GEOLOGICAL SURVEY CIRCULAR 564

Occurrences of Gold and 

Other Metals in the Upper 

Chulitna District, Alaska

Occurrences of Gold and 

Other Metals in the Upper 

Chulitna District, Alaska

By C. C. Hawley and Alien L. Clark 

GEOLOGICAL SURVEY CIRCULAR 564

Washington 1968
United States Department of the Interior

STEWART L. UDALL, Secretory

Geological Survey

William T. Pecora, Director

Free on application to the U.S. Geological Survey, Washington, D.C. 20242
CONTENTS

Page

Abstract ----------------------------------- 1

Introduction --------------------------------- 1

Acknowledgments ----------------------------- 1

Colorado Creek area- ---------------------------- 1

Golden Zone area ------------------------------ 4

Breccia pipe and mineralized rock -------------------- 7

Economic significance of the deposit ------------------- 7

Blind Creek area- ------------------------------ 9

Long Creek area- ------------------------------ 9

Conclusions and recommendations -------------------- 11

Stream-sediment samples- ------------------------- 11

Districtwide summary and recommendations- --------------- 12

References- --------------------------------- 13

ILLUSTRATIONS

Page

Figure 1. Index map showing location of the upper Chulitna district - - - 2

2. Map showing the location of four mineralized areas in the

upper Chulitna district -------------------- 3

3. Generalized geologic map of the Colorado Creek area ----- 4

4. Generalized geologic map of the Golden Zone mine area - - - - 5

5. Sections of the Golden Zone porphyry stock and breccia

pipe ------------------------------ 6

6. Generalized geologic map showing assay data, Golden Zone

mine ------------------------------ 8

7. Map showing distribution of mineralized rock, Golden Zone

mine ------------------------------ 10

8. Generalized geologic map of the Blind Creek area ------- 11

9. Generalized geologic map of the Long Creek area ------- 12

10. Map showing location and gold concentration of streamsediment samples, upper Chulitna district ---------- 13

TABLES

Page

14 Table 1. Analyses of samples from the Colorado Creek area ------

2. Analyses of samples from the Golden Zone, Blind Creek, , 

and Long Creek areas ---------------------

3. Analyses of stream-sediment samples, upper Chulitna , R 

district- ----------------------------

III

Occurrences of Gold and Other Metals 

in the Upper Chulitna District, Alaska

By C. C. Hawley and Alien L Clark

Abstract

Gold and other metals form deposits clustered in three parts of 

the upper 'Chulitna district, near Colorado Creek, the Golden Zone 

in Bryn Mawr Creek, and Long Creek. Trace amounts of gold in 

thick quartz veins are in the major Blind Creek fault zone, and 

scattered small vein deposits and anomalous amounts of gold and 

other metals in stream sediments indicate widespread mineralization in the district.

The mineral occurrences at Colorado Creek and the Golden Zone 

are associated with small quartz dioriteporphyry stocks; they are 

of vein, disseminated, and breccia-pipe types. Gold accounts for 

most of their value, but the deposits are complex and contain abundant arsenic and locally abundant antimony, copper, silver, and 

zinc, and some molybdenum, tin, cadmium, and bismuth. The deposits at Long Creek are apparently clustered around small quartz 

porphyry plugs. They contain copper, subordinate amounts of gold 

and silver, and trace amounts of tin and molybdenum.

INTRODUCTION

Gold and other metals occur in breccia pipes, veins, 

and disseminated deposits at several places in the 

upper Chulitna district, on the southern flank of the 

Alaska Range. The main purpose of this report, made 

as part of the U.S. Geological Survey's Heavy Metals 

program, is to call attention to four areas that contain deposits of gold or other metals. From north to 

south these are: Colorado Creek, Golden Zone, Blind 

Creek, and Long Creek. The main economic features 

of each area are:

Colorado Creek area. A stock of biotite quartz diorite porphyry about 1,500 feet wide by 2,000 feet long 

has associated arsenic-gold-antimony deposits which 

contain minor amounts of copper, bismuth, and tin. 

One sulfide-rich body appears to be a breccia pipe 

similar to that of the Golden Zone.

Golden Zone area. The main mineralization at the 

Old Golden Zone mine is in a breccia-pipe deposit 

that is 200 to 300 feet across and probably extends in 

depth to more than 1,000 feet. Although the grade of 

the deposit is uncertain, it is estimated to contain 

more than $10,000,000 worth of m etal s, principally 

gold, silver, and copper, but with anomalous amounts 

of tin, molybdenum, bismuth, cadmium, and boron.

Blind Creek. A major fault zone at Blind Creek 

contains quartz-rich breccia filling as much as 200 

feet thick which contains a trace of gold, arsenic, lead, 

and zinc.

Long Creek. Gold- and silver-bearing copper occurrences are widely distributed near Long Creek. The 

main copper concentration is at the old Copper King 

prospect, but very sparse amounts of chalcopyrite, 

molybdenite, and pyrite occur in quartz porphyry plugs 

nearby. An area of strongly hornfelsed rocks, centered 

around the main quartz porphyry plugs, possibly is 

underlain by a quartz porphyry stock at shallow depth.

Results of stream-sediment sampling in the district 

are shown in figure 10 and table 3.

The upper Chulitna district, southeast of Mount 

McKinley National Park (fig. 1), is only 8 to 10 miles 

from the Alaska Railroad, but at present is best 

reached by small fixed-wing aircraft or helicopter, 

because roads into the district from the railroad have 

been abandoned.

A cknowledgments

We gratefully acknowledge the aid and encouragement received from J. J. Mulligan and J. H. Herdlick, 

U.S. Bureau of Mines. Because the only underground 

mine workings of the area, those of the Golden Zone 

mine, are now inaccessible, much assay data is taken 

from maps contained in a report by Mulligan, Warfield, 

and Wells (1967) or from unpublished maps furnished 

by H. R. Beckwith, General Manager of Cemco, Inc., 

or C. H. Herbert.

We would also like to acknowledge the help of Jon 

Alan Benfer, who served as field assistant, and of 

Cliff Hudson, bush pilot of Talkeetna, Alaska, who 

furnished skilled transport to and from the area.

COLORADO CREEK AREA

Arsenic-gold-antimony deposits in the Colorado 

Creek area (fig. 2) are associated with a small stock 

of hornblende-biotite quartz diorite porphyry. The 

stock is bisected by the deep canyon of Colorado Creek. 

The stock itself is almost inaccessible except at the 

bottom of the canyon (approximately 200 feet deep), 

but it appears generally bleached and locally contains disseminated chalcopyrite (as at the locality 

noted, fig. 3). The northern and southern contacts of 

the stock, as exposed in the canyon, are both iron 

stained, and the southern contact is marked by a zone 

of tactite, approximately 2 feet wide, containing

1
Base from U.S. Geological Survey 

1:250,000 series 1 Healy, 1956

Figure 1. Location of the upper Chulitna district.

abundant garnet, actinolite, and epidote. The surrounding rocks are hornfelsed and locally are strongly sulfidized.

The main sulfide occurrences are (1) at apreviously 

unprospected knob about 750 feet west-southwest of 

the Silver King prospect, and (2) at the Silver King 

prospect itself. The Silver King prospect pits are 

about 6,000 feet north of the location shown on the 

Healy A-6 quadrangle map (scale, 1:63,360). Another 

occurrence is about 750 feet southwest of the main 

Silver King prospect pits, where an arsenopyritestibnite-quartz lode as much as 10 feet wide crops 

out in Colorado Creek. The new occurrence (locality 

1) is a highly sulfidized mass of altered porphyry 

and hornfels at least 50 feet across that strongly resembles the highly broken and sulfidized rock of the 

Golden Zone pipe. Arsenopyrite is very abundant, but 

some chalcopyrite is present, and spectrographic 

analyses of samples show highly anomalous amounts 

of bismuth, cobalt, and tin in some samples (table 1). 

The gold content of samples (table 1) was generally 

less than 10 ppm (parts per million), but one sample

(1A) showed 170 ppm gold by atomic absorption analysis.

The old pits at the Silver King prospect are in moderately to strongly sulfidized hornfels. Stibnite occurs 

in thin veins in the southernmost main pit and is accompanied locally by gold (sample 7A, table 1). Other 

samples from the Silver King pits contained from 

0.08 to 6.2 ppm gold in addition to markedly anomalous 

amounts of arsenic and copper; copper ranges from 

about 150 ppm to 2 percent (20,000 ppm).

The composite vein or lode exposed in Colorado 

Creek south of the stock consists of distinct hanging 

and footwall veins in a 10-foot-wide shear zone. The 

largest vein fissure in the lode, the one sampled, 

is about 4 feet wide; it contains stibnite and a small 

amount of gold (sample 9, table 1). A nearby vein 

(sample 10, table 1) assayed about 20 ppm gold, more 

than 10 percent antimony, and some lead and zinc.

Except in the canyon of Colorado Creek, exposures 

are very poor, and therefore it is possible that sulfidized rocks are much more widely distributed than
presently known. The contacts of the mineralized rocks 

at the Silver King prospect and at the knob west of the 

pits are not exposed, but the mineral deposits at each 

place appear to be of either disseminated or brecciapipe type and could be explored by geophysical techniques, trenching, or drilling. Extensive sulfidization 

at both these places is indicated, particularly by the 

very high values of arsenic and iron, and at the Silver 

King by high copper values as well. The amounts of

these elements near Colorado Creek are very similar 

to their abundances at the Golden Zone deposit, as may 

be seen by comparing the analyses in tables 1 and 2.

Further evidence of mineralization in the Colorado 

Creek area is given by the anomalous metal values at 

and near the old Liberty and Lucrata prospects (Nos. 

11, 12, and 13, table 1).

Base from U.S. Geological Survey 1:63,360 series: 

Healy A-6, 1953 and Healy B-6, 1954

SCALE 1:63360 

0 1 2 MILES

CONTOUR INTERVAL 100 FEET 

DATUM IS MEAN SEA LEVEL

Figure 2. Location of four mineralized areas in the upper Chulitna district.

3
GOLDEN ZONE AREA

The Golden Zone mine area was described by Capps 

(1919, p. 226-227), Ross (1933, p. 321-325), and 

Hawley, Clark, and Benfer (1968), and the mine was 

sampled by the U.S. Bureau of Mines in 1950-51 

(Mulligan and others, 1967). Claims were staked in the 

area as early as 1912, but production prior to 1941 is 

unknown. A little gold and silver were produced in 

1941-42, but the mine has been inactive since.

The deposit is in and near a breccia pipe in a quartz 

diorite porphyry. Vein deposits of the area, not discussed in this report, include the Mayflower, East, 

Little, and Lindfors. The Golden Zone itself is held by 

assessment on the BOB group of claims by Cemco, 

Inc., of Anchorage, Alaska, whose General Manager, 

H. R. Beckwith, was helpful in furnishing information 

on ore grade and other data.

The Golden Zone area is largely underlain by volcanic siltstone and conglomerate of Permian or Triassic age (Ross, 1933) that were invaded by biotite 

quartz diorite porphyry, probably in early Tertiary 

time. The Golden Zone breccia-pipe deposit, is approximately in the center of a small, very steep-walled 

porphyry stock (figs. 4 and 5). The deposit is in the 

brecciated and shattered material of the pipe and in 

adjacent parts of the quartz diorite porphyry. In approximate order of abundance, the metallic minerals 

of the deposit are arsenopyrite, pyrite, chalcopyrite, 

sphalerite, and galena. Trace amounts of molybdenum 

and tin occur in the mineralized rock (table 2), and 

cassiterite was identified from the deposit by Walter 

Gnagy of the U.S. Bureau of Mines (written commun., 

1967). The strongly mineralized rock is nearly white 

to very pale brown and has been strongly sericitized,

Biotite quartz diorite porphyry r;

Argillite, mainly hornfelsed, 

and limestone, and greenstone, undivided

Contact

Dashed where inferred; dotted where 

concealed

Fault or barren vein

Dashed where inferred; dotted where

concealed

Vein, showing dip 

Dashed where inferred

* 

Brecciated rock, abundant sulfides

Disseminated sulfides

py, pyrite 

aspy, arsenopyrite 

cc, chalfocite 

cpy, chalcopyrite 

po(?) pyrrhotite

Adit Trench

Sample locality

See table 1

Geology by A. L. Clark, 1967

Figure 3. Generalized geologic map of the Colorado Creek area.
silicified, and carbonatized. The spectrographic analyses show anomalous amounts of boron, probably reflecting tourmaline which was identified in thin sections 

of the altered rock.

The breccia-pipe deposit is exposed at the surface 

and has been explored by two adits (fig. 4) and by numerous diamond-drill holes drilled from the 200-footlevel adit. One steep-angle hole (DH-1) l,025feetlong

was drilled by the U.S. Bureau of Mines in 1950-51 

(fig. 5, section B-B'). A long crosscut adit, the 500- 

foot level (fig. 4) was begun in about 1939 but was abandoned about 900 feet from the deposit. None of the 

workings are presently accessible, but one segment of 

the contact of the breccia pipe is well exposed at the 

surface, and the drill core from the deep Bureau of 

Mines test has been preserved.

EXPLANATION

Volcanic siltstone and conglomerate, 

mainly altered

Contact

Long-dashed where approximately located; 

short-dashed where inferred

Fault or barren vein

Long-dashed where approximately located;

short dashed where inferred

75

Open cut

':'Jy. Projection of .':. ' '.' .' '. ' \^^ ' ' \x."' 

:*'Mayflower vein ' :' '.' -' ;'o^- ^O\VrV-' 

.Pas?.

Sample locality

O See table 2 

in

55 

F Disseminated sulfides

of ore pass ;

Breccia pipe

Lined pattern is veinlike breccia zone

:--:--: : ^sV. .-.:. ::;::.: ::-:.-.--v.V-:.--.,**'* : : < -. . : :. . . . /: ! - = * 5»

/:::^::::::tt^X ' ' ' ''''': ^W# P^ta,1

-. '':' '.:::'.. '. . '!'// //level. Alt

Mine workings from maps by W. E. Dunkle, 1938-41; 

and Mulligan, Warfield, and Wells, 1967

100 100 

I

200 

I

300 FEET 

I

Geology adapted from planetable survey by C. C. Hawley, 

A. L. Clark, and J. A. Benfer 1967

DATUM IS APPROXIMATE MEAN SEA LEVEL

Figure 4. Generalized geologic map of the Golden Zone mine area.
3700' r3600' -

3500' -

3400' -

3300' -

3200' -

3100' -

3000' -

2900'

Assays, gold only

No. Value*

1. 10.66 

2. 6.00 

3. 12.07

Material tested

Average sludge plus' core 

Sludge only 

Average sludge plus core

3000' -

2900

2800'

Geology from surface mapping by C. C. Hawley, 

J. A. Benfer, and A. L.Clark, 1967;examination of 

drill core U.S. Bureau of Mines DH-1 by 

C.C. Hawley, 1967; and by inference from 

company mine maps. Assay data from 

Mulligan, Warfield, and Wells (1967) and from 

Company maps, published with permission

Assays, gold only

No Value*

l: 2.45 

2. 6.30 

3. 1.40-3.85 

4. <1.40

Material tested

Sludge only 

do. 

do 

do.

"Value in dollars per ton

Figure 5. Sections of the Golden Zone porphyry stock and breccia pipe. See figure 4 for

location of lines of section.
Breccia Pipe and Mineralized Rock

EXPLANATION

Volcanic siltstone and conglomerate

Stippled where bleached or hornfelsed 

Shown only on section

2: </5

S CZ(T,

go<

Contact 

Dashed where inferred

Fault 

Dashed where inferred

Vein

Dashed where in/erred

Breccia pipe

Halo shown on figures 6 and 7 indicates 

results of sampling and is not shown 

on sections. Dashed line bounding 

core indicates assay boundary and 

is shown in section only

Drill hole cut by section

Shows gold value in dollars per ton in

sludge at point of section

Drill hole in or near plane of section

O 1=1 

Mine openings

Figure 5. Continued.

The Golden Zone breccia pipe is exposed on a small 

knob north of BrynMawr Creek, particularly in a shallow opencut (fig. 4). At the surface, the pipe is approximately circular in plan and is slightly more than 200 

feet across. Drill holes and mine maps indicate that 

it enlarges slightly with depth. At an altitude of about 

3,400 feet (fig. 5), the pipe appears to be about 200 

feet long by slightly more than 250 feet across; at an 

altitude of 3,200 feet, the width, based on one projected 

and one drilled contact, is as much as 300 feet across. 

Judged by other breccia pipes described in the geologic literature, it is probably more complex than 

shown in figure 5. Two distinct zones of concentric 

fracturing probably are present in the pipe on the 200- 

foot level one zone coinciding with the marginal ore 

zone, discussed later, and a second, outer zone nearly 

coinciding with the curving drift driven southward 

from a point about 240 feet from the adit portal (fig. 

4). The one deep drill hole in the pipe (section B-B', 

fig. 5) shows that the pipe continues to a depth of at 

least 850 feet, and almost certainly to a much greater 

depth.

Exposures in the opencut and mine maps of the 100- 

foot level (fig. 6) show a concentric veinlike breccia 

zone that encircles the western part of the pipe and is 

locally separated from it by slightly altered rocks. 

The rocks in this concentric zone are subrounded to 

angular blocks of porphyry that are strongly silicified 

and sericitized and are separated from other blocks 

by arsenopyrite-quartz-chalcopyrite-rich fillings. 

Some blocks appear to have been slightly rotated. The 

main part of the pipe, as exposed in the cut, has a 

sharp boundary, but is less fractured than the concentric breccia zone; its fragments only locally show 

evidence of rotation. The sulfide minerals in the main 

body of the pipe form fracture fillings and blobs in 

shattered, highly altered rocks.

Economic Significance of the Deposit

The ore grade of the Golden Zone breccia pipe 

varies and has proved to be difficult to determine by 

drilling (Mulligan and others, 1967). It seems probable, 

however, that a relatively high-grade part approximately coincides with a strongly fractured zone that 

bounds the pipe. This zone, called the marginal zone, 

encloses a core of weakly mineralized rock and in 

turn is enclosed in a halo of altered and weakly mineralized rock.

The marginal zone is exposed in an opencut at the 

surface and is fairly well defined on the 100-foot level 

by assay values (fig. 6). On the 100-foot level, the 

outer part of the marginal zone is a breccia of veinlike form that appears to be from 15 to 25 feet wide 

and to average, on the basis of channel samples cut by 

other geologists and engineers, 0.30 oz (ounce) gold
per ton, 2.94 oz silver per ton, and about 0.9 percent 

copper. The outer boundary of the marginal zone is 

defined by a fault contact; the inner boundary is probably gradational. On the basis of unpublished geologic maps of the 100-foot level, which show strongly 

mineralized rocks close to the veinlike breccia, the 

entire marginal zone is estimated to be about 60 feet 

across. In the opencut, the veinlike breccia zone is

about 15 feet across and assays about 0.45 oz gold 

per ton, and 3 oz silver per ton (15 ppm and 100 ppm 

respectively, sample 2, table 2). The sample shows 

marked concentrations of bismuth, cadmium, copper, 

lead, tin, and zinc. The rock in the main body of the 

pipe in the opencut (sample 1) contains slightly less 

than 0.1 oz gold per ton, about 6 oz silver per ton, and 

anomalous amounts of the same elements as sample 2.

.*>!' : 

0.40 Au; 1.10 Ag (A) 

,0.40 Au; 2.00 Ag (A) 

,'^,0.28 Au; 2.20 Ag (A) 

0.14 Au; 1.00 Ag (A) 

.0.12 Au; 0.60 Ag (A)

8.0 0.08 Au; 1.35 Ag (B) 

Zi 9.0 0.06 Au; 0.8 Ag (B)

Percentage 

and zinc i

of copper,

n samples 1-9

0.08 Au; 0.30 Ag (u)

Trace Au; 

0.30 Ag (u)

Copper 

1. 1.75 

2. 1.35 

3. 1.2 

4. 0.85 

5. 0.92 

6. 0.76 

7. 0.89 

8. 0.31 

9. 0.18

Lead 

<0.05 

0.05 

0.07 

0.07 

<0.05 

<0.05 

0.05 

<0.05 

0.05

Zinc 

0.13 

<0.05 

<0.05 

0.27 

0.34 

0.53 

0.98 

<0.05 

<0.05

0.04 Au; 0.40 Ag (u)

0.10 Au; 3.00 Ag (u)

U.S. Bureau of Mines sample data from Mulligan, 

Warfield, and Wells (1967);'U.S. Geological Survey 

samples collected by Harry Townsend and J. G. Shepard. 

1925, company data published by permission

0.32 Au; 4.70 Ag (u) 

-0.16 Au; 2.39 Ag (u) 

.0.03 Au; 2.50 Ag (A) 

0.07 Au; 3.00 Ag (A)

Portal, 100-foot level, 

Golden Zone mine

Geology modified from unpublished U.S. Geological 

Survey data collected by Harry Townsend and 

J. G. Shepard, 1925, and by authors by inference 

from company maps, 1937-40

80

I

120 FEET 

I

EXPLANATION

Halo

Fault 

Dashed where inferred

__ j___ 

Inaccessible workings

Ventlike breccia Shattered breccia

Core

Inferred assay boundary 

of marginal zone

 C- 0.40 Au; 1.10 Ag (A)

Channel sample locality, showing Au and Ag 

in ounces per ton, and sample collector:

(A), Company

(B), C7.S. Bureau of Mines 

(u), C/.S. Geologifal Survey

Raise

Figure 6. Generalized geologic map showing assay data, 100-foot-level adit, Golden Zone mine.
On and near the 200-foot level, numerous assays 

from channel samples or sludge from low-angle drill 

holes suggest an oval-shaped marginal zone, with 

maximum dimensions of about 120 by 240 feet, enclosed in a weakly mineralized halo about 370 by 500 

feet across (fig. 7). Assays in the marginal zone range 

from about 0.06 oz gold per ton to more than 0.6 oz 

per ton and average about 0.21 oz per ton; less abundant assay data suggest a value of from $1 to $3 for 

other metals, principally silver and copper. The core 

area, although penetrated by some drill holes, is essentially of unknown value. The average assay value 

of 228 samples in the halo area is about 0.04 oz gold 

per ton. Although most samples in this zone contain 

0.01 oz gold or less per ton, widely scattered samples 

or groups of samples contain more, thereby raising 

the average significantly. As noted above, the ovalshaped marginal ore zone on the 200-foot level is 

probably surrounded in part by an arcuate zone of 

strong fracturing, and groups of assays from this 

zone, particularly in the curving drift south and west 

240 feet from the portal (fig. 7), are higher in value 

than the general average of the halo. This suggests 

in turn, that more detailed work in the halo may delineate zones distinctly richer than the average.

The only check on the grade of the deposit as estimated from channel samples or drill core and sludge 

is from mining in 1941-42, when the Golden Zone 

produced 869 tons of concentrates that contained 1,581 

oz gold, 8,617 oz silver, and 42,659 Ibs copper (Mulligan and others, 1967). According to H. R. Beckwith 

of Cemco, Inc. (written commun., 1967), these concentrates came from about 1,730 tons of ore yielding 

an average grade, from one lot of 1,480 tons, of approximately 0.99 oz gold per ton, 4.5 oz silver per 

ton, and 1.4 percent copper; a second lot of 250 tons 

was of lower grade, but both lots were appreciably 

higher than the grade determined by channel sampling. 

It seems apparent from the location of the opencut 

and of raises on the 100- and 200-foot levels (figs. 6, 

7) that this ore was mined largely from the marginal 

zone. The tonnage figure seems reasonable for the 

short period of mining activity, the size of the mill, 

and the amount of tailings, and so the grade of the 

deposit may have been underestimated by conventional 

sampling.

Although the grade and subsurface dimensions of the 

deposit are imperfectly known, rough calculations 

based on assays from the 200-foot level indicate a 

likelihood of about 260,000 tons of material, containing possibly 0.14 oz gold per ton, per 100 feet of depth. 

The fairly abundant assay data from surface, underground workings, and drill holes down to about 400 

feet also permit a rough calculation of the hypothetical 

value of metals in the upper part of the deposit. Calculations from these data show about $10,000,000 

worth of metals in the upper 400 feet of the deposit, 

including the marginal zone and the appreciably lower

grade core and halo. The single deep U.S. Bureau of 

Mines drill hole shows that the pipe extends to at 

least 850 feet in depth and is at least weakly mineralized below 400 feet, so that the $10,000,000 figure 

is minimal. Furthermore, if the value of metals has 

been underestimated by conventional sampling, as 

data on the 1941-42production suggest, the $10,000,000 

value is too small. The deposit appears to warrant 

further study and exploration.

Particular attention should be given to the possibilities of vertical or horizontal zoning in the pipe. 

The possibility of vertical zoning is suggested principally by the complex metal assemblage in the Golden 

Zone and nearby deposits. Horizontal zoning in the 

deposit itself is apparently indicated by data from 

U.S. Bureau of Mines drill hole 1, which shows an 

inverse correlation of copper with gold at the eastern 

edge of the pipe, with copper enriched relative to gold 

just outside the pipe.

BLIND CREEK AREA

The Blind Creek area (fig. 8) is about 1 mile west of 

the Golden Zone and is mainly underlain by volcanic 

siltstone and conglomerate. It is cut by a major fault 

zone striking north-northeast which records a late 

period of strike-slip deformation by nearly horizontal 

slickensides. Locally the fault zone contains quartz 

veins and quartz-cemented breccia zones as much as 

200 feet across. The quartz ranges from white and 

massive to a faintly opalescent type with a colloform 

structure; locally it is limonite stained or contains 

pyrite.

Assays of the quartz veins and associated pyritic 

material show very minute amounts of gold, although 

none was seen. Two samples were collected; sample 

BC-1 (table 2) was a composite grab sample of quartz 

and limonitic quartz collected from residual fragments 

in the soil over a distance of several hundred feet. It 

contains slightly more gold (0.06 ppm) than the detection limit (0.02 ppm). Sample BC-2 (table 2) was 

a short (2.0-foot chip) sample collected over a strongly 

pyritic part of the vein; it contains slightly more gold 

(0.30 ppm) but still not in amounts approaching commerical value. The samples also contain measurable 

amounts of silver, trace or greater amounts of arsenic, 

and one sample shows 150 ppm lead and a trace of 

zinc (<200 ppm).

Although the Blind Creek occurrence has no apparent economic value, it is reported because of the 

large size of the quartz veins and because the controlling Blind Creek fault zone apparently is a major 

premineral throughgoing structure.

LONG CREEK AREA

The Long Creek area (fig. 9) is south of the Golden 

Zone and appears to have a slightly different type of 

mineralization. Copper sulfides occur widely in small

8-381 O - 68 - 2
amounts and are concentrated near the Copper King 

prospect. The copper minerals occur in veins, in 

massive replacement of favorable strata, and disseminated in bleached areas in predominantly red 

volcanic siltstone and conglomerate.

The Copper King prospect, once known as the Hector, 

is on land restaked by Mark Ringstad, Fairbanks, in 

April 1967. The workings consist of several shallow 

trenches, all of which expose copper minerals. Massive chalcopyrite and pyrrhotite are exposed as a 

lensoid mass about 5 feet thick in trench No. 3 (sample 

location 2 and 3).

The trenches are all in hornfelsed locally calcareous 

siltstone, which is cut by small dikes and plugs of 

quartz porphyry. The quartz porphyry and adjacent

hornfels are cut by siliceous veinlets on several 

fracture trends, and the siliceous veinlets contain 

very sparse amounts of molybdenite, chalcopyrite, 

and pyrite. The molybdenite is seemingly more abundant in the quartz porphyry than in the hornfels, and 

the pattern of mineralization suggests a zonal distribution of copper around the quartz porphyry masses.

Samples from the main trenches at the Copper King 

(Nos. 1-4, Long Creek area, table 2) contain from 

about 0.5 to 2 percent copper, 1 to 3 oz silver per ton, 

gold worth about $1 to $8 per ton, and detectable 

amounts of bismuth, zinc, and tin. Mineralized rock 

from the prospect is also represented by sample 6, a 

grab sample of sacked ore that is probably from the 

same trench as samples 2 and 3. Molybdenum, visibly

Portal, 200-foot 

level

Core

Sparsely (?) mineralized 

shattered quartz diorite 

porphyry

Sample localities 

in drifts and 

drill holes

Raise

Mine workings and sample locations from 

Mulligan, Warfield, and Wells, 1967

Figure 7. Distribution of mineralized rock, 200-foot-level adit, Golden Zone mine.

10
present as molybdenite in veinlets in quartz porphyry 

near the prospects, was not detected at the prospect, 

but was found in a trace amount (15 ppm) in weakly 

veined porphyry (sample 5).

Conclusions and Recommendations

The known copper mineral occurrences of the Long 

Creek area are small but are locally rich in copper; 

the molybdenite deposits are small and of very low 

grade. Nevertheless, the sulfide mineral occurrences 

are numerous and widespread. Because of this and the 

apparent association of deposits with quartz porphyry, 

more exploration of the area is justified. Geophysical 

exploration, particularly by induced polarization, 

would be desirable, as well as additional trenches 

and shallow drill holes.

STREAM-SEDIMENT SAMPLES

Anomalous amounts of gold and other elements are 

found in some stream-sediment samples from the 

district (fig. 10 and table 3). The largest anomalous 

values in gold are in Bryn Mawr and Colorado Creeks.

Sample 24 from Bryn Mawr Creek was taken just 

below the Golden Zone mine, where any naturally oc- 

.curing gold may have been augmented by gold from 

the mine debris. However, two uncontaminated rightlimit tributaries to Bryn Mawr Creek, represented by 

samples 17 and 27, are also anomalous, indicating 

bedrock mineralization in their headwaters. Sample 

12, from near the mouth of Bryn Mawr, while not 

anomalous in gold, is highly anomalous in arsenic 

and copper (table 3), as is sample 11 from an adjacent 

stream. Since mining activity in and near the Silver 

King prospect has probably not been extensive enough 

to contaminate Colorado Creek, sample 8 is believed 

to approximately represent the natural gold value of 

the stream. The drainage nearest the Copper King 

prospect, sample 43, has detectable amounts of silver 

and arsenic, but little else to indicate mineralization.

With the exception of sample 9, most anomalous 

gold values are in a linear belt that extends northeast from near the head of Long Creek to Colorado 

Creek, or subparallel to the major direction of faulting recognized in the district by Ross (1933).

EXPLANATION

Older rocks, undivided 

Contact, approximately located

Fault, showing dip

Dashed where approximately located;

dotted where concealed

-=.ssssSSsSSSSS 

Quartz vein

BC-2 

Sample locality

See table 2

1000

I

Geology by C. C. Hawley, 1967

Figure 8. Generalized geologic map of the Blind Creek area.

11
DISTRICTWIDE SUMMARY AND 

RECOMMENDATIONS

Gold and other metals are concentrated at several 

places in the upper Chulitna district, in particular, 

the Colorado Creek, Golden Zone, and Long Creek 

areas. Trace amounts of gold occur in strong quartz 

veins of the area, as at Blind Creek. Many more mineral occurrences, particularly of vein type, are known, 

and, because surficial deposits cover much of the 

district, probably many deposits are buried. The 

dominant structural grain of the region is northeasterly, and scattered mineral occurrences known 

both northeast and southwest of the district indicate 

that the full extent of the district is not known. We 

believe that more prospecting is justified in the area, 

particularly in Colorado Creek and near the Golden 

Zone deposit. Our experience indicates that there are 

outcropping mineral occurrences to be found, but 

because of the cover by surficial deposits, geophysical 

prospecting seems particularly appropriate in a search 

for new disseminated and breccia-pipe mineral deposits.

Vf ? Soar^elv/ Hiccamiri9+^ e"VlV/vV * ^ \ v& nnr$nrEXPLANATION

Surficial deposits

Quartz diorite porphyry Quartz porphyry

Older rocks, undivided

Patterned where strongly hornfelsed

Contact

Dashed ivliere approximately located; dotted 

where concealed

Fault, showing dip

Dashed where approximately located;

dotted where concealed

Sulfides

X ^c 

Prospect Trench

^

Sample locality 

See table 3

1000 1000

I

2000 FEET 

__J

Geology by C. C. Hawley, 1967

Figure 9. Generalized geologic map of the Long Creek area.

12
f^DUNKLE COAL

SILVER KING 

PROSPECT,

Insufficient amount 

of sample

^COPPER KING 

PROSPECT Samples collected by J. A. Benfer 

and C. C. Hawley, 1967

EXPLANATION

O <0.02

O 0.02-<0.04

0.04-0.08

>0.08

Gold concentration, 

in parts per million

Base from U.S. Geological Survey 

1:63,360 topographic quadrangles: 

Healy A-6, 1953, and Healy B-6, 1954

Figure 10. Location and gold concentration of stream-sediment samples, upper Chulitna district.

REFERENCES

Capps, S. R., 1919, Mineral resources of the upper 

Chulitna region [Alaska]: U.S. Geol. Survey Bull. 

692, p. 207-232.

Hawley, C. C., Clark, Alien L., and Benfer, J. A., 

1968, Geology of the Golden Zone mine area, 

Alaska: U.S. Geol. Survey open-file rept.

Mulligan, J. J., Warfield, R. S., and Wells, R. R., 

1967, Sampling a gold-copper deposit, Golden 

Zone mine, south-central Alaska: U.S. Bur. Mines 

open-file rept.

Ross, C. P., 1933, Mineral deposits near the West 

Fork of the Chulitna River, Alaska: U.S. Geol. 

Survey Bull. 849-E, p. 289-333.

13
Table 1. Analyses of samples from

[Analyses, except of gold, are semiquantitative spectrographic by D. J. 

series 0.1, 0.15, 0.2, 0.3, 0.5, 0.7, 1.0, 1.5, and so on, or bythe following 

---, not looked for. Results are given in parts per million except for 

sorption are by W. L. Campbell and A. L. Meier. Gold analyses byfire 

Samples: Localities are shown in figure 3; all are chip samples; lengths

Sample 

No.

1A

B

C

D

E

F

2

3

4

5A

5B

C

6

7A

B

8A

B

C

D

9

10 

11 

12

13

Limits

Lab. 

No.

ACK 018

ACL 010

Oil

012

013

014

ACK 013

012

014

015

ACL 107

108

ACK 016

017

ACF 200

ACL 015

016

017

018

020

019 

ACK 019 

010

Oil

Field 

No.

67ACx 162

296A

B

C

D

E

152V

151

153

154

67ACx 154E

154W

155

156

156V

297

297A

29 7B

297C

299

67ACx 298 

166 

136

137

of determination

Ag

50

L

L

N

L

3

7

5

L

1.5

1.5

0.5

50

70

3

L

10

7

N

7

10 

3 

100

.5

.5

As

10,000

N

200

N

200

>10,000

>10,000

1000

300

7000

>10,000

10,000

>10,000

10,000

300

200

500

700

500

10,000

7000 

N 

>10,000

500

200

Au

200

N

N

N

N

L

15

N

N

N

N

N

N

30

N

N

N

N

N

N

15 

N 

50

N

10

A^

170

N

N

0.02

N

10

6.2

.2

.1

.08

.4

.1

.2

15

1

N

.04

.2

.02

.5

23 

.08 

24

.3

.02

A«2/

282

___

N

N

N

7.3

 

0.1

 .-

 

...

_ _

___

___

 

N

.07

.1

N

 

19.0 

50

.6

.05

B

N

100

N

N

10

N

10

L

L

L

N

N

15

150

15

10

10

10

N

10

100 

100 

10

15

10

Ba

300

2000

300

2000

1000

300

300

150

70

200

300

300

70

100

30

300

1500

700

1500

700

100 

1500 

150

300

5

Be

N

N

N

1

1

N

L

L

L

L

1

1

N

L

N

1

1

1

1

1

1

L 

N

N

1

Bi Cd

>1000 N

N N

N N

N N

N N

300 N

700 N

N N

N N

10 N

20 N

N N

70 N

10 N

N N

N N

N N

15 N

10 N

10 N

10 20 

N N 

1000 N

15 N

10 20

Co

150

N

N

5

10

700

1000

10

15

150

150

15

700

5

N

5

15

70

10

300

7 

20 

300

30

5

Cr

20

300

70

150

70

20

5

100

20

50

50

30

10

30

N

100

70

150

150

70

30 

150 

30

300

5

Cu

300

100

200

20

50

500

500

1500

500

1000

1000

300

20,000

500

150

50

1500

1000

150

2000

200 

700 

700

200

5

La

N

200

N

30

N

N

N

N

70

N

N

N

N

L

70

N

N

N

30

50

N 

N 

N

N 

20

Mo

N

5

5

N

5

N

30

N

N

N

N

N

N

N

N

N

10

5

N

50

N 

N 

N

N 

5

 ' Atomic absorption.

 ' Fire assay or fire assay-atomic absorption.

 Specific instrumental or chemical method.

Location Sample No. and description Location

1A, 2-foot. Hornfels with abundant arseno- 2 

pyrite, pyrite, and limonite.

IB, 1-foot. Hornfelsed argillite, weakly 3 

mineralized with disseminated arsenopyrite. 4

1C, 3-foot. Hornfels, pervasively stained by 

limonite. 5

ID. Biotite quartz diorite, altered to clay and 

sericite.

IE. Hornfels marginal to ID.

IF, 6-inch. Massive sulfide veinlet. Primarily arsenopyrite, pyrite, and quartz. Weak 

copper (azurite) stain.

Sample No. and description

2. 2-foot. Vein material, primarily arsenopyrite. Strongly limonite-stained.

3. 1-foot. Sericitized quartz diorite with 

strong limonite gossan.

4. Hornfels near limonite-stained fault zone.

Strongly sheared. 

5A, 8-foot. Altered hornfels near face of small

prospect pit. Contains minor arsenopyrite;

pervasive limonite stain. 

5B, 10-foot. Same as 5A on east side of pit. 

5C, 10-foot. Same as 5A on west side of pit.

14
the Colorado Creek area

Grimes, E. E. Martinez, and R. T. Hopkins, Jr., and are reported in the 

symbols; N, not detected; L, detected but below limit of determination; 

Fe, Mg, Ca, Ti, which are given in percent. Gold analyses by atomic abassay-atomic absorption are by W. D. Goss and Claude Huffman, Jr. 

shown with description where known]

Mn

1500

3000

2000

700

1500

1500

30

500

1000

700

700

700

200

150

20

500

2000

1500

300

150

1000

200

30

700

10

Mb

L

10

10

10

N

N

L

L

L

L

10

10

N

N

N

10

10

10

10

10

10

L

L

L

10

Ni

5

20

5

30

50

30

300

15

30

150

50

20

200

5

L

50

30

50

30

30

30

50

30

150

5

Pb

200

20

10

10

10

20

L

L

L

L

10

10

10

100

500

10

10

15

10

20

300

15

700

L

10

Pd^/

0.012

 

___

 

...

 

<.004

 

 

___

___

_ 

 

___

 _

_ 

___

 

__

__ 

<.04

<.004

.01- 

.004

Pt-' Rh-' Sb

<0.01 < 0.005 200

 N

_ _ N

N

N

 ' 200

 200

<.01 <.005 N

___ ___ f}

___ 100

100

___ ___ N

500

 > 10, 000

 >10,000

___ ___ N

__ N

__ N

. N

200

 >10,000

150

<.l <.05 700

^.01 <.005 L

.004 .005 100

Sc

7

50

15

10

20

L

N

20

7

15

15

10

N

10

N

15

10

15

10

15

10

N

7

20

5

Sn

70

20

100

N

N

N

N

N

N

N

N

N

N

N

N

20

50

15

N

N

N

N

N

10

10

Sr

N

500

N

1000

700

100

N

150

50

L

70

70

N

N

N

700

100

700

700

50

70

L

50

700

50

V

50

200

100

70

150

20

N

70

50

70

100

70

10

70

L

100

100

150

70

100

70

500

50

150

10

W

N

N

N

N

N

N

N

N

N

N

50

N

N

N

N

N

N

N

N

N

N

N

N

N

50

Y

30

20

N

15

20

20

N

15

20

N

15

15

15

15

N

10

20

15

15

15

15

20

15

15

10

Zn

N

N

200

N

N

N

N

N

N

N

N

N

N

N

N

N

200

N

N

N

1500

N

L

N

200

Zr

20

30

30

150

100

20

150

50

30

L

50

70

30

70

N

150

50

50

150

100

70

70

50

50

20

Fe Mg

15 0.1

10 2

15 .1

2 2

5 2

15 .05

15 <.02

10 1.5

10 .7

15 .2

15 1.5

10 .7

20 .3

7 .3

0.2 L

2 2

10 .5

7 2

3 1.5

1.5 .15

7 .7

10 .3

20 .5

10 3

.05 .02

Ca

7

5

10

2

3

5

L

1.5

3

3

2

1.5

1.5

0.05

L

2

20

3

3

.7

3

.2

.15

2

.05

Ti

0.07

.5

.15

.5

.5

.07

.07

.15

.1

.15

.2

.2

.15

.3

.01

.07

.5

.2

.5

.3

.7

.15

.07

.5

.001

Location Sample No. and description

6. Contact zone between alteredquartzdiorite

and hornfels that contains disseminated arsenopyrite. 

7A, 6-inch. Hornfels containing disseminated

arsenopyrite and stibnite. 

7B, 1-foot. Arsenopyrite vein containing minor

stibnite. 

8A, 14-inch. Tactite at margin of quartz diorite plug. Tactite is mainly composed of

magnetite, epidote, garnet, and actinolite. 

8B, 14-inch. Same zone as 8A. 

8C, 1-foot. Hornfels peripheral to tactite

zone.

Location

10

Sample No. and description

8D. Chip of altered quartz diorite associated 

with tactite and hornfels of 8B and 8C.

9. 4-foot. Arsenopyrite vein, sparse stibnite. 

Vein is on footwall of 10-foot shear zone, 

1- to 2-foot hanging-wall vein inaccessible.

10. 1-foot. Stibnite-pyrite vein material.

11 -_---__ 11. Gossan developed from arsenopyritepyrite veinlets in altered hornfels.

12 ------- 12. Arsenopyrite-pyrite vein with minor

quartz.

13 ------- 13 ( 2-foot. Hornfels containing disseminated

pyrrhotite(?).

15
' Table 2. Analyses of samples from the Golden

[Analyses, except of gold, are semiquantitative spectographic by Arnold 

series 0.1, 0.15, 0.2, 0.3, 0.5, 0.7, 1.0, 1.5, and so on, or by the following 

not looked for. Results are given in parts per million except for Fe, 

are by A. L. Meier, R. L. Miller, and T. A. Roemer. Gold analyses by

Sample Lab. 

No. No.

Field

No. Ag As Au Ba Be Bi Cd Co Cr Cu La Mo

Golden Zone area (sample localities shown in fig. 4)

1

2

3

4

5

6

7A

7B

ACF 117

116

119

ACE 627

9-255 to

9-272

ACF 118

Oil

012

67AHx 43

42

46

46D

D128680

- 128697

67AHx 45

12 8A

128B

200

100

20

10

2

30

150

100

7000

10,000

>10,000

3000

3000

> 10, 000

> 10, 000

>10,000

N 4.2

10 15

N 5

N .4

N .8

20 25

10 9.4

L 4.2

1.9

14.8

5.3

 

- 

25.0

 

150

150

100

200

-

70

15

50

700

700

500

300

500

150

N

200

1

N

1

1

1

N

L

L

30

50

70

N

L

200

30

L

200

50

20

30

<50

20

300

500

L

L

20

10

10

N

15

10

100

30

70

50

150

10

L

100

>5000

>5000

1500

500

200

300

1000

500

30

30

20

<50

<30

20

N

N

N

N

N

L

3/

23

N

N

N

Blind Creek area (sample localities shown in fig. 8)

BC-1 

2

ACF 068 

091

67AHx 196 

197

0.5 

1.5

L N 

1000 N

0.06 - 

.30

 L 

 10

200 

300

1 

1

N 

N

N 

N

L

N

7 

20

20 

30

N N 

N N

Long Creek area (sample localities shown in fig. 9)

67AHx

1

2

3

4

5

6

7

8

9

ACF 096

097

098

099

061

060

062

ACE 613

ACF 095

, 218-1

-2

-3

-4

169

168

170

219

216

100

50

50

30

0.7

150

1.5

.5

2

N

N

N

200

N

L

N

N

N

L

N

L

N

N

N

N

N

N

6.8

1.2

8.0

1.3

N

0.2

.1

N

.06

 10

 L

 L

 L

 L

10

 L

15

 L

300

1500

2000

150

1000

2000

200

300

150

N

N

N

N

1

L

N

L

N

100

100

100

100

N

50

N

N

N

N

N

N

N

N

30

N

N

N

20

70

20

150

5

100

30

70

15

7

15

20

20

L

10

1000

1000

10

15,000

20,000

10,000

5000

50

? 20, 000

100

20

2000

N

50

20

N

N

30

N

<50

N

N

N

N

N

15

N

N

N

N

Limits of determination .5 200 10 .02 .05 10 10 20

Golden Zone area Continued

^'. Atomic absorption.

i Fire assay or fire assay-atomic absorption.

 ' Specific instrumental or chemical method.

Location Sample No. and description Location 

Golden Zone area:

1 -.---__ Composite of random chips collected at about 6 -------

3.0-foot intervals over 150 feet in Golden

Zone opencut. 7 -------

2 ------- 15.0-foot chip sample of veinlike breccia

zone, abundant arsenopyrite and quartz, 

locally abundant scorodite and copper stain.

3 (Golden Zone

mine) - - - Mill feed; crushed ore from 1942 operations 

in mill hopper, Golden Zone mill.

4 (Golden Zone

mine) - - - Coarse tailings, Golden Zone mill.

5 (U.S. Bureau Blind Creek area:

of Mines

DH-1)- - - Average (approximate geometric mean) of 18 BC-1 

composite sludge samples from DH-1. 

Maximum gold content in any sample, 6.3 

ppm. Molybdenum, detected in all samples, 

was determined quantitatively to range from BC-2 - - - - - 

6 to 43 ppm. Samples furnished by U.S. Bureau of Mines.

Sample No. and description

Grab sample of arsenopyrite-quartz ore, 

Little vein. Abundant scorodite.

7A. East vein: Grab sample of arsenopyriterich vein material.

7B. East vein: Grab sample of galena-sphalerite-arsenopyrite vein material. 

(See Mulligan and others (1967) for analyses 

of channel samples of East vein.)

Composite sample of quartz and 1 i m o n i t i c 

quartz. Sample consists of random chips 

picked up on traverse of several hundred 

feet along course of vein.

2.0-foot chip sampleofpyritic-quartzveinon 

wall of main quartz vein.

16
Zone, Blind Creek, and Long Creek areas

Parley, Jr., R. H. Heidel, and E. E. Martinez, and are reported in the 

symbols: N, not detected; L, detected but below limit of determination; -, 

Mg, Ca, Ti, which are given in percent. Gold analyses by atomic absorption 

fire assay-atomic absorption are by J. E. Troxel and Claude Huffman, Jr]

Mn Nb Ni Pb Sb Sc Sn Sr W Y Zn Zr Fe Mg Ca Ti

Golden Zone area (sample localities shown in fig. 4) Continued

300 20 5 300

150 20 L 700

300 L 15 300

700 10 7 500

 0.04 <0.1 <0.05 200 15 30 150 70 N 10

<.02 <.05 <.025 500 15 50 150 150 N 15

<.008 <.02 <.01 500 15 N 200 70 N N

 N 5 N 0 100 N 10

7000 150 10 0.7 1.5 0.3

2000 150 15 .3 1.0 .3

1000 100 15 .72 .3

2000 70 5 1.5 3 .3

500 L

20 <20

500 N

500 N

70

N

30

50

20

5000

10,000

15,000

 ___

<.04 <.l

 

 

___

<.05

 

 

L 

700 N

1500 L

1000 20

10 150

N 100

N N

100 N

100 N 15

L N N

10 N N

50 N L

L

N

10,000

> 10, 000

50 

30 15

N 10

L 10

__

.3 <.05

.5 1

.7 .3

.03

.03

.15

Blind Creek area (sample localities shown in fig. 8) Continued

150 N 

300 N

7 

10 150 N

L 

10

N 

N

N 

L

100 

30

 N N 

L

L 

20

2 0.2 

2 .7

0.1 

.7

0.1 

.1

Long Creek area (sample localities shown in fig. 9) Continued

2000

700

700

2000

200

1000

700

1500

300

10

N

N

N

N

L

N

N

30

N

10

50

70

50

50

7

100

200

500

30 .

5

N

L

L

10

10

N

L

30

N

10

 N 10

 . N 10

 ___ jj 15

 N 15

 N N

 N 10

 N 30

 40i' N

 _ N 5

.01-

.008 .004 .005 100 5

30

30

30

50

N

70

N

N

N

10

L

N

N

N

200

N

200

200

N

50

70

100

100

200

15

50

100

70

100

10

N

L

N

N

N

N

N

N

N

50

30

20

30

30

L

20

20

15

30

10

L

300

200

200

N

1500

N

N

N

200

15

10

20

50

70

L

30

15

10

20

7

7

7

7

1.5

10

5

7

3

.05

1

1.5

1.5

2

0.5

1

5

10

.2

.02

5

1.5

1.5

1

0.5

2

2

7

.7

.05

0.1

.1

.2

.2

.1

.1

.3

.3

.05

.001

Location Sample No. and description 

Long Creek area:

2.0-foot chip across strongly mineralized 

layer in hornfelsed argillite. Layer strikes 

N. 82° W., dips 52° NE., and can be traced 

for about 100 feet.

10.0-foot chip across massive chalcopyrite 

and pyrrhotite. Sulfide-rich zone trends N. 

10° W., and probably dips to the east. Material from this same pit reported by Ross 

(1933) assayed 0.22 oz per ton Au, 4.9 oz 

per ton Ag and 7.34 percent Cu.

Random pieces of sulfide-rich material, same 

trend as sample 2.

Composite of sulfide-bearing chips; main 

sulfide-bearing zone trends about N. 80° E.

Grab sample of quartz porphyry cut by 1/4- 

inch quartz veinlets on 2-inch to 2-foot 

spacing. Veinlets on several'fracture sets 

including: N. 30° W., dipping 65° NE.; N.25" 

E., dipping 52° NW.; and N. 85° E., dipping 

44° NW. Sparse molybdenite, chalcopyrite, 

and pyrite in quartz veinlets.

Location Sample No. and description 

Long Creek area Continued

Grab sample of sacked mv.

Composite grab sample of chips collected 

at four corners of outcrop area in finegrained tuff and volcanic breccia which has 

very fine disseminated chalcopyrite in altered breccia fragments.

Composite grab sample of chips collected on 

outcrop of green volcanic conglomerate. 

Green stain probably caused by chromium 

or nickel (see spectrographic analyses).

Grab sample of copper-stained gossan, 

sheared limestone host rock.

17
Table 3. Analyses of stream-sediment

[Analyses, except of gold, are semiquantitative spectrographic by D. J. Grimes, 

0,15, 0.2, 0.3, 0.5, 0.7, 1.0, 1.5, and so on, or by the following symbols: 

looked for. Results are given in parts per million, except for Fe, Mg, Ca, 

A. L. Meier, R. L. Miller, and T. A. Roemer. Sample localities are shown in

Sample 

No.

1

2

3

4

5

6

7

8

9

10

11

12

12a

12a

12a

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

Lab. 

No.

ACK 006

005

007

004

003

008

002

ACE 649

650

651

ACF 104

103

ACE 646

647

648

ACF 069

ACE 609

610

611

ACF 032

ACE 607

606

605

604

603

602

ACF 028

026

027

029

031

030

033

082

081

Field 

No.

67ACx 257

256

258

254

253

259

176

169

173

88

67AHx 31

30

239 a

239 b

239 p

67ACx 64

Hx 98

99

100

101

67AHx 96

95

94

93

92

91

70

68

69

71

73

72

103

87

86

Ag

N

N

0.5

N

N

N

N

N

N

N

2

1.5

N

N

L

3

N

.7

N

N

N

N

N

N

N

N

3

N

N

N

N

N

N

N

N

As

N

N

N

N

N

N

N

N

N

N

1500

5000

N

N

N

3000

N

200

N

N

N

N

N

N

N

N

5000

N

N

N

N

N

N

N

N

Au

N

N

N

N

N

N

N

0.4

.04

N

N

N

N

.02

N

.04

N

N

N

.04

N

N

N

 

N

N

.7

.06

N

.04

N

.02

N

N

N

B Ba

70 1500

70 1000

100 1500

50 1000

70 1500

70 1000

50 700

30 700

50 1000

70 1000

70 700

70 500

100 1000

100 1000

70 1000

100 300

70 1000

70 1000

50 700

50 500

100 2000

100 1000

100 3000

100 1000

50 700

50 700

100 700

150 300

100 300

50 2000

150 700

100 500

100 500

70 500

50 700

Be

1

1

1

L

1

1

L

1

L

1

N

N

L

1

L

1

1

1.5

1

1

1

1

1.5

1

1

1

1

1

1

1

1

1

L

L

N

Bi Cd

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

10 N

N N

N N

N N

N N

N N

N N

N N

N N

Co

15

15

15

10

15

20

15

20

15

20

20

30

15

15

20

20

20

20

15

7

30

20

20

20

20

20

20

20

20

20

20

20

20

20

20

Cr Cu

300 70

200 70

200 70

70 50

300 70

200 70

150 70

200 70

150 50

150 70

300 100

1500 300

200 30

150 50

2000 30

300 200

150 100

100 150

150 70

150 30

150 100

150 100

150 100

150 70

150 70

150 100

100 300

200 100

300 150

700 100

70 100

100 100

70 70

70 70

300 70

La

'N

N

N

L

N

L

N

N

20

N

30

N

N

N

N

N

20

50

20

20

N

30

20

20

N

N

30

N

20

N

20

30

N

L

N

18
samples, upper Chulitna district

E. E. Martinez, and Arnold Farley, Jr., and are reported in the series 0.1, 

N, not detected; L, detected but below limit of determination; -, not

Ti, which are given in percent. Gold analyses are by atomic absorption by

figure 10]

Mo

N

N

N

N

N

N

N

N

N

N

N

N

N

N

15

N

N

N

N

N

N

N

7

N

N

N

N

N

N

N

N

N

N

N

N

Mn Nb

700 L

500 L

700 L

700 L

500 L

700 L

700 L

700 L

700 L

700 L

5000 L

1000 L

1000 L

1000 L

2000 L

700 L

700 L

1000 L

700 L

700 L

1000 L

1000 L

700 L

700 L

700 L

700 L

700 L

700 L

700 L

1000 L

1000 L

1000 L

700 L

700 L

700 L

Ni

70

100

70

30

70

100

50

70

50

30

70

70

100

70

200

100

70

70

50

30

70

70

100

70

50

70

50

100

100

70

30

30

30

30

150

Pb

15

15

20

15

15

15

15

10

15

20

30

30

10

10

20

200

30

70

20

15

15

30

15

20

20

20

70

10

20

15

20

20

20

30

20

Sb

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

Sc

20

15

15

15

20

15

10

15

15

15

20

20

10

10

10

20

15

15

15

15

15

15

15

15

15

20

15

20

20

30

20

20

20

15

15

Sn

N

N

N

N

N

N

N

N

"N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

Sr V W

100 150 N

150 150 N

150 100 N

70 70 N

100 150 N

100 100 N

70 70 N

100 150 N

100 100 N

100 150 N

150 100 N

150 150 N

150 70 N

150 100 N

150 100 N

70 100 N

70 100 N

100 150 N

70 100 N

50 70 N

100 150 N

50 150 N

150 150 N

50 100 N

70 150 N

150 150 N

70 100 N

100 200 N

150 150 N

150 150 N

150 150 N

100 150 N

150 150 N

150 150 N

100 100 N

Y

20

15

20

15

20

15

15

15

20

20

10

10

15

15

15

15

15

20

15

15

15

20

30

20

15

20

15

15

15

15

15

200

15

15

15

Zn

L

L

L

L

L

L

N

L

L

N

L

L

L

L

L

N

L

500

L

N

200

L

200

L

N

N

200

N

N

L

N

N

N

N

L

Zr Fe

150 5

100 5

150 7

150 3

150 5

150 5

100 3

150 5

150 3

100 5

150 15

100 15

50 3

50 5

70 5

150 7

100 5

150 5

150 3

150 1.5

150 5

150 3

150 7

100 5

100 7

100 7

70 5

70 5

70 5

70 7

100 7

100 7

70 7

100 7

70 5

Mg

1.5

1

1.5

.7

1.5

1.5

.7

1.5

1

1

.7

1.5

1.5

1.5

1.5

1.5

.7

.7

1

.7

1

.7

.7

.7

1

1.5

1

3

2

2

1.5

1.5

1.5

1.5

1.5

Ca

0.7

.3

.5

1.5

.7

.5

.2

.5

.3

.5

.7

.7

3

2

3

1.5

.2

.3

.7

.2

.5

.15

.7

.2

.3

.5

1

2

1.5

.7

.5

.3

.7

.7

.3

Ti

0.5

.5

.5

.5

.5

.5

.3

.3

.5

.5

.2

.5

.3

.3

.3

.5

.3

.3

.5

.3

.5

.7

.5

.3

.5

.3

.5

.5

.5

.5

.5

.7

.5

.5

.3

19
Table 3.--Analyses of stream-sediment

Sample

No.

33

34

35

36

37

38

40

41

42

43

44

45

46

47

48

49

Limits

Lab.

No.

ACF 084

085

083

055

035

* 034

070

072

071

073

074

075

077

076

078

079

Field 

No.

67AHx 89

90

88

115

114

113

75

77

76

78

79

80

82

81

83

84

of determination

Ag

N

L

N

N

N

N

N

N

N

L

7

N

N

N

N

N

.5

As

N

N

N

N

N

N

N

N

N

L

N

N

N

N

N

N

200

Au

N

N

N

.02

N

.02

N

N

N

N

N

N

N

N

N

N

.02

B

70

50

30

70

50

50

70

30

70

30

70

70

70

70

70

70

10

Ba

700

500

500

300

500

700

700

500

700

500

300

700

700

700

700

700

5

Be

L

L

L

L

L

L

L

L

L

L

L

L

L

L

L

L

L

1

Bi

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

10

Cd Co

N 20

N 15

N 20

N 15

N 20

N 15

N 20

N 15

N 20

N 15

N 30

N 20

N 20

N 20

N 20

N 20

20 5

Cr Cu

150 70

150 50

300 50

150 70

150 70

100 70

100 70

150 100

300 100

150 100

2000 70

200 70

200 70

500 100

1000 100

150 70

5 5

La

N

N

N

N

N

L

N

N

N

N

N

N

N

N

N

N

20

20
samples, upper Chulitna district Continued

Mo Mn

N 1500

N 700

N 700

N 700

N 700

N 700

N 700

N 700

N 700

N 700

N 1000

N 700

N 700

N 700

N 700

N 1000

5 10

Nb

L

L

L

L

L

L

L

L

L

L

L

L

L

L

L

L

10

Ni

50

50

100

50

50

30

50

70

100

70

300

100

150

150

150

150

2

Pb

20

70

15

15

15

15

10

15

20

20

70

20

30

20

15

20

10

Sb

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

100

Sc

15

10

15

15

15

30

15

15

15

15

15

15

15

15

15

20

5

Sn

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

10

Sr V W

100 100 N

50 100 N

70 100 N

100 100 N

100 100 N

300 100 N

150 100 N

200 150 N

70 150 N

50 100 N

L 100 N

150 100 N

200 100 N

200 150 N

300 150 N

150 150 N

50 10 50

Y

15

15

15

15

15

15

15

15

20

15

15

15

15

15

15

15

10

Zn

L

L

L

N

N

N

N

N

N

N

L

N

N

N

N

N

200

Zr

100

70

70

100

70

70

100

150

150

70

70

100

100

100

100

100

20

Fe

5

5

5

3

3

5

5

5

7

3

7

5

5

7

7

5

.05

Mg

2

1

1.5

1

1

1

1.5

1.5

1.5

1

3

1.5

2

2

2

.15

.02

Ca

.3

.15

.2

.5

2

.5

1

1.5

.5

.5

.2

1.5

1.5

1.5

2

.3

.05

Ti

.7

.3

.3

.5

.5

.5

.5

.5

.7

.3

.3

.3

.5

.5

.7

.3

.001

21

U. S. GOVERNMENT PRINTING OFFICE : 1968 O - 298-381