INVESTIGATION OF KASNA CREEK COPPER PROSPECT,

LAKE KONTRASHIBUNA, LAKE CLARK REGION, ALASKA

BY R. S. WARFIELD AND F. A. RUTLEDGE

* * * * * * * * Report of Investigations 4828

UNITED STATES DEPARTMENT OF THE INTERIOR

Oscar L. Chapman, Secretary

BUREAU OF MINES

J. J. Forbes, Director

Workon manuscriptcompleted August 1951. The Bureau of Mines will welcome reprinting

of this paper, provided the following footnote acknowledgment is made: "'Reprinted from

Bureau of Mines Report of Investigations 4828."

Decembaer 1951
INVESTIGATION OF KASNA CREEK COPPER PROSPECT,

LAKE KONTRASHIBUNA, LAKE CLARK REGION, ALASKA

by

R. S. Warfieldi/ and F. A. Rutledgel/

CONTENTS

Page

Introduction and summary ........... ........ ....... . 1

Acknowledgments .......................................... 1

Location and accessibility ....... ........................ 1

Physical features and climate ...... ..................... 2

History and production ......... . ............ 3

Property and ownership . .... .. ... .. ....................... ......... . 3

General geology .......................................... 3

Description of deposits .................................. 4

Work by Bureau of Mines . .... . . . .............. . 5

Metallurgical tests ....... ................................. 6

Appendix I ............................................... 9

Appendix II ........................................... 10

ILLUSTRATIONS

Follows

1. Index map of Alaska ....... ..................... 2

2. Location map of Kasna Creek ................... . 2

3. Topographic and claim map of Kasna Creek copper

deposit .......... ............................ 2

4. Assay map Gilt Edge ore body, Kasna Creek ...... 6

5. Assay map Barnes ore body, Kasna Creek ......... 6

/ Mining engineer, Bureau of Mines, Juneau, Alaska

Report of Investigations 4828
:: :; INROUC-TION AD) SUMM%4RY

The Kasna Creek copper deposit near Lake Kontrashibuna in the Lake Clark

region, Alaska, was the object of an investigative project by the Bureau of

Mines during the fall of 1948. Recessed because of inclement weather, it

was completed in,1949. This project was a part of the Bureau of Mines progranmin Alaska for the development of critical and strategic minerals.

The oreboadies. are.-contact-replaeement deposits in limestone. Mineralization is mainly specular and micaceous hematite associated with chalcopyrite, calcite, chlorite, quartz, and amphibole. The deposit, on the right

limit of Kasna Creek approximately 2 miles from the shore of Lake Kontrashibuna, is composed. of-two mineralized zones that range in altitude from 2,350

to 2,650 feet.

Thls report contains a brief history of the prospect, description of

the phy'sical setting of" theiprorty, its geology, and the factual results

at. the woik performed by the Bureau of Mines.

ACOWULEDGAEMIs

The- investigations at Khsnia Creek were made by the Alaskan Branch of the

Mining Division, under the -supervision of G. D. 'jermain, Chief.

Analyses of sampleswere-mde by H. E. Peterson-, chemist, Salt Lake City

Branch, l!btallurgical.-Division, Salt Lake City, Utah. Petrographic identifications of rock specimens were made by LaInr G. Evans of the above station.

Metallurgical tests to -determine the amenability of a composite sample to

current metallurgical:praectices were under the direction of C. H. Schack,

metallurgist, Salt Lake City, Utah. .

The cooperation, of the. St. Eugene Mining Corp., Ltd., N.P.L., Vancouver,

B. C., holders of the property by option, is gr atefully aclsnowledged.

LOCATION AMD ACCESSIBILITY

The Kasna Creek copper prospect is in the Lake Clark region, Southwestern Alaska, about.160 miles southwest of Anchorage, Alaska (fig. 1). The

mineralized zone crops out on the right limit of Kasna Creek approximately

2 Milos f rom Lake Kontrashibuna; it can. be' reached by a narrow, steep trail

that starts at the confluonce of Kasna Creek and Lake Kontrashibuna: (fig. 2).

Access to the area is difficult except by air. The Civil Aeronautics

Administration maintains an airport at Iliamna on the north side of Lake

Iliamna . Three airlines maintain regular schedules from Anchorage: Alaska

Airlines, Northern Consolidated Airlines, and Pacific Northern Airlines.

4489 -1-
The passenger rate from Anchorage to Ilianna in 1949 was $44 plus tax; the

cargo rate was 6 cents per pound. At Iliamna float planes can be chartered

to fly men and equipment to Lake Kontrashibuna. Rates vary from $30 to $60

an hour depending on size and capacity of the plane under charter.

In August 1949, Babe Alsworth completed construction of an air strip

at Tanalian Point on Lake Clark that canv ccomodate a DC-3. From Tanalian

Point, it is only 15 minutes by air to the project area.

PHYSICAL FEAZURS AND CLIME -

Lake Clark, one of the largest fresh water -lakes in Alaska, heads in

the Chigmit Mountains at the base of the Aleutian Range; it- surface is 220

feet above sea level. The lake is about 52 miles long and 1 to 4-1/2 miles

wide. Lake Clark discharges into Bristol Bay via ther-Newh2den' Riveri

Iliamna lake, and the KvichaR River.

-Kontrashibuna Lake, altitude 560-feet, drains .via the Tanalian River

into Iake Clark at Tanalian Point . Tanalian Ftzit io on the-southeast shore

of Lake Clark approximately midway of its length. The Tanalian River pro-:-

vides an excellent opportunity for hydroelectric power. Tanalian Falls,

near the outlet of Lake Kontmshibuna;, a shtar,<Arop of 60 feet,, 'a the

Tanalian River descends 340 f et iin-the 4 .1l/2 Jilese. between take Kstraphibuna and Lake Clark* The flow has been estimated at.sc900 second-feet during

medium high water.

Kontrashibuna Lake is well within the western limits of the Chigmit

Mountain province and-is surrounded by peaks 4,000 to 5,000 feethigh. The

topography shows the results of recent glaciation. U shaped and hanIging

valleys are common. Among the peaks forming the headwaters of lake

Kontrashibuna are numerous alpine-type glaciers These supply -the 'glacial silt or "milk" that gives the lake its slate-b1e colbr.;

The copper prospc t is on Kasna Creek, a small tributary to Lake

Kontrashibuna. Kasna Creek flows into the lAke zTrom the south about 8

miles from the lake's outlet.

The shores of ,both Kontrashibuna Lake and Iake. Clarki are. covered with

a forest of spruce, cottonwood, and birch. MaYxy of-the -spruce reach sawlog

proportions and are suitablc for building purposes. At Tanalian Point on

Lake Clark, two small sawmills produced luhnber for local consumption at $125

nor M.

Timberline is from 1,000 to 1,500 feet above sma leVel. Thickets of

alders are interspaced among the larger trees espebially along the s1bpes;

it places they make access very difficult. A carpet of mosses, lichens:,

grasses, and:d other small plants cover.the ground in the forest and at"

higher altitudes,

The climate in the region is not extremes. The nearest place whore

weather data has been recorded is at Tanalian Pointy where obser~ations

have been made for 4 years. The mran asinual temperature for the period

4489 - 2-
M~~~~~~~~~A

SEWARi 1. Iye x m

P ~ 5e,'hel CREEK mre

07e/ llFgure1.hIdexmapofAlaka
1 0 15 4V :,t/5 3O

ax L~~~r

Sf~~~~~~~tFW 1tL~~~~~~~~~~~

zv'c ~ Fguez-Lctinmpo KsaCek
cw~~~e F i r , /g/ ~~~~~~KENDLL

KING BARNS

-OUJTLINE OF OKE BOD

-C-..4 CHANNEL SAMPLES

/o 00 ao200 3w 400 SW

SCALE IN FEET

F .RCir 1950

Figure 3. Topographic and claim map of Kasna Creek copper deposit.
was 31.60 F. Freezing temperatures can be expected from the first of August

to the middle of June. Highest and lowest temperatures recorded were 800 F.

and -38° F., respectively. The average annual precipitation was 26.68 inches,

which included 67.0 inches of snow. Because KEsna Creek is at a higher

elevation than Tanalian Ibint, more snowfall and lower temperatures can be

expected.

HISTORY AND PRODUCTION

The initial location of claims covering the Kasna Creek copper prospect

was made in 1906 by Charles Brooks and C. von Hardenber.. In 1909 the deposit was visited by a party of the Geological Survey,?/ and the mineral

occurrence was first described.

In 1910 the deposit was acquired by Richard M. Edwards of Houghton,

Mich. Two examinations were made for him, one by Alexander Legatt, Butte,

Mont., in 1911 and one in 1913 by W. R. Crane, Pennsylvania State College,

Pa.

Alexander Smith made an examination of the Kasna Creek deposit during

the sumier of 1943 for the St. Eugene Mining Corp., Ltd., N.P.L., Vancouver,

B. C., Canada. The property was Later acquired under option by this company.

No production has been obtained from this deposit.

PROPERTY AND OWNERSHIP

The property is in the Iliama mining district in southwestern Alaska.

It consists of the following nine patented mineral claims; Cook, Peary,

King, Barnes, Platsburg, Gilt Edge, Kendall, Belle, and Cyanide. The Kasna

Creek group of claims were surveyed under U. S. Mineral Survey No. 973, and

patent No. 486281 was granted Aug. 10, 1915. Figure 3 is a claim map and

general location map of the deposit at Kasna Creek.

The Kasna Creek claims are owned by the Richard M. Edwards' estate.

R. L. Edwards, 2303 Raker Avenue, Everett, Wash., is administrator. In

January 1950, the claims were under option to the St. Eugene Mining Corp.,

Ltd., I1.P.L., Vancouver, B. C., Canada.

GENERAL GEOLOGY

The copper mineralization at Kasna Creek is in a limestone belt 1,500

feet wide. The belt of limestone is exposed on both shores of Kontraslibuna

Lake and extends to the eastern shore of Lake Clark. Martin and KatzY considered this limestone to be Paleozoic, probably Davonian, in age. In their

geological maps of the area, the limestone on the south shore of Lake

Kontrashibuna is shown in contact on the west with Lower Jurassic porphyries

2J Martin, G. C., and Katz, F. J., A Geological Reconnaissance of the

Iliamna Region, Alaska; Geol. Survey Bull. 485, 1Ol2, p. 121.

3 Martin, G. C., and Katz, F. J., Work cited in footnote 2, p. 3

4489 3
and tuffs. The porphyry facies range in composition from acid rhyolites, through quartz porphyries, dacites, and mica andesites to intermediate

hornblende andesites. -Fine-grained granular rocks, usually with porphyritic

texture, are also present. The rock forming the eastern contact with the

limestone was not mapped. However, the approximate boundary of the main

granite mass forming the core of the Chigmit Mountains is shown 2 miles

farther east.

Specimens taken by the bureau of Mines indicate that the limestone belt

is in contact with a rhyolJte porphyry on the east and that diorites (?)

form the western contact and apparently terminate the limestone on the south.

The boundaries of the limestone are in part intruded with small basalt porphyry dikes and sills with which small lenses and veinlots of specular hematite are associated.

The limestone and. included raineralizod .zones strike from N. 150 E. to

N. 300 E. and dip 700 to 800 to the northwest.i

DESCRIPTION OF DEPOSITS

The Kasna Creek prospect consists -oof two deposits - the Gilt Edge on

the Gilt Edge claim and the Barnes on the King Claim (figs. 3, 4, and 5).

Both deposits are of the contact metamorphic type. Mineralization

consists mainly of specular henatite, fibrous amphibole, chlorite, calcite,

and quartz. The deposits are not homogeneous; bands of nearly pure hematite, fibrous amphibole, and included altered limestone are present. The

bands or lenses are neither continuous nor in any sequence, and the lenses

do not follow any recognizable pattern.

Chalcopyrite es disseminated throughout the mineralized area as scattered grains. It-also is concentrated in lenses and small veins of nearly

pure chalcopyrite. The massive chaXcopyrite contains numerous inclusions

of sphalerite, which range in grain size from minus-48- to plus-560-

(theoretical) mesh.

Both the hanging wall and foot wall of the deposits are composed of

fine-grained limestone in which a small amount of quartz and pyrite is

disseminated.

The deposits are separated by a small tributary of Easna Creek. This

tributary may mark the trace of a fault; however, it is more likely that

the mineralization lensed out at this particular location and that the two

ore bodies are separate contact retamorphic deposits instead of faulted

segments of the same deposit. :

The Gilt Edge deposit (figs. 3 and: 4) crops out on the right limit of

Kasna Crcek, 350 feet east of the creek. The mineralized zone lies along

the steep mountain slope paralleling Kasna Creek. It is exposed throughout

a strike length of 1.050 feet and a vertical range from 2,350 to over 2,550

feet in altitude. The average width of the deposit is 250 feet. On the

south, the deposit starts at the small tributary of Kasna Creek separating

the deposits.

4489 -4 -
Development at the Gilt Edge deposit consists of one adit. This adit

was started in the fine-grained limestone, which forms the hanging wall of

the depoeit, andvwas driven into the middle of -the mineralized zone near

the location of trench -E#,. The tunnel portal is now caved, and consequently

the adit is ineccessible..

The Peoon4 of the miin deposits,, the Barnes, forms the east wall of the

canyon of Kasna Creek throughout most of the length of the King claim (figs.

3 and 5). For over 1,000 feet, the western contact follows along the creek,

and the deposit forms-;a series of cliffs, 20 to 4o feet high. The strike of

the deposit then swings .about.100 to the eaet and into the slope of the hill

until, at the -Ieation of the caved adit near trench '"R" (fig. 3), the creek

is 80, feet from the edge of the mineralized zone and approximately 60 feet

lower.

The Barnes deposit is transected by nine gulleys, which give excellent

exposures for sampling. The mineralized zone is 1,340 feet long, averages

50 feet in width, and is exposed throught a vertical range of 330 feet,

from 2,335 to 2,665 feet in altitude.

,,:,0A large proportion of the steep slopes forming the Gilt Edge- deposit is

covered with talus material., This obscures the outcrop 'and makes trenching

and mapping difficult-. Farther to the north on the Cyanide claim, additional mineralization can be traced from exposures in the galleys. Copper

mineralization is very weak, and the Zone is not a part of-the Gilt Edge

deposit. Another adit was ostarted. on the Belle claim near the creek level

to expnxwe this showing while the required development for patenting was

being carried. out, -but the -adit did not penetrate the deposit and is' in

the hanging-wall Jimestone for its entire length.

A small mineralized l2ens crops out on the Kendall clatri 300 feet east

of and 225 feet higher in elevation than the eastern border of the Gilt Edge

deposit (see figurea .3-and 4). This zone is roughly elliptical in shape,

with dimensions of 80 andi.00 feet.

Two additional claims,. the Cook and the Peary, south of the end lines

of the Barnes and Ydag clairs,> have been patented. On one of these, the

Peary, approximately 1,200 feet south of the Barnes deposit, is a small

zone of pyrite mineralization. This zone was not sar.mpledbyr the Bureau of

Mines; previous sampling indicated that it does not contain copper.

WORK BY HUJEAU OF MINES

The Bureau of N4nes. program of trenching, sampling, and napping the

deposits of copper mineralization at Kasna Creek was begun September 25,

1948. Camp was established at the mouth of Kasna Crqek on lake Kopnrashibuna,

and. a trail was cleared to the deposit. However, only 32 samples could be

taken before snow and inclement weather prevented completion of the work;

consequently, the project was recessed Oct. 11, 1948. The program was resumed July 15, 1949, and all of the proposed work was completed by Sept. 27,

1949. Covered sections of the deposits were exposed at irregular intervals

by approximately 1,225 feet of hand-dug trenches; 417 channel samples, from

4489 -5-
grooves averaging 1 inch by 3 indche, were C utW the `teh bottoms. As

takwnf, each sample represented a 5-foot iheoiuel anid i iwelid approxittely t9

pounds per linear foot. These were crushed and reducad befbre-shipment to6

an average weight of 8 pounds per sample. All samples were analyzed for copper and iron. The .lay-out of the trenches :in the two ddposits ahd the samp-

.ing results are shown in figures 4 and 5.

omposites of all samples from each trench refe ilAed for gold, 8ilvtr, lead, zinc, and sulfur; only traces or vet quantities of theseelemnts were found., as indicated by appendix t. Spectrob pic analyses

were mede of composites of each of the deposits, with the rebults shown in

appendix II.

: MALUMGICAL .- lBS¶ B

The average analyses of the Gilt Edge and -kitnes- deposits are 0.69 and

1.14 percent of copper, respectively. After eliinatin' the northern lovergrade part of the Gilt Edge deposit, a composite sample of the Barnes and

the remaIider of the Gilt Edge deposit averaged 0.95 percent Cu, 27.5 percent Fe, and 30.1 percent Si02. A sUmmary of the reulsutlt berficiation it*ts

by C. Ho. Schack, metallurgist,7Bureau of Mies, follows;

A microscopic exatridnation revealed the copper i sent as::

finely crystalline chalop'yrite &ssociated with a; gonhe c osed

chiefsly of hematite and lesser amounts of inetite, tlc, part

ally' altered :pyrite, quartz, and calcite. The hefntite occird s :

fine needle-like crystals, which are veir friableo. Grindig to

about 200-mesh will be required to liberate the copper from the

iron mineralb and thase mianerals from the gangue constituents.

The ore-dressing testsw made on the sample incladed gravity concentration with a spiral, magnetic separator, and a series8 `f

flotation tests. The spiral- and magietic-separation tests were

made to explore the Possibility of rejectIng a low-grade tailing before fiie grinding, whereas the flotation here tests made to .'

study the feasibility of making sepoarate copper and iron concentrates after fine grinding.

For the spiral test, the ore was roll-crushed dry to minus20-mesh and then fed to a spiral oencentrator in which a primary

concentrate was made. The tailings and middlings from the initial

pass through the spiral were recombinedand retreated to make a

second concentrate, a middling, c sand tailing, xiqd ea slime prod-

-uct. 7he results of this test re given in the ±o'win-tabe.

4489 -6 -
CU FE ~~~~~CU FE CU FE Cu FE Cu FE Cu FE CU FE

K20.78 Cu GO 24E I-I 0.28 30.4 H-I 0.25 31.0 El0.43 22.8 E-3 0.72 531 0-I- 0.48 40.1 L- 10.04 18.0 24.0 1-2 0.28 27.4 14-2 1.02 36.8 E-2 0.28 20.6 E-33 1A42 24A 0-2 0.71 27.4 * - 00 2- 28 K4-3 0W8 358 1- .149. -3 0.34 1 86 E-3 0.28 21.2 E-34 0.00 42.7 0-3 1.07 20.8 14- 0.78 23.8 1-4 0.18 10.2 H- .03 786 E-4 0.14 38.0 E-35 0.23 30.6 0-4 0.43 23.4 L- LL 3 0. 3-0 28.4 K_ 15 0.90 38.8 1-S 0.27 14.6 H4-S 0.02 0.2 E-5 0.78 24.6 E- 380.72 28.2 D-5 0.50 28.2 *L-4 .4 7 14-8 0.20 43.0 1-7 0.58 56.8 1-7 0.18 14.2 E-7 2.52 29.8 E-3 0.4835 2 . D -7 2.41 184 4 L-7 0.3437298 14-7 0.73 28.4 1-8 0.28 18.8 14-8 0.08 0.0 E-7 2-52 2486 E- 30 030 2362 D-8 1.93 18.4 L-8 0.1 41*7. K-8 0 66 19.2 1~~-S 0.30 18.4 H4-8 015178 i6 -a 2152 31. E-37 0.48 238. 0-8 2.413 1840 L-8 0.55 27.0 K4-0 

K10- 0.42 22.8 149 0.28 18.2 14-0 0.20 ISO E- 0.80 31.8 E-40 0.12 22.4 D-0 1.34 21.8 . L- 0..819413.4 0.88 19.2 1-00.00. -10 0.25 10.2 E-10 0.74 383 6-41 0.24 18.2 0-I0 1.44 20.8 L-I0 0.5 37.8 K4-I1 0.'20 20.8 1-11 0.12 10.2 H11-I 0.10 18.8 E-11 0.82 43.0 E-42 0.50 10A D-Il 1.74 20.8 - L-I0 0.77 37.4 K4-12 0.07 21. 1-12 0.03 34.4 H4-12 0.37 11.0 -2 1.03 272 E-43 0.10 10.8 D-42 0.07 38.0 L-20.70 31.0 1-3 0.021. 1.13 0.08 42.7 H4-13 0.*8 45A E-13 0.48 348 E-44 0.35 20.8 0-43 5.40 25.8 L-13' 0.73 38.2 141 .017.8" 531-4 H-405 056 27.0 E-14 1.30 18. E-45 0.31 270 0-14 3.33 44.7 Cu FI4 .02. Cu1 CU FE ~~1-18 0.54 40.0 H1 -I 1.11 28.2 E-IS GOO 2786-4 0.85 23.8 -5 1.75 25.0 0 C5U5 FE. L-14 0.84 23.0 FE2 S 1-18 0.84 320 H4-181 0.08 178 E-48 5.72 38A E-47 0.88 23.2 088.4 24.4 0-38 1085 1433 L-15 1.54 231.2 J-I 18.8 0.02 I-I? 005 85.8 14-17 0.22 21.0 E-17 0.05 8.8 E-48 1.08 28.8 -17 .821.884 J-2 J-3 0.05 17. 8 I-S0.04 H471-18 O0.0 28* E- 027 651i. E-41) 0.27 40.1 D-18 1.4937 2 7813 18.4 0.09 a8811 0.558.7 14-10 027 37. -002 813 65 .0 320__04 03 U F J-4 0.30 27.0 1-20 005 41.0 H4-20 0 0812. _.32 28. E-20 0.92 40.0 E-51 * 36.4 0-0D5 8 -30 0.3 10.2-I 013. J5 0.05 21i.8 1-21 005 28*s 1H-21 0.18 10.4 E-21 023 42.7 E-52 0,66 32.0 -1 0. 58 20~3 B-1012. -3 0.18 37.2 J_80718812 0.1 24H1-22 05.4 30.2 -23825A E-53 0.28 314 022 0.80 25.0 0-4 0:1 . -4 0.21 51.3

J-7 0.04 150 1-23 0.02 8.0o420.57 E-23 1.78 370 DE2440034420.0 0-23 0.38 288. 1-6 0.24 15.8 1-24 0.04 15* 14-24 062 36* E-24 2.57 2 54 E-550.44 25.0 0-44 189 . -5 042 35.8 .J1-0 0.24 1501-25 134 34.8 En25 1,8 37 E-58 0.07 12.0 D-25 0.09 34.0 B-8 0.72 41.1 .11 .322.8 14-8 073, 32* -2 1.58 2786 E-57 0.02 4.2 0-28 0.22 388 -7 0,10 21.2 44-27 015 30O E-27 0.82 38.4 E-58 0.00 12.2 0-27 1.38 315 -8 0.10 2 1.0 017 2 JD E-11111 3.52 2500-28 1.82 18.8 8-9 0.0 42.1 26 240 0i7 6~~~~~~~-2? 3.225D-20 0.72 20.3 8-IC 0.07 30.0 E-W ,0 03 -30 1.38 38.0 B-11 4.15 20.8 6-30 43* 0.30 0~~~~~~~~~-31 0.57 370 8-12 1.48 242 - - 076 328 0-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~32 0.1 165-13 4 10 23.5 - 0-330.15 21.4 8~~~~~~~~~~~~~0 -14 2 2820.8 CU FE

0:116 9~~~~~-lI 0 82 20.8 A-2 0220.

- 8~~~~~~~~~~~~ 1.15 25,2 ~ ~~~~~~~~~~~~~~~~~~~~

A- 3 2 30 33.0 -* 8~~~~~~~~~~~~~ 0.84 17.0 ~ ~~~~~~~~~~~~-I A43.028 S ~~~~~~~~~~~~~ 043 388 ~~~~~~~~8-19 A-S 2. 002. -- '.. 8-2~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~;O0 070 28A_. 2.7 28 * 8-21 0.86 328 A-? 2.48 20.4~~~~~~~~~~~~~~~~~~~~~~~

* -~~~~~~~~~~ 1 81 68A-S ~~~~~~~~~~~~~~~~~~~~

2 10 23.0 -230.252 4 I 12 262 A-B A-I0 0.68 0.39 33 2Y.08

I-25 0.44 214 A-Il 2.10 18.2

.... 8~~~~~~~-26 0.862 260D A-12 1.3'4 1.2 -* -27 03 35.4 A413 0.55 146.8 CU FE 22 013117.2 A-14 0.4846 ---- -I 0.1417.6 20 0.17 23.2 A-IS 4.10 16.8

6- Q0 6 144 A-18 2.17 22.4 * -3 Q00 4 is A-17 0.47 13.2 6-4 5 0 5' 144 -I 0.45 8.2 -~~~~~~~7---- S -S 00415. A-IS 0.24 .4 7.2~~~~~~~~~~~~~~~~~~~~~~~

. I A-20 1.07 17.4

LEGEND F-I 0* aS 0 003 20. OUTLINE Of ORE BODY F2 062 87. 293 Q0.0 20.0 ' TRENCH ~~~~~~~~~~~~ 050 21 ~~~~~~~~~~ F-31 000 8.6' ~~~ ~ CU ~~~F-3 FE CHNE SAPL F-4 0.62 20. F-32 0.3 4.2 008 22.6 F-S 0.44 24. -33 34 22. C-2 0.02 44.41u F F..8 06"239 F -3407 24 C-3 012 -704 F94 E9 K-7 

Cu 

SAMPLE 

PERCENT NO 

COPPER F-? 2OT 0:7 F-35 0.30 224 C-4 C-S0.34.82-2A10818:40 GO0 *94 -5 .1 80 N . 1.5 0. F-311 0.10 2A C5 aSn 27. C-2906 1.4 2.8 N

FE PERCENT ~~~~~~IRON F-I0 1.58 31.3 F-311 0L14 340. C:78 0:4 O- *: :2 .12 F-I1 1.47 48.7 _..3 0.08 20.8 C-8 0.7643.a C-33 0.33 22.4 F-12 0.617.2 F-40 G08 25.8 C-I0 0.8411 C-33 0.37 26.8 FI0.830.0 F-4l 072 20. 4 C-I .6 8.2 C-34 0.22 48.81

F-I 0. 13 470O F-42 0.1 7.84 C-42 0.20 31 C-358 017 2 2.8 F-IS .26 31.0 F-43 0.621.4 C-30~ 55 C-37 0.20215.2

IF-IS 0.67 36.8 1-402 5.2 C-14 I. s35 C-36 0.30 3016 100 ~~~~ 5 ~ 3. ~ F-45 ~~~~~~F-17 030 13.2 C-I5 1.78 4. C-30 043 20 29 200 300 ~ ~~~~~~~~FIS0*81 10.5 F-45 048 14.8 C-IS 0587 3. -0 14. 50 100 300 400 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~F-IS O"'6 2-5. F-47 0.88 45.4 C-I?40.57220. F-20 0.63 ISA ~~~F-48 007 18.4 C- 8 0.37 20.4 SCALE ~~~~~F-2 IN FEET 0006 22.0 F-40 014 15.0 C-B .642. SCAA..E IN FEET ~~~~~~~~~~~~~~ 0.26 19.2 ~~~~~F-2 F-SO0.5 24.80 -2 1.432* MARCH 1950 F-3 0.04 5.0 F-5I .5 20.8 C-2012.16 324. F40.0 248 F-52 05746. C-22 1.25 31.6 F-S020 16.0 F-5305 220O C-23 1.72 27.6

F50.00 11.2 F-5402 18.2 C-24 0.28 55.7 FV0.24 24.0 F-SS 01 -25 0.53 40.1 F-2 0.08 I18.0 -F-SO00 lE C28 2.28 26.0

Figure 4. - Assay map Gilt Edge ore body, Kasna Creek.
CU FE -I 303 23.8 R2 5 12 23.2 2-50 2085 / -4 We 41.8 -- ~~~~ R-~~5 0.10 40.4 S / R-e 0.87 248

'S. / R-7 288 21.2 R- D14 20.0 Ft R-9 0.6 33.° g S R-10 IJ2 25.2

*/CU FE " 1.92 34/8 ' 

-_2 0.28 Z7/ CU FE/ ---- OUTLINE OF OREBODY-3 0. 11 20.4 717 n CHANNEL SAMPLE 0.50 ^,>/ 1 0.0 \ / w-4 192. .4 -5 0.82 0.2 Z-O 0.78 /6.

CUZ-4 1.52 108 Z-5 081 3286 Z-0 230 20.4 -7 0.87 32.2

CU FE v-I 1.07 31.4 L-2 0.5I7 42 Cu FE S Y-~~~~~~~3 08 70 -l 0.20 17.0 MARCFIY-4 :. 208 92 . 17.4

Y v-s 0.10 248 X-8 0.02 10.2

3-5 2.04 29.4 X-i 2.20 242 X-7 1.20 36.2 X-8 0886 19.0

CU FE

LEGEND W i 0.20 17.4

OUTLINE OF ORE BODY 4- .14 23.4

-I TRENCH W-i07 20.2

n CHANNEL SAMPLE W50.70 22.0 CU FE

R-I SAMPLE NO. 4.32 24.0 I 0.4.19.2

CU PERCENT COPPER U3041.

FE PERCENT IRONU- . 20

0 80 00 30 200 400 500~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~U- 02,

MARCI-I 1950~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- 0 *1.

v-I 108 0.07 N. -110.22D.

V-0 10.2 1.03 T-l 0.05 0.35.2 V-7 10.0 085 T-2 0.04 34.2 9

V-S 2J21043T-0033137.

50 100 300 400 500 10 1. T4 .0 7%~~~~~~~~~~~~~~~~~~~VV-5 4.2423.4 T- 014.

Figure 5.- Assay map Barnes ore body, Kasna Creek.
Spiral concentration.

mQus-,?0-Mjh ore

Distribution,

V ;eights, Assay | , Oxenttprodu~c l -; *. -. .aPeent Fe Cu Fe i Cu

Con-ceh'tate71-t.... 35.6 1.10 0...' 66,. : 2. 9..+ 61 .7

Conmntr~e 2 ... -.~. ..,I. .2-.8 32*.5 - ,05oI .2 v 3.2*

Midig ' i o 2*57 ****'i* .NY ***'3 ,$l. ;.I: 2 .9C

Milng ...,....**.... '27.0 .58 i14.4 -I4f.8 17.2

Slime 1 0...,......... 23.5 1 9 .. .05.0

Cau3 tedr PCdXS ...... 1000 27.8 .93 100,0. '100.0

The data given show that neitheii a Iowv-g;&d& reject product nor

a high-ggrade iron-coppe;' toncentrate can be mnde- by spir- lconcentration. f ore crushed to minus.-206nesh, The- pnciil lea-".

son for the poor results is the lack of liberati~on between gh.ngue and ore minerls.. Appreciable copper and iron also.ere : lost in~ the untreatabU'lslnin fractions

In thb mtgretic-separation test, the ore yes crnshed!dry to

minus-20-mesh and then 'screeW sized into minus-20- 35-eshj mles 

minus-35-. p1is-65r-irrsh, minus-65- plus-15o0mesh, and'mlnus-1, Vi

mesh fractions. Each sized fraction was then passed through a

dry magnetic separator twice, with a highly magnetic fraction

remo'i*IdUring the first pass and a-'.less magnetic fractilon duringt deqbhd pass. the results were poor; only 4percent'of

the iron was recovered s as 'highly magnetic fractiorii ssayin'g 49 percent Fe ahd 6.8 percent Cu. The second mgnetic coneen - a

trate contained. 30 percent of `the iron , and -47 percent of the

copper in a product -assaying t5 percent Fe and 1 .3' percent ,* -

The nonmagnetic fraction contained 30 percent of the iron 411di &

30 percent of the copper in a product assaying 15 percent Fe

and 0.7 percent Cu. The data also showed that the finer the

sized fraction treated the cleaner the magnetic concentrate and

the lower its copper content. These facts further indicate that

poor separation is due chiefly to lack of liberation of the

minerals.

Since treatment of the ore at relatively coarse sizes failed

to give a satisfactory separation of copper and iron minerals from

gangue, a series of flotation tests was made using various grinds

and reagent combinations. In these tests, a copper concentrate

was floated using first sulfide-mineral collectors and then the

iron-oxide minerals were floated using fatty acid-type collectors.

However, none of the various conditions tried proved entirely successful in recovering both a copper concentrate and an iron concontrate. When grinds as coarse as 65-mesh were employed, lowgrade copper and iron concentrates were obtained and, when finer

grinds were used, considerable iron and copper could not be recovered from the large amount of slimes present in such finely

ground ore pulps. The results of a typical test are given in the

following table,

4489
Flotation o3 ;oirl and. nJireraMs,.

' mi nus.6L-neshAid ,-. .

Distribution,

... . We l ght, Assay,. Pexcen'-..

P~~oduct p~ercent Fe - Fe Cu.

Cu. concentrate . 3.6 30.0 15,.3 305 .T 

Cmezed ire canQentrate.. '36.9 33 -5 , - -. s0 6o 33-9

Fe cleaner tfiling. '46.4 30,9 -- i3-T49.2- 1228-

Rougher tailing ... 1.1 10;.12 I..... -

CalcUlated heads ,.; .. , 0 29.0 - .03 100.0

It is npteorthy tJat no hlgh-grade iron concentrat was.

mad.-.by flotation. This may be attribvted to 8l1iy nature of

the ore and the poor se~potivity obtainod with fatty-acid.

collectors o0 thisa tgp of ore pulp. Only about 50 perO4at o$f

the coppor was recovered in the copper concentrate, which

assayed only 15 percent Ou. Tis product .omid be, up6'a4ed. jY -

rofloating. It is also possible that a part of the copper in

the cleaned, iron concetrate could be recovered- by relip#Ing

this poduct ozd refloatin. as a microscopic .s.tudy of -the.

produet revealed most of the,,copper-i the prodsqt was sU1ll

looked with the iron oxides..

,7he facts doteoinod by -the ore dxossingloan be syz d .' 

as follows *. This typo .of ore Cdm=.t be cQrentrato:;&b , oXzn .

motho.da at relativvl coarseo, sizks. irthor, veon by fiie..

grining, and flotation; only low recov jes in low-Srade popper

produats Cjro.:9ossiblo. None of the methods tred proe..efftctiyo

for rocovoring the iron-oxid content of tho ore as a sqarate

pro duct. . .

-4:9- . .. . ,i , ' , . .. ,t

I. , /,K . '. ' . 8.' - '' " ' ,# ;'' *.
AMAIX~l I. -ANA.L'!S 0F COMPOSITE SANPIflS

- - - - -~

A-i.to A.-2l~, izel <0***** o.0o. 0,.2 1.55 /0.i 2~4.2O .1 1.5

toi 2, ci. .1005 d1 .1 3 . ~ .. 8

B-4 tlo-B-21, inclo Oi . 1.11 < .1 3010 4., 0,3

B.-22 to B-29, ixici. '........ .L .74 < .1 25.2. ..952.100

c-i to c-16,ic........1 . .64 <,-I 38A0 .. 05 .,55

C-17 to C-32, incl. ....... •005 .2 1.24 < .1 29A1?, <.05 .99

C-33 to C-40, mncl. AO00AAA, < 5 <. .2 8 .1 20;.• 05 .34

D-1 to D-22, iu. .nc....01 . 1,73 < .1 27Q.0 •,QO 1.67.

* ~~~D-23 toD-I44, inci. .. .0.05 A.... ,.2 .58 <- .1 23.. .<

E-1 to E-19, incl. ...... , .,.*005 .3 1.09 < .1 324*0 <? 0

E-20 to E-38,, ici. .. ,... 0~ 005 .2 1 r24 < .1 34.8. <,05 ,92

E-39 to E-58, inkcl. i f•...005, .1 .38 <-,.1 2P-,Q < 0, .69.

F-1ito F-18, inci. ..005. .21 .86 <C .1 31.2~, .<5, .1.85

F-19 to F-36, incl. <...... .005 .1 f 32 <.1l 2Q.2 <.~Q5. - .-32

F-37 to F-56, inci. 06SDa4~ V v? <2.005 .1 '.27 < .1 19A.4 • ?5~ 74'

G-i to G-5, imcl. l<c-005 <.I .09 < .1 1~.2. 4<•15.. y25 H-i to'H-21,m. 05 .1 1.30 01.1 226.w •X'0, r33

H-22 to H-.28, ihcl. *.4'.%',*r<.005 .1 .56 <.1 32.4 , <-~.05 .4

I-i to I-24, inci. <' -j005 .11 .23 .1 j29.6, . .05, .43,

J-1 to J-10, inci. <005 - .1 .12 < .1 19.4 ~ <.05 .19~

K-1 toi(-14 , inci, <.005 .1 .32 < .1 25.8 -<.05 .25

L-1 toL-J16, minal < .005 *i .49 ~<.1 31,.2 <.05,- .45

1R-1 toR-l0, inci. .......-. K.005' .2 1.78 <...i 27.8- .05- 1.94

S-i to S-5, inci. 4 a*.9 4 0005 .1 .77 -12 .1 23.6 .. 1- .91

T-1 to T-5, mnci. . *..-.....O ... 1..005 .3 .88 < .1. 3$ .0 .. * 1.-57

U-i .to .U-i4, mc. 005-. .1. .34 < .1 20,4.- .25:a-.,09:

V-it V1-10, inci *.* ~ 'i; .01 .3 .34 < i.1 20.0. . 4.24.

W-1ito w-6, inci. *.......... < .005 .2 1.27 < .1 23.0 .1 2.55

X-1ito X-8, imc.l .. ,*.. .005 .2 1.31 < .1 22.2 .1 3.42

Y-1 to Y-6, inci. ....... 005 j 2 1.13 <.1 -29.4 .1 3.08

Z-i to Z-7. inci....... 1.47 < .1 125.0 .1 13.21

4489 - -
4* m <-_ I!. SPAESMC-. .

ra_ *site O : llt Baxhes IIAe ' :ComTs i*1 ' Gil* 3dse "

Ce.: *. ... S + Li. _ - -

Ni ~~+ 4' P , - t. - Ec' .. .A ;7 ' ;.'_ A.- _

Mb or O Oi.*.,*t+ + . W _ .... Ir -

6 0 O +- [d 0 lolv- - -S 

+ -lj b la- .4~'lA .t~r. , T Fi 'Pa ;; _..

r'b *s 4@..o -A;*'_w I: e...a........ 4 -

Sl5 Pb - 13h V 10 k ' 1~~* .'+ I + ' _r 4"*-*; S+o,_,_aXs- A. " '........,' ,...

As:- . - - Uv . ._ ._. In.,,,-;,...... _ ' , Pt I+ i - C Ta, V!l 40 * 13h 4 0 11 o*#;^s. s . A ' : :_'

Nr *te , Prsn. + -. Abre t 'Tr, - Trac_ *; . - N*W-0 * . . . ... -_ .

Pt0 .- O .'. 4 4 . . .... W . 4.4 

dt. .- u.. ot. Mine, P P Tr. a . Hf 0 0 * O*4v -%

4489 - }0-

Int.,- Bu. of Mines,, Pgh., Pa.