relatively low conductivities (105 to 188 microsiemens per centimeter). With respect to 

drinking water standards, none of the significant inorganic 

parameters listed by the Alaska Department of Environmental 

Conservation and U.S. Environmental Protection Agency (pH, 

Ag, Al, As, Ba, Be, Cd, Cl-

, Cr, Cu, F-, Fe, Hg, Mn, Na, Ni, 

NO3

-

, Pb, Se, SO4

2-, Tl, and Zn) exceed established maximum 

contaminant levels. The dominant sulfide minerals in the Kennecott deposits, chalcocite and djurleite, are relatively stable in 

the surficial environment. These geochemical data suggest that 

Kennecott-type deposits are relatively benign to the environment, due to the large amount of carbonate rocks present, the 

resulting high buffering capacity of waters, the absence of acidgenerating minerals, and the scarcity of metals that could be 

mobilized at higher pH values.

Waters in the Bremner district have pH values ranging 

from 6.3 to 7.9 and are classified as calcium type and sulfate 

type. Conductivities range from 86 to 220 microsiemens per 

centimeter, and alkalinities range from < 10 to 26 parts per 

million (as calcium carbonate). In two instances, manganese 

concentrations are slightly above and pH is slightly below maximum contaminant level guidelines. In waters, the low alkalinities, predominance of sulfate over bicarbonate, near neutral pH 

values, and low dissolved metal contents are the result of the 

geologic setting—pyrite- and calcite-bearing quartz veins that 

cut carbonate-poor slates of the Cretaceous Valdez Group. 

Variation in leachate chemistry from mine waste and mill tailings samples is probably due to the relatively higher pyrite content compared to calcite in the mill tailings, a result of 

concentrating gold-bearing, pyrite-rich ore for milling. Highly 

anomalous mercury, used historically to amalgamate gold at the 

abandoned mill, is found in tailings at the Lucky Girl mill, and 

native mercury and gold-mercury amalgam were panned from 

mill products. Slightly anomalous mercury is found in two 

stream sediments directly below the mill. However, all water 

samples from the Bremner area, including those collected 

below the mill tailings, have mercury concentrations two orders 

of magnitude below the maximum contaminant level of 2 parts 

per billion.

Baseline geochemical data were collected at Gold Hill 

when placer mining activities were idle. Water samples are 

calcium-bicarbonate-dominant, and probably reflect the common presence of calcite veinlets in the area, which is underlain 

by marine, volcanic, and intrusive rocks. Waters are near 

neutral (pH 7.3 to 8.5), with conductivities ranging from 52 to 

416 microsiemens per centimeter and alkalinities from 16 to 

150 parts per million; metal contents are below established 

maximum contaminant levels. Significantly, however, these 

data suggest that waters in the Big Eldorado basin have less 

acid-neutralizing capability than waters elsewhere in the Gold 

Hill area, a characteristic that should be considered if the Big 

Eldorado Creek area is disrupted. Surface waters in the Gold 

Hill area contain the highest mercury concentrations found in 

the study, but even these are two orders of magnitude below the 

maximum contaminant level of 2 parts per billion.

The natural conditions at Orange Hill and Bond Creek 

demonstrate that mines and mills are not the sole sources of 

acidic, metalliferous waters in the environment. Bedrock is 

predominantly bleached, iron-stained, clay-altered granodiorite. 

1

<eppinger@usgs.gov>.

2

 Wrangell-St. Elias National Park and Preserve, Alaska; 

<Danny_Rosenkrans@nps.gov>.
2 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

Chalcopyrite, molybdenite, and pyrite and its alteration products 

are common. Surface water samples are calcium- and particularly sulfate-dominant, and they have total dissolved solids generally above 2,000 parts per million, values for pH ranging from 

3.5 to 8.4, and conductivities from 192 to 3,080 microsiemens 

per centimeter. In nearly every sample, maximum contaminant 

levels are exceeded for sulfate, aluminum, iron, and manganese, 

and total dissolved solids. In several samples maximum contaminant levels are exceeded for cadmium, copper, nickel, antimony, 

and zinc. Other elements that are found in relatively high concentrations in waters include cobalt, molybdenum, strontium and 

the rare-earth elements. Sediments and rocks contain anomalously high levels of most of the elements listed herein. The low 

pH values, high sulfate, and high metal contents in many surface 

waters at Orange Hill and Bond Creek are due to the abundance 

of pyrite and associated sulfate minerals in altered rocks, and the 

absence of acid-consuming minerals. Leachate chemistry from 

samples of disaggregated, clay-altered bedrock indicates that 

during wet periods, initial waters flowing over the widespread 

altered bedrock would be acidic and metalliferous.

Nabesna was repeatedly sampled during a range of climatic 

conditions including summer periods of dry weather, intermittent rain, and extended rain, and during spring breakup. Major 

ion composition varied considerably in water samples from the 

Nabesna area. Calcium is the major cation, due to the dissolution of abundant carbonates. Anion composition varies from sulfate-dominant proximal to mines and the mill, to bicarbonatedominant at distal sites. High sulfate reflects the dissolution of 

pyrite and, to a lesser degree, pyrrhotite. Total dissolved solids 

and alkalinities vary considerably over more than two orders of 

magnitude, pH varies from 2.2 to 8.6, and conductivities range 

from 58 to > 4,500 microsiemens per centimeter. Maximum 

contaminant levels are exceeded for aluminum, arsenic, cadmium, copper, fluoride, iron, manganese, lead, sulfate, zinc, and 

total dissolved solids for samples collected during the spring 

breakup and summer rain events. Manganese and sulfate exceed 

maximum contaminant levels in samples collected during all 

sampling periods. Other elements found in high concentrations 

include cobalt, molybdenum, and the rare-earth elements. 

Leachates from sulfate-rich mill tailings samples have pH values 

from 2.2 to 8, high conductivities in the thousands of microsiemens per centimeter, and high concentrations of the elements 

listed herein as well as several additional ones. Stream sediments and rocks are anomalous in most of these elements. The 

season and surface flow conditions are important controlling factors on the major- and trace-element compositions of surface 

waters at Nabesna. 

Introduction

Environmental geochemical investigations were carried out 

between 1994 and 1997 at several areas in Wrangell–St. Elias 

National Park and Preserve (WRST), Alaska. Surface water, 

bedload sediment, rock, mine waste, and mill tailings were collected from several mineralized areas: (1) the historic Kennecott 

copper mill and nearby Bonanza, Erie, Glacier, and Jumbo 

mines; (2) the historic mill and gold mines in the Bremner district; (3) the historic and active gold placer mines at Gold Hill; 

(4) the large, extensively altered, unmined copper-molybdenum 

deposits at Orange Hill and Bond Creek; and (5) the historic 

Nabesna gold mine/mill and surrounding areas (fig. 1). The 

purpose of the study was to characterize the geochemistry of 

these mineralized areas, to identify potential environmental 

geochemical hazards, and to determine baseline levels for 

selected elements. In this report, we focus on the hydrogeochemical media, the principal avenue for movement of 

metals from rocks and sediments into the aquatic biota. Results 

of solid media sampling are discussed as they pertain to the 

water samples.

In this cooperative effort between the U.S. Geological Survey (USGS) and the National Park Service (NPS), we addressed 

specific WRST land-management concerns in the different areas 

studied. Although our methodology did not vary from area to 

area, the land-management questions varied considerably. 

Specifically, (1) at Kennecott, a site recently acquired by the 

NPS, are there geoenvironmental hazards related to the mines 

and mill? (2) At Bremner, is mercury, once used for gold 

extraction at the now-abandoned mill, present in water at levels 

posing a hazard to visitors? (3) At Gold Hill, what are baseline 

metal concentrations in surface water during periods of placer 

mining inactivity? This is important in any attempt to measure 

environmental effects from active placer operations at Gold Hill. 

(4) At the Orange Hill and nearby Bond Creek deposits, what 

are natural background metal concentrations in surface waters at 

these unmined areas where active claims are held? Finally, (5) 

at Nabesna, what is the extent of metal dispersion in surface 

waters downstream from the mill site and what are the metals 

involved? The Environmental Protection Agency (EPA) initiated a site investigation (SI) at Nabesna to evaluate the site’s 

potential for inclusion on the National Priorities List. However, 

the SI process did not include an extensive or complete site 

characterization (Environmental Protection Agency, 1995a).

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 paleolatitudes 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 lie 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). Rocks of the Tertiary to Quaternary Wrangell Lava 

volcanic field and unconsolidated glacial and fluvial deposits 

locally cap the accretionary rocks.

The Kennecott mill and its associated copper deposits (fig. 

2A) are located in the central part of the McCarthy 1° × 3° quadrangle. The Kennecott mill complex lies at the base of Bonanza 

Peak (2,128 m), along the margin of the Kennicott Glacier, at 

about 610 m in elevation, whereas the mines that supplied the 

mill are located more than 1,500 m higher on the steep slopes of 

Bonanza Peak (fig. 1). Present access to the Kennecott mill and 

associated mines is via foot or hired van from McCarthy. The 

Bremner mines and mill (fig. 2B) are located in the southwestern 
3

Delta

Copper River

Rive

B

r

remner

Nabesna

R i v e r

C o

p

p e r

Chiti na

R i v er

Kennicott River

P a r k 

P a r k 

G U L F O F A L A S K A

River

NizinaRiver

Co

p

p

er

G l a c i e r M a l a s p i n a

B a g l e y I c e f i e l d

Kennicott

Glacier

B e r i n g

G l a c i e r

Nabesna Rd

 to

Richardson

Hwy

Alaska

Highway

4

1

1

4

10

1

McCarthy

Road

Glenn Hwy

Copper Center

Glennallen

Chistochina

Slana

to

Anchorage

Delta Junction to Tok

Gulkana

Gakona

Park

Headquarters

Tonsina

Chitina

Kennicott

McCarthy

Valdez

to

Chisana

Devil's Mountain Lodge

to Tok

S A I N T E L I A S M T N S

N U T Z O T I N

M T N S

C H U G A C H M O U N T A I N S

W R A N G E L L

M O U N T A I N S

Mt Sanford

Mt Drum

White Mtn

Mt Allen

Mt Wrangell

Mt

Blackburn Regal Mtn

Bonanza Peak

Mt

Churchill

Nelson Mtn 

Hanagita Pk

Haydon Pk

ALASKA

STUDY AREA

U.S. CANADA

X X

X X

X X

KENNECOTT MINES

BREMNER MINES

NABESNA

MINE

CARL CR

HORSFELD

BAULTOFF

JOHNSON CR

BOND CREEK

GOLD HILL

ORANGE HILL

U

N I T E D S T

A

T E S

C

A

N

A

D

A

A L A S K

A ,

Y

U

K

O

N ,

P r e s e r v e

P r e s e r v e

P r e s e r v e

P r e s e r v e

P r e s e r v e

K l u a n e

N a t i o n a l

P a r k

P a r k 

P a r k 

P a r k 

S a n c t u a r y

K l u a n e

G a m e

W i l d l i f e R e f u g e

N a t i o n a l

T e t l i n

Nabesna

Glacier

Wrangell-St Elias

National Park and Preserve

Ri ver

146° 144° 142° 140°

62°

60°

0 10 20 KILOMETERS 

0 10 20 MILES

part of the McCarthy 1° × 3° quadrangle. Elevation varies from 

about 1,070 m in the valley of Golconda Creek, to more than 

1,830 m in the surrounding mountains. The area is accessible 

only by bush plane to a remote airstrip at Bremner. Gold Hill 

(fig. 2C) is located in the Chisana mining district in the southeastern part of the Nabesna 1° × 3° quadrangle, about 9.6 km 

northeast of the remote community of Chisana. Elevation in this 

relatively hilly area varies from about 1,220 m near the base of 

Gold Hill, to 1,811 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. The Orange Hill deposit (fig. 2D) is located 

in the south-central part of the Nabesna 1° × 3° quadrangle, 

about 21 km southeast of the Nabesna mine, near the terminus of 

the Nabesna Glacier. The Bond Creek deposit (fig. 2E) is about 

6.4 km east of Orange Hill. Topography is subdued near the valley bottom at the base of Orange Hill (about 900 m in elevation) 

but climbs steeply into rugged mountains rising to more than 

2,440 m immediately east of Orange Hill and throughout the 

Bond Creek area. Both areas are accessible only by bush plane 

to a remote airstrip at Orange Hill. The Nabesna gold mine and 

mill (fig. 2F) are located in the south-central part of the Nabesna 

1° × 3° quadrangle, along the north edge of WRST. Topography 

varies from relatively subdued near the confluence of Cabin and 

Jack Creeks (about 854 m in elevation), 6.4 km below the 

Nabesna mill, to the steep slopes and cliffs of White Mountain 

(about 1,860 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 over an unmaintained State right-of-way at the 

end of the Nabesna road.

Not surprisingly, variation in water and sediment chemistry is widespread across the different areas, and is dependent 

Figure 1. Locations of areas studied in Wrangell–St. Elias National Park and Preserve, Alaska.

Introduction
4 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

A

B

C

D

E

F

predominantly on the deposit type and local geology. Thus, for 

each area studied, the geologic setting, results, and interpretations are described separately, following an overview of 

methodology. 

Acknowledgments

We thank the Wrangell–St. Elias National Park and Preserve staff for logistical help. We thank the following for 

Figure 2. Present-day setting of areas studied in Wrangell–St. Elias National Park and Preserve, Alaska. A, Kennecott mill; closest building is 

ammonia leaching plant, glacial debris in immediate background, Mt. Blackburn in far background. Mines were located along contact of dark 

rocks (Nikolai Greenstone) and overlying light rocks (Chitistone Limestone), as seen above mill. B, Bremner district, collapsed mill at Lucky Girl 

mine. C, Gold Hill, breached placer dam and flume, Coarse Money Creek. D, Orange Hill area, hydrothermally altered bedrock along Nikonda 

Creek; Harq Creek is leftmost creek, horizontal distance across photo is approximately 1 km. E, Bond Creek area, unnamed glacier-fed stream 

flowing through altered bedrock into Bond Creek in distance, stream pH 5.4, conductivity 1,550 μS/cm; note geologist D. Rosenkrans for scale. F, 

Nabesna mill with pyrite-rich mill tailings in foreground. Mines were located on White Mountain above the mill.
5

allowing access to their properties: James Harrower of the Great 

Kennicott Land Co., Kennecott Corporation, Northwest 

Exploration (owners of the patented claims at Orange Hill), and 

Kirk Stanley, owner of the Nabesna mine. The following U.S. 

Geological Survey personnel assisted in sample preparation and 

analyses: 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, and B.H. Roushey, S.J. Sutley, P.M. 

Theodorakos, and S.A. Wilson.

Methods

This description of sample collection, preparation, and 

analysis is distilled from Eppinger and others (1999). Samples 

were collected at Kennecott in August of 1994 (dry period; no 

precipitation), at Bremner and Orange Hill in August of 1996 

(dry period, no precipitation), and at Gold Hill and Bond Creek 

in August of 1997 (mostly dry, intermittent rain). The Nabesna 

site was repeatedly sampled during these same periods and also 

in April-May 1997 (spring breakup, an annual period of very 

wet conditions during which extensive melting of snow and ice 

occurs), and in September 1997 (following an extended 3-week 

rainy period).

The principal sample medium was surface water, but rock, 

mine waste, mill tailings, bedload stream-sediment, heavymineral concentrate, and precipitate samples were also collected 

(table 1). Elements determined, methods used, and details on 

sample collection and preparation are given in table 2. Sample 

localities are shown in figures 3, 4, 5, 6, and 7 for the Kennecott, 

Bremner, Gold Hill, Orange Hill/Bond Creek, and Nabesna 

areas, respectively. Although not discussed in this report, we 

also collected willow samples from 32 sites around and below 

the Nabesna mill tailings (Eppinger and others, 1999).

Water samples were collected from available natural water 

sources, principally from flowing streams, but also from seeps, 

springs, and ponds. Water samples collected include (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, (4) an acidified, filtered sample for ferrous iron content, 

and (5) a preserved, filtered sample for mercury content. The 

unacidified samples were kept cool prior to analysis. Samples 

were filtered and acidified to pH < 2 with ultra-pure acid to prevent precipitation of metals and bacterial growth (table 2). 

Other water data collected and recorded on-site include temperature, pH, conductivity (a measure of electrical conductance; the 

more ions a solution contains, the higher its conductivity), dissolved oxygen content, an estimate of the water flow rate, total 

acidity (a measure of water’s base-consuming capacity; only for 

1997 samples with pH < 7), and total alkalinity (a measure of 

water’s acid-consuming capacity; for all samples with pH > 4.5). 

These data are given in Eppinger and others (1999).

Bedload stream sediments were collected below mines and 

mills and from nearby unmined areas, at water-sample sites 

where sufficient sediment was present. A few pond and spring 

sediments were also collected. Mineralized and unmineralized 

rock samples were collected generally as composite chip samples from outcrop, alluvium, mine waste, and mill tailings. A 

few precipitate samples were collected at Nabesna and Orange 

Hill, as flocs precipitating out of metalliferous waters onto the 

underlying substrates. The precipitates were analyzed chemically and mineralogically by X-ray diffraction. Because elements related to mineral deposits are commonly found in heavy 

minerals, pan concentrates were collected to provide chemical 

and mineralogical information. Most pan concentrate samples 

were collected from the same active alluvium as sediment samples. Some samples were also collected from mill tailings and 

mine waste.

Several mine waste, mill tailings, and mineralized bedrock 

samples were collected for leaching, using a synthetic meteoric 

water leach test. A modification of the EPA Synthetic Precipitation Leaching Procedure 1312 (Environmental Protection 

Agency, 1994) was used. This method is used to determine 

mobility of inorganic analytes present in samples of soils, wastes, 

and waste waters. For dry samples from mine waste and mill tailings, leachate composition can be used to mimic initial meteoric 

waters flowing off tailings, prior to dilution by adjacent surface 

flow and streams. Prior to leaching, splits of the solid samples 

were made for mineralogical analysis by X-ray diffraction.

 Methods

No. of samples-- 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 9 3 2 1 1 1 1

 Anal. dupes 1 1

Leach 18 12 2 1 3

 Anal. dupes 3 1 1 1

Rock 56 24 10 7 3 7 5

 Anal. dupes 2 1 1

Concentrate 51 11 7 14 5 5 9

 Anal. dupes 1 1

Precipitate 7 2 5

Table 1. Sample media collected at study areas in Wrangell–St. Elias National Park and Preserve, Alaska. 

[Site dupes, quality control sample site duplicates; anal. dupes, quality control analytical duplicates split from sample in laboratory]
6 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

Table 2. Elements determined, analytical methods, and collection/preparation procedures used. 

[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, coldvapor atomic absorption; AF, atomic fluorescence; AA, atomic absorption; IE, specific-ion-electrode atomic absorption; ES, semiquantitative emission spectrography; IC, ion chromatography; CO, colorimetry; Arbogast, 1996; Eppinger and others, 1999]

1 Water samples and leachates were filtered at 0.45 μm, collected in acid-rinsed polypropylene bottles, and acidified with ultrapure nitric acid. Water samples for Hg analysis were filtered as above, collected in acid-rinsed glass bottles with Teflon lids; and 

preserved with potassium dichromate/nitric acid. Water samples for Fe2+ analysis were filtered as above, collected in opaque darkbrown polypropylene bottles, and acidified with ultra-pure hydrochloric acid. 2 Stream sediments were composited 1-kg samples from active alluvium. In the laboratory, samples were air dried, sieved to 

minus-80 mesh (0.177 mm), and pulverized for chemical analysis. Clean quartz sand was pulverized between samples to reduce 

risk of contamination. Composited rock chip samples were coarsely crushed to pea-sized pieces, split with a Jones splitter, and pulverized as described for sediments. 3 Precipitates 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 split for chemical and mineralogical analysis by X-ray diffraction. Clean quartz sand was hand ground between samples. 4 Pan concentrate samples (about 7 kg) were collected as grab samples in areas where heavy minerals tend to accumulate, and 

panned until 1 to 3 percent of the original sample remained. In the laboratory, the samples were sieved to minus-20 mesh (0.84

mm), gravity separated using bromoform (specific gravity about 2.85), and then separated into magnetic, weakly magnetic, and nonmagnetic fractions. The nonmagnetic fraction, which commonly contains ore-related minerals such as sulfides, gold, and other 

native metals, was hand ground as described for precipitates. 5 Composite 1-kg samples for leaching were collected from the upper 2.5 cm of the surface layer. In the laboratory, samples 

were dried and sieved to minus-0.375 mesh (9.5 mm). Deionized water used for leaching was acidified with sulfuric acid/nitric acid 

(60/40 weight percent mixture) to a pH of 4.20. Using a ratio of 20:1 water to sample, 1 liter of water was added to 50 g of sample and the mixture was rotated at 30 ± 2 rpm for 18 ± 2 hours (Environmental Protection Agency, 1994). Following rotation, pH, 

conductivity, temperature, oxygen content, and alkalinity were determined on the leachates. The leachates were then filtered at 0.45 

μm, collected into polypropylene bottles, and acidified with ultra-pure nitric acid.

Sample media Method Elements determined

1Water, 

filtered/

acidified

MW Ag, Al, As, Au, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge,

Hf, Ho, In, Ir, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os, P, Pb, Pd, Pr, Pt, Rb,

Re, Rh, Ru, Sb, Sc, Se, SiO2, Sm, Sn, Sr, Ta, Tb, Te, Th, Ti, Tl, Tm, U, V, W, Y, Yb,

Zn, Zr

EW Al, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Si, Sr, Ti,

V, Zn

CO Fe2+

CV Hg

AF Hg

Water, 

filtered/not 

acidified

IC Cl-

, F-, NO3

-

, SO4

2-

1,5Leachates, 

filtered/

acidified

MW Same as above, but omitting Ir, Lu, Os, Pd, Pt, and Rh

EW Same as above, but also including Ag, As, Sb, and Sn

2Sediments, 

rocks

ET Ag, Al, As, Au, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Eu, Fe, Ga, Ho, K, La, Li, Mg,

Mn, Mo, Na, Nb, Nd, Ni, P, Pb, Sc, Sn, Sr, Ta, Th, Ti, U, V, Y, Yb, Zn

EP Ag, As, Au, Bi, Cd, Cu, Mo, Pb, Sb, Zn

HY As, Sb, Se

GF Au

CV Hg

AA Tl

IE W

3Precipitates ET Ag, Al, As, Au, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Eu, Fe, Ga, Ho, K, La, Li, Mg,

Mn, Mo, Na, Nb, Nd, Ni, P, Pb, Sc, Sn, Sr, Ta, Th, Ti, U, V, Y, Yb, Zn

EP Ag, As, Au, Bi, Cd, Cu, Mo, Pb, Sb, Zn

4Concentrates ES 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, Zr
7

A large number of chemical elements were determined 

using a variety of quantitative and semiquantitative analytical 

techniques (table 2). Descriptions and quality assurance/quality 

control (QA/QC) protocol for most of the analytical methods are 

found in Arbogast (1996). 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 constituted 19 percent of the total 

number of samples analyzed. Reference standards were interspersed with batches of samples, and the analyses of the standards were checked to assure that reported values were within

±20 percent of the accepted values. Chemical and mineralogical 

data are found in Eppinger and others (1999).

In subsequent sections of this report, water classifications, 

based on relative amounts of major cations and anions, follow 

those of Piper (1944), Hem (1985), and Drever (1997, fig. 2 of 

Appendix 1). For water samples where carbonate (CO3

2-) and 

bicarbonate (HCO3

-

) are present, bicarbonate is overwhelmingly 

dominant. Thus, the term “bicarbonate” is used exclusively 

when discussing these species. Carbonate and bicarbonate concentrations were determined from measured pH and total alkalinity, following equations of Deutsch (1997, p. 13–14). These 

equations assume that carbonate alkalinity ≡ total alkalinity, a 

reasonable assumption for most natural waters (Hem, 1985, p. 

106; Drever, 1997, p. 46). In discussing water chemistry, emphasis is given to the following significant inorganic parameters 

listed by the Alaska Department of Environmental Conservation 

(AKDEC) drinking water standards (Alaska Department of 

Environmental Conservation, 1994) and by the U.S. Environmental Protection Agency (Environmental Protection Agency, 

1995b): pH, Ag, Al, As, Ba, Be, Cd, Cl-

, Cr, Cu, F-, Fe, Hg, Mn, 

Na, Ni, NO3

-

, Pb, Se, SO4

2-, Tl, and Zn. Thallium was not found 

in concentrations exceeding 0.4 ppb (parts per billion) in any of 

the surface water samples collected and will not be discussed 

further. The AKDEC primary maximum contaminant level 

(MCL) for Tl is 2 ppb (Alaska Department of Environmental 

Conservation, 1994). Primary MCL values are regulatory waterquality action levels established by the AKDEC, whereas secondary MCL values are nonregulated recommended water-quality goals. In general, differences in metal concentration between 

filtered/acidified and unfiltered/acidified water samples are minimal, indicating that most metals are present as dissolved species; 

therefore the unfiltered/acidified samples will not be discussed 

further.

The subjective term “anomalous” and its synonyms are 

used as relative terms with respect to average crustal abundance 

values of Fortescue (1992), to background data for various sample media provided by Rose and others (1979), and to examination of data distributions for samples collected in this study.

Kennecott

Geology, Deposit Setting, and Mining History

Stratabound copper deposits in the Kennecott area are 

found in the lower part of the Upper Triassic Chitistone Limestone, near the disconformable contact with the underlying 

Middle to Upper Triassic Nikolai Greenstone (fig. 3). Basalt 

flows of the Nikolai Greenstone are mainly tholeiitic, have a high 

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

(MacKevett and others, 1997). The Chitistone Limestone grades 

upward into the Upper Triassic 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 copper. MacKevett and others (1997) suggested that the Kennecott 

deposits formed through the following sequence: (1) copperenriched 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 536,000 t (metric tons) of copper and around 

100 t 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 copper from 4.02 million t 

of ore.

Early Russian explorers reported implements of copper 

used by Copper River native peoples 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 to Washington State for processing. 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 

 Kennecott

~
8 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

6500

4000

5500

6000

3500

3500

3000

4000

4500

5000

5500

600

5500

6000

5000

4500

4000

2000

2500

3000

3500

1500

2000

250

3000

3000

2500

3000

3500

4000

450

5

0

000

3000

4500

5000

5500 6000

6500

6000

5500

5000

4500

4000

3500

30 00

Tif

Kennicott River

National Cr

Amazon Creek

Bonanza Creek

Creek

Jumbo

142°55' 

61°30'

142°50'

McCarthy Road

AERIAL

TRAM

AERIAL TRAM

MOTHER LODE MINE

JUMBO MINE BONANZA MINE

Bonanza Peak

Kennicott

R i d

g e B o n a n z a

Bonanza

Ridge

K e

n

n

i

c

o

t

t

G

l

a

c i e r

R o o t G l a c i e r

ERIE MINE

Porphyry Mountain

McCarthy

landing strip

McCarthy Creek

glacial debris

GLACIER MINE

4KE002

=6KE016

6KE015

4KE008

4KE013

4KE007

4KE006

4KE012

4KE011

4KE010

4KE009

4KE005

4KE004

4KE003

4KE001

4KE014

 0 1 2 3 4 KILOMETERS 

 0 1 2 MILES

61°26'

61°33'

Qu

Tif

Tif Tif

Tif

Tif

Qu

Qu

Qu

Qu

Qu

Qu

Qu Qu Qu

Qu

Kc

Kc

Kc

Qu

Tif Tif

Tif

Tif

Kc

Tif

Ks

Ks

TRn

TRn

n

Kc

Ks

TRn

TRn

TRn

TRc

TRc

c

TRc

TRn

TRnz

nz

TRc

JTRm

JTRm

TRc

TRnz

TRc TRnz

TRn

TRn

TRn

TRc TRn

TRn TRc TRnz

TRn

TR

TR

TR

Tif

TRn

Figure 3 (above and facing page). Generalized geology and site locations for samples collected in Kennecott mine area, Alaska. 

Geology generalized from MacKevett (1970, 1972, 1974) and MacKevett and Smith (1972). Base from U.S. Geological Survey 1:63,360 

McCarthy B-5 (1970), B-6 (1959), and C-6 (1959). Contour interval 500 ft.
9

production in 1938 because of low reserves, low copper prices, 

and labor problems (MacKevett and others, 1997). Presently, 

the mill area remains intact (fig. 2A), and carbonate-rich minewaste rock remains below caved adits high above the mill on 

Bonanza Ridge. 

Results of Study

Thirteen surface water samples were collected from below 

the Bonanza mine, from a rainwater pool below the Kennecott 

mill, from a small spring flowing from Kennecott mill tailings, 

from National Creek above and below the mill, and from several 

additional creeks distal to the mines and mill (fig. 3). At the 

time of sampling, no water was observed flowing from mine 

adits. Samples collected both proximal and distal to mines and 

the mill have similar chemistries. All 13 waters collected in the 

Kennecott area are classified as calcium-bicarbonate type waters 

(fig. 8A). With respect to other major cations and anions, there 

are only slight concentrations of sulfate, very low chloride, and 

low concentrations of magnesium, sodium, and potassium. All 

waters are near neutral, with pH values ranging from 7.7 to 8.2, 

and conductivities ranging from 105 to 188 μS/cm (microsiemens per centimeter), except for a spring sample flowing from 

the base of the Kennecott mill tailings, with a value of 436 μS/

cm (fig. 8B). Alkalinities range from 45 to 80 ppm (as calcium 

carbonate), except for the same spring sample with a value of 

230 ppm. This spring sample also has the highest copper concentration from the area (67 ppb copper), well below the 

AKDEC secondary MCL of 1,000 ppb (fig. 8C). None of the 

AKDEC significant inorganic parameters having primary or 

secondary MCL values are found to exceed established limits 

(fig. 8B,C).

A perusal of sediment, rock, and concentrate data reveals 

anomalous concentrations for several elements (see Appendix) 

(Eppinger and others, 1997, 1999). Many of the stream sediments collected at water sample sites contain anomalous concentrations of arsenic, copper, and mercury and weakly 

anomalous concentrations of Ag, Au, Cd, Pb, Sb, and Zn. Rock 

samples exhibit an anomalous metal suite similar to that found 

in sediments. Alluvial heavy-mineral concentrates are variably 

anomalous in Ag, As, Bi, Cd, Cu, Pb, Sn, and V.

Interpretation

Surface water samples from the Kennecott area have low 

metal concentrations that are generally comparable to worldwide average surface water concentrations (Eppinger and others, 

1997, table 4). Only slight differences in cation and anion content are found between samples proximal and distal to the mines 

and mill. The low metal concentrations are due primarily to two 

geologic controls, the widespread host carbonate rocks and the 

absence of unstable sulfide minerals. Chitistone Limestone 

hosts the deposits and is widespread throughout the area. The 

limestone greatly increases the buffering capacity of surface 

waters and results in near neutral pH values, reducing metal 

mobility. Kennecott-type deposits lack unstable sulfide minerals, such as pyrite, whose weathering commonly results in formation of acidic waters. Further, minerals containing elements 

such as zinc or uranium, which could be mobilized in neutral or 

higher pH waters, are uncommon in Kennecott-type deposits. 

The dominant sulfide minerals in the Kennecott deposits are 

chalcocite and djurleite, both copper sulfides that are relatively 

stable in the surficial environment. Although sediment, rock, 

and concentrate data indicate that high concentrations of potentially toxic elements such as arsenic, cadmium, copper, and mercury are found in mill and mine-waste piles, these metals are not 

mobilized because of the absence of acid-generating minerals in 

Kennecott-type deposits and the waste piles and mill tailings 

derived from them.

The geologic controls just described are also responsible 

for the calcium and bicarbonate composition of the waters. 

Both ions are likely derived from the abundant carbonate bedrock in the area. The absence of acid-generating minerals precludes consumption of the bicarbonate ion. The sparse sulfate in 

the waters is surprising, as gypsum from sabkha horizons is an 

integral part of the genesis of the deposits (MacKevett and 

others, 1997). Perhaps the gypsum was completely consumed 

during formation of chalcocite and djurleite. Alternatively, 

perhaps the gypsum-rich rocks are peripheral to the deposits 

themselves, beyond areas sampled in this study.

 EXPLANATION

 Surficial deposits (Quaternary)—Undivided alluvial, colluvial, 

 and glacial deposits

 Dacite and dacite porphyry (Tertiary)—Dikes and sills

 Schulze Formation (Upper Cretaceous)—Siliceous shale with 

 uncommon sandstone and siltstone

 Chititu Formation (Cretaceous)—Dominantly mudstone and 

 shale with lesser siltstone and limestone. Includes 

 metamorphosed Chititu Formation (Kch) of MacKevett 

 (1974) and MacKevett and Smith (1972)

 McCarthy Formation (Lower Jurassic? and Upper Triassic)—

 Impure limestone, chert, shale, and minor siltstone. Includes 

 both upper member (Jmu) and lower member (Jml) of 

 MacKevett (1970, 1972, 1974) and MacKevett and Smith 

 (1972)

 Nizina Limestone (Upper Triassic)—Limestone with layered 

 and nodular chert

 Chitistone Limestone (Upper Triassic)—Limestone, dolomite, 

 and minor nodular chert. Contains local solution pits and 

 caverns

 Nikolai Greenstone (Upper to Middle Triassic)—Subaerial 

 amygdaloidal basalt flows

 Contact, approximately located

 Fault contact, approximately located—Dotted where 

 concealed

 Adit

 Mine

Qu

Tif

Ks

Kc

Jm

nz

c

n

 Kennecott
10 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

Qu

Kv

Qu

Kv

Qu

Kv

Qu

Qu

Kv

Kv Kv

Kv

Kv Qu

Qu

Kv

Kv

Kv Kv

Qu

Qu

Kv

Kv

Kv

Qu

Qu

Kv

Kv

Qu Kv

Kv

Qu

Qu

Kv

Ti

Kv Qu

Kv

Qu Qu

Qu

Qu

Kv

Kv

Kv

Kv Qu

2 0 0 0

4 0 0 0

4 0 0 0

5 0 0 0

3 0 0 0

5 0 0 0

6 0 0 0

7 0 0 0

6 0 0 0

5 0 0 0

4 0 0 0

4 0 0 0

5 0 0 0

5 0 0 0

6 0 0 0

6 0 0 0

7 0 0 0

6 0 0 0

6 0 0 0

5 0 0 0

5 0 0 0 5 0 0 0

4 0 0 0

5 0 0 0

5 0 0 0

6 0 0 0

4 0 0 0

6 0 0 0

4 0 0 0

5 0 0 0

6 0 0 0

4 0 0 0

5 0 0

6

0

0 0 0

7 0 0 0

3 0 0 0

4 0 0 0

5 0 0

2

0

0 0 0

3 0 0 0

5 0 0 0

6 0 0 0

6 0 0 0

5 0 0 0

6 0 0 0

North Fork

Bremner

River

Amy

Creek

Golconda Creek

Monahan Creek

Standard Creek

Ptarmigan

Creek

Shovel Cree k

=6BR001

=6BR010

6BR002

6BR003

6BR004

6BR005

6BR006

6BR013

6BR014

6BR007

6BR008

6BR009

6BR011

6BR012

GRAND PRIZE MINE

LUCKY GIRL MINE

SHERIFF MINE

YELLOWBAND MINE

AND MILL

landing strip

0 1 2 3 4 5 KILOMETERS

0 1 2 3 MILES

143°37'30" 143°17'30"

60°57'30"

61°00' 

61°05'

143°35' 143°30' 143°25' 143°20'

Qu

 EXPLANATION

Qu Surficial deposits (Quaternary)—Undivided alluvial, colluvial, and glacial deposits

Ti Intrusive rocks (Tertiary)—Granodiorite and tonalite with subordinate hypabyssal rocks

Kv Valdez Group (Cretaceous)—Flysch deposits, commonly metamorphosed to greenschist facies

Contact, approximately located

Glacier or ice

Rock glacier

Lake

Adit

Mine or prospect

The spring sample below the Kennecott mill that contains 

relatively elevated copper and alkalinity concentrations also contains the highest total dissolved solids (TDS, a calculated estimate of all dissolved constituents) (fig. 8A) and elevated nitrate 

(11 ppm as NO3

-

). Although still below the AKDEC primary 

MCL of 44 ppm for nitrate, the nitrate concentration from the 

spring is the second highest concentration found in all water 

samples collected throughout this WRST study. The spring 

flows from the base of mill tailings on Nikolai Greenstone and is 

located below the abandoned ammonia leaching plant at the 

Kennecott mill (fig. 2A). X-ray diffraction of a pervasive red 

stain that coats the basalt in wet areas reveals an amorphous, 

likely organic, compound. White crusts rimming the water’s 

edge are calcite, likely accounting for the higher conductivity 

and TDS at the site. It is unclear whether the nitrate in the water 

is related to the breakdown of ammonia (NH3) used in the 

leaching process or to nearby pit toilets used by private landowners higher up on the tailings piles. 

Anomalous concentrations of mercury are found in rock 

samples (as much as 520 ppm mercury in chalcocite ore) and in 

Figure 4. Generalized geology and site locations for samples collected in Bremner area, Alaska. Geology north of lat 61° N. from 

MacKevett (1978), south of lat 61° N. from George Plafker (unpub. mapping, 1998). Base from U.S. Geological Survey 1:63,360 McCarthy 

A-7 (1959) and Bering Glacier D-7 (1984). Contour interval 1,000 ft.
11

sediments (as much as 3 ppm mercury) at Kennecott (Eppinger 

and others, 1997, 1999). The only form of mercury identified is 

cinnabar, a mercury-sulfide mineral that is very stable in the 

surficial environment. The most important aspect when evaluating the effect of mercury to surrounding aquatic systems is not 

total mercury concentrations, but conversion to bioavailable, 

organic mercury compounds, such as methylmercury, which is 

water soluble and highly toxic to all organisms (Gray and others, 1996). Although at Kennecott we have not analyzed mercury in water or studied mercury speciation, the likelihood of 

significant mercury present in the water column or of conversion to methylmercury is low, because the form of mercury 

(cinnabar) is highly stable, and the surface water is oxidized 

and has relatively high pH values (pH 7.7–8.2) (J.E. Gray, 

written commun., 1999).

A specific WRST management concern at Kennecott is 

whether geoenvironmental hazards related to the mines and mill 

exist. Geochemical data collected in this study suggest that 

Kennecott-type deposits are relatively benign to the environment, owing to the large amount of carbonate rocks present, the 

resulting high buffering capacity of waters, the absence of acidgenerating minerals, and the scarcity of metals that could be 

mobilized at higher pH values. 

Bremner

Geology, Deposit Setting, and Mining History

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 the Bering Glacier quadrangle by 

George Plafker (unpub. mapping, 1998), the sources of the following summary. Outcrops in the mountainous region around 

the Bremner gold deposits are predominantly of the Cretaceous 

Valdez Group, and intervening valleys are filled with unconsolidated Quaternary alluvial, colluvial, and glacial deposits (fig. 4). 

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

and argillite, and minor schist, slate, and phyllite; and are turbidite deposits that formed as extensive deep-sea fans. Rocks of the 

Valdez Group in the Bremner area have been variably metamorphosed to chlorite- or biotite-grade greenschist facies and have 

northwest-striking foliation and lineaments. Hypabyssal, 

hornblende-rich, early to middle Tertiary granodiorite and 

tonalite plutons, and dacite dikes and sills cut the Valdez Group 

in the study area. Large Tertiary intrusions cutting rocks of the 

Valdez Group are found about 13 km northeast and 8 km south 

of the Bremner deposits. During our study of the Bremner 

deposits, individual as well as swarms of granodiorite and dacite 

dikes were observed, all generally less than 2 m thick. We also 

noted pervasive thin quartz veins and veinlets cutting the Valdez 

Group metasediments.

Although 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 3 m thick and were interpreted by Moffit as reworked 

bench gravels. The fluvial reworking of the bench gravels 

reconcentrated the gold accumulated 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 to be 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 adits at three levels following a northwest-trending, 

near-vertical, pyrite-rich, banded white quartz vein cutting slate. 

Brecciated portions of the vein are as thick as 2 m, vuggy, and 

iron oxide rich. Ore at the adjacent mill site consists 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, contains iron-oxide clots, pyrite, chlorite, 

sericite, free gold, calcite, and probably arsenopyrite. Although 

production records from the Bremner district are scant, 

MacKevett (1976) listed placer gold production at between 

2,000 and 3,000 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 1930’s, 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 considerably reduced from that 

reported by Moffit (1914), consisting of prospecting at the 

mouth of Standard Creek and on Golconda Creek along a 4-km 

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 (fig. 2B), but several cabins remain standing. 

Mill tailings and mine waste piles are evident at the mill and 

lode mines. Extensive hand-stacked boulder piles and an abandoned backhoe remain along Golconda Creek as evidence of the 

previous placer operations.

Results of Study

Ten surface waters were collected from nine sites, including mine drainage flowing from the Lucky Girl mine, a stream 

below the Lucky Girl mill, a stream below the Yellowband mine, 

 Bremner
12 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

4500

4500

4000

5500

5000

4000

4500

4500

4000

5500

4500

5000

4500

4500

5000

4500

5000

5000

6000

6500

6000

5500

5000

6500

5000

5000

4500

4000

4000

5000

5000

TKdm

TKp Kc

TKdm

Qw

Qc

Qc

Qa

Qa

Qc

Qc

TKdm

Kc

Qa

Qc

Qc Qw

Kc

Kc

QTg

Qc

Qc

Qw

Kc

QTw

Qs

Qc

Qw

Kc

Kc

Qw

Kc

TKd Qw TKd

Kc

Kc

Qc

Ks

Qc

Kc

Qog

KJa

TKu

TKu

Qog

Qc

Jg KJa

Qc

Jg Jg

Qu

Qa

Qog

Qs

TKu

KJa

Qog

Qs

Qog

KJa Jg

TKu

TKu

TKd

Qa

KJa

Qog

KJa

TKdm

KJa

Qc

Qc

Qa

Qw

Qs

Qs

KJa

KJa

Qrg Qw

KJa

Qa

Qw

Alder

Big

Cr

Poorman

Gold Run Cr

B o n a n z a

Chathenda Cre ek

C r e e k

Canyon Creek

Chicken Cr

Glacier Creek

Paulson Cr

Sargent Cr

C h a v o l d a C r e e k

Eldorado Creek

Gulch

Coarse Money Cr

N.P. Nelson

Hill

Gold Hill

Salt Cr

Bug Gulch Snow

Gulch

Little Eldorado Cr

Skookum Cr

7GH017

7GH001

7GH002

7GH003

7GH004

7GH005

7GH006

7GH007

7GH008

7GH009

7GH010

7GH011

7GH012

7GH013

7GH014

7GH015

7GH016

1" = 1500' (At D-Size Plot)

141 55' o 141 50' o

62 08' o

62 05' o

 0 1 2 3 4 5 KILOMETERS 

 0 1 2 3 MILES

a stream flowing from the base of a rock glacier north of the 

Yellowband mine, and several streams more distal to the mines 

and mill (fig. 4). All the waters are classified as calcium- and 

sulfate-type waters (fig. 9A). Calcium is overwhelmingly the 

dominant major cation and sulfate is the major anion, followed 

by bicarbonate. Chloride, magnesium, sodium, and potassium 

are negligible components. Values for pH range from 6.3 to 7.9 

(fig. 9B), with the lowest value from water below the Lucky Girl 

mill (site 6BR006, fig. 4). The pH values for mine drainage 

flowing from both the Lucky Girl mine (site 6BR001) and from 

the stream below the Yellowband mine (site 6BR010) are both 

7.9. Conductivities range from 86 to 160 μS/cm, except for the 

Lucky Girl mine drainage sample, which has a value of 220 μS/

cm. Alkalinities (as calcium carbonate) range from < 10 ppm 

(from a site on Golconda Creek upstream of mining activity) to 

26 ppm (from the Lucky Girl mine adit). With respect to the significant inorganic parameters for drinking water—pH, Ag, Al, 

As, Ba, Be, Cd, Cl-

, Cr, Cu, F-, Fe, Hg, Mn, Na, Ni, NO3

-

, Pb, 

Se, SO4

2-, Tl, and Zn—only pH and manganese exceed established AKDEC MCL values (fig. 9B, C). Water flowing from 

below the Lucky Girl mill, at pH 6.3, is slightly below the pH 6.5 

secondary MCL. Water flowing from the base of the rock glacier north of the Yellowband mine (fig. 4, site 6BR011) is 

slightly high in manganese, with a value of 53 ppb (sample site 

duplicate was 61 ppb Mn). The secondary MCL for manganese 

is 50 ppb. All other water samples contain < 10 ppb manganese.

Stream sediments collected at water sample sites contain 

anomalous arsenic and copper, and slightly anomalous silver, 

gold, bismuth, selenium, and zinc (see Appendix) (Eppinger 

and others, 1999). Rock samples contain anomalous concentrations of these same elements, plus cadmium, molybdenum, and 

lead. Alluvial heavy-mineral concentrates are variably anomalous in Ag, As, Au, Cu, Pb, and W. Leachates from mine waste 

(two sites) contain high aluminum and relatively elevated tungsten, whereas a leachate from mill tailings contains high concentrations of arsenic, iron, and manganese, and relatively 

elevated gold, lead, and zinc. The mill tailings leachate pH is 

4.2, and the waste leachates are pH 8.3 and 8.7. Conductivities 

of the leachates are all 100 μS/cm or less. Alkalinities on the 

leachates with pH exceeding 4.5 are 35 and 50 ppm (as calcium 

carbonate).

Interpretation

For waters at Bremner, alkalinities are all relatively low, 

sulfate is the predominant anion over bicarbonate, pH is near 

neutral, and dissolved metal contents are low. These features 

Figure 5 (above and facing page). Generalized geology and site locations for samples collected in Gold Hill mine area, Alaska. Geology 

generalized from Richter and Jones (1973). Base from U.S. Geological Survey 1:63,360 Nabesna A-2 (1960). Contour interval 500 ft.
13

 EXPLANATION

Qu Surficial deposits (Quaternary)—Undivided alluvial, colluvial, and glacial deposits

Qa Alluvium (Quaternary)—Fan, cone, and flood plain deposits; includes Qal and Qaf of Richter and Jones (1973)

Qc Colluvial deposits (Quaternary)—Undifferentiated colluvium and landslide deposits; includes Qcu and Qcl of Richter and Jones (1973)

Qrg Rock glacier deposits (Quaternary)—Includes active and recently active rock glaciers

Qw Glacial drift (Quaternary)—Undifferentiated glacial and fluvioglacial deposit of Wisconsin age

Qog Glacial drift (Quaternary)—Undifferentiated older glacial deposits

Qs Solifluction deposits (Quaternary)—Chiefly bedrock rubble but may include older glacial drift deposits

QTg Boulder and gravel deposits (Quaternary to Tertiary)—Weakly consolidated and poorly sorted fluvioglacial(?) deposits locally

 interbedded with volcanic ash. On Gold Hill gravels contain disseminated native gold (Moffit, 1954) and may be in part

 source of Bonanza gold placers 

QTw Wrangell Lava (Pleistocene, Pliocene, Miocene)—Chiefly andesitic to basaltic flows and associated volcanic rocks

TKp Andesite porphyry (Tertiary to Cretaceous)—Massive porphyry with conspicuous phenocrysts of altered plagioclase

TKd Porphyritic diorite (Tertiary to Cretaceous)—Intrusive masses of augite-hornblende diorite

TKdm Pyroxene diorite-monzonite (Tertiary to Cretaceous)—Gradational from pyroxene diorite west of Red Hill Creek to potassic

 pyroxene diorite, pyroxene monzonite, and hornblende monzonite east of Red Hill Creek. Pyroxene largely altered to

 actinolite and chlorite

Tku Undifferentiated intrusive rocks (Tertiary to Cretaceous)—Dikes and sills of andesitic and basaltic composition and irregular

 bodies of feldspar porphyry

Ks Continental sedimentary rocks (Cretaceous)—Conglomerate, coarse-grained sandstone, siltstone, and mudstone

Kc Chisana Formation (Cretaceous)—Marine and subaerial volcanic andesite flows, volcaniclastic lahars and avalanche deposits,

 volcanic sandstone and siltstone, and lenses of marine sedimentary rock; unconformably overlain by Ks

KJa Argillite and mudstone (Cretaceous to Jurassic)—Interbedded with graywacke, locally calcareous sandstone, pebble

 conglomerate, pebble mudstone, pelecypod coquina, and silty limestone

Jg Graywacke-argillite (Jurassic)—Rhythmically interbedded argillite-siltstone-graywacke; metamorphosed to hornfels near

 larger intrusive bodies 

 Contact, approximately located

 Dike

 Fault contact, approximately located—Dotted where concealed

 Thrust fault, approximately located—Dotted where concealed; sawteeth on upper plate

Lake or pond

Adit

 Prospect

 Cabin

are explained by the geologic setting of the deposits—pyriteand calcite-bearing quartz veins (generally) following granitic 

dikes that cut predominant, carbonate-poor slates. The predominant ions in the waters, calcium, sulfate, and lesser bicarbonate, 

are the result of weathering of the pyrite (producing acid and 

sulfate) and by vein calcite dissolution (producing calcium and 

bicarbonate). The acid is consumed by the bicarbonate, keeping 

pH values near neutral and metal mobility to a minimum. However, alkalinities are naturally low in waters both distal and 

proximal to mining and milling activities. The low alkalinities 

and minor bicarbonate suggest that most of the available carbonate is being consumed by the neutralization process. Disturbing 

mine waste or mill tailings, whether by human-induced or natural means, would probably disrupt this naturally established 

equilibrium and might necessitate further active treatment.

Minor sphalerite, observed in ore at the Lucky Girl mine, is 

probably the source of the slightly elevated zinc in the waters. 

The highest concentration found in Bremner waters is 10 ppb 

zinc, which, curiously, is from the sample containing relatively 

high manganese described previously. This sample (6BR011) 

 Bremner
14 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

Nikonda

Creek

Monte Cristo Creek

Bond

Creek

N a b e s n a R i v e r

California Creek

Harq Cr

06 00

8000

6000

4000

4000

3000

5000

5000

5000

7000

6000

5000

7000

8000

4000

5000

3000

6000

5000

8000

7000

6000

7BC004

7BC003

7BC006 6OH001

6OH002

6OH003

6OH004

6OH005

6OH006

6OH007

6OH008

6OH009

6OH010

7BC001

7BC002

7BC005

7BC008

7BC007

7BC009

Kg

Tp

Kg

Qu

Qu

QTw

Kg

Tp

Tp

Qu Kg

Tp

Qu

Qu

Qu

Qu

W

Tp

Qu

Qu

Kg

Qu

Kg

Tp

Tp

Qu

Kg

Qu

Pl

Kg

Tp

Qu

Tp

Pl Pl

Pl

Pl

Pl

Qu

RT n

Tp

Pl

Pl

Tp

Pl

Tp

Qu

Pl

Tp

Tp

Pl

Pl

Tp

Qu

Qu

Pl

Qu

Pl

Tp

Pl

Tp

Tp

Tp Kg

Qu

Qu

Kg

Qu

Qu Tp

Kg

Tp

Kg Tp

Kg

Kg

Kg

Qu

Kg

Kg

TRn

TR

TR

n

Pa

TRPa

TRn

RT Pa

TRPa

TRPa

TRPa

RT Pa

TRPa RT Pg

RT Pa

TR

TR

n

Pa

Qu

QTw

QTw

QTw

QTw

QTw

 PP v

142 55' 142 50' 142 45'

62 14'

62 12'

62 10'

Tp Tp

Qu

Kg

Pl

Pl

Tp

o

o o o

o

o

RT n

RT n RT n

RT l

RT n

RT l

RT l

RT l

RT n RT n

RT n

 PP v

 PP v

 PP v

 PP v

 PP v

 PP v

 PP v

 PP v

 PP v

 PP v

 PP v

 PP v

 PP v

 PP v

 PP v

 PP v

 PP v

N a b e s n a

G l a c i e r

Bond Creek

area

Orange Hill area

landing strip

62 15' o

143 00' 142 40'

62 08'

0 1 2 3 4 5 KILOMETERS

0 1 2 3 MILES

o o 

o

Figure 6 (above and facing page). Generalized geology and site locations for samples collected in Orange Hill and Bond Creek areas, Alaska. Geology generalized from Richter (1973). 

Base from U.S. Geological Survey 1:63,360 Nabesna A-4 (1959). Contour interval 1,000 ft.
15

 EXPLANATION

Qu Surficial deposits (Quaternary)—Undivided alluvial, colluvial, 

 and glacial deposits

QTw Wrangell Lava (Pleistocene, Pliocene, Miocene)—Chiefly 

 andesitic to basaltic flows and associated volcanic rocks

Tp Hornblende-plagioclase porphyry (Tertiary)—Dikes, sills, and

 small bodies of andesite to latite composition

Kg Nabesna batholith (Cretaceous)—Undifferentiated plutonic 

 rocks; chiefly biotite-hornblende granodiorite

l Limestone (Triassic)—Micritic, nonfossiliferous limestone; 

 locally converted to magnetite-calc-silicate tactite near plutons

n Nikolai Greenstone (Middle to Late Triassic)—Subaerial 

 amygdaloidal basalt flows; near plutons metamorphosed to 

 massive amphibolite

Pa Argillite (Triassic to Permian)—Chiefly argillite with calcareous

 siltstone, chert, and carbonaceous, limy shale

Pg Gabbro (Triassic to Permian)—Dikes, sills, and irregular bodies

 of augite gabbro

Pl Limestone (Permian)—Fossiliferous limestone; locally 

 converted to calc-silicate tactite near plutons

Pv Volcanic rocks (Permian and Pennsylvanian)—

 Undifferentiated andesitic flows, tuffs, and volcaniclastic rocks;

 locally contains siderite, barite, pyrite, and quartz-pyrite-

 chalcopyrite veins

Altered rocks (age uncertain)—Limonite stained and 

 hydrothermally altered rocks

Contact, approximately located 

Fault contact, approximately located—Dashed where inferred,

 dotted where concealed

Glacier or ice

Prospect

Cabin

contains the highest cobalt (6 ppb), copper (18 ppb), and nickel 

(12 ppb) found in waters at Bremner, including those draining 

the mines and mill. Although these metal concentrations are all 

well below the AKDEC MCL values, their combined presence 

in the sample is noteworthy. Stream sediment from the site contains the highest arsenic, copper, and zinc (see Appendix) found 

in Bremner area sediments, including those draining the mines 

and mill. The rock glacier from which the water and sediment 

are derived is distal from known deposits, but the metals in the 

water and sediment suggest that the rock glacier or the basin 

above may contain mineralized rocks. These metal concentrations are apparently natural and unrelated to historic mining 

activity.

The low element content in leachates from mine waste is a 

result of the associated high pH values. Curiously, pH values of 

the waste leachates are higher than those found in surface 

waters in the area. This feature is probably due to the presence 

of calcite in the mineralized veins and associated dumps, but 

the general absence of carbonate elsewhere in bedrock. 

Leachate data suggest that the mine waste would not be 

expected to generate acidic, metalliferous waters during wet 

periods. However, the acidic, metal-bearing mill tailings 

leachate suggests that initial waters flowing from the finely 

ground tailings pile during rain events or spring breakup would 

likely be acidic and metalliferous. The overall minor volume of 

mill tailings present at the Lucky Girl mill, and rapid dilution 

by adjacent streams, would reduce the downstream impact in 

this event. Metals in leachates, found in excess of the AKDEC 

primary and secondary MCL’s, include aluminum, arsenic, iron, 

manganese, and zinc (see Appendix). We reemphasize here that 

the metals in leachates mimic initial waters flowing off tailings, 

prior to dilution by adjacent surface flow and streams. However, surface flow from the mill tailings probably contributes to 

overall metal loading of the stream and associated sediment. 

The differences in behavior of leachates from mill tailings compared to those from mine waste are probably due to the relatively higher pyrite content compared to calcite in the mill 

tailings, a result of the selective concentration of gold-bearing, 

pyrite-rich ore for milling.

WRST resource staff were concerned whether mercury, 

used historically to amalgamate gold at the abandoned Bremner 

mill, was present in waters at levels posing a hazard to visitors. 

Mine waste and ore samples from the Bremner area do not contain mercury exceeding the 0.02 ppm analytical detection limit. 

However, 170 ppm mercury is found in tailings at the Lucky 

Girl mill, and native mercury and gold-mercury amalgam were 

panned from mill product samples. Anomalous mercury in 

stream sediments is found at two sites (both 1 ppm mercury) 

directly below the mill, but not elsewhere in the Bremner area. 

These data support, and historical records confirm, the presence 

of anthropogenic mercury in tailings and sediment at the Lucky 

Girl mill. However, all 10 water samples from the Bremner 

area, including water flowing from the Lucky Girl mine adit and 

water from below the mill, contain less than 0.025 ppb 

mercury—well below the AKDEC MCL of 2 ppb. This suggests 

that mercury was not being mobilized in surface water during 

the dry summer sampling period in 1996. Whether mercury is 

mobilized during wet periods or spring breakup is unknown. 

Leachate samples were not analyzed for mercury.

Gold Hill

Geology, Deposit Setting, and Mining History

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 (fig. 5). The 3,000-m-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 

 Gold Hill
16 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

4000 3000

6000

5000

6000

5000

6000

5000

4000

3000

40

30

00

00

3 0 0 0

2500

3000

3000

2500

50

0

4000

3000

0

7NA062

6NA026

4NA019

4NA018

6NA028, 7NA039,

7NA063, 7NA070

7NA040, 7NA072

Sample sites in this area

 shown in figure 7B

6NA022

7NA056

NA008

4NA021, 7NA054

4NA020, 7NA745

4NA015

4NA014

4NA016

4NA017

4NA013

4NA012

6NA023, 7NA057

7NA058

6NA025, 7NA059

7NA060

6NA024

7NA051

4NA007

7NA064

7NA071,

4NA009

7NA055

6NA027

7NA053 7NA044

7NA049

{

7NA052

7NA050

6NA030

7NA047

7NA041, 7NA048, 7NA073

 Devil's

Mountain

Devil's Mountain

 Lodge

landing

strip

J

a

c

k s i n a

Sk o o k um

Nabesna

Road

Nabesna Mine

 and mill

 White

Mountain

C r e e k

C r e e k

R a v e n 

 H i l l s

Windy Lake

Virginia

Lake

Fish Creek

Lake

Whitham Lake

J a ck

C r e e k

Rambler Mine

C

r

e

e k

J a c k

C a b i n C r e e k

A

QTw

Kc

Qu

Kc

Kc

QTw

KJs

Kc

Kc

KJs

KJs

Ks TKd

TKd

TRl TRl

TRl

Ks

Qu Qu

Qu

Ks

Ks

Qu

TKd

TRl

TRl

TRl

Qu

Qu

TRn

PPtl

TRn

Qu

Pm

Pm

Pm

Pm

TRn

Qu

TRl

KJs

QTw

Qu

Qu

Qu

Qu

Qu

KJs

TRl

Kg Kg

Kg

Kg

TRl

KJs

Kg TRl

TRl

TRl

Kc

Kc

PPtl

 0 1 2 3 4 5 KILOMETERS

 0 1 2 3 MILES

62°20'

62°25'

143°05' 143°00' 142°55'

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 underlying Gold Hill is concealed by Quaternary 

glacial gravel and sand deposits, fluvioglacial(?) deposits, 

solifluction deposits, and alluvial deposits.

The gold-bearing placer gravels are Quaternary to Tertiary, 

and lie near or on volcanic and sedimentary rocks of the 

Chisana Formation (Richter and Matson, 1972). All placer 

Figure 7 (above and facing page). Generalized geology and site locations for samples collected in Nabesna mine area, Alaska. 

A, Geology generalized from Richter (1971) and Lowe and others (1982). B, Detailed site locations for samples collected at 

Nabesna mill. Base from U.S. Geological Survey 1:63,360 Nabesna B-4 (1970) and B-5 (1960). Contour interval 500 ft.
17

Nabesna

 mill

4NA011, 6NA029,

7NA036, 7NA043,

7NA046, 7NA061,

 7NA069

4NA010

4NA002

4NA001

4NA003 4NA004

4NA005

6NA035 4NA006

6NA034

7NA042

6NA033

6NA032

6NA031

7NA066

7NA038

7NA065

7NA067

7NA068

7NA037

7NA074

barrels

to Devil's Mtn. Lodge

(about 2.4 km)

road

N

Approximate limit

 of upper tailings

to Nabesna mill

62 ̊ 22' 20"

143 ̊00'00"

Approximate limit

 of lower tailings

B

Braid of Cabin Creek,

approximately located

0 30 METERS

0 5 0 100 FEET

EXPLANATION

4NA001 Sample site and field number

Old backhoe cut in tailings

Drainage gully cutting mill tailings

EXPLANATION

Qu Surficial deposits (Quaternary)—Undivided alluvial, colluvial, and glacial deposits

QTw Wrangell Lava (Pleistocene, Pliocene, Miocene)—Chiefly andesitic to basaltic flows and associated volcanic rocks

TKd Diorite (Tertiary to Cretaceous)—Small diorite bodies

Kg Granodiorite to quartz diorite (Cretaceous)—Stocks and dikes

Kc Chisana Formation (Cretaceous)—Basaltic to andesitic flows, breccias, and interbedded volcaniclastic rocks

Ks Continental sedimentary rocks (Cretaceous)—Arkosic sandstone, siltstone, and shale

KJs Nutzotin Mountain Sequence (Lower Cretaceous and Upper Jurassic)—Calcareous argillite, siltstone, and graywacke

l Limestone (Upper Triassic)—Includes thin-bedded (tl) and massive (ml) limestone units of Lowe and others (1982)

n Nikolai Greenstone (Middle to Late Triassic)—Subaerial amygdaloidal basalt flows. Includes units n of Lowe and others

 (1982) and Pb of Richter (1971)

Pm Mankomen Group (Lower Permian)—Argillite and subordinate interbedded calcareous siltstone and grit

Pt Tetelna Volcanics (Permian and Pennsylvanian)—Interbedded andesitic flows, lahars, tuffs, and volcaniclastic rocks

 Contact, approximately located

 Fault contact, approximately located—Dotted where concealed

 Mine

mines in the district are found in an area 8 km in diameter, centered on Gold Hill; they include Little Eldorado Creek (some of 

the richest ground), Bonanza Creek and its tributaries, Coarse 

Money Creek (fig. 2C), 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 g (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 galena-sphalerite-chalcopyritecalcite-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). No production has been reported 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 1913, resulting in initial claims on Bonanza Creek, where 200 oz of gold was 

recovered in 2 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 fewer 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 

and suction-dredge activities take place (fig. 2C).

 Gold Hill
18 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

Sulfate

+

C hloride

Sodium

+

Potassium

Calc ium

+

Magnesium

Sulfate

C arbonate

+

Bic arbonate

Magnesium

Calcium Chloride

20

40

60

80

20

40

60

80

80 60 40 20 20 40 60 80

80

60

40

20

20

40

60

80

80

60

40

20

8 0

6 0

4 0

2 0

%meq/L

0

400

800

1200

1600

2000

Total dissolved solids

 (parts per million)

CATIONS ANIONS

A

800

Results of Study

The Gold Hill area was visited during a relatively dry summer period in 1997. No activity was underway at any of the 27 

placer claims, none of which had been worked since the previous 

summer. This provided the opportunity to collect baseline 

geochemical data during a period of relative quiescence. Sixteen 

surface water samples were collected at 15 sites upstream and 

downstream of active placer claims and also from sites distal to 

placer activities (fig. 5). 

Intermediate volcanic, volcaniclastic, and marine sedimentary rocks crop out in the Gold Hill area. Calcite veinlets are 

common in all areas, except for Big Eldorado Creek and upper 

Gold Run Creek, and iron-rich sedimentary carbonate rocks 

were observed locally. Near the confluence of Little Eldorado 

and Bonanza Creeks, outcrops of propylitically altered andesite 

and lithic tuff are found, both containing chlorite, disseminated 

pyrite, and calcite veinlets. In most areas sampled, pyrite, gold, 

and epidote are common in alluvial heavy-mineral concentrates, 

and cinnabar is found locally. The only lode deposit observed 

was a prospect consisting of calcite-quartz vein breccia, with 

galena, sphalerite, chalcopyrite, siderite, and cerussite. A rock 

sample from the prospect contains highly anomalous Ag, Au, 

Cd, Cu, Hg, Pb, Sb, and Zn; and slightly anomalous Mn and Mo 

(site 7GH007, Eppinger and others, 1999).

The surface waters at Gold Hill are calcium-bicarbonatedominant, with minor contributions of sulfate, magnesium, 

sodium, and potassium (fig. 10A). Values for pH range from 7.3 

to 8.5. The lowest pH values are found along Big Eldorado 

Creek, in both the active placer area and upstream of areas of 

placer activity. Conductivities range from 52 to 416 μS/cm, and 

average 250 μS/cm; the highest values are from sites along 

Bonanza Creek and the lowest values from sites along Big Eldorado Creek. Alkalinities range from 16 to 150 ppm (as calcium 

carbonate), with the lowest values from sites along Big Eldorado 

Creek (fig. 10B). None of the significant inorganic parameters 

for drinking water—pH, Ag, Al, As, Ba, Be, Cd, Cl-

, Cr, Cu, F-, 

Figure 8 (above and facing page). Geochemical data from 13 water samples, Kennecott area. A, Piper diagram showing major ion composition (Piper, 1944). Square, sample collected below mines or mill; triangle, 

sample collected distal to mines and mill; radius of open circles represents relative total dissolved solids in 

parts per million; values for ions are given as percent milli-equivalents per liter. B, C, Box and whisker diagrams showing summary statistics for selected ions and field parameters. B, Major cations, anions, pH, 

conductivity, dissolved oxygen, and alkalinity; C, Trace cations. Abbreviations used: Cond, conductivity; 

D_O2, dissolved oxygen; Alk, alkalinity; TDS, total dissolved solids; μS/cm, microsiemens per centimeter; MCL, 

maximum contaminant level; REE, sum of rare-earth elements. R indicates that qualified values were replaced 

with one-half of the qualified value prior to calculating statistics. See text (p. 7) for explanation of primary and 

secondary MCL values.
19

Cond

D_O2

Alk

F-_R

Cl-_R

NO3

- _R

SO4

2- _R

Ca_R

K_R

Mg_R

Na_R

Si_R

Al_R

Fe_R

Mn_R

TDS_R

MAJOR CATION, ANION, OR FIELD PARAMETER

1

2

3

4

5

6

7

8

9

pH

0.0001

0.001

0.01

0.1

1

10

100

1000

10,000

100,000

CONCENTRATION, IN PARTS PER MILLION

EXCEPT Al AND Mn (PARTS PER BILLION)

AND CONDUCTIVITY (uS/cm)

Ag_R

As_R

B_R

Ba_R

Be_R

Cd_R

Co_R

Cr_R

Cu_R

Hg

Li_R

Mo_R

Ni_R

Pb_R

Sb_R

Sc_R

Se_R

Sr_R

Th_R

Ti_R

U_R

V_R

Zn_R

REE_R

TRACE CATION

CONCENTRATION, IN PARTS PER BILLION 0.0001

0.001

0.01

0.1

1

10

100

1000

10,000

100,000

no data

no data

B

C

Maximum concentration

Minimum concentration

25th and 75th percentiles

Median value

2

Primary MCL

Secondary MCL

EXPLANATION FOR B AND C

2 2 2 2

2

2

2

2

2

2

2

2 = upper MCL

 for pH

= lower MCL 

 for pH

Fe, Hg, Mn, Na, Ni, NO3

-

, Pb, Se, SO4

2-, Tl, and Zn—are found 

exceeding the AKDEC MCL values (fig. 10B, C). Waters at 

three sites along Bonanza Creek have pH values of 8.5, matching 

the AKDEC secondary MCL upper limit for pH.

A review of sediment, rock, and concentrate data in 

Eppinger and others (1999) reveals elevated concentrations for 

several elements (see Appendix). Stream sediment and rock 

samples collected at water sample sites contain anomalous gold 

and slight to moderately anomalous concentrations of As, Bi, 

Hg, Sb, Se, Sn, and Zn. In addition, rock samples contain anomalous concentrations of Ag, Cd, Co, Cu, Mo, Pb, and V. Alluvial 

heavy-mineral concentrates are variably anomalous in Ag, As, 

Au, B, Ba, Bi, Cd, Cu, Pb, and Zn.

Interpretation

The predominant calcium-bicarbonate composition of surface waters is likely related to the common presence of calcite in 

bedrock and alluvium in the Gold Hill area. Chemical breakdown of disseminated and vein pyrite probably accounts for the 

minor concentrations of sulfate in waters. The predominance of 

 Gold Hill
20 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

Calc ium

+

Magnesium

Sulfate

80

60

40

20

8 0

6 0

4 0

2 0

Sulfate

+

C hloride

Sodium

+

Potass

um

arbonate

+

Bic arbonate

Magnesium

20

40

60

80

20

40

60

80

80

60

40

20

20

40

60

80

C

i

Calcium Chloride

80 60 40 20 20 40 60 80

%meq/L

CATIONS ANIONS

A

0

200

400

600

800

1000

Total dissolved solids

 (parts per million)

400

calcite over pyrite results in pH values above neutral. Minor 

magnesium, sodium, and potassium components in the surface 

waters may be related to locally altered intermediate igneous 

rocks in the area. 

Surface waters from Big Eldorado Creek have the lowest 

pH and alkalinity values in waters from the Gold Hill area. 

Along Big Eldorado Creek, green diorite is predominant in outcrop and alluvium; carbonate was not observed. Although presently concealed by recent alluvial deposits, relatively recent 

lode exploration and placer operations along Big Eldorado 

Creek exposed a pyrite-rich vein underlying the active channel 

between the sampled water sites 7GH013 and 7GH015 (fig. 5). 

Present physical evidence of the pyrite-rich vein consists of a 

pile of disaggregated quartz-, kaolinite-, and pyrite-rich rubble 

adjacent to the creek bottom at site 7GH014. Geochemical 

analysis of the vein material reveals 0.48 ppm gold, 14 ppm bismuth, and 7 ppm antimony, but no other anomalous metal concentrations. A small amount of ore was found at a cabin at site 

7GH013, but the source of the ore is undetermined. The ore 

contains pyrite, chalcopyrite, galena, and idaite (Cu3FeS4), and 

is highly anomalous in Ag, As, Au, Bi, Co, Cu, Pb, Sb, and Zn 

(Eppinger and others, 1999). Weathering of pyrite-rich cobbles from veins underlying the Big Eldorado drainage basin 

could be the reason for stream waters there having slightly 

lower pH (7.3) and alkalinity (16 ppm as calcium carbonate), 

compared to elsewhere in the area (mean alkalinity, 91 ppm; 

median, 100 ppm; all Gold Hill water samples). Flow of chemically dissimilar ground water through pyritic or altered bedrock, and subsequent mixing with surface waters could also 

result in the slightly lower pH and alkalinity. The low alkalinity and absence of visible carbonate minerals suggest that water 

in the Big Eldorado basin has less acid-neutralizing capability 

than water elsewhere in the Gold Hill area. This characteristic, 

along with the known presence of pyritic rocks in the drainage, 

suggests that water quality should be monitored if the naturally 

reestablished equilibrium along Big Eldorado Creek is disrupted, either by human-induced or natural means.

Relatively low pH (7.3) and alkalinity (16 ppm as calcium 

carbonate) from site 7GH015, collected above placered areas 

along Big Eldorado Creek, suggest that mineralized (pyritic?) 

Figure 9 (above and facing page). Geochemical data from 10 water samples, Bremner area. A, Piper 

diagram showing major ion composition (Piper, 1944). Square, sample collected below mines or mill; triangle, 

sample collected distal to mines and mill; radius of open circles represents relative total dissolved solids in 

parts per million; values for ions are given as percent milli-equivalents per liter. B, C, Box and whisker 

diagrams showing summary statistics for selected ions and field parameters. B, Major cations, anions, pH, 

conductivity, dissolved oxygen, and alkalinity; C, Trace cations. Abbreviations used: Cond, conductivity; 

D_O2, dissolved oxygen; Alk, alkalinity; TDS, total dissolved solids; μS/cm, microsiemens per centimeter; MCL, 

maximum contaminant level; REE, sum of rare-earth elements. R indicates that qualified values were replaced 

with one-half of the qualified value prior to calculating statistics. See text (p. 7) for explanation of primary and 

secondary MCL values.
21

Cond

D_O2

Alk

F-_R

Cl-_R

NO3

- _R

SO4

2- _R

Ca_R

K_R

Mg_R

Na_R

Si_R

Al_R

Fe_R

Mn_R

TDS_R

MAJOR CATION, ANION, OR FIELD PARAMETER

1

2

3

4

5

6

7

8

9

pH

0.0001

0.001

0.01

0.1

1

10

100

1000

10,000

100,000

CONCENTRATION, IN PARTS PER MILLION

EXCEPT Al AND Mn (PARTS PER BILLION)

AND CONDUCTIVITY (uS/cm)

Ag_R

As_R

B_R

Ba_R

Be_R

Cd_R

Co_R

Cr_R

Cu_R

Hg

Li_R

Mo_R

Ni_R

Pb_R

Sb_R

Sc_R

Se_R

Sr_R

Th_R

Ti_R

U_R

V_R

Zn_R

REE_R

TRACE CATION

CONCENTRATION, IN PARTS PER BILLION 0.0001

0.001

0.01

0.1

1

10

100

1000

10,000

100,000

2 2 2 2

2

2

2

2

2

2

2

2 = upper MCL

 for pH

= lower MCL 

 for pH

B

C

Maximum concentration

Minimum concentration

25th and 75th percentiles

Median value

2

Primary MCL

Secondary MCL

EXPLANATION FOR B AND C

veins like that at site 7GH014 may be present higher in the 

drainage. Stream sediment and concentrate data support this 

hypothesis. Site 7GH015 contains the highest gold (2.1 ppm) 

found in sediments from the Gold Hill area, as well as anomalous tin and zinc. Anomalous silver, gold, bismuth, and cadmium are also found in an alluvial heavy-mineral concentrate 

from the site. The Big Eldorado drainage lies within the eastern 

part of an area with potential for porphyry copper±molybdenum 

deposits (Richter and others, 1975), and the sulfide-bearing 

veins and chemically distinct ground water may be manifestations of the larger mineralizing system.

Cinnabar was observed in alluvial heavy-mineral concentrates from sites along upper Bonanza Creek above the confluence with Little Eldorado Creek. Highly anomalous mercury 

and antimony (both 120 ppm) are found in a rock sample from a 

prospect in the same area. Several rock and sediment samples 

collected elsewhere in the Gold Hill area contain elevated concentrations of mercury and antimony (Eppinger and others, 

1999). Surface waters in the Gold Hill area contain the highest 

mercury concentrations found in the WRST study. Two of these 

comparatively high values, 0.054 ppb and 0.036 ppb mercury, 

are from sites along Bonanza Creek. Relatively high mercury 

 Gold Hill
22 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

Calcium Chloride

80 60 40 20 20 40 60 80

%meq/L

Sulfate

C arbonate

+

Bic arbonate

80

60

40

20

80

60

40

20

Sodium

+

Pota

sium

20

40

60

80

Magnesium

20

40

60

80

Sulfate

+

C hloride

Calc ium

+

Magnesiu

20

m

40

60

80

8 0

6 0

4 0

2 0

s

CATIONS ANIONS

A

0

400

800

1200

1600

2000

Total dissolved solids

 (parts per million)

800

values are also found in waters from upper Gold Run (0.035 

ppb) and upper Big Eldorado (0.033 ppb) Creeks. Water from 

the latter site also contains a comparatively high (relative to all 

WRST samples) concentration of antimony (0.2 ppb). We stress 

that although unusual in the context of all waters sampled from 

WRST, these mercury concentrations in water are two orders of 

magnitude below the AKDEC primary MCL of 2 ppb for mercury. Nevertheless, the presence of (1) cinnabar in concentrates, 

(2) anomalous mercury in rocks, and (3) high antimony in rocks, 

sediments, and waters is interesting and probably indicates a 

high-level epithermal setting for lode deposits in the area. 

However, the presence of mercury alone in sediments and water 

may result from dual origins: natural mercury related to the 

epithermal deposits, or anthropogenic mercury related to gold 

recovery during historic placer operations. (Modern-day suction 

dredge operators report that they periodically recover native 

mercury that has accumulated in stream beds).

At Gold Hill, a WRST resource management question 

was, “What are baseline metal concentrations in surface waters 

during periods of placer inactivity?” Data on baseline conditions during quiescent periods are necessary to measure 

environmental changes resulting from active placer operations. Our data show that during the dry summer 1997 sampling period, none of the significant inorganic parameters for 

drinking water listed by the AKDEC were found in concentrations exceeding established primary or secondary MCL’s. 

However, some of the parameters measured were found at levels equal to (pH) or just below (aluminum and TDS) the secondary MCL’s for these parameters (fig. 10B). Trace elements 

were all found in concentrations at least one order of magnitude below established MCL values (fig. 10C). Whether these 

parameters exceed established limits during high-flow periods 

such as rain events and spring breakup, or during periods of 

placer mining activity, is unknown. The combined minimum, 

maximum, median, 25th, and 75th percentile values listed in 

figure 10B and 10C provide ranges of values expected for 

baseline conditions for surface waters during quiescent, latesummer, dry conditions.

Figure 10 (above and facing page). Geochemical data from 16 water samples, Gold Hill area. A, Piper 

diagram showing major ion composition (Piper, 1944). Square, sample collected below mines or mill; triangle, 

sample collected distal to mines and mill; radius of open circles represents relative total dissolved solids in 

parts per million; values for ions are given as percent milli-equivalents per liter. B, C, Box and whisker 

diagrams showing summary statistics for selected ions and field parameters. B, Major cations, anions, pH, 

conductivity, dissolved oxygen, and alkalinity; C, Trace cations. Abbreviations used: Cond, conductivity; 

D_O2, dissolved oxygen; Alk, alkalinity; TDS, total dissolved solids; μS/cm, microsiemens per centimeter; MCL, 

maximum contaminant level; REE, sum of rare-earth elements. R indicates that qualified values were 

replaced with one-half of the qualified value prior to calculating statistics. See text (p. 7) for explanation of 

primary and secondary MCL values.
23

Cond

D_O2

Alk

F-_R

Cl-_R

NO3

- _R

SO4

2- _R

Ca_R

K_R

Mg_R

Na_R

Si_R

Al_R

Fe_R

Mn_R

TDS_R

MAJOR CATION, ANION, OR FIELD PARAMETER

1

2

3

4

5

6

7

8

9

pH

0.0001

0.001

0.01

0.1

1

10

100

1000

10,000

100,000

CONCENTRATION, IN PARTS PER MILLION

EXCEPT Al AND Mn (PARTS PER BILLION)

AND CONDUCTIVITY (uS/cm)

Ag_R

As_R

B_R

Ba_R

Be_R

Cd_R

Co_R

Cr_R

Cu_R

Hg

Li_R

Mo_R

Ni_R

Pb_R

Sb_R

Sc_R

Se_R

Sr_R

Th_R

Ti_R

U_R

V_R

Zn_R

REE_R

TRACE CATION

CONCENTRATION, IN PARTS PER BILLION 0.0001

0.001

0.01

0.1

1

10

100

1000

10,000

100,000

2 2 2 2

2

2

2

2

2

2

2

2 = upper MCL

 for pH

= lower MCL 

 for pH

B

C

Maximum concentration

Minimum concentration

25th and 75th percentiles

Median value

2

Primary MCL

Secondary MCL

EXPLANATION FOR B AND C

Orange Hill and Bond Creek

Geology, Deposit Setting, and Mining History

Rocks in the vicinity of the unmined 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 (fig. 6). 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 (fig. 2D, 

E). Suites of alteration minerals include biotite-quartz, quartzsericite, and late-stage chlorite-sericite-epidote (Richter, 1973; 

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

and 2 × 3 km at Bond Creek (Richter and others, 1975).

 Orange Hill and Bond Creek
24 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

Mineralization products consist 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 100–320 million t 

grading 0.30–0.35 percent copper and 0.02–0.03 percent molybdenum. The Bond Creek deposit contains an estimated 500 

million t grading 0.15–0.40 percent copper and 0.02 percent 

molybdenum (Young and others, 1997).

Neither Orange Hill nor Bond Creek has 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 1930’s, several copper lode claims were held at 

Orange Hill and several hundred meters of drill core had been 

obtained (Stewart, 1931; Van Alstine and Black, 1946). Sporadic exploration in the 1960’s and 1970’s 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 remained at Orange Hill. Evidence of exploration activity 

at Bond Creek in 1997 consisted of three small wooden drilling 

platforms and associated debris.

Results of Study

Stream and spring water samples collected include eight 

samples from seven sites at Orange Hill and nine samples from 

eight sites at Bond Creek (fig. 6). Most samples were collected 

from drainages underlain by hydrothermally altered rocks. Bedrock is predominantly bleached, iron-stained, clay-altered granodiorite. Quartz stockwork containing chalcopyrite and lesser 

molybdenite is common. Pyrite and iron-oxide pseudomorphs 

after pyrite were observed both in the stockwork and disseminated in the granodiorite, and pyrite is abundant in alluvial 

heavy-mineral concentrates. Other minerals identified in outcrop and alluvium include azurite, chlorite, epidote, gypsum, 

jarosite, potassium feldspar, malachite, montmorillonite, sepiolite, sericite, and silica. Ferricrete deposits cementing alluvium 

(as thick as several meters) were observed locally along drainage 

bottoms. At Bond Creek, magnetite, derived from alteration of 

mafic minerals (hornblende?), was observed. Calcite was noted 

only in unaltered areas.

Waters in the area are calcium- and particularly sulfate-dominant (fig. 11A). Bicarbonate is a minor component in four water 

samples, all from the Orange Hill area. Three of the waters containing bicarbonate were collected outside the areas of hydrothermal alteration. The fourth sample containing bicarbonate was 

collected along California Creek from a site where malachite and 

azurite were observed in alluvium. Magnesium is a minor component in the waters and is highest in samples from highly altered 

areas. Total dissolved solids exceed 2,000 ppm in most of the 

water samples. Values for pH range from 3.5 to 8.4 (pH mean, 

6.1; median, 5.4) (fig. 11B). Conductivities range from 192 to 

3,080 μS/cm (conductivity mean, 1,361 μS/cm; median, 1,292 

μS/cm). In general, pH values are lower and conductivities are 

higher in samples from Bond Creek than in those at Orange Hill. 

Alkalinities range from < 10 to 125 ppm (as calcium carbonate). 

Only four samples have alkalinities exceeding 50 ppm, and all 

were from the Orange Hill area. Acidities, calculated only on 

seven Bond Creek samples with pH values below 7, range from 

40 to 540 ppm (as calcium carbonate).

For the major ions, the AKDEC MCL is exceeded in several samples for fluoride and iron. In nearly every sample collected, secondary MCL’s are exceeded for sulfate, aluminum, 

manganese, and TDS (fig. 11B). Water from eight sites has pH 

values below 5.5, well below the AKDEC lower secondary 

MCL of pH 6.5. Trace cations are also found in relatively high 

concentrations (fig. 11C). In several samples, primary MCL’s 

are exceeded for cadmium, nickel, and antimony; and secondary 

MCL’s are exceeded for zinc. Nearly half the samples collected 

exceed the secondary MCL of 1,000 ppb for copper. Other elements not having established MCL values, but found in relatively high concentrations relative to worldwide averages (Hem, 

1985; Martin and Whitfield, 1983), include cobalt, molybdenum, strontium, and the rare-earth elements (REE).

A perusal of sediment, rock, concentrate, and leachate data 

in Eppinger and others (1999) reveals anomalous concentrations 

for numerous elements (see Appendix). Many of the stream 

sediments collected at water sample sites contain very high concentrations of copper, molybdenum, and zinc, and moderately 

high concentrations of Ag, As, Au, Ba, Cd, Fe, Hg, Mn, Pb, Sb, 

Se, and V. Rock samples exhibit an anomalous metal suite similar to that found in sediments. Alluvial heavy-mineral concentrates are variably anomalous in Ag, Ba, Co, Cu, Fe, Mo, Pb, Sr, 

W, and Zn. Leachates from three sites in disaggregated, clayaltered bedrock contain high concentrations of Al, Co, Cu, Fe, 

Mn, REE, SO4

2-, and Zn. The leachate pH ranges from 3.2 to 

3.6, and conductivities range from 1,260 to 2,340 μS/cm.

Interpretation

The low pH values and high sulfate in many surface waters 

at Orange Hill and Bond Creek are due to the abundance of 

pyrite and associated sulfate minerals present in altered rocks, 

and the sparse carbonate minerals. Outside the areas of alteration, carbonate minerals are more common, and waters have 

higher pH values and alkalinity concentrations. This situation is 

well illustrated at Orange Hill along Harq Creek (fig. 6). The 

lower 1 km reach of the creek is underlain entirely by pyritic, 

sulfate-rich, clay-altered bedrock. Along this lower reach, pH 

ranges from 3.6 (site 6OH006) to 4.6 (6OH003) and alkalinities 

are nil. Estimated flow at its mouth is 1,860 L/min (500 gal/

min). Immediately above the area of alteration, the pH is 7.7 

(site 6OH007) and alkalinity is 42 ppm (as calcium carbonate). 

Carbonate sedimentary rocks are present in the basin above site 

6OH007.
25

Calcium is the dominant cation in the surface waters. In 

unaltered areas, where alkalinities and pH values are higher, the 

source of calcium is likely carbonate minerals. However, carbonate is scarce in areas of altered bedrock. In these areas, the 

source of the calcium may be gypsum and clay-altered plagioclase feldspar. Altered feldspar could also be the source of elevated REE in the surface waters. The higher magnesium found 

in acidic waters from highly altered areas could be due to alteration of mafic minerals (hornblende?). The high TDS and high 

conductivity in many of the water samples are due to the abundant major- and trace-ion content found in the samples (fig. 11B, 

C). High acidities, ranging from 180 to 540 ppm (as calcium 

carbonate), found in four water samples at Bond Creek indicate 

that the base-consuming potential of these waters is high.

Leachates derived from disaggregated, clay-altered bedrock 

have low pH values, high conductivities, and high content of several anions and cations—commonly found in concentrations 

exceeding AKDEC MCL’s. This indicates that during rainstorms 

and spring breakup, initial waters flowing over the widespread 

altered bedrock would likely be acidic and metalliferous.

The specific WRST land-management question regarding 

Orange Hill and Bond Creek was, “What are the natural background metal concentrations in surface waters?” During the 

August 1996 and 1997 sampling periods, many of the significant 

inorganic parameters for drinking water listed by the AKDEC 

were found in concentrations well above established primary 

and secondary MCL’s (fig. 11B, C). Leach data suggest that 

many of these parameters would also exceed established limits 

during wet periods such as rain events and spring breakup. The 

wide ranges of values listed in figure 11B and 11C illustrate the 

varied natural background composition of surface waters at 

Orange Hill and Bond Creek.

Porphyry copper-molybdenum deposits are typically the 

result of extensive hydrothermal mineralizing systems that can 

affect many square kilometers of land. Orange Hill and Bond 

Creek are no exception, having haloes of hydrothermally altered 

rocks that cover approximately 3 km2 and 6 km2, respectively 

(Richter and others, 1975). The subarctic climate, high relief, 

and presence of permanent and transient snowfields in the heads 

of minor valleys and glaciers in the upper parts of major valleys 

provide a continuous source of water that passes through and 

over the altered bedrock (fig. 2E). During rain events and spring 

breakup, the amount of surface flow (and probably associated 

ground-water flow) is greatly increased. These features, coupled 

with the fact that pyrite and its alteration products are widespread in the altered rocks whereas carbonate or other neutralizing minerals are volumetrically insignificant, result in the 

common presence of acidic, metalliferous surface waters in 

these otherwise pristine areas. Orange Hill and Bond Creek are 

excellent examples that demonstrate that mines and mills are not 

the sole sources of acidic, metalliferous waters in the environment. The present erosional level of the mineralized rocks at 

Orange Hill and Bond Creek indicates that the natural background conditions have probably been acidic and metalliferous 

for several tens of thousands of years.

Our data show that water quality is significantly degraded 

in altered areas at Orange Hill and Bond Creek. However, for 

the parameters we measured, water quality is generally good 

outside the areas of alteration. Because of the physiographic 

setting, downstream effects from the naturally acidic, metalliferous waters are minimal. The waters at Orange Hill flow into the 

high-volume, glacier-fed Nikonda Creek immediately above its 

juncture with the huge glacier-fed Nabesna River—the major 

river in the region. Similarly, degraded waters flow into Bond 

Creek, another high-volume, glacier-fed creek, immediately 

above its juncture with the Nabesna River. Turbidity is high in 

Nikonda Creek, Bond Creek, and the Nabesna River, due to the 

abundance of suspended glacial flour; and high alkalinities 

would be expected. Through mixing, neutralization of the acid 

and precipitation of the metals onto colloidal iron- and aluminum-oxides would be expected, followed by rapid dilution by 

the high-volume rivers. In fact, these processes were all 

observed at the junction of Harq Creek with Nikonda Creek, 

along a distance of about 50 m.

The water quality concerns discussed here relate primarily 

to drinking water standards of the AKDEC and EPA. However, 

the naturally occurring metalliferous, low pH waters found at 

Orange Hill and Bond Creek are not necessarily detrimental. 

These waters and the surrounding soils and bedrock create 

unique ecosystems that certain biota can thrive on. Low pH 

soils can, for example, provide habitat for rare plant life or serve 

as mineral licks for animals. At Orange Hill and Bond Creek, 

the acidic, metalliferous waters, soils, sediments, and rocks are 

critical components of a larger, naturally functioning ecosystem.

Nabesna

Geology, Deposit Setting, and Mining History

Rocks exposed near the Nabesna mine are predominantly 

Upper Triassic limestone; lesser underlying Nikolai Greenstone, 

a subaerial amygdaloidal 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) (fig. 7). 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) 

that have potassium-argon 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 are pyrite, pyrrhotite, magnetite, and chalcopyrite, with minor galena, sphalerite, 

arsenopyrite, and stibnite. Gangue minerals include 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 

 Nabesna
26 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

Sulfate

+

C hloride

Sodium

+

Potassium

Calc ium

+

Magnesium

Sulfate

C arbonate

+

Bic arbonate

Magnesium

Calcium Chloride

20

40

60

80

20

40

60

80

80 60 40 20 20 40 60 80

80

60

40

20

20

40

60

80

80

60

40

20

8 0

6 0

4 0

2 0

%meq/L

CATIONS ANIONS

A

0

2000

4000

6000

8000

10000

Total dissolved solids

 (parts per million)

4000

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 t of ore at 25 g/t gold. Wayland (1943) also reported 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 54 t of ore per day. In the 

1930’s 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 Nabesna mill and associated buildings are 

standing but in disrepair. A small amount of stockpiled ore 

remains near the old tram, and mine-waste rock remains near 

the mill and on slopes below caved adits high on White Mountain. A thin (less than 1 m thick) veneer of finely ground, pyriterich and iron-oxide-rich mill tailings is present over a severalthousand-square-meter area below the mill (fig. 2F).

Figure 11 (above and facing page). Geochemical data from 17 water samples, Orange Hill and Bond Creek 

areas. A, Piper diagram showing major ion composition (Piper, 1944). Square, sample collected from Orange 

Hill; triangle, sample collected from Bond Creek; radius of open circles represents relative total dissolved 

solids in parts per million; values for ions are given as percent milli-equivalents per liter. B, C, Box and whisker diagrams showing summary statistics for selected ions and field parameters. B, Major cations, anions, 

pH, conductivity, dissolved oxygen, and alkalinity; C, Trace cations. Abbreviations used: Cond, conductivity; 

D_O2, dissolved oxygen; Alk, alkalinity; TDS, total dissolved solids; μS/cm, microsiemens per centimeter; MCL, 

maximum contaminant level; REE, sum of rare-earth elements. R indicates that qualified values were 

replaced with one-half of the qualified value prior to calculating statistics. See text (p. 7) for explanation of 

primary and secondary MCL values.
27

Cond

D_O2

Alk

F-_R

Cl-_R

NO3

- _R

SO4

2- _R

Ca_R

K_R

Mg_R

Na_R

Si_R

Al_R

Fe_R

Mn_R

TDS_R

MAJOR CATION, ANION, OR FIELD PARAMETER

1

2

3

4

5

6

7

8

9

pH

0.0001

0.001

0.01

0.1

1

10

100

1000

10,000

100,000

CONCENTRATION, IN PARTS PER MILLION

EXCEPT Al AND Mn (PARTS PER BILLION)

AND CONDUCTIVITY (uS/cm)

Ag_R

As_R

B_R

Ba_R

Be_R

Cd_R

Co_R

Cr_R

Cu_R

Hg

Li_R

Mo_R

Ni_R

Pb_R

Sb_R

Sc_R

Se_R

Sr_R

Th_R

Ti_R

U_R

V_R

Zn_R

REE_R

TRACE CATION

CONCENTRATION, IN PARTS PER BILLION 0.0001

0.001

0.01

0.1

1

10

100

1000

10,000

100,000

B

C

Maximum concentration

Minimum concentration

25th and 75th percentiles

Median value

2

Primary MCL

Secondary MCL

EXPLANATION FOR B AND C

2 2 2 2

2

2

2

2

2

2

2

2 = upper MCL

 for pH

= lower MCL 

 for pH

Results of Study

Over three field seasons, 55 surface water samples were 

collected at Nabesna during a range of climatic conditions 

including summer periods of dry weather, intermittent rain, and 

extended rain; and during the snow and ice melt at spring 

breakup. Several sites were repeatedly sampled during these 

periods, including sites upstream of the mine and mill, at the 

base of the mill tailings, along a 2.5 km reach of Cabin Creek 

downstream of the mill tailings, and sites outside the influence 

of the mines and mill (fig. 7). Surface water samples were also 

collected on the mill tailings during wet periods.

Major ion composition of the waters varied considerably 

(fig. 12A). In all water samples collected, calcium is the major 

cation. Magnesium is also a major component, but only in samples from sites distal to the mines and mill. Major anion composition varies from sulfate- to bicarbonate-dominant. Chloride 

content is negligible. Total dissolved solids vary considerably 

from 63 to 7,100 ppm (TDS mean, 722 ppm; median, 361 ppm). 

Values for pH vary from 2.2 to 8.6 (pH mean, 6.7; median, 7.4) 

(fig. 12B). Conductivities range from 58 to more than 4,500 μS/

cm (conductivity mean, 743 μS/cm; median, 492 μS/cm). Lowest pH and highest conductivity values are found in waters collected directly on finely ground mill tailings during wet periods. 

 Nabesna
28 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

Sulfate

+

C hloride

Sodium

+

Potassium

Calc ium

+

Magnesium

Sulfate

C arbonate

+

Bic arbonate

Magnesium

Calcium Chloride

20

40

60

80

20

40

60

80

80 60 40 20 20 40 60 80

80

60

40

20

20

40

60

80

80

60

40

20

8 0

6 0

4 0

2 0

%meq/L

CATIONS ANIONS

A

0

2000

4000

6000

8000

10000

Total dissolved solids

 (parts per million)

4000

Alkalinities, calculated on the 47 samples with pH above 4.5, 

range from < 50 to 350 ppm (mean, 116 ppm; median, 100 ppm, 

all as calcium carbonate). Acidities, determined on three 1997 

samples with pH values below 7, range from 60 to 220 ppm (as 

calcium carbonate).

For the major ions, the AKDEC primary MCL is exceeded 

in two spring run-off samples for fluoride. Secondary MCL’s are 

exceeded for sulfate, aluminum, iron, manganese, and TDS (fig. 

12B). Trace ions vary widely. Primary MCL’s are exceeded for 

arsenic, cadmium, and lead, and secondary MCL’s are exceeded 

for copper and zinc (fig. 12C). Most samples exceeding AKDEC 

MCL’s were collected during the spring breakup and extended 

summer rain sampling periods. Other elements not having 

established MCL values, but found in relatively high concentrations relative to worldwide averages (Hem, 1985; Martin and 

Whitfield, 1983), include cobalt and, to a lesser degree, molybdenum and the REE.

A review of sediment, rock, and concentrate data reveals 

anomalous concentrations for several elements (see Appendix) 

(Eppinger and others, 1997, 1999). Stream sediments collected near the mill and mines contain anomalous As, Au, Cu, 

Pb, and Zn, and slightly anomalous Bi, Cd, Co, Mo, Sb, and 

Se. Sediments collected distal to the mill and mines are variably anomalous in these same elements plus silver and iron. 

Weakly anomalous mercury is found in stream sediments 

below the Nabesna mill tailings. Rock samples from mill tailings, stockpiled ore, mine waste, mineralized outcrop, and 

mineralized alluvial cobbles contain variably anomalous concentrations of the preceding elements, plus manganese and 

tungsten. Anomalous mercury is found only in the mill tailings samples. Alluvial heavy-mineral concentrates near the 

mill and mines are variably anomalous in Ag, As, Au, Ba, Cu, 

Fe, and Pb. Concentrates distal to the mill and mines contain 

anomalous concentrations of Ag, As, Au, Cd, Co, Cu, Fe, Pb, 

Figure 12 (above and facing page). Geochemical data from 55 water samples, Nabesna area. A, Piper 

diagram showing major ion composition (Piper, 1944). Square, sample collected below mines or mill; triangle, 

sample collected distal to mines and mill; radius of open circles represents relative total dissolved solids in 

parts per million; values for ions are given as percent milli-equivalents per liter. B, C, Box and whisker 

diagrams showing summary statistics for selected ions and field parameters. B, Major cations, anions, pH, 

conductivity, dissolved oxygen, and alkalinity; C, Trace cations. Abbreviations used: Cond, conductivity; 

D_O2, dissolved oxygen; Alk, alkalinity; TDS, total dissolved solids; μS/cm, microsiemens per centimeter; MCL, 

maximum contaminant level; REE, sum of rare-earth elements. R indicates that qualified values were 

replaced with one-half of the qualified value prior to calculating statistics. See text (p. 7) for explanation of 

primary and secondary MCL values.
29

Cond

D_O2

Alk

F-_R

Cl-_R

NO3

- _R

SO4

2- _R

Ca_R

K_R

Mg_R

Na_R

Si_R

Al_R

Fe_R

Mn_R

TDS_R

MAJOR CATION, ANION, OR FIELD PARAMETER

1

2

3

4

5

6

7

8

9

pH

0.0001

0.001

0.01

0.1

1

10

100

1000

10,000

100,000

CONCENTRATION, IN PARTS PER MILLION

EXCEPT Al AND Mn (PARTS PER BILLION)

AND CONDUCTIVITY (uS/cm)

B

C

Maximum concentration

Minimum concentration

25th and 75th percentiles

Median value

2

Primary MCL

Secondary MCL

EXPLANATION FOR B AND C

Ag_R

As_R

B_R

Ba_R

Be_R

Cd_R

Co_R

Cr_R

Cu_R

Hg

Li_R

Mo_R

Ni_R

Pb_R

Sb_R

Sc_R

Se_R

Sr_R

Th_R

Ti_R

U_R

V_R

Zn_R

REE_R

TRACE CATION

CONCENTRATION, IN PARTS PER BILLION 0.0001

0.001

0.01

0.1

1

10

100

1000

10,000

100,000

2 2 2 2

2

2

2

2

2

2

2

2 = upper MCL

 for pH

= lower MCL 

 for pH

and Zn. Leachates from mill tailings (10 samples), mine 

waste (1 sample), and mineralized outcrop above a mine adit 

(1 sample), contain particularly high concentrations of As, Co, 

Cu, Fe, Pb, and Zn, and high concentrations of Ag, Al, Au, B, 

Bi, Ca, Cd, Ce, Cr, Mg, Mn, Mo, Ni, REE, SO4

2-, Sr, Te, Th, 

Ti, Tl, U, and V. Leachate pH varies from 2.2 to 8.0, with 10 

of the leachates having pH 3.4 or less. Conductivities of the 

leachates range from 2,400 to 5,300 μS/cm, except for one 

sample with 200 μS/cm. Two leachates with the highest pH 

values, both mill tailings samples, have the lowest 

conductivities. Calcite was the dominant mineral identified 

by X-ray diffraction in the solid phases of these two samples prior to leaching. Numerous secondary minerals were 

also identified by X-ray diffraction in the solid phases of the 

tailings, waste, and outcrop samples prior to leaching: gypsum (CaSO42H2O), rozenite (FeSO44H2O), natrojarosite 

(NaFe3(SO4)2(OH)6), kalinite (KAl(SO4)211H2O), copiapite 

(Fe14O3(SO4)1863H2O), magnesiocopiapite 

(MgFe4(SO4)6(OH)220H2O), butlerite (Fe(OH)SO42H2O), 

rostite (Al(SO4)(OH)5H2O), starkeyite (MgSO44H2O), 

 Nabesna
30 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

aplowite (CoSO44H2O), jarosite (KFe3(SO4)2(OH)6), 

hydronium jarosite ((K,H3O)Fe3(SO4)2(OH)6), aluminocopiapite ((Mg,Al)(Fe,Al)4(SO4)6(OH)220H2O), fibroferrite 

(Fe(OH)SO45H2O), ferrian sepiolite 

((Mg,Fe)4Si6O15(OH)26H2O), cacoxenite 

(Fe4(PO4)3(OH)312H2O), and carbonate hydroxylapatite 

(Ca10(PO4)5CO3(OH)F) (Eppinger and others, 1997, table 8). 

The presence of soluble sulfate minerals in solid phases 

corresponded well with leachates having low pH values and 

relatively high metal content (Eppinger and others, 1997).

WRST resource staff requested data on the seasonal 

variation and extent of metal dispersion downstream from 

the mill site in surface waters. Figure 13 shows the arsenic 

and manganese content in surface waters collected along 

Cabin Creek during four different sampling periods: dry 

summers of 1994 and 1996, the April-May spring breakup in 

1997, and an extended 3-week rainy period in late summer 

1997. During the dry summer periods, arsenic content was 

consistently low (less than 3 ppb) throughout the sampled 

reach of Cabin Creek. There was no surface flow from the 

mill tailings during these dry periods. In contrast, arsenic 

was found in excess of the AKDEC MCL of 50 ppb at 

water sample sites on the mill tailings and at the base of the 

1 Dry summer; no flow from mill tailings.

2 Spring breakup, with flow from mill tailings.

3 Short summer rain event; no flow from mill tailings.

Sample No. pH Conductivity

(μS/cm)

Sulfate:bicarbonate ratio Trace-element content

14NA011 near-neutral

(7.1)

mod high

(582)

1:1 (sulfate 180 ppm; 

bicarbonate 180 ppm)

mod (sum 1,600 ppb)

27NA036 low

(2.8)

high

(1,620)

high sulfate; no bicarbonate (sulfate 970 ppm; 

bicarbonate 0)

extremely high (sum 

190,000 ppb)

37NA061 near-neutral

(7.3)

low

(58)

0.17 (sulfate 5 ppm; 

bicarbonate 30 ppm)

low (sum 79 ppb)

[mod, moderate/moderately; μS/cm, microsiemens per centimeter; ppb, parts per billion; 

ppm, parts per million]

Interpretation

Major ions found in surface water samples are principally controlled by the geologic substrate. Upper Triassic 

limestones are predominant, followed by Triassic amygdaloidal Nikolai Basalt, and Jurassic to Cretaceous calcareous 

The few distal water samples in figure 12A containing 

relatively high sulfate content are from sites where pyrite 

was observed in alluvial heavy-mineral concentrates (site 

4NA013) or where sulfate-rich water plumes from the mill 

tailings advanced farther down Cabin Creek during high-flow 

conditions at spring breakup (sites 7NA040, 7NA044, 

7NA049). In contrast, three water samples proximal to 

mines and the mill plot in the bicarbonate field in figure 

12A. These three samples contain higher bicarbonate relative to sulfate because they were collected during an intermittent rain event, when the well-buffered Cabin Creek water 

flow was relatively high, but no runoff water was observed 

flowing from the tailings pile.

Element content in surface waters at Nabesna varies 

widely (fig. 12B, C). The season and surface flow conditions 

are important controlling factors for the major- and traceelement compositions of the surface waters. Downstream of 

the mill, this feature was largely a function of the relative 

amount of surface flow, whether waters were actively flowing 

over and through the mill tailings piles (as found during the 

spring breakup), or whether the piles were dry (typical during 

summer months). For example, analysis of samples collected 

from the same site at the base of the mill tailings (fig. 7) 

produced these results: 

bicarbonate-dominant waters are from distal sites. This feature 

reflects the dissolution of pyrite and, to a lesser degree, pyrrhotite, 

both common sulfide minerals in the mine waste and mill tailings. 

The lower pH values, higher conductivities, higher TDS, and 

higher metal content of waters proximal to the mines and mill are 

directly related to dissolution of pyrite. In the mill tailings, 

dissolution of pyrite is further enhanced because the pyritic ore 

was ground to fine particle size during milling practices.

argillite and siltstone. Cretaceous granitic bodies intrude 

these rocks. Tertiary to Quaternary andesitic and basaltic 

Wrangell Lava caps the older 

rocks. Carbonate minerals are 

abundant in the sedimentary 

rocks and locally fill amygdules 

in the basalt. Dissolution of 

carbonate accounts for the high 

calcium and bicarbonate in the 

waters (fig. 12A). Although less 

certain, the relatively higher 

magnesium present in some of 

the samples (all distal to the mines 

and mill) is probably due to the 

greater abundance of Wrangell 

Lava and Nikolai Basalt relative to 

other rock types in these areas. A 

close look at figure 12A reveals that 

nearly all sulfate-dominant water 

samples are from sites proximal to 

mines and the mill, whereas 
31

C a b i n C r e e k

Jack C r eek

2K 1K 500 1000 1500 2000 3K 4K 5K 6K 7K 8K 9K 1OK 11K FEET

750 500 250 100 200 300 400 500 600 700 1K 2K 3K METERS

0

8

9, 55

42

38

37

74

11, 29,

36, 69

41, 73

44

40,72 53

50

71

51 25, 59 23, 57

28, 39, 70

Change in 

 scale

Change in 

 scale

Jacksina

trail

Mill

tailings

tailings

Nabesna road

Increasing distance from Nabesna mill

Arsenic in filtered/acidified water

 Nabesna mine area

8

9

55 55D

42

38

37

36

74

11

29

29D

69

73

70 71

51 50

53

40 41

44

28 72

39

25

59

57

23

AKDEC primary

MCL: 50 ppb

Dry summers,

1994 and 1996

Extended wet period, 

summer 1997

0.1

1

10

100

1,000

10,000

100,000

Manganese in filtered/acidified water

 Nabesna mine area

8

9

55

55D

42

38

37

74

36

41

44

40

70 71

51

59

25

57

50 39

72

73

11

29

29D

69

28

23

53

AKDEC primary

Dry summers, MCL: 50 ppb

1994 and 1996

Extended 

wet period, 

summer 1997

Spring breakup, 1997

Spring breakup, 1997

ARSENIC, IN PARTS PER BILLION MANGANESE, IN PARTS PER BILLION

0.1

1

10

100

1,000

10,000

100,000

Figure 13. Sketch map and distribution of arsenic and manganese in water along Cabin Creek above, on, and below Nabesna 

mill tailings piles. Patterns similar to that for As were observed for Ag, Al, Be, Cd, Cr, Co, Cu, F-

, Fe, Pb, Mo, Ni, SO4

2-, and Zn. 

AKDEC MCL, Alaska Department of Environmental Conservation maximum contaminant level. See text (p. 7) for explanation of 

primary and secondary MCL values. Numbers in figures refer to sample field numbers. D, site duplicate. Note that sketch map 

is distorted for simplification and has two scale breaks.

 Nabesna
32 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

tailings during the spring breakup and extended summer wet 

periods. However, the arsenic concentrations during these wet 

sampling periods fell to levels similar to those found during dry 

sampling periods within about 500 m downstream of the lowermost tailings. Similar patterns were observed for Ag, Al, Be, 

Cd, Cr, Co, Cu, F-

, Fe, Pb, Mo, Ni, and Zn. Fluoride, aluminum, copper, iron, and zinc were found in concentrations in 

excess of established AKDEC MCL’s only in waters collected 

on or near the base of the mill tailings. For these five ions, the 

concentrations fell below established MCL’s within 850 m of 

the lowermost mill tailings. In contrast, manganese and sulfate 

were the only ions found to exceed AKDEC MCL’s in samples 

collected during all sampling periods. Manganese (fig. 13) was 

found in low concentrations (10 ppb or less) above the mill, but 

climbed to levels exceeding the AKDEC secondary MCL of 50 

ppb in samples collected on and below the mill. During wet 

periods, manganese concentrations remained above the MCL 

throughout most of the sampled reach of Cabin Creek. During 

dry periods manganese concentrations paralleled those found 

during wet periods, but at lower concentration levels. However, 

in all periods manganese concentrations were below the MCL’s 

prior to reaching the mouth of Cabin Creek, about 2.5 km below 

the lowermost mill tailings pile. Sulfate concentrations fell to 

background levels in a much shorter interval, within about 1,300 

m below the lowermost tailings pile.

During spring breakup and extended rainy periods, acidic, 

metal-bearing, sulfate-rich waters derived from the mill tailings 

piles are mixed with and diluted by well-buffered, high-pH, 

bicarbonate-rich surface and ground water derived from surrounding carbonate-rich bedrock. The mixing raises the pH, 

which initiates precipitation of ferri-hydroxides. Most metals 

are co-precipitated with the ferri-hydroxides. Metalliferous, 

rusty-red ferri-hydroxide precipitates are common along Cabin 

Creek from the base of the mill tailings to the Jacksina trail 

crossing at site 6NA028 (figs. 7, 13) (Eppinger and others, 

1999). Downstream of this point, ferri-hydroxides are more sporadically distributed. Elements such as manganese remain in 

solution at the higher pH levels, so manganese concentrations 

remain high. Dilution alone appears to be the controlling factor 

on manganese concentration downstream from the mill tailings. 

Zinc, which can respond similarly to manganese at higher pH 

values, was found in concentrations below the AKDEC MCL of 

5,000 ppb in all water samples except three, from sites directly 

on the mill tailings piles. The minor abundance of zinc in waters 

downstream of the mill tailings is most likely a reflection of the 

low zinc content in the skarn deposits at Nabesna.

Samples collected in 1994 contain anomalous mercury in 

Nabesna mill tailings (several samples, as much as 1.5 ppm 

mercury) and slightly anomalous mercury in stream sediment 

from Cabin Creek directly below the tailings (site 4NA011, 0.4 

ppm)(Eppinger and others, 1997). However, anomalous mercury is not found in mine waste, ore rocks, or other sediments 

from sites peripheral to the mill tailings. Water samples collected in 1994 were not analyzed for mercury. Stream sediment 

samples collected in 1996 and 1997 along Cabin Creek confirmed slightly anomalous mercury in sediments below the mill 

tailings (6NA025, 6NA029, 7NA058, 0.5 to 1.3 ppm mercury). 

Mercury was determined in 15 water samples collected on mill 

tailings and along Cabin Creek to the junction of Jack Creek 

about 2.5 km downstream, during spring breakup, summer rain, 

and dry periods of 1996 and 1997. None of the water samples 

contain high concentrations of mercury. Values for mercury 

range from 0.013 to 0.032 ppb, well below the AKDEC MCL of 

2 ppb. The multi-season water sampling at Nabesna indicates 

that mercury is not mobilized during wet periods or spring 

breakup. An anthropogenic origin for the mercury in mill tailings and related sediments, ascribed by Eppinger and others 

(1997) to a short-lived, unsuccessful attempt to recover gold 

(Wayland, 1943, p. 193), is still believed to be the most likely 

origin for the anomalous mercury. The possibility of higher 

mercury concentrations at depth in the mill tailings should be 

considered prior to any disturbance of the mill tailings.

Discussion

As illustrated in figure 13, conclusions drawn on water 

sample data can vary considerably, depending on the water flow 

conditions and season when a water sample is collected. Unless 

mine adits are continuously draining (a feature not found at 

most sites visited in WRST), timing can hamper the collection 

of mine drainage samples. For example, at Nabesna water flows 

over mine waste and mill tailings for only short periods throughout the year; the area is completely dry or frozen the majority of 

the time. Our data show that, in the absence of surface water, 

leachates of mine waste and mill tailings provide an approximation of expected metal content and pH. Water data derived from 

the Nabesna mill tailings, collected during spring breakup and 

extended wet summer periods, are in the “high acid/high metal”

portion of the Ficklin plot, a diagram that shows pH versus the 

sum of selected dissolved metals (fig. 14A) (Plumlee and others, 

1994). Data from Nabesna mill tailings leachates plot in this 

same field. Data from two other Nabesna mill leachates plot in 

the “near neutral/low metal” field. Both of these samples contain abundant calcite, which raises the pH and inhibits metals 

going into solution. Data for all other water samples from the 

Nabesna area plot in the “near neutral/low metal” field.

The acidic, metal-rich water samples from the Nabesna 

mill area are similar to several water samples collected from the 

unmined Orange Hill and Bond Creek areas (fig. 14A). The 

Orange Hill/Bond Creek water samples in the “moderate acid/

high metal” field are derived from highly altered areas. Data 

from leachates from samples of sulfate-rich, altered, disaggregated bedrock plot in the same field, and in the “moderate acid/

low metal” field. In the absence of water, the leachates from 

Nabesna and Orange Hill/Bond Creek would have provided 

good estimates of initial waters prior to dilution and buffering 

by adjacent surface flow and streams.

Figure 14B shows pH versus dissolved metal content for 

the Bremner, Kennecott, and Gold Hill waters. Data from all 

surface waters plot in the “near neutral/low metal” field. Data 

from samples from Kennecott and Gold Hill plot in this field 

because of the abundant carbonate minerals and attendant high 

alkalinity of waters from these areas, features that inhibit 

mobility of most metals. Mine drainage from the Lucky Girl 

mine at Bremner has high pH and low metal content because of 

the calcite gangue minerals present in the veins. The two 

leachates from Bremner having data that plot in this same field 
33

pH

SUM Cd + Co + Cu + Ni + Pb + Zn, IN PARTS PER MILLION

0.0001

0.001

0.01

0.1

1

10

100

1,000

10,000

100,000

-2 -1 0 1 2 3 4 5 6 7 8 9

Nabesna waters, near mines/mill

Nabesna waters, distal to mines/mill

Nabesna leachates

Orange Hill/Bond Cr. waters, no mines

Orange Hill/Bond Cr. leachates

Other mine drainage for comparison 

High acid,

low metal

Moderate acid,

high metal

High acid,

extreme metal Moderate acid,

extreme metal

Near neutral,

extreme metal

Near neutral,

high metal

High acid,

high metal

Moderate acid,

low metal

Near neutral,

low metal

pH

0.0001

0.001

0.01

0.1

1

10

100

1,000

10,000

100,000

-2 -1 0 1 2 3 4 5 6 7 8 9

Kennecott waters, near mines/mill

Kennecott waters, distal to mines/mill

Bremner waters, near mines/mill

Bremner waters, distal to mines/mill

Bremner leachate

Gold Hill waters, near placers

Gold Hill waters, distal to placers

Other mine drainage for comparison

A

High acid,

low metal

Moderate acid,

high metal

High acid,

extreme metal

Moderate acid,

extreme metal

Near neutral,

extreme metal

Near neutral,

high metal

High acid,

high metal

Moderate acid,

low metal

Near neutral,

low metal

SUM Cd + Co + Cu + Ni + Pb + Zn, IN PARTS PER MILLION

B

are from mine waste piles at the Lucky Girl and Yellowband 

mines (fig. 4). Calcite gangue, present in the mine waste, 

results in the high pH/low metal character of the leachates. 

However, one Bremner leachate sample plots in the “moderate 

acid/low metal” field. This sample is from the Lucky Girl mill 

tailings pile. The tailings pile probably produces more acidic 

waters because sulfide minerals (chiefly pyrite) were pulverized and concentrated in the piles by milling practices. Free 

gold was observed in iron-oxide pseudomorphs after pyrite in 

hand specimens at the Lucky Girl mill—a reflection of the 

spatial association of gold with pyrite that the early miners 

recognized.

Figure 14. Ficklin diagrams of pH versus dissolved metal content in water samples collected from Nabesna, 

Orange Hill and Bond Creek (A); and Kennecott, Bremner, and Gold Hill (B). Small + symbols are values for minedrainage waters from diverse mineral deposits for purposes of comparison (data from Plumlee and others, 

1994).

 Discussion
34 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

At Nabesna, waters flowing from the mill tailings piles, and 

leachates of the tailings material, are very acidic and metal-rich. 

However, springs emanating from the tailings are not present 

throughout most of the year. Water coming from the tailings 

piles is derived from snow/ice buildup during winter months, 

and from summer rain. During the spring breakup and extended 

rainy periods, we observed alkaline, near neutral pH, low-conductivity surface water (derived from areas above the mill tailings) flowing down the Nabesna road between the upper and 

lower tailings piles (figs. 7B, 13). This water flows onto the 

lower mill tailings, increasing the volume of subsequently 

degraded water. Construction of berms and ditches adjacent to 

the tailings piles to divert and control surface flow from these 

“uncontaminated, off-site” sources would reduce total discharge 

off the tailings piles and reduce down-drainage impacts.

Orange Hill and Bond Creek are two members of a group 

of porphyry deposits found in a metallogenic belt that crosses 

the northeastern portion of WRST from Chistochina to Baultoff (fig. 1). Other porphyry systems, all smaller than Orange 

Hill and Bond Creek, include Baultoff, Horsfeld, Carl Creek, 

and Johnson Creek (Richter and others, 1975; Nokleberg and 

others, 1995). An obvious question is, “Are these unmined 

deposits affecting water quality, as was found at Orange Hill 

and Bond Creek?” The geologic setting, style of alteration 

present, and size of areas of altered rocks allow for speculation. The porphyry deposits exhibit variably sized haloes of 

altered rocks consisting principally of iron oxide and sulfate 

minerals resulting from weathering of iron sulfides (Richter and 

others, 1975). Other alteration minerals include chlorite, sericite, albite, pyrite, and actinolite (Nokleberg and others, 1995). 

Host granitoid rocks are part of the Klein Creek pluton. The 

largest deposits are Baultoff, which has a 2 km2 area of altered 

rock, and Horsfeld, which has a 1.2 km2 area of altered rock. 

The other named deposits have areas of altered rock of 0.3 km2

or less, and numerous unnamed areas of alteration are also 

present (Richter and others, 1975). Altered rocks at Baultoff 

are underlain entirely by Cretaceous diorite (Richter, 1976). 

Horsfeld and Carl Creek are underlain by near-equal amounts 

of Cretaceous diorite and Cretaceous marine sedimentary and 

volcanic rocks. Johnson Creek is underlain almost completely 

by Cretaceous marine sedimentary rocks, and the area of 

altered rocks is just 0.005 km2 (Richter, 1976; Richter and others, 1975). Based on the size of altered bedrock areas and on 

the mapped geologic units, one would expect rocks at Baultoff 

to be carbonate poor. If so, surface waters draining the altered 

areas at Baultoff probably are similar in pH and composition to 

those at Orange Hill and Bond Creek. Based on the descriptions of mapped geologic units, carbonate minerals are likely 

present at Horsfeld, Carl Creek, and particularly at Johnson 

Creek. If so, surface waters draining these areas are probably 

higher in pH and not as metalliferous as those at Orange Hill 

and Bond Creek.

Conclusions

Results from this study demonstrate that bedrock geology 

and mineral deposit type are critical aspects that must be 

considered in evaluating environmental geochemical effects of 

historic or active mine areas. Although this connection is 

intuitively obvious to most earth scientists, it is commonly overlooked in the environmental and regulatory arenas. For example, the large stratabound Kennecott copper deposits are 

relatively benign to the environment because of the predominance of carbonate rocks, the resulting high buffering capacity 

of waters, the absence of acid-generating minerals, and the 

absence of metals that could be mobilized at higher pH values. 

In contrast, pyrite-rich deposits, such as those at Nabesna, 

Orange Hill, and Bond Creek, can generate acidic, metalliferous 

waters. At the Nabesna skarn deposits, where carbonate rocks 

are widespread and fundamental to the formation of the deposits, waters surrounding deposits are well buffered and help to 

reduce overall downstream effects. However, at the Orange Hill 

and Bond Creek Cu-Mo porphyry deposits, surface and ground 

waters become acidic and metalliferous as they flow through 

large areas of sulfate-rich, altered bedrock, generally without 

the natural remediating effects of carbonate rocks.

Orange Hill and Bond Creek are naturally occurring, 

unmined, mineralized areas that demonstrate that mines and 

mills are not the sole sources of acidic, metalliferous waters in 

the environment—another commonly overlooked fact in the 

environmental and regulatory arenas. Established water quality 

standards for numerous inorganic parameters are exceeded at 

Orange Hill and Bond Creek under completely natural conditions. Natural background conditions at Orange Hill and Bond 

Creek have probably been acidic and metalliferous for several 

tens of thousands of years. However, the naturally occurring 

metalliferous, low pH waters found at Orange Hill and Bond 

Creek are not necessarily detrimental. They create unique ecosystems that certain biota can thrive on. Orange Hill and Bond 

Creek may be useful as unmined analogs to previously mined 

porphyry Cu-Mo deposits elsewhere, where premining background data are lacking for water and sediment quality. 

Weather conditions and season when water sampling is 

undertaken can strongly influence the resulting geochemical 

signatures and associated interpretations. At Nabesna, results of 

sampling during dry summer periods downstream of the mill 

indicated minimal overall effects: waters were near neutral in 

pH and metal concentrations were low to moderate. However, 

samples collected at the same sites during the snow and ice melt 

at spring breakup and following extended summer rainy periods 

were very acidic and metalliferous.

In the absence of active mine drainage, surface flow, or 

springs at mine waste and mill tailings piles, leachates of 

composited waste and tailings can provide data that approximate the pH and metal composition for initial meteoric waters 

flowing from the piles, prior to dilution by adjacent surface 

flow and streams. Leachates from mill tailings at Nabesna 

have pH and metal contents similar to those found from surface runoff collected on the tailings. Similarly, leachates from 

disaggregated altered bedrock at Orange Hill and Bond Creek 

mimic adjacent stream waters in pH and metal content. For 

mine- and mill-related geoenvironmental sampling, leachates 

should be considered as a sample medium under those 

circumstances when repeated sampling during wet and dry 

seasons is not possible.
35

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Manuscipt approved for publication August 13, 1999

Published in the Central Region, Denver, Colorado

Graphics by authors and Gayle M. Dumonceaux

Photocomposition by Gayle M. Dumonceaux

Edited by L.M. Carter
37

Appendix. Basic Statistics for Sediments, Rocks, Alluvial Heavy

Mineral Concentrates, and Leachates for Samples from All Areas 

Studied in Wrangell-St. Elias National Park and Preserve, Alaska

[Only data for elements considered anomalous in each area are shown; average crustal 

abundance values from Fortescue, 1992; Sediment, minus-80-mesh stream sediment; Concentrate, alluvial heavy-mineral concentrate; Leach, leachate following EPA 1312 leach 

procedure; # unqualified, number of samples not qualified by “>”; NA, not applicable; sediment, rock, and concentrate are all in parts per million, except Fe (percent); leachates are 

all in parts per billion, except SO4 (parts per million)] 2-
38 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

Ag Al As Au B Ba Bi Cd Co Cu Fe Hg

Average crustal abundance 0.08 83600 1.8 0.004 9 390 0.0082 0.16 29 68 62200 0.086

Kennecott

Sediment, n = 13

# unqualified 6 13 10 12 13 13

minimum 1 11 0.002 0.13 75 0.02

maximum 3 230 0.3 9.5 5000 3.1

mean 2 73 0.033 2.4 1500 0.69

standard deviation 0.89 74 0.09 3.7 2000 1.1

Rock, n = 10

# unqualified 4 27 4 8 9

minimum 9 24 0.002 4 4 0.08

maximum 640 7900 0.1 73 380000 520

mean 270 2600 0.017 23 49000 59

standard deviation 270 3100 0.037 33 130000 170

Concentrate, n = 7

# unqualified 7 4 12 4

minimum 1 500 70 50 1500

maximum 300 10000 70 300 >50000

mean 87 4400 NA 180 14000

standard deviation 110 4200 NA 180 24000

Bremner

Sediment, n = 9

# unqualified 4 77 2 9 7

minimum 0.1 26 0.003 14 31 0.023

maximum 0.7 240 0.18 17 1300 1.3

mean 0.45 140 0.05 15 320 0.38

standard deviation 0.3 87 0.07 2.1 500 0.6

Rock, n = 5

# unqualified 5 45 32 5

minimum 2 10 2.2 14 3 21

maximum 18 810 9.8 69 4 1500

mean 7.8 300 5.9 33 3.5 500

standard deviation 6.8 380 3 31 0.71 650

Concentrate, n = 4

# unqualified 3 31 4

minimum 1 500 300 150

maximum 300 700 300 300

mean 100 630 NA 230

standard deviation 170 120 NA 87

Leach, n = 3

# unqualified 333 3

minimum 99 0.4 0.03 57

maximum 390 1700 0.05 480

mean 240 570 0.037 210

median 150 980 0.012 240

Gold Hill

Sediment, n = 16

# unqualified 11 10 14 16

minimum 16 0.005 11 0.03

maximum 250 2.1 20 0.2

mean 50 0.22 14 0.09

standard deviation 68 0.66 2.9 0.05

Rock, n = 7

# unqualified 6 67 3277 7

minimum 0.1 12 0.007 14 2 6 35 0.02

maximum 390 3300 59 3000 980 210 49000 120

mean 87 590 8.5 1000 490 50 7300 17

standard deviation 160 1300 22 1700 690 74 18000 45
39

Ag Al As Au B Ba Bi Cd Co Cu Fe Hg

Concentrate, n = 14

# unqualified 8 2 4 10 6 2 3 13

minimum 3 700 70 30 200 30 50 15

maximum 1000 1000 >1000 >2000 >10000 >2000 200 2000

mean 410 850 130 530 1900 65 120 220

standard deviation 490 210 57 720 4000 49 76 540

Orange Hill/Bond Creek

Sediment, n = 16

# unqualified 7 12 16 16 12 16 16 16

minimum 2 17 0.006 89 0.06 120 4.7 0.02

maximum 23 110 0.99 2200 4.8 4600 9 0.39

mean 6.6 57 0.15 670 1.6 1100 6.4 0.079

standard deviation 7.4 29 0.27 480 1.5 1300 1.3 0.087

Rock, n = 10

# unqualified 10 6 10 6 9 10

minimum 0.3 11 0.008 0.05 53 0.62

maximum 73 79 2 4.7 13000 16

mean 10 43 0.29 1.2 1700 6.5

standard deviation 23 29 0.62 1.8 4200 6.3

Concentrate, n = 9

# unqualified 9 8 999

minimum 2 1000 50 50 2

maximum 15 >10000 150 7000 30

mean 7 5600 88 1500 12

standard deviation 5 4000 32 2200 8.4

Leach, n = 3

# unqualified 3 333

minimum 4600 2.4 13 480

maximum 140000 380 6500 3000

mean 51000 140 4100 1400

standard deviation 77000 210 3600 1400

Nabesna

Sediment, n = 25

# unqualified 9 18 4 5 11 25 25 25 16

minimum 2 11 1 14 1 9 27 1.6 0.02

maximum 31 2100 5 70 32 120 910 25 1.3

mean 12 400 2.5 37 4.5 23 180 7 0.24

standard deviation 12 620 1.7 23 9.2 21 240 5.1 0.36

Rock, n = 24

# unqualified 18 22 24 18 15 23 24 24 17

minimum 7 23 0.006 10 4 2 72 1.1 0.02

maximum 110 3100 32 310 95 130 12000 49 1.5

mean 30 800 6.1 89 19 46 2400 21 0.42

standard deviation 24 730 7.8 73 27 37 2600 13 0.46

Concentrate, n = 7

# unqualified 5 22 7 1777

minimum 1.5 700 20 50 50 20 10 1

maximum 20 1000 100 10000 50 1000 5000 15

mean 7.3 850 60 1600 NA 200 1300 6.4

standard deviation 7.9 210 57 3700 NA 360 1800 5.4

Leach, n = 12

# unqualified 9 11 12 2 4 9 11 12 12 11

minimum 0.02 8.1 0.5 1 200 0.02 6 0.3 8 1

maximum 27 130000 4000 11 400 27 200 1000 87000 900000

mean 5.3 20000 540 6 250 7.5 40 370 18000 84000

standard deviation 9.6 37000 1200 7.1 100 11 58 390 25000 270000

 Appendix
40 Environmental Geochemical Studies, Wrangell–St. Elias National Park and Preserve, Alaska

Mn Mo Pb REE Sb Se SO4

2- Sn Sr W V Zn

Average crustal abundance 1060 1.2 13 0.2 0.05 2.1 384 1.2 136 76

Kennecott

Sediment, n = 13

# unqualified 7 13 13

minimum 4 0.4 35

maximum 46 3.3 130

mean 27 1.2 79

standard deviation 15 0.91 30

Rock, n = 10

# unqualified 78 59

minimum 0.5 0.1 85 14

maximum 2.4 1 390 260

mean 1 0.44 280 85

standard deviation 0.73 0.37 130 77

Concentrate, n = 7

# unqualified 5 37

minimum 300 70 30

maximum 10000 150 500

mean 2600 98 250

standard deviation 4200 46 150

Bremner

Sediment, n = 9

# unqualified 9 9

minimum 0.12 70

maximum 1.5 170

mean 0.49 110

standard deviation 0.45 36

Rock, n = 5

# unqualified 15 5 5

minimum 10 65 0.14 35

maximum 10 860 3.9 610

mean NA 420 0.95 230

standard deviation NA 310 1.6 240

Concentrate, n = 4

# unqualified 3 4

minimum 30 100

maximum 200 200

mean 100 140

standard deviation 89 48

Leach, n = 3

# unqualified 33 23

minimum 2.4 0.73 0.2 0.6

maximum 72 87 7.1 57

mean 26 30 3.7 20

median 40 50 4.9 32

Gold Hill

Sediment, n = 16

# unqualified 2 11 16 16

minimum 2 0.2 36 86

maximum 7 0.8 100 180

mean 4.5 0.34 47 110

standard deviation 3.5 0.17 16 27

Rock, n = 7

# unqualified 37 46 3 77

minimum 2 16 3 0.2 11 38 45

maximum 16 46000 120 9.9 22 230 160000

mean 7 6700 35 3.3 15 140 23000

standard deviation 7.8 17000 57 3.6 6.3 67 60000
41

Additional anomalous elements for Nabesna leachates: Ca, Ce, Cr, Mg, Ni, Te, Th, Ti, Tl, and U.

Mn Mo Pb REE Sb Se SO4

2- Sn Sr W V Zn

Concentrate, n = 14

# unqualified 13 4

minimum 50 700

maximum 10000 15000

mean 3100 5400

standard deviation 3700 6800

Orange Hill/Bond Creek

Sediment, n = 16

# unqualified 16 14 16 13 16 16 16

minimum 470 5 11 1 0.32 110 56

maximum 2500 320 1200 9 9.5 200 2800

mean 1300 81 130 3.1 2.7 150 500

standard deviation 600 100 300 2.4 2.3 25 680

Rock, n = 10

# unqualified 10 8 9 5 10 10 10

minimum 21 6 6 1 0.11 12 25

maximum 3200 800 230 5 24 220 870

mean 750 160 52 2.6 5.5 91 310

standard deviation 1100 270 75 1.5 9.7 58 340

Concentrate, n = 9

# unqualified 28 72 7

minimum 20 20 200 50 500

maximum 50 700 2000 100 2000

mean 35 240 990 75 910

standard deviation 21 290 540 35 520

Leach, n = 3

# unqualified 333 3

minimum 100 32 790 110

maximum 4200 490 3900 600

mean 2400 190 2000 360

standard deviation 2100 260 1700 250

Nabesna

Sediment, n = 25

# unqualified 25 5 23 6 13 25

minimum 330 2 4 3 1 31

maximum 5000 16 2500 14 3 1600

mean 1100 7.2 310 6.2 1.7 230

standard deviation 990 5.8 570 4.2 0.63 320

Rock, n = 24

# unqualified 24 18 21 21 22 15 24

minimum 37 1.6 11 0.7 0.1 1.4 20

maximum 6100 70 6500 17 4.1 22 7300

mean 1300 15 1200 7.2 1.9 7.5 920

standard deviation 1600 19 1700 5.1 1.2 6.5 1500

Concentrate, n = 7

# unqualified 6 1

minimum 20 1500

maximum 500 1500

mean 160 NA

standard deviation 200 NA

Leach, n = 12

# unqualified 12 5 12 10 4 12 6 11

minimum 8.2 0.63 0.51 5.6 48 14 0.4 100

maximum 12000 35 3000 84 5100 700 29 10000

mean 2300 9.9 750 29 2300 290 9.1 3500

standard deviation 3200 14 1200 29 2100 180 11 3400

 Appendix