DIAMOND DRILLING THE GYPSUM CAMEL PROSPECT,

IYOUKEEN COVE, CHICHAGOF ISLAND,

SOUTHEASTERN ALASKA

;

BY G. D. JERMAIN AND F. A. RUTLEDGE

* * * * * * * * * Report of Investigations 4852

4t ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

UNITED STATES DEPARTMENT OF THE INTERIOR

Oscar L. Chapman, Secretary

BUREAU OF MINES

J. J. Forbes, Director

Work on manuscript completed October 1951. The Bureau of Mines will welcome reprinting

of this paper, provided the following footnote acknowledgment is made: eReprinted from

Bureau of Mines Report of Investigations 4852."

April 1952
DIAMOND DRILLING THE GYPSUM-CAMEL PROSPECT

IYOUKEEN COVE, CHICHAGOF ISLAND,

SOUTHEASTERN ALASKA

by

G. D. Jermainh/ and F. A. Rutledge2/

4~~~~~~~~~~~~~~~

CONTENTS

Page

Introduction.........,......................... 1

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

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

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

History, production, and ownership.,.....,............ 2

Mine workings.......................................... 3

Description of deposit........ . .......... .. "..O. 3.. 3

Work by the Bureau of Mines ................

Bibliography.........************************........*.. 5

ILLUSTRATIONS

Follows

FBg. page

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

2. Index map of Chichagof Island, Alaska ......... .... 2

3. Iyoukeen Cove, Chichagof Island .................... 2

4. Gypsum-Camel deposit, Iyoukeen Cove ......... , 2

5. Drill holes and underground workings .............. 2

6. Geologic sections, Gypsum-Camel prospect........ .. 2

1/ Former chief, Mining Branch, Bureau of Mines, Juneau, Alaska

2/ Mining engineer, Bureau of Mines.

Report of Investigations 4852
INTRODUCTION

The Bureau of Mines investigated the Gypsum-Camel deposit on Iyoukeen

Cove, Chichagof Island, Southeastern Alaska, from April 21 to August 26, 194.8,

as a part of the United States Department of the Interior program for developing an Alaskan construction industry. As gypsum is one of the components

necessary for the manufacture of cement and one of the raw materials for

plaster and'plaster-board products, it is desirable to locate and develop a

readily accessible deposit of gypsum in Alaska.

In 1928, B. D. Stewart3/ of the Territorial Department of Mines surveyed

the gypsum deposits at IyoukeeP Cove, and during the summer of 1946 George M.

Flint, Jr., and Edward H. Cobb~Yof theFederal Geological Survey examined and

mapped the old workings at Gypsum-Creek and the prospect at Iyoukeen Cove.

Both the Territorial Department of Mines and the Federal Geological Survey

recommended the Gypsum-Camel prospect as warranting a diamond-dxrilling program by the Bureau of Mines.

The Bureau of Mines project consisted of cleaning out and sampling the

old underground workings and diamond. drilling from the surface to ascertain

the lateral extensions of the deposit.

ACXNOWLEDGMEl BTTS

The sam~pling and diamond-drilling program at Iyoukeen Cove was under the

direct supervision of G. D. Jermain, chief, Alaskan Branch, Mining Division

of the Bureau of Mines..

Analytical determination of samples were made by H. E. Peterson, chemist,

Salt Lake City Branch, Metallurgical Division, Bureau of Mines, Salt Lake

City, Utah.

Acknowledgment also is made to Dave Housel of Seattle, Wash., for the

use of his cabins at the. prospect and a historical resume of the prospect.

LOCATION AND ACCESSIBILITY

The gypsum deposit at Iyoukeen Cove is on tidewater on a smnall bight

facing Chatham Strait approximately 1-1/2 miles northeast of Gypsum Creek on

Chichagof Island (figs. 1, 2, and 3). The area is 32 miles southwest of

3j Stewart, B. -D., The Occurrence of Gypsum at Iyoukoan Cove, Chichagof

Island, Alaska: Geol. Survey Bull. 824-E, 1931, pp. 173-181.

4/ Flint, George M., Jr., and Cobb, Edward H., Preliminary Report on the

Gypsum Deposits near Iyoukeen Cove, Chichagof Island, Southeastern

Alaska: Gool. Survey prclim. mimeo. rept.

4595 -1 -
Diamond-drill hole 2 was drilled 60 feet northwest of a point midway

-between the faces of adits 2 and 3 (fig. 5), and no gypsum was found. Bedrock was penetrated at 105 feet 8 inches, which agrees very closely with the

depth of overburden expected from the slope of the old erosion surface exposed in the adits. This hole was bottomed at 166 fect 6 inches in limestone,

Both adits 2 and 3 show lumps of gypsum in blue and brown clay in the face

and probably have reached the western limit of the deposit, since gypsum was

not found in hole 2.

Sections through the adits and diamond-drill holes are shown on figure 6.

The gypsum is mostly pure white, although in places it grades to a light

bluish gray. It is usurally fine-grained and translucent approaching alabaster

in gradc.

The location of samples taken is shown on figure 5, and analyses and

descriptions are given in table 1,

TABIE 1. - Analysecs of Samples, Gypsum-Camel prospoct, percent

Sam-- I

ple Comb i 'Free

No. Description IIH20 C02 CaO M20 SO %si R2 03 NaCltH20

1 Blue and brown clay with 1.1T20.9 29.6 T 13 120.6 2 001|1.1

gypsum. ! 1

2 Clay with gypsum. 10.71 9.0 3o.4 2.6 25.85 2.8 4.4 .01 ,49

3 Gypsum. 114.9 6.4 1.319 2.2 135.01 5 6 2.0 .01 .08

4 do. 14.7 5.2 29,613.8 134.251 8.2 2.4 1 .01 .34.

5 do. 11.1 12.9 33.8;3.4 26.551 8.0 2.6 .01 .37

6 Gypsum with some clay scemS,. 7.9 12.3 129-313.7 18.6£ 17.8 5.4 .011 .81

7 Gypsum with some gravel. 9 124.2 333I5. 4 I 3.0 21.4 6.8 .01. 08

83 do. 3,7 120.6 33w3 3-3 81.151 19.2 6.4 .O11- ,71

9 dO. i 1.6124.9 35.015.6 3.1 19.8 6.2 .0111.05

10 Gypsum. . f16.1 3.95131.41.75 39,251 4.p 1.2 .011 .20

11 do. 17.7 2.70 32.5 1.0 !42.2 2.4 .8 .011 A.09

12 Gypsum with some clay seams. 8.4 16.7 33 l15 5 ;20.15 10.2 2.8 .0l .51

13 do. .13.8 4.65 28.1 4:5 32.2110.2 3.2 .01 .41

14 do. 11.81 8.15 28.5 5.5 2..0 11.2 2.4 o.01 .66

15 Gypsum and clay. 9.8 4.75 22.1 4.5 i21.1 21.6 11.2 .0111.48

16 Gypsum with somw clay seams.15.7 2.70 20.512.7 ,37.35 7.0 2.2 .01 .34

17 do 6,5 16.2 30.9|6.2 16.05 15.8 IL.2 .011 .72

18 do. 15.0 3.60 29.8 11.1 *36.2 1 7.4 3.2 .011 .39

19 Gypsum. 15.0 1.40 30.2 2.55 40.7' 6.2-' 1.8 :01 .15

20 Gypsum with some clay seams.12,.7 4.70 28.0 3.55 31.3 11.9 3.9 .01; .40

21 do. 12.0 4.60 29.1 2.95129.9 j12.3 3.2 | .01 , .25

22 Gypsum with some gravl. 6.1 1.1 28.1 2.90 15.2 121.2 0

WORK BY BUM0U CF MINES

The Bureau of Mines proGram originally outlined for development of the

Gypsum-Camcl prospect includod additional drill holes west of hole 2 along the

4595 - 4-
Juneau by air and on the airline route between Juneau and Sitka. Stops by

the Alaska Coastal Airlines will be made upon request during their regular

flights but are dependent on weather. Iyoukcen Cove offers no shelter to

winds from the southeast, and too high a swell prohibits landings. Rates

by air from Juneau to Iyoukeon CovG in 1948 were $18.00 plus 15 percent

federal tax per person and 9 cents a pound for freight with a $10.000

minimum charge per stop.

The mailboat between Juneau, Sitka, and waypoints makes the trip once a

week and will stop if requested. Dave Housel of Seattle Wash., and associates

at one time had a short wharf at the property for unloading equipment and

supplies. At present, all supplies have to be landed by small boats, and a

new wharf will be required before the property can be operated.

PHYSICAL FEATUTES AND CLIMATE

Chichagof Island presents all the appearance of its recent glaciation.

U-shaped valleys and hanging valleys are common through out the mountainous

interior oI' the island. The lower flanks of the mountains and the bench

lands along the valleys and the coast are deeply mantled with glacial till.

In the immediate vicinity of the GypSUn1 prospect, the effects of a rising

coast line are evidenced by the partly consolidated beach sand containing

marine shells exposed above the rrpsum in the old workings and the marine

terrace under which the adits have been driven.

The drainage in the. Gypsim-Camcl area is by numerous short, parallel

streams flawing southeastwrard into Chatham Stxrait (see fig. 4). The combination of heavy precipitation, dense vegetation, and poor drainagce has

formed numerous muskog flats along the benches and moderate slopes.

Dense forests, mainly hemlock with spruce, cedar, and white ash, cover

all but the steepest slopes. An undergrowth of devil's club, blueberry

bushes, alder, and ferns is found. intermixed with the timber. and extends from

tidewater to near the tops of the mountains.

The climate of the region:is extremely mild. Since no weather records

are available for Iyoukeen Cove, an average has been taken of the averages

for .Sitka and Juneau, Alaska, where records have been kept for over 40 years.

A mean annual temperature of 42.90 F. and cool summers with mean temperatures

of 51.70 to 55.90 F. show that temperature variation is small. Only 1 month -

January, with 300 F. - has an average under 320 F.

Average precipitation is 85.59 inches, which includes 75.8 inches of

snowfall.

HISTORY, PRObuCTION, AD CVWNIERSHIP

The gypsum at Iyoukeen Cove was discovered by Robert Greenwald of Hoonah,

Alaska, in 1910. Greenrald, before the discovery, had been employed as a

miner at the property of the Paci|fic Coast Gypsum Co, on Gypsum Creek and

recognized the yellowish brecciated limestone outcropping along the shore as

4595 - 2-
the same formation underlying the gypsum at Gypsum Creek. The gypsum does

not outcrop at Iyoukeen Cove.

Dave Housel of Seattle, Wash., now (March 1950) has the controlling interest in the property, which consists of eight placer claims. Gypsum

and Gypsum 1, 2, 3, 4, 5, 6, and 7. The claims are known as the GypsumCamel group,

Though there has been very little production of gypsum from this deposit,

the property on Gypsum Creek, 1-1/4 miles west of the area, produced approximately 500,000 tons2/ before 1926.

MINE WOmFI=GS

Five adits have been driven westward into the gently sloping bench that

rises steeply from the beach at the gypsum-Camel prospect (figs. 4 and 5).

Two of the adits - 1 and 5 - are driven into the buff limestone breccia and

limestone underlying the gypsum. Another (No. 4 ) was driven around the

caved portion of adit 2 to open up the face of gypsum exposed in that adit.

Addlitional devolopment consists of three winzes from adit 3 and a short sublevel drift 30 foot below adit 3 (,ee figs. 5 and 6). The total of all dovelopment work is 1,060 feet.

DESCRIPTION OF DEPOSIT

The gypsum at Iyoukcen Cove is in a small synclinal basin lying unconformably on buff brecciated limestcne. This brecciated limestone is exposed

200 feet south of adit 2 and 80 feet north of adit 3, making a total distance

of 520 feet between exposurcs of the formation underlying the gypsum. However, it is probable that the north-south dimension of the deposit is less

than 450 feet.

Diamond-drill hole 1 was drilled vertically 38 foot S. 150 E. of the

portal of adit 3 (soe fig; 5). This hole cut the following formations:

From- To- Formation

Ft. in. Ft. in.

0 0 1 0 Soil and glacial till.

1 0 4 6 Large boulders in beach sand, marine shells.

4 6 7 0 Lbrge beach pebbles and beach sand.

7 0 15 8 Beach sand and marine shells, partly consolidated.

15 8 20 0 Fragments of gypsum in clay,

20 0 24 2 Gypsum. '' - '6

24 2 25 0 Liimestone.

25 0 27 0 Gypsum, . -

27 0 28 0 Limestone.

28 0 30 0 Gypsum30 0 32 5 Limestone.

32 5 34 1 Clay and limestone.

34 1 44 0 Brecciated limestone.

44 0 44 1-1/2 Gypsji=

44 1-1/2 63 0 Brecciated limestone,

j Stewart, B. D., Thb Occurrence of Gypsum at Iyoukoen Cove, Chichagof

Island, Alaska: Geol. Survey Bull. 824-E, 1931, p. 173.

4595 -3-
% F I C C E O 91 G\ oC K8-

Figure map 1. of 

-Alaska. Index ~ ~ ~ ~ .12
S~~~~~~~~P

Figure IexmapofCigOIs s

Figure 2 Index map of Chichagof Island, Alaska.
| =G M.AL DEPOSIT:

\ii \ , 9 REEF EXPOSED

i am ~~~~~~~~~~~~~~~~~~~~HALF TIDE

EXPLANATIONS 8 0

COVERED

GYPSUM EXPOSED '" 6

BUFF LIMESTONE BRECCIA V

v ~~~~~~~ 0 ~~~~~~1000 2000 AD IT /__

SURFACE TRAMLINE JUNE 1948

MODIFIED FROM U.S.GCS.

Figure 3.- Iyoukeen Cove, Chichagof Island.
j. *~~~~~~~~~~

\IT y /VYOUKEEN COVE

SCALE IN FEET

AUG. 1948

EXPLANATION

LI MESTONE

M WED I FROM U. S.

FEOLOGICAL SURdVEY

Figure 4. - Gypsum-Camel deposit, Iyoukeen Cove.
IDI

0 DIAMOND DRILL HOLE 2

DIAMOND DRILL HOLE I

ADIT 4

LEGEND

3 SAMPLE LOCATION 0 WINZE'DT2

0 DIAMOND DRILL HOLE , ADIT2 0 _ GYPSUM

LINE OF SECTION

0 20 40 s0

SCALE IN FEET

AUGUST 1948

Figure 5. - Drill holes and underground workings.
__ DD HOLE 2

GLACIAL TILL -

_ L ~~~~~~~~~~~~~~GLACILTL

UItb - L. 0.0. HOLE I

--------- Wn-W-CW-T~br---~' L

SECTION A-B

LEGEND

- _ 5 100 IS _ GYPSUM

LAYER MARINE SWELLS

SCALE IN FEET SCALE: FLUMPS GYPSUM IN CLAY LUMPS GYPSUM, GRAVEL,O CLAY

MARCH 1950

D.D. HOLE 2

GLACIAL TIll

DDHOLE I

0 g ._ ~~~~~~~~~~~~~~ _ _ ~~~~CAVED _

----------------------------------- £-O*la----------------------- -----

SECTION C-D

Figure 6. - Geologic sections Gypsum-Camel deposit.
axis of the synclinal basin. If gypsum had been found here, other holes would

have been drilled north and south of this line to test the breadth of the deposit. When no gypsum was found in hole 2, this plan was abandoned, since it

was apparent that the western boundary of the deposit was near the faces of

adits 2 and 3.,

The caved ad its were cleaned out and samples of the gypsum taken for

analysis. Attempts were made to pump out the vertical winze in adit 3 so

that the gypsum reported in the bottom of the winze and along the sublevel

drift could be sampled. The water was lowered 24 feet, but the pump available

would not lift the water below this depth. There was still 5 feet of water in

the winze and drift, and it could not be examined and sampled.

The inclined winze in adit 3 was pumped out and 11 feet 6 inches of gypsum

containing numerous clay seems was exposed.

The thickness of glacial till, especially the large number of boulders

in the till, caused many difficulties in putting down the drill holes. Several

innovations were tried to expedite the drilling.

In drill hole 1, on the beach, shaped charges were tried as a means of

clearing a way through the boulders. This was not successful because the

boulders were in water-fillcd beach sand and the hole would slough before

casing could be driven. It finally was necessary to put a shaift down 10 feet

to get below this layer of glacial boulders and beach send..

In hole 2, a much greater thickness of overburden with a large number of

boulders, sand, and 4lay necessitated another approach, Conventional methods

with sawtooth bit and chopping bits gave little progress, as the boulders

fell in, which prevented driving the standpiping ahead. In addition, sand

ran in and filled both hole and standpipe. The wash water necessary in

using the conventional methods was an adverse factor aggravating the

difficulties.

It was thought that the most feasible method would bo to churn-drill

through the overburden. Since no churn drill was available and to use the

cathead on the drill would be both slow and difficult, it was decided to

build a small churn-drill attachment to fit on the head of the diamond drill

in lieu of the drill head.

A churn drill was made locally and fitted to the diamond-drill motor by

removing the hydraulic head and fitting a 10-1 reduction gear in place of the

bevel gear. A walking beam with frame was added; and thus, at small cost, an

adequate and compact churn drill was constructed, which was very successful.

Figures 5 and 6 show the adits that penetrate the gypsum and the locations of the samples. Tnienty two samples were taken.

4595 5
BIBLIOGRAPHY

BROOIC, A. L., and OTHERS. Mineral Resources of Alaska, 1912. Geol. Survey

Bull. 542, 1913, pp. 50-51.

FLINT, GEORGE M., JR., and COBB, EDWARD H. Preliminary Report on the Gypsum

Deposits near Iyoukeen Cove, Chichagof Island, Southeastern Alaska. Geol.

Survey prelim. mimeo. rept., 4 pp. .

STEWARTY B. D. The Occurrence of Gypsum at Iyoukzecn Cove, Chichagof Island,

Alaska. Geol. Survey Bull. 824-3, 1931, pp. 173-181.

IWRIGHT, C. W. The Building Stones and Materials of Southeastern Alaska.

Geol. Survey Bull, 345, 1908, pp. 124-125.

4595 -6-

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