14

Tsivat River

2120

GULF

<——I6 miles of
shoreline omitted

W 143°-00'

N
Chiuki River
N 67° O7- 30"
~~ Approximate _wiC'h_——————————
216
214 |
a 215 °
-) e °
2ll 210 209 208 207
LEGEND
OF ALASKA Drill Hole °
Shovel Sample o
Q ! 2 3 4

SS |
Scale in miles

FIGURE 4, - Bering Glacier Area Between Tsivat and Kaliakh Rivers.



35

Sample No. 102 was not pan-concentrated in the field; instead, the bulk

sample (total auger-hole borings) was shipped for laboratory treatment and

analysis. Field observations indicated sample No. 102 was representative of

the best heavy-mineral concentration in the Sea Otter area.

TABLE 18. - Petrographic examination of nonmagnetic fractions,

Dry Bay--Sea Otter

[Code: 1 = major constituent, 2 = small amount, 3 = trace,

and - =

not detected]

Sample number

Mineral constituent

>
>

51B

61

102

105

Ilmenite...
Zircon..
Rutile

Garnet..
Staurolite.
Pyroxene.
Topaz...
Sphene

Epidote.
Ampibole.
Olivine.
Apatite.
Tourmaline.
Chlorite.
Feldspar.
Calcite.
Quartz.......-

POERNWWEIENWWHIS

ww ms

hrenmeoe

lw WW

PRPRPwWPE REN WORD

Inwne

pene

ly Ww

1

PRereriw

ew

lo tw

Ko
Pre Pwt re wrtt ola

ee)

Peer trrors

peree

bRRePwe

tee



31

yeah? LES

70

fo)
. a> LEGEND
\e eo . Drill hole.
Ss >
= ° t 2
ee

Seale in miles.

Approximate width

of beach sands.

SL ne
74

° 73
71 7

ALAS K A

GULF OF

FIGURE 9. - Akwe.


a I — i
NRL? 7 ' H
| So CF LEGEND Ros
as par Drill hole ° ae,
eZ a Shovel sample oO crete ean
Sg = AIS Oy
oS Hig l 2 3 4 Se
4 S, '
VA ta Scale in miles om —o
bea \ ;
BA _— _— 7
rN — —
= ae — by Li 7
= EYsyVV\ oy FA po4
& ere . ~
ENVIS I) ZY Vr were Fg
ENS ToS
Mma \ std) fa / ( ( (Sy -\
I a 4 > \—
oY J, 8 OS AS
SD er i Tp
TS \ cw ey - 7 LD 7p
TN sy Ten
| yy Sane Sg fake oy
Sy ae A REE
- i — a —, *, 5 i A Sx < Y’ Fay Wt
— > 2364 > Gyo8
| nA 0 = a 3% yO |
SS eR NS
ON S42
~~ -—2 ‘ 4% *
~¢ — —- 2 } a
- jo --- 9-H F==-9
\22 —O.. ~~ — Tes os 109 10
12 —_ _ — io 107
GULF OF ALASKA ley Point —e
3
‘ ay
ote x
Re)

FIGURE 13. - La Perouse.

INT.eMULOF MINES,POH. PA. 3690


GENERAL GEOLOGY AND DESCRIPTION OF DEPOSITS

The geology of the eastern Gulf of Alaska region has been described by
Blackwelder,” Martin,® Mertie,® and others. The following brief discussion
is based on a summary of the geological information contained in the various
publications and on field observations by Bureau of Mines engineers.

The sands along the tidal zone are the products of marine erosion, trans-
portation, and deposition. They are the result of abrasion of glaciofluvial
material by wave action. The streams and rivers flowing from the icefields of
the foothills and back country are building a plain of sand, gravel, and silt
out into the Gulf. The strong ocean currents sweep the sand along the coast
where it is deposited in bars and spits.

The coastal plain is glacial detritus that in places, notably between
Yakataga and Icy Bay and near Lituya Bay, is being attacked directly by wave
action. The broader expanse of the coastal plain northwest of Yakataga and
between Yakutat Bay and Grand Plateau Glacier is composed of glaciofluvial
material that at one time had been worked by the action of the sea. The rem-
nants of old shorelines are evidence of the withdrawal of the sea because of a
gradually rising coastline.

The foothills are composed of sedimentary and metamorphosed sedimentary
rocks that have been subjected to intense folding and faulting. Some evidence
of the oil potential in these rocks is shown by invertebrate fossil remains of
marine origin and by many oil seeps found in the vicinity of Yakataga and Icy
Bay.

Boulders and pebbles of igneous rocks are a common constituent of glacial
detritus along the coastline. These rocks comprise various phases of both
acidic and basic intrusives and are indicative of the rocks that will probably
be found in the precipitous back country. The garnetiferous metamorphic
equivalents of both sedimentary and igneous rocks, commonly found along the
shore near Lituya Bay, indicate zones of contact metamorphism that are either
obscured by moraine or occur beyond the investigated area.

The black sand minerals, notably magnetite, ilmenite, and rutile, are
probably derived from the basic igneous rocks of the region. The abundant
garnet is probably of contact metamorphic derivation.

The coastal region around the head of the Gulf of Alaska is one of the
great seismic regions of the world. Uplifts of 47 feet have been recorded in
the Yakutat Bay area.t° Earthquakes originating in the vicinities of Yakutat

7Blackwelder, Eliot, Reconnaissance on the Pacific Coast From Yakutat to
Alsek River: Geol. Survey Bull. 314, 1907, pp. 82-88.

®Martin, G. C., Preliminary Report on Petroleum in Alaska: Geol. Survey
Bull. 719, 1921, pp. 34-42.

°Work cited in footnote 4.

10Tarr, R. S., and Martin, Lawrence, The Earthquakes at Yakutat Bay, Alaska,
in September, 1899: Geol. Survey Prof. Paper 69, 1912, p. 21.


18

fi;
ve,

Approximate width
SH beR Eh AAISE

128~—=e
129s
130NS
G ULF

Icy Cape

A LAS

5!

LEGEND
Drill hole e
Shovel sample fo)
{ 2 3
Scale in miles.

Yahtse

FIGURE 6. - Icy Bay.



36

TABLE 19. - Auger-hole and shovel sampling results,

Dry Bay--Sea Otter

Adjusted Pounds per cu. yd. in-place
Sample | Total Material at measured Magnetic Nonmagnetic
number | depth, bottom of hole vol. loose, fraction fraction
feet cu. yd. Iron Tid, Ti0,
36 7.7 Gravel and water 0.029 0.4 @) 20.3
37 12.0 do. 038 & ¢C) 3
38 7.7 Loose sand 2024 7 el 6
39 8.8 Fine gravel 024 4 C) 2.3
40 11.4 Sand and water 041 3 ¢) 2.2
340A - - +010 8.0 7 21.5
4l 7.7 Sand and water -029 4 @) 26
42 2.0 Gravel -010 6.2 5 43.2
342A - - 014 59.2 4.3 526.9
43 11.5 Sand and water +029 5.6 3 2.7
44 8.3 Gravel and water .019 2.4 2 21.5
45 16.3 Sand and water 038 7.4 7 S44
46 16.0 do. +050 3.4 2 2671.6
47 5.6 do. -012 1.0 al 2.1
47A 3.2 do. .007 6.0 7 15.9
48 6.9 do. +011 3 (oo) 6
49 10.2 do. +012 1.8 +2 2.4
50 9.0 do. -023 3 @) 25
51 6.7 Gravel +018 1.6 CG) 2.5
851A - - +005 2.7 al 22.0
60 2.2 Sand and water 005 7.7 +6 24.4
61 7.2 do. 022 5.8 5 52.8
62 13.5 do. 036 16.2 1.4 °7.8
63 8.6 do. 022 9.9 -8 2 64.9
95 4.7 Gravel 014 5.6 6 6.5
96 9.9 do. +031 2.2 +2 3.3
97 6.3 do. 017 5 Cc) 8
98 7.3 do. -019 5 eC) 8
99 8.4 do. +024 4.9 +6 7.2
100 5.4 do. +014 3.7 4 5.0
101 7.8 do. 014 6.8 8 11.2
102 12.7 do. -048 12.2 1.8 20.0
*103 - - +005 2.0 @) 1.6
104 7.3 Gravel +018 1.9 3 3.0
105 9.2 do. -024 9.4 1.6 16.5
1 Trace.

2Trace eU in table concentrate.

3 Shovel sample.
4Trace Au.

50.0065 troy oz. Au per cubic yard.

®Trace eU in table tailing.

70.0034 troy oz. Au per cubic yard.


CONTENTS

Summary.......
Introduction.
Acknowledgments ....seeeeeceeee
Location and accessibility....
Physical features and climate.
History and production........
Property and ownership........e.
General geology and description of deposits.
Work by the Bureau of MineS...cesssesecsssseoee
Field investigations.............
Laboratory investigations........
Sampling methods and equipment.
Calculation of sampling results
Areas investigated...csccccceseccceee
Bering Glacier..
Yakataga....eseee

Icy Bay....
Malaspina.......

Yakutat.

Akwe....

Dry Bay--Sea Otter....sssseeeee

Lituya Bay--La Perouse.........

ILLUSTRATIONS

Index map of Alaska... .eeeeeeceeees
Map of the area studied.... dee eeeceees
Bering Glacier area between Kiklukh and Seal Rivers..
Bering Glacier area between Tsivat and Kaliakh Rivers
Yakataga..sscccceesseees
Icy Baysccccesccceevee
Malaspina.......seee0e
Yakutat...
Akwe..seee

Bee
FPOCMINDUPWNH
iJ
4
<

a
o
»
°
or
i
o
q

12. Lituya Bay
La Perouse.

et
w&

ba}
Cy
jo

WOOMYNAUWNNH


29

head sample assayed 36.8 percent acid-soluble, Fe, 11.3 percent Ti0,, 0.51
percent Zr0,, and less than 0.02 ounces of Au or Ag per ton. The sand was
screen-sized with standard Tyler sieves, and the component fractions were
analyzed for titania content. The results are shown in table 14.

TABLE 14. - Composite sample screen analysis, Yakutat

Weight, | Assay, percent | Distribution,
Product (mesh) percent Tio, percent TiO,
+65 7.10 7.3 4.6
-65, +100 57.28 11.3 58.0
-100, +200 35.26 11.8 37.2
-200 +36 6.0 +2
Calculated head.. 100.00 11.2 100.0

A sample was treated on a high intensity magnetic separator to produce a
magnetite concentrate, ilmenite concentrate, garnet concentrate, and non-
magnetic product. The latter was tabled to concentrate the heavy minerals.
Results are shown in table 15.

TABLE 15. - Composite sample magnetic and gravity concentration, Yakutat

Distribution,
Product Weight, | Assay, percent percent

percent| Fe | TiO, | ZrO, | Fe TiO,
28.70] 67.7] 3.5 |0.05 | 53.2 9.2
16.25 | 36.5 | 37.0] - 16.3 | 55.2
30.50] 26.8| 8.8] .06 | 22.4] 24.5
Nonmagnetic concentrate 7.25| 16.8] 8.5 | 6.6 3.4 5.6
Nonmagnetic tail... . . 17.30] 10.0] 3.5] - 4.7 5.5
Calculated head.. seeeee 100.00 | 36.5 11.0 | .51 | 100.0 | 100.0
Combined magnetite and ilmenite...... 44.95] 56.5 ]15.7 | - 69.5 44

The iron concentrate was composed chiefly of magnetite with some extremely
intimate intergrowths of ilmenite; hornblende and garnet were estimated to
make up less than one-half percent impurities. The ilmenite fraction was
estimated to be 99 percent ilmenite intergrown with magnetite plus about 0.5
percent each of hornblende and garnet. Because the test was run to produce a
high-grade ilmenite concentrate, considerable titania was lost in the garnet
fraction. Microscopic examination indicated that the garnet fraction con-
tained an estimated 60 percent spessartite, 25 percent ilmenite, 15 percent
hornblende and hypersthene, plus a trace of zircon.

The nonmagnetic fraction of the sand was tabled to further concentrate
the heavy minerals. The concentrate from this process was composed of an
estimated 30 percent hornblende and augite, 20 percent garnet, 10 percent
zircon, 14 percent ilmenite, 10 percent epidote, 8 percent quartz, calcite,
and apatite, 4 percent hypersthene, and 4 percent sphene and rutile. Radio-
metric analysis showed a uranium equivalent content of 0.016 percent, which
was probably due to the radioactivity of zircon. Approximately 90 percent of
the total zircon was recovered in this product.


15

TABLE 3. - Petrographic examination of nonmagnetic fractions, Bering Glacier

(Code: 1 = major constituent, 2 = small amount, 3 = trace,
and - = not detected]

Mineral Sample number

+206] 2 8 | 209] 210|211}212]2 213] 2
3

wa
i
nN
Pwr wwold
no
a
nD

rrirwe ole
Cy
Nn

constituent |2
Magnetite...
Hematite
Zircon.
Rutile..
Garnet..
Staurolite.....
Augite..
Sphene.
Epidote.
Hornblende
Olivine.
Apatite
Biotite
Chlorite
Feldspar..
QuartZ...eceeee
Greenstone
fragments..... - - - - - 1
Shale fragments} 2 | 2 2}/-]2/)242
Sandstone
fragments.....| - | - -|-J/]-]-]-j]-[- -|[-|]- -|[-|-
Mineral ample numb.
constituent _|220 5122612271228
Magnetite...
Hematite...
Zircon..
Rutile....
Garnet....

wo

rytr_wst wld
INwows

PNyt www
ryt www
PN Eww

PRRPwYwWINWwW!t WIS
PRPRwWwWINT WWW
PNNPEWIEN!E WWI
PWNHtEWIN! WWE

1
ttrwre
tonne
Pee
pyee
rrywe
INnet

PRR POWER EP WWINwwet Wd
POF EWINWIEWIwW! BW

PORT WI RPEPWWInwoet

PNPWIWRRwE

wort
Pee
Nir
wert
NERO
Por
Por
PRP?
Pye?
HN

1
1
1
1
1
1
Nt
'
'

Nv
Nv
a

1234

URN EWEN ww wwIS
In
ty
IN
es
IN
No
Ry
IN
So
nN
i
nN
jr

PNWwWwWwID

Hornblende.....
Olivine. o-
Apatite
Biotite.
Chlorite
Feldspar
Quartz....
Greenstone

fragments.....] 1
Shale fragments | 1
Sandstone

fragments.....| - - - - - - - - - - 1 - 1 1
1Shovel sample.

INN IE WENWWWUID
PNNIEWIENWWWWID
INN EWIENWWWN
PNP TwWIENWWWN
INEPT wWIN!T WON
PONT WINWWYNN|N
INN ENWN!WWN]D
PNET WWEWHOWNID

INNIEwWIENIT WWW
INN EWEN WOWNID

rune

1
'
'
1
'
1
'

w
1
1
'

'
1

Nine
mo
at
oo
oe
oe
moa
to

wn
NN
BPNIWwE
PN

In
Be PPR BEN NT WON 1 WWI

BR
Pe
e
Be
w



21

Icy Bay

Several exploratory oil wells have been drilled in the area west of Icy
Bay (fig. 6). During these activities three airstrips and several access
roads were constructed; two of the airstrips are suitable for DC-3 or equiva-
lent airplanes. However, the oil exploration project had been terminated
before August 1957, and the roads and airstrips were deteriorated through
lack of maintenance.

The coastline shown in figure 6 is generally composed of hard packed
beaches that are suitable for small bush plane operations. Landing barges
have been used successfully along the shores of Icy Bay, however, caution
should be exercised when entering the Bay by small vessel because dangerous
ice floes are always present. Only the most experienced boatman should
attempt entering the tidal estuary of the Yahtse River.

A total of 31 samples, consisting of 22 auger-hole and 9 shovel samples,
was taken along the exposed beaches between Johnston Creek and Icy Cape and
between Point Riou and the mouth of Yahtse River. Samples were also collected
from a part of the inner shoreline of Icy Bay. Petrographic examination
(table 7) of the nonmagnetic fraction from select samples shows the mineral
constituents of sands in the Icy Bay area to be similar to that of the sands
in the Yakataga area. A summary of auger-hole and shovel sample results is
shown in table 8.

TABLE 7. - Petrographic examination of nonmagnetic fractions, Icy Bay

[Code: 1 = major constituent, 2 = small amount, 3 = trace,
and - = not detected]

Sample number
158 | 158A | 159 | 162

~

POPE TRE Rw ON NT WE
im
KO

POT RPWWRIT RP WWWNN?! WIE

Mineral constituent
Magnetite.....
Pyrite...
Tlmenite.
Chromite.
Zircon..
Xenotime. eee
Rutile........ee.
Garnet..ccssccceveee
Limonite....
Pyroxene....
Sphene..
Epidote.
Hornblende.
Zoisite..
Olivine.....
Chlorite.
Quartz...

rwWroww
rwrnwe

PRENIRPPePNINIt eS
rwoWwnNe

Pewt~ninet

Hb wweet
IWR EOP wt Pr ePNIENI EI

-



17

kN NAY”
\ . iS SS YS <s NY Guyot \ Glacier ) ]
at? <a \ SY’ LEU ae VK 1) ae 42)
we ° ~ 2 se LS’ sy — QV) ey
Shovel sample. O AS = + Bye’ a
to) 2 3 4 SSA Cree, ~ e x
Scale in miles. y crest re 4
Rye y ars ke 3
- A Crit >
whe (River \”
Ame eh

Anite Rive

(Ag
oy © KN
MH --a SS
194 s 3 - 139 140 141
° rd © Ae 138
= & 6 eet
OS _ » ¢ ' )yx
- 153 133 734 iss 136 137 yore
Approximate width of
beach sands.
S S ie 183
is %
Cape Yakataga
ea G ULF OF \ ALAS KA

FIGURE 5. - Yakataga.


30

The nonmagnetic table tailing consisted chiefly of hornblende, augite, and
hypersthene, with lesser amounts of garnet and epidote, approximately 4 per-
cent tourmaline, 2 percent zircon, and 4 percent combined sphene, quartz, cal-
cite, apatite, and altered feldspar. A trace of radioactivity was noted.
Chromium was detected spectroscopically in this and in the nonmagnetic concen-
trate, but no chromium mineral was identified.

Akwe

The Akwe River area (fig. 9) is accessible by small aircraft. The beaches
are sandy, are usually hard packed, and may be used as bush plane fields; two
small auxiliary airstrips have been constructed in the area. During the
summer, four-wheel-drive trucks are used to haul salmon from the tidal estuary
of the Akwe River to the mouth of the Alsek River. An unimproved road follows
the grassy crest of the ocean-front dune eastward to the Alsek River (fig. 10).

A total of 22 auger-hole samples was taken between the Italio and Akwe
Rivers and along the Akwe spit. The mineral constituents of the nonmagnetic
fractions from four representative samples are shown in table 16. A summary
of sampling results is shown in table 17.

TABLE 16. - Petrographic examination of nonmagnetic fractions, Akwe

(Code: 1 = major constituent, 2 = small amount, 3 = trace,
and - = not detected]

Sample number
59 70 vi
1 1

Mineral constituent 5:

Ilmenite.
Chromite
Zircon..
Rutile.....
Garnet...
Pyroxene
Sphene
Epidote....
Amphibole..
Tourmaline..
Feldspar.
Calcite.
Quartz...

tReet nw

PeENtEPRPINE
PWOEPNNRPHE EN YES

NONT HERO BNOwWE HIE

'
BENT

1



12

TABLE 2. - Bulk sampling results, Bering Glacier

Sample number

218 232 233
Total depth in feets..cecceeee 20.8 11.1 22.6
Material at bottom of hole.... Water Sand Water
Adjusted measured volume
loose, cubic yard.......eee- 0.050 0.026 0.053
Table concentrate:
Magnetic fraction:
Pounds iron per cubic yard 1.1 0.4 1.7
Pounds TiO, per cubic yard 0.3 0.1 0.4
Petrographic analysis..... Fine grained Fine grained Fine grained
titaniferous titaniferous titaniferous

Nonmagnetic fraction:
Pounds eU per cubic yard..
Petrographic analysis.....

Table reject:? Petrographic
analysis.

magnetite in
quartz and
shale.

None
Chiefly quartz,
altered plagi-
oclase feld-
spar, epidote,
and horn-
blende. Small
amounts of
garnet and
orthoclase;
traces of zir-
con, olivine,
chlorite, apa-
tite, chromite,|
and ilmenite.
No tin miner-
als or
scheelite.

Quartz, chlo-
rite, altered

magnetite in
gangue.

0.007

Chiefly epidote
crystals, with
less chlorite,
quartz, horn-
blende, and
garnet. Traces
of altered
feldspar. No
tin minerals,
chromite ,
ilmenite,
zircon, or
scheelite.

Quartz,
altered feld-

magnetite in
gangue.

None

Aggregates of
fine minerals
including chlo-
rite, epidote,
quartz, horn-
blende, and
garnet. No

tin minerals

or scheelite.

Quartz and
quartz aggre-

plagioclase spar, dark gates and dark
and epidote, shale frag- shale

with less ments, some fragments.
hornblende chlorite and

and shale epidote.

fragments.

1No eU in all samples.


° 200 400 600

Scale, Miles

C Ce
fay

CANADA

FAIRBANKS

ALASKA

ANCHORAGE

>

« ce)

Ps
S a

Ss t

vy (Oo

So pFLe CCE

see LH pAc Ay

FIGURE 1. - Index Map of Alaska.

Yakataga, a small settlement near the Duktoth River (fig. 5), is the dis-
tribution center for the section of coast extending from Cape Suckling east to
Icy Bay. The airport at Yakataga is maintained and operated by the Federal
Aviation Administration and is large enough for air transport planes. Although
Yakataga has about 30 permanent residents, there are no stores or facilities
to serve the public. A weekly mail service is maintained by air carrier from
Cordova, 150 miles to the west. Charter flights from Cordova can be arranged
with scheduled and nonscheduled carriers at that city. During the field
investigation a small aircraft with wheel landing gear was available at
Yakataga for charter flights along the coast.

The coast in the vicinity of Yakataga is open to the full sweep of the
ocean with no shelter for even a small boat. All landing on this part of the
coast must be made through the surf, except near Cape Yakataga where there is
some protection during calm weather. In the early days large vessels anchored
in the Yakataga roadstead and lightered supplies ashore in the protection of
the reef. Today most heavy freight is shuttled by barge from Cordova and is
landed on the Yakataga beach during calm weather.



TABLE 12. - Auger-hole and shovel sampling results, Yakutat

27

Pounds per cu. yd.

Total Adjusted in-place Gold,
Sample|depth,; Material at measured Magnetic |Nonmagnetic | troy oz.
number} feet | bottom of hole |vol. loose,| fraction fraction per

cu. yd. Iron |TiQ, TiO, cu. yd.
1 6.4 Gravel 10.017 50.5| 3.4 | 723.2 6)
2 10.1 | Sand and water 2.026 8.7] .6 25.7 @)
3 9.9 do. +026 25.9] 1.7 213.8 @)
4 20.1 do. +053 33.6] 2.1 416.1 @)
5 16.5 |Gravel and water 053 27.9] 1.7 218.5 @)
6 19.7 do. +065 15.5] .8 26.4 @)
7 20.0 | Sand and water +057 30.5] 1.6 212.6 @)
8 19.3 do. +067 19.7] 1.1 | ? 49.1 @)
9 9.5 do. 026 100.9] 7.0 455.9 @)
10 4.0 do. -010 69.2] 8.7 | 2 *72.2 eC)
11 16.8 do. 067 27.4) 1.9 | ? 413.9 @)
512 - - 010 306.0]16.1 498.2 @)
13 10.3 | Sand and water +032 28.9] 2.0 216.8 @)
14 19.2 do. +059 49.0| 2.9 | ? *21.4 @)
15 | 22.6 do. 084 14.0] .8 26.4 @)
16 2.2 do. .007 104.9] 7.0 | ? *39.5 @)
617 - - - 11.7] 1.8 11.9 @)
18 12.4 | Sand and water .038 -5| C) 3 0.00052
519 - - 014 33] @) +2 00052
520 - - 014 1] @) 2.2 @)
5o1 - - 014 -1] (7) +2 @)
522 - - .010 1.2] .2 ll (-)
23 9.3 | Sand and water 024 6.0] .5 3.5 @)
24 | 11.9 do. 036 18.1] 1.7 11.6 @)
25 8.5 do. 019 150.3] 6.5 | ? 447.4 @)
26 6.8 do. 019 25.8] 1.1 210.6 00012
27 4.0 do. 014 <9] 1 9 @)
28 7.6 do. .017 8.4] 65 4.7 @C)
29 4.9 do. 012 8.1] .4 4.4 @)
30 6.5 do. 014 32.9] 1.4 213.3 @)
31 16.8 do. 043 22.6] 1.2 211.5 @)
32 6.8 do. 014 53.0] 2.6 433.2 @)
33 8.5 do. 019 11.7] .8 6.8 @)
34 2.0 Silt -005 -8] 4 @) (o)
35 1.0 | Sand and water 003 1.0| (7) 21.3 @)
l1Theoretical volume computed by using 0.3-foot diameter of auger hole.

2Trace eU in
5 None.

“Trace eU in
® Shovel sampl
Span tailings
7 Trace.

table concentrate.

table tailing.
ey
from sample 16.


24

20 _p0 LEGEND
ae” Drill hole. © wo
19 Shovel sample. O o
Cr) \ 2 3 4 \
ee
Scale in miles. &..
| 5
e,.
2 >
3 Pa
° L .
§ “ 2 2
£ fo Cy
x - .
“
Yakutat if
= = Yokut ’ %
ls 9 3
. fr °
< Airp ”
5 =
|= °
34
-)
Approximate width
of beach sands.
path ng age
~~_ Wms a BT mmm lam’ a
Small vessel_anchorage oan? - = 29 28
° J 30
Ocean S 27 eo 32 3I
Cape 25 26 33
_ _ A LAS K A

FIGURE 8. - Yakutat.


RECONNAISSANCE STUDIES OF ALASKAN BEACH SANDS,
EASTERN GULF OF ALASKA!

by

Bruce |. Thomas? and Robert V. Berryhill?

SUMMARY

Reconnaissance studies of beach sands along the eastern part of the Gulf
of Alaska were conducted by the Bureau of Mines to determine if any of these
coastal areas warranted investigations as possible sources of valuable miner-
als. Because of difficult access and limited transportation facilities only
a minimum of sampling, surveying, and camping equipment was utilized to obtain
spot samples from key areas as well as information indicating the location,
size, and character of the deposits. Such data were obtained from beaches
located along approximately 247 miles of the Gulf of Alaska coastline during
parts of the 1957 and 1958 field seasons. A total of 201 3-inch-diameter auger
holes, spaced roughly at 1 mile intervals, were bored by hand methods to depths
ranging from 3 feet to 27 feet; also 33 shovel samples were collected from
selected localities. Samples were reduced to a rough concentrate in the field
by panning; the rough concentrates were shipped to the Bureau of Mines labora-
tory at Juneau for further concentration and for petrographic and chemical
analyses. Particular attention was given to the heavy-mineral content of the
concentrates, although the types and relative amounts of rock-forming minerals
were also determined.

The reconnaissance indicated that, generally, the valuable mineral con-
tent of the beach deposits was too low to be of further interest except in the
vicinity of Yakutat and Lituya Bays where erratic but possibly significant
concentrations of magnetite and/or ilmenite were found. At Yakutat, about 20
miles of beachline extending southeasterly from Ocean Cape, yielded samples
containing from 1 pound to over 300 pounds of iron and from a trace to over
100 pounds of titanium dioxide (Ti0,) per cubic yard of beach material. How-
ever, the higher grade samples represented local concentrations of minor
importance. The general tenor of the Yakutat beach, as indicated by the
airthmetical average of 27 auger-hole samples, is about 35 pounds of iron
and 20.5 pounds of titanium dioxide per cubic yard of beach material. Ilmenite
is the predominant heavy mineral of the beach deposits in the vicinity of
Lituya Bay, but it was found in concentrations only in limited areas near the

1Work on manuscript completed February 1960.
®Mine examination and exploration engineer, Alaska Office of Mineral Resources,
Bureau of Mines, Juneau, Alaska.


ii

12.
13.

15.
16.

17.
18.

19,
20.

21.

TABLES

Bore sampling equipment...
Bulk sampling results, Bering Glacier............
Petrographic examination of nonmagnetic fractions,
Bering Glacier...
Auger-hole and shovel sampling results, Bering
Glacier. cecccccccscccecececescccccccscscesseerseees
Petrographic examination of nonmagnetic fractions,
Yakataga.ccceccccccncccccccncnceccscssccesessees
Auger-hole and shovel sampling results, Yakataga..
Petrographic examination of nonmagnetic fractions,
Tey Bay.ccccssccccccccccscccccccvcecsessvessveseces
Auger-hole and shovel sampling results, Icy Bay......
Petrographic examination of nonmagnetic fractions,
Malaspina....ccccccccccccccccvcccccereesceeeceseens
Auger-hole and shovel sampling results, Malaspina....
Petrographic examination of nonmagnetic fractions,
Yakutat cccsccscccccrcccececscscssesescescsceces
Auger-hole and shovel sampling results, Yakutat
Screen analysis, Yakutat..
Composite sample screen analysis, Yakutat.
Composite sample magnetic and gravity concentration,
Yakutat...
Petrographic examination of nonmagnetic fractions,
AKWE .. eee c cece cece cree eee neseneeecneeesceres
Auger-hole and shovel sampling results, Akwe..
Petrographic examination of nonmagnetic fractions,
Dry Bay--Sea Otter. .seececereccscccccscceecsceceees
Auger-hole and shovel sampling results, Dry Bay--
Sea OLter eee ceeceee ese re sree ceceveccnecevseceens
Petrographic examination of nonmagnetic fractions,
Lituya Bay--La Perouse... .eeeeeeeeseceececeeeceteee
Auger-hole and shovel sampling results, Lituya Bay--
La Perouse sesssccccsscccccresccsversscvvessscesvees

36
37

38


13

Approximate
of beach

width
sands.

———
x —“—
~ — SS
XQ “_
xX —___
Xe \___ BERING GLACIER oe
wa _ yet x
+

GULF
f°) ! 2 3 4

ALASKA

Scale _in_ miles

LEGEND

Drill hole
Shovel sample

FIGURE 3. - Bering Glacier Area Between Kiklukh and Seal Rivers.


Special acknowledgment is extended to Mr. George Nelson of Icy Bay for
his kind and courteous assistance to the field crew while they were working in
that area. The many services and courtesies, as well as helpful suggestions,
given by the fishermen along the coast are greatly appreciated. Detail maps
of the areas studied are modified from maps of the Geological Survey.

LOCATION AND ACCESSIBILITY

The area investigated is approximately 247 miles long and comprises a
narrow strip of coastline along the Gulf of Alaska between the Kiklukh River
(latitude 60° 01' N.; longitude 143° 50' W.) and Icy Point (latitude 58° 25'
N.; longitude 137° 10' W.) (figs. 1 and 2). Icy, Yakutat, and Lituya Bays
provide the only sheltered anchorages along this section of coast.

During favorable weather the area is readily accessible by airplane or by
boat; experienced airplane pilots and boatmen travel the coast with relative
ease. The area is subject to severe storms common to the Gulf of Alaska.

Yakutat, situated on a bay of the same name and about midway along the
Gulf coast, is the largest settlement in the area. It has a permanent popula-
tion of about 300, two general stores, a bulk fuel oil and gasoline dispensing
depot, a post office, and a radio station. Yakutat also has the only pro-
tected harbor that can accommodate large ocean-going vessels. The harbor and
port facilities are adequate for present needs of the community and surround-
ing area. A large airport, about 4 miles from town, can accommodate and
service multimotored aircraft. This facility is operated and maintained by
the Federal Aviation Administration. The U.S. Coast Guard operates an aid-to-
navigation station near the entrance to Yakutat Bay. The Fish and Wildlife
Service maintains a field station at Yakutat during the commercial fishing
season.

Large ocean-going vessels will deliver freight to Yakutat from West Coast
and Alaskan ports when consignments aggregate enough tonnage to justify stop-
ping at the port. During the commercial fishing season, small boats fre-
quently call at Yakutat. Small vessels seek the sanctuary of Yakutat's
protected harbor during severe storms on the Gulf. Large, multimotored air
transports, flying between Anchorage and Juneau, stop twice weekly to dis-
charge mail, passengers, and freight. Several small aircraft are based at
Yakutat to service the coastal area on a nonscheduled basis.

Most of the travel within the coastal region is done in small airplanes
with wheel landing gear. Good landing areas are plentiful along the hard
packed sand beaches. In addition to the beaches, there are small airstrips
which have been constructed at selected locations along the coast (figs. 3,
4, 6, 7, and 8).

In the summer fishermen move along the coast in their small boats. This
means of travel is slow and uncertain because of frequent storms. These
fishermen are exceptionally skilled boatmen, and they are well acquainted
with the coastal waters. They navigate the estuaries of the many large
streams that discharge into the Gulf as well as the treacherous entrance
to Lituya Bay and the dangerous ice floes of Icy Bay.


the old Yakataga dune, by 5 holes.
west bank of the White River and from the old Yakataga dune.

are shown in table 5. Auger-hole and shovel sampling results are shown in

table 6.

Shovel samples were collected from the

19

The results of
petrographic examination made of the nonmagnetic fractions from select samples

Auger-hole sample No. 193, taken at the mouth of the White River, inter-
The sands recovered
from the stringer panned well for gold, but a series of additional auger holes
fanned on a 50 foot radius from No. 193 failed to intercept any extension of

cepted a 1-3/4-inch black sand layer at 3.7 foot depth.

the layer.

TABLE 5. - Petrographic examination of nonmagnetic fractions, Yakataga

[Code:

1 = major constituent, 2 = small amount, 3 = trace,
and - = not detected]

Mineral constituent

Sample number

137

181

184

193

197

nN
f=)

fa

Tlmenite...ccccccececccevees
Chromite.
Zircon...
Rutile......
Garnet....
Limonite.
Staurolite
Augite..
Sphene..
Epidote...
Hypersthene.
Hornblende........
Olivine...
Chlorite
Feldspar
QuartzZ....eee
Shale fragments.........e.+-

tworwne

PNNNIEWI

PRWITWNWWHWWIWWWHWt

INNNN 1 WWWWWWIRITWW

189

INIEwWWIwWINntet

rPwnt

PwWILWWIRPWNNW

INDwrwe

PrwwtHFwnnvofo

NwWwWwwt wet

Pworriwtntld

WN HW twws

TWNWEWWWWIWItHWWIn|d

iN)
POWN ILENE WWI WI WIS



bureau of mines US. BUREA
p | report of investigations 5986 "9. £Ox tiga MINES UBRA,

JUNEAU, ALA

RY

SKA 99802

RECONNAISSANCE STUDIES
OF ALASKAN BEACH SANDS,
EASTERN GULF OF ALASKA

By Bruce I. Thomas and Robert V. Berryhill

UNITED STATES DEPARTMENT OF THE INTERIOR
BUREAU OF MINES

1962




Sandy beaches, which are constantly pounded by the surf, characterize
most of the ocean-fronting tidal zone. The exceptions are short beach sec-
tions comprised of coarse glacial moraine, notably at Malaspina Glacier, the
entrance to Yakutat Bay, Cape Fairweather, and the entrance to Lituya Bay.
The coast is cut by many large glacial streams that issue from the icefields
of the back country. These streams are swift, muddy, subject to large sea-
sonal variations in flow, and have developed pronounced coastal flood plains.
Many smaller clear-water streams flow from the foothill country and cut the
coastline. Long sand spits have developed at the estuaries of these clear-
water streams. The northwesterly trend of the spits indicates the direction
of the onshore ocean currents and major storms.

The coastal plain and the lower slopes of the foothill range are covered
with dense vegetation consisting of many varieties of berry and thorned
bushes, willow, and alder. Much of the coastal plain is covered by moss,
small lakes, and grass-covered bogs. Grass and strawberry plants grow pro-
fusely along the crests of the sand dunes that parallel the coastline. Timber
is generally small and consists mainly of spruce and hemlock. Inland and to
the south of Lituya Bay, spruce grows as large as 8 feet in diameter. Most
animals common to Alaska live in the region.

The Gulf of Alaska is generally quite placid during the summer, but
severe and often lengthy storms occur from early fall to late spring. The
warm gulf stream has a marked affect on the climate of the low coastal fore-
land. The summers are warm, and the winters are relatively mild. At Yakutat
the temperatures range from a summer high of 84° F. to a winter low of minus
15° F. The total annual precipitation varies from 112 inches at Yakataga to
135 inches at Yakutat. The wet month is usually October, and the dry month
is usually June.

HISTORY AND PRODUCTION

Beach sand deposits along the Gulf of Alaska coast have been worked for
their gold content at various times during the past 100 years. There is no
record of these deposits ever being worked for other minerals. The discovery
of ruby-tinted black sand containing gold created a minor gold rush at Yakutat
Bay during the year 1887.° Auriferous sands were found on the western beach
of Khantaak Island, on Logan Beach, and at many points along the shores of
Yakutat Bay. The deposits at Black Sand Island were also mined for their gold
content around the turn of the century. Gold production from the deposits in
the vicinity of Yakutat Bay was carried on in a desultory manner for many
years. Figures are not available, but production is believed to have been
small.

The beaches along the Gulf of Alaska in the vicinity of Lituya Bay were
mined sporadically for their gold content by the Russians until Alaska was
purchased by the United States in 1867. The first work by Americans was done
in 1894; 1896 was reported the best year for mining when 150 to 200 men were

Starr, R. S., and Butler, B. S., The Yakutat Bay Region, Alaska: Geol. Survey
Prof. Paper 64, 1909, pp. 164-170.


| |
cordove |
* : ST. ELIAS RANGE
Kiklukh River | -——)
oe we. |
60° / a
qicy Boy aS 60'
Con? 4 $s Qwera spi
S
6 y va
lp %
7
4 Cope Fairweather
< ag tituya Bay
° 40 80 120 N S ley
Scale in miles. kr
°
58 4
144° 142° 140°

FIGURE 2. - Map of the Area Studied.

There are only a few miles of graveled roads along the eastern Gulf
coast. Individual automotive operations are limited by the large streams
entering the Gulf. Travel by car or truck is limited to those areas in and
adjacent to Yakutat and Cape Yakataga, and to some areas between the larger
streams and rivers.

PHYSICAL FEATURES AND CLIMATE

The St. Elias Range, with its many snow-covered peaks 8,000 to 18,008
feet in altitude, is the most prominent feature of the eastern Gulf of Alaska.
Amid the peaks of the mountain range is a vast icefield which feeds the huge
glaciers that extend almost to the coast. Along the coastal flank of the
precipitous range are relatively steep fronted foothills from 3,000 to 4,000
feet high. The foothills are separated from the Gulf of Alaska by a coastal
plain which varies in width from one-fourth mile to 15 miles.

The coastline is relatively uniform except where it is broken by Icy,
Yakutat, and Lituya Bays. These bays cut back into the relatively steep
fronted foothills where the lobes of glaciers reach the margins of the bays'
inland waters.


38

TABLE 21. - Auger-hole and shovel sampling results,

Lituya Bay--La Perouse

Adjusted Pounds per cu. yd. in-place
Sample Total Material at measured Magnetic Nonmagnetic
number depth, bottom of hole | vol. loose, fraction fraction
feet cu. yd. Iron TiO, TiO,
80 8.1 Gravel 0.017 4.6 0.4 33.4
81 7.0 do. -017 4.3 4 120.4
82 12.0 Fine gravel 038 6 @) 33.3
83 13.5 Loose sand 040 9 el 36.0
84 8.0 Gravel +027 1.1 @) 31.0
485 - - 014 5.3 4 6.7
86 4.0 Gravel -010 16.5 1.9 18.2
87 9.4 do. +024 5.4 9 8 59,6
88 8.3 do. 029 1.7 ol 6.1
89 9.2 do. 026 8 @) 4.3
90 6.3 do. 019 1.0 @) 5.1
91 6.1 do. 014 9.6 -6 651.6
92 3.1 do. -008 3 eC) 2.6
493 - - 014 2 @) 6 71.0
494 - - 014 4 @) 3.1
107 12.0 Gravel 031 1.8 @) 7.9
108 8.2 do. 019 5.4 +2 19.7
109 6.4 do. -016 +6 @) 4.0
110 5.2 Boulders 014 6 @) 7.5
4112 - - 014 +2 @) 31.4
113 14.0 Sand +034 6.5 4 38.1
114 5.7 Coarse gravel -012 6.0 4 3 633.4
115 6.6 do. 014 9 @) 7.2
116 2.9 do. 007 +2 @) 67
117 6 Bedrock -002 el @) 5
118 4.6 Boulders .010 al @) 6 3
119 3.5 Gravel 008 4.3 @) 343.7
120 3.4 do. -008 1.1 @) 1.3
121 6.0 do. 014 12 @) 8
122 2.6 do. .007 2.6 4 35.6
4123 - - 005, 4.6 +6 89.5
4124 - - .010 3 @) 3.3
4126 - - +010 @) ©) 7

1Trace Au.

2 Trace.

3Trace eU in table tailing.

*Shovel sample.

50.0103 troy oz. Au per cubic yard.
®tTrace eU in table concentrate.
70.00078 troy oz. Au per cubic yard.
®None.


26

Yakutat

The beach deposits in the vicinity of Yakutat (fig. 8) are readily acces-
sible by auto, rail, and air transportation. About 11 miles of graveled roads
serve the requirements of the community, but additional roads are being built
to provide access for oil exploration. An unimproved road along the beach
provides ready access to the deposits between Ocean Cape and Lost Creek. Those
deposits between the Ahrnklin River and the Dangerous River are accessible by
small aircraft landing on the beach or on a small aircraft strip, or by rail
to the Situk River and then by small boat up the tidal estuary of the Ahrnklin
River. The railroad, built years ago, is still used to haul fish to Yakutat.

Investigations in the Yakutat area consisted of 29 auger-hole samples and
1 shovel sample (fig. 8). Sandy beaches on Khantaak Island and at Logan Bluff
{not shown, about 12 miles north of Khantaak Island) were examined; four
shovel samples, two from each locality (samples 19 to 22 inclusive), were
collected from these beaches. The minerals in the nonmagnetic fractions from
select samples are listed in table 11. Auger-hole and shovel sampling results
are summarized in table 12.

TABLE 11. - Petrographic examination of nonmagnetic fractions, Yakutat

[CGode: 1 = major constituent, 2 = small amount, 3 = trace,

and - = not detected]
Sample number

Mineral constituent 8 12 15 25 30
Scheelite.. see seeeee 3 - 3 - -
Pyrite - 3 - - -
Tlmenite 2 1 2 2 2
Zircon.. 3 3 3 3 3
Rutile 3 3 3 3 3
Garnet.. 1 2 1 1 1
Pyroxene 1 1 1 2 2
Topaz. 3 3 3 3 3
Sphene... 2 3 2 3 3
Epidote.... 2 2 2 1 1
Hornblende. 1 1 1 1 1
Apatite.... 3 - 3 - -
Chlorite.... 3 - 3 - -
Feldspar...... 3 3 3 - -
Calcite....... 3 3 3 - -
Quartz. .seeeeeesseseeeeee 3 3 3 3 3



25

TABLE 9. - Petrographic examination of nonmagnetic fractions, Malaspina

[Code: 1 = major constituent, 2 = small amount, 3 = trace,

and - = not detected]

Sample number

Mineral constituent

un

a
00

172

174

an
io
ia
oo

PYLLte reece cece eee e reece erence ceeseeeveees

Zircon,
Rutile....
Garnet..
Limonite
Augite.
Sphene.
Epidote.

Hornblende
Zoisite.
Olivine.
Feldspar
Calcite...
Quartz......
Shale fragments......----eeeee eee ee eter eee?

PRN TWWWONWWWYD

tRore

PPNRNWWWHOW I WLWID

trore

PwWNwWwWwWw

PHWHEWIRWwWE

1WNWWWW

RPrPWN!WNwuwst

PWN wWwWwwl
PORrwWwWwuwl

PPwWN 1! wWnwuwt
INN ENWIERwWw?

TABLE 10. - Auger-hole and shovel sampling results, Malaspina

Adjusted Pounds per cu. yd. in-place

Sample | Total Material at measured Magnetic Nonmagnetic

number | depth, bottom of hole | vol. loose, fraction fraction
feet cu. yd. Iron TiO, TiO,
165 14.3 Sand and water 0.043 0.2 @) 0.5
166 2.3 Coarse gravel -007 +2 GC) 3
167 10.3 Loose sand +026 5.0 0.7 24.7
168 4.4 Gravel +014 +6 1 21.2
169 9.1 Coarse gravel 024 3 ¢) 4
2170 - - +014 7 +2 +6
3172 - - 014 6 a 1.3
173 4.2 Gravel +012 3 ol 4
174 10.2 do. +034 5 al 4.8
175 9.9 Coarse gravel .029 5 eC) 8
176 5.2 Gravel +012 1.3 2 22.0
177 8.2 Coarse gravel 022 1.9 3 42.3
178 10.6 do. 026 2.7 4 ®2.5
179 3.6 Gravel .007 5 @) 28
180 4.2 Coarse gravel 014 4 @) 5

iTrace.

2trace Au.

Shovel sample.

“Trace eU in table concentrate.
50.0034 troy oz. of Au per cubic yard.


mouth of Eagle Creek, between Lituya Bay and Steelhead Creek, and near the
outlet of Crillon Lake. Auger-hole samples from these areas indicated a
titanium dioxide content (as ilmenite) of 20 to 52 pounds per cubic yard.
Because of equipment limitations, samples could not be obtained from deposits
of coarse or unconsolidated gravel or from below the water table.

The principal heavy minerals occurring in most of the beach sand concen-
trates are magnetite, garnet, and ilmenite, with lesser to trace amounts of
rutile, zircon, chromite, and gold. Traces of platinum have been reported
from sands adjacent to Cape Yakataga and Lituya Bay, but none were detected
during this study. All samples were tested for radioactivity; only trace
amounts were detected.

INTRODUCTION

Black sands are known to occur in unconsolidated marine deposits at many
localities along the 6,640 miles of Alaska's coastline. The easily accessible
beaches have long been prospected for gold and in some localities, as at Nome
on the Seward Peninsula, have been enormously productive. Prospecting for
other minerals in these deposits has been either cursory or entirely neg-
lected. If no indications of gold in paying quantities were found on prelimi-
nary examination, the beach deposit received little or no further attention.
Some less accessible areas, such as those along the eastern coast of the Gulf
of Alaska, have been recognized as containing potentially commercial black
sand deposits. Some gold has been recovered from these deposits, notably in
the vicinities of Cape Yakataga and Lituya Bay. However, few attempts have
been made to evaluate the accessory heavy-mineral content.

During the summer of 1957 and May of 1958 the Bureau of Mines conducted
preliminary studies to indicate the heavy-mineral content of the beach sands
along the eastern shoreline of the Gulf of Alaska. The purpose of the study
was to spot-sample key areas with a minimum amount of equipment to determine
if detailed studies would be warranted. Physical and chemical studies were
made in the laboratory on field samples.

The geological formations in the region behind the Gulf coast are con-
sidered favorable host rocks for mineral deposits. The extremely rugged
topography, many live glaciers, turbulent streams, and severe storms make
entry into this back region difficult and sometimes hazardous. These condi-
tions, however, are favorable to rapid erosion of mineral deposits in the
glaciated areas and for concentration of minerals along the comparatively
narrow, low lying beaches. Reconnaissance studies of the heavy-mineral con-
tent of these beaches provides an indication of the character and of mineral-
ization in the adjacent mountainous regions.

ACKNOWLEDGMENTS

Fieldwork along the Gulf coast was greatly aided by use of Federal Avia-
tion Administration facilities at Yakataga and Yakutat. Federal Fish and
Wildlife Service accommodations and transportation facilities at and near
Yakutat contributed much to the field accomplishments.


16

TABLE 4. - Auger-hole and shovel sampling results, Bering Glacier

Adjusted
Sample | Total | Material at measured Pan concentrate! ? Pounds iron
number |depth,| bottom of vol. loose,| Total weight,| Percent | per cu. yd.
feet hole cu. yd. _grams iron in place
204 18.2 |Sand and water 0.044 200 4.8 0.5
205 18.2 do. +047 211 2.9 3
5206 - - 014 127 3.1 6
207 20.3 | Sand and water +053 147 5.1 3
208 11.0 do. +025 148 2.9 4
209 9.4 do. +026 150 4.0 5
210 13.2 do. +035 159 4.5 4
211 18.3 do. +041 167 4.8 4
212 7.3 do. -017 163 5.1 1.1
$213 - - 014 122 3.6 6
214 20.6 Sand +049 487 2.8 +6
215 18.3 | Sand and water +019 175 2.5 5
216 20.1 do. +050 464 2.6 5
217 16.9 do. +035 268 2.7 5
219 8.3 Gravel +024 315 4.2 1.2
220 20.5 | Sand and water -048 464 4.9 1.0
221 32.3 do. +081 989 4.7 1.3
222 4.2 Gravel -014 205 4.0 1.3
223 5.9 | Sand and water 014 242 4.1 1.5
224 11.0 do. +024 255 4.2 1.0
225 12.4 do, +032 201 4.4 +6
226 13.9 Gravel -035 290 4.6 8
227 16.4 | Sand and water +045 292 4.2 6
228 9.8 do. +026 192 4.3 7
229 5.0 Log +012 138 4.5 1.1
230 9.0 | Sand and water +022 192 3.7 7
231 7.9 Log -020 200 3.8 8
8234 - - +014 115 3.3 +6
235 3.7 Mud +005 81 3.1 11

leU percent <0.001 in all samples.
2No Au noted in any pan concentrate.
3 Shovel sample.

Yakataga

The area shown in figure 5 may be traversed in a specially equipped,
four-wheel-drive, balloon-tired truck, but during the investigation a truck
was not available, and the area was traveled on foot. The beaches shown east
of Cape Yakataga are generally composed of loose sand and gravel that is not
suitable for bush plane landings. During periods of high water the glacially
fed White River is impassible, and access to that part of the coast east of
the White River must be on foot or by truck, from Icy Bay (fig. 6).

Twenty-nine auger samples were taken between the Duktoth River and Munday
Creek in the Yakataga area. The shore zone was sampled by 24 auger holes, and


33

TABLE 17. - Auger-hole and shovel sampling results, Akwe

Adjusted Pounds per cu. yd. in-place
Sample Total Material at measured Magnetic Nonmagnetic
number depth, | bottom of hole | vol. loose, fraction fraction!
feet cu. yd. Iron TiO, TiO,
52 8.2 Sand and water 0.019 1.3 @) 30.6
53 9.9 do. 024 1.4 @) 8.7
54 20.2 Compact sand 062 3.4 0.1 31.2
55 16.1 Sand and water +043 2.4 1.0 8.9
56 14.4 do. 2043 1.8 1.0 847
57 9.9 do. 026 1.8 el 847
58 11.5 do. 031 2.3 al 31.0
59 8.5 Driftwood +022 5.6 3 32.1
64 5.0 Sand and water 012 10.5 8 34.5
65 3.4 do. 007 6.2 4 3.2
66 7.3 do. 017 5.1 3 31.7
67 12.0 do. -031 5.0 3 3 42.0
68 13.8 do. +034 6.0 3 32.0
69 15.4 do. 038 3.5 +2 41.1
70 6.1 do. 014 3.5 22 1.3
71 6.5 do. 012 2.5 al 1.2
72 6.1 do. 014 7.8 3 $3.2
73 6.1 do. 2014 4.9 +2 3.2
74 7.5 do. 019 8.4 4 33.2
75 10.0 do. +024 6.7 4 42.7
76 6.2 do. 014 1.3 @) 36
77 16. Compact sand -036 6 @) 3
1No Au in all samples.
? Trace.

3Trace eU in table concentrate.
“Trace eU in table tailing.

Dry Bay--Sea Otter

Access to the Dry Bay--Sea Otter area (figs. 10 and 11) is by small air-
plane. With the exception of coarse terminal moraine material below the Grand
Plateau Glacier and at Cape Fairweather, the beaches are sandy and generally
suitable for small plane landings. Several small airstrips have been con-
structed in the area. Four-wheel-drive trucks traverse unimproved roads which
provide a means for hauling salmon caught in the Akwe (fig. 9), East, and Dohn
Rivers to the mouth of the Alsek. On the Alsek the salmon are transferred to
fish packers that anchor in the protection of the river estuary.

A total of 31 samples were recovered from auger holes located in the area
shown (figs. 10 and 11). Four shovel samples were also collected. Petro-
graphic examinations of nonmagnetic fractions of select samples are shown in
table 18. Table 19 is a summary of the auger-hole and shovel sampling results.


34

width
sands

Approximate
of beach

G
UL,
OF
LEGEND
Drill hole.
Shovel sample.
fe) | 2 3 4

es}

Scale in miles.

FIGURE 11. - Sea Otter.


22

TABLE 8. - Auger-hole and shovel sampling results, Icy Bay

Adjusted Pounds per cu. yd. in-place
Sample Total Material at measured Magnetic Nonmagnetic
number depth, bottom of hole vol. loose, fraction fraction
feet cu. yd. Iron Tio, TiO,
128 2.2 Coarse gravel 0.007 0.5 O.1 0.6
129 4.0 do. .010 ) 2 1.1
130 3.1 do. -010 4 al 3
131 6.2 Gravel +019 4 1 +6
132 3.7 Coarse gravel +010 +2 @) 3
142 3.6 Sand and water .007 2 @) 4
143 6.4 Coarse gravel +014 5.4 1.0 26.4
144 7.3 do. +022 al GC) 218
145 2.4 do. 007 1.5 4 23.4
146 2.2 Loose sand O11 2.1 3 co)
147 10.9 Sand and water +029 +6 +2 245
148 7.4 Coarse gravel .019 3 @) 4
149 5.6 do. 014 4 el 2 805
150 3.1 Sand and water +005 +8 +2 21.8
#151 - - +019 1.8 4 $1.8
4152 - - 014 +2 @) 284
153 3.2 Gravel .007 wl eC) 2.2
154 2.3 Shale +005 8 al $5.2
155 2.4 do. +005 1.4 +2 71.5
“156 - - 024 3.9 4 22.6
4157 - - 2024 6.0 +6 2 54.8
#158 - - +024 4.6 5 24.7
*158A - - +010 1.7 3 1.8
#159 - - +029 5.7 “5 2 841
*159A - - -010 3.0 4 3.0
160 - - +024 6.2 7 25.1
161 5.9 Loose sand -014 1.0 al 1.3
162 8.3 Sand and water 024 5 @) 25
163 6.3 Shale .017 2.4 2 2.1
164 8.2 Gravel and water +022 9 «1 21
171 4.6 Coarse gravel +014 2 C) 3
1Trace.
2Trace eU in table concentrate.
Strace Au.
* Shovel sample.
®Trace eU in table tailing.
Malaspina

Access to the coastline along the Malaspina foreland (fig. 7) is by small bush
Even during the calm summer weather,

plane landing on the hard packed beaches.
heavy swells and pounding surfs generally prohibit any onshore landings.

no inhabitants in the area.

There are

The sandy beaches along the Malaspina foreland were sampled by 13 auger holes

and 2 shovel samples.
similar to the sands along beaches to the west.

sand is small as shown by the summary of sampling results (table 10).
gold were detected only in a few samples as shown by footnote references.

Petrographic examinations (table 9) show the sands to be
The heavy-mineral content of the
Uranium and


This publication has been cataloged as follows:

Thomas, Bruce Ira

Reconnaissance studies of Alaskan beach sands, eastern
Gulf of Alaska, by Bruce I. Thomas and Robert V. Berryhill.
[Washington] U.S. Dept. of the Interior, Bureau of Mines [1962]

ii, 38 p. illus., tables. 27 cm. (U.S. Bureau of Mines. Report
of investigations, 5986)

1. Sand. I. Berryhill, Robert V joint author. Il. Title. Ill.
Title: Alaskan beach sands. (Series)

TN23.U7 no. 5986 622.06173

U. S. Dept. of the Int. Library





39

“Aciep \ 126

——— — — a) . 7 =, —
cai”, 4 AN LiTuy, 5 A441) ie = ak i YF ]

SX
\
\
\
wrem
Ua yh
Echo Creek
Creek

One mile of wm 2 yy
shoreline omitted. y o &
~~~ 2% 4-2---+. ° C2)
° ° @ 7 wy
85 86 8 BS ia - cy
8s ° ~~? TSS *
90 >= Py
8 ° 91 94
8 9S Cc
80 -
as 92
$ ~
Y) Qi: °
» 93BNN >
ce ‘ £
G ‘i > N
U : ~
Lf saJev ~ eee
LEGEND or
Drill hole (-) CG jy fF Ng BEB CE ----- 5
Shovel sample ©
s
te) | 2 3 4 3
Scale in miles. °
> OF ALASKA
26° &
a.
Ns Y
- — _ j

FIGURE 12. - Lituya Bay.


and Lituya Bays have caused physical changes in the glaciers and shorelines;
the effects of waves, avalanches, and faulting are evident. Ground subsidence
and waves caused by earthquakes have claimed lives in both Lituya and Yakutat
Bays; a devastating earthquake in July 1958 took the lives of three people ‘on
Khantaak Island, Yakutat Bay, and two people in Lituya Bay.

WORK BY THE BUREAU OF MINES

Field Investigations

The objectives of the Bureau of Mines work, along 247 miles of narrow
coastline in the eastern Gulf of Alaska, were to determine the heavy-mineral
constituents of the sandy beaches and to ascertain which areas have the heavi-
est concentrations of these minerals. The work consisted of spot sampling the
beach sands with auger borings or shovel samples; the samples were pan-
concentrated in the field, then analyzed physically and chemically in the
laboratory.

The Bureau of Mines program began May 5, 1957, recessed from September 3,
1957, to May 6, 1958, and was completed on May 28, 1958. During the field
investigations 201 auger holes were drilled by hand; total footage drilled was
1,732 feet. Test holes were spaced at intervals of 1 mile or less along the
sand beaches; a total of 33 shovel samples were collected to supplement the
auger test holes. Much of the travel between drill holes was on foot, requir-
ing back-packing of sampling equipment and samples.

Laboratory Investigations

Beach-sand samples submitted to the laboratory for physical and chemical
analyses were treated as shown on the following flowsheet.

The samples were weighed
upon receipt at the laboratory.
The screen, table, and magnetic
separation products were
Saved weighed; iron, TiO,, and eU

(radiometric uranium equivalent)
analyses were completed, and
the results were recorded in
percent. The weights of metals
in the sample products were com-
eU% puted from these data. Petro-

Pulp saved graphic examinations were made
Nonmagne!
fraction

ie
jon

separati

of the nonmagnetic fraction of
approximately every fifth sam-
ple to determine its mineral

constituents. Several samples
were too small for table treat-

f l ical I I l ment, and others contained
Acid soluble Ti0g% [ev% ] To Ti02% Gold Petro hi 2 toe .
iron % 2 2 oz/ton| | examination| insufficient light material to

NOTE: eU= Radiometric uranium equivalent, justify table concentration.



11

panning end point; the desired end point was 100-percent heavy-mineral recov-
ery. Laboratory results and field observations indicated that the percentage
of heavy-mineral recovery decreased as total heavy-mineral content increased.
Field checks indicated almost 100 percent recovery in samples containing few
heavy minerals.

Calculation of Sampling Results

The auger holes were not of uniform diameter because of sloughing from
the walls. Therefore, without refined methods of core control, a volume com-
puted by using the diameter of the auger and depth of hole was considered
unsatisfactory. The measured volume loose (pan count times volume per pan)
of the boring from each hole was used instead to determine the approximate
in-place volume. Field measurements indicated that beach sand had a swell
factor of about 1.48; the in-place volume was computed using this swell fac-
tor. Contained metals were calculated in pounds per in-place cubic yard.

Areas Investigated

Bering Glacier

Access to the beach deposits between Cape Suckling and the Duktoth River
is gained by use of a small bush plane; landings are made along the beach.
The rivers dissecting the area, notably the Seal, the Tsiu (not shown), and the
Kaliakh, are glacial, deep, and have tidal estuaries. Traveling this section of
coast on foot would necessitate fording these rivers, which would be hazardous
during the summer and impossible during most of the remainder of the year.

Twenty-nine auger-hole samples and three shovel samples were taken from
the beaches between the Kiklukh and Seal Rivers and between the Tsivat and
Kaliakh Rivers in the Bering Glacier area (figs. 3 and 4). The lack of heavy
minerals in these sands indicated detailed physical and chemical analysis of
all samples would not be justified; three representative bulk samples (total
hole recovery) were treated according to the flowsheet previously shown. A
summary of the bulk sample results is shown in table 2. The pan concentrates
of 26 holes and 3 shovel samples were analyzed for acid soluble iron, tested
for eU, and examined petrographically. A summary of petrographic examinations
of nonmagnetic fractions is shown in table 3; auger-hole and shovel sampling
results are shown in table 4.


RECONNAISSANCE STUDIES
OF ALASKAN BEACH SANDS,
EASTERN GULF OF ALASKA

By Bruce I. Thomas and Robert V. Berryhill

» x» » © 4 &% 4 » »& » » report of investigations 5986

UNITED STATES DEPARTMENT OF THE INTERIOR
Stewart L. Udall, Secretary

BUREAU OF MINES
Marling J. Ankeny, Director


32

TM.
A~ aS
Airstrip Mo >
ae ~_~~_ __ —_
io — —
fon TM~- —_
~ Y am—~ TM — —_—_————
= KP AND ~~,
= . . HN TM_ La Tr _—_—_
Approximate width ‘ TM~ ~~ Ey,
toTMN G L a —_
of beach sonds.—y re N UMS OA Cig, —
eect ~ - “PT "ty “SN _ ~~ -F_ a
—$ e487 anaes
50 49 4
9 st
K A
ALA S
LEGEND
Drill hole. (=)
Shovel sample. ©O
°. ! 2 3
3° Scale in miles.
5 RV
oe
&
_— >
—— = - __ _
FIGURE 10. - Dry Bay.


20

TABLE 6. - Auger-hole and shovel sampling results, Yakataga

Pounds per cu. yd. Gold,
Total Adjusted in-place troy oz.
Sample | depth, Material at measured Magnetic | Nonmagnetic per
number | feet bottom of hole | vol. loose,| fraction | fraction cu. yd.
cu. yd. Tron |Ti0, TiO,
133 6.8 Gravel 0.019 0.5/0.2 0.3 0.0027
134 4.2 silt +008 +3] .1 +6 @)
135 9.9 Gravel +024 +3] 41 24 (oo)
136 9.0 do. +019 -1/@) 21 C)
137 4.2 Coarse gravel .010 -2/A) 6 eC)
138 2.8 do. 007 -2/¢) 7 @)
139 2.0 | Sand and water .005 8] .2 1.7 @)
140 6.0 do. +018 1.0] .2 22.0 e)
141 3.0 Coarse gravel .007 3.3] .7 4.8 @)
181 4.2 Gravel 014 -3/¢) 7 C)
182 3.3 do, 014 +31C) 2.5 ¢)
183 2.9 do. -010 1.2] .3 2 31.5 +0040
184 | 11.4 | Coarse gravel 026 2.6| .9 22.6 @)
185 10.9 Clay +030 +8] 43 1.0 +0040
186 7.3 Coarse gravel .019 «5] 22 4 @C)
187 9.7 Silt +024 +6| .2 2 6 +0031
188 3.8 Gravel +010 1.3] .3 21.0 C)
189 8.9 | Sand and water -020 +210) 4 @)
#190 - - +014 +210) 1.3 C)
191 6.2 | Sand and water 014 -2/@) 3 -0021
192 7.3 Silt 017 C)1@) al @)
193 9.9 | Gravel and water 032 1.0] .3 27 +0596
4194 - - .010 @)/@) 21 C)
195 5.3 Gravel +014 +21) 28.2 +0031
196 7.0 Silt +017 23) 21 25 -0013
197 11.3 | Gravel and water +029 1.7] .4 21.7 +0036
198 6.0 Coarse gravel 014 6.1/1.8 7.3 0174
199 7.1 Rock -018 2.0] .6 2.3 +0056
200 1.5 Silt +025 1.4) .4 1.4 -0039
201 | 11.0 | Gravel and water 029 2.2) .7 22.5 Cc)
202 10.4 do. +024 6.2}1.8 25.6 ©)
1 Trace.

® Trace eU in table concentrate.
3tTrace eU in table tailing.

*Shovel sample.




28

Samples 16 and 17 are respectively the pan concentrate and pan tails of
the same auger hole borings. Laboratory analysis indicated the pan concentra~
tion recovered about 90 percent of the total acid-soluble iron and about 77
percent of the total Ti0,. Screen analysis of samples 12 and 16 (table 13)
indicated a marked concentration of titanium mineral in the finer sizes, the
mineral being a finely interlocked magnetite-ilmenite. Sample 12 is repre-
sentative of a 0.1-foot aeolian concentration along the crest of the ocean-
fronting dune. Localized black sand veneers from 0.1 to 0.2 foot thick are
typical along the coast shown. Sample 25 is representative of sands that have
been river concentrated in a small area at the mouth of the Situk River.

TABLE 13. - Screen analysis, Yakutat

Magnetic separation
Product Weight Magnetic, Nonmagnetic
(mesh) Grams Percent weight Weight Assay, percent
percent percent eu TiO, l 2x0,
Sample 12°
+35 0.0 - - - - - -
-35, +48 3.4 0.30 17.65 82.35
-48, +65 76.9 6.87 5.20 94.80 } 0.001 8.5 | 0.08
-65, +100 751.1 67.11 33.82 66.18 0 18.5 8
-100, +200 287.5 25.69 80.90 19.10 }
-200 3 203 50.00 50.00 2002 | 29-5 | 3.2
Sample 16 (panned concentrate)
+35 2.1 0.49 33.33 66.67 }
-35, +48 16.0 3071 9.37 90.63 9.002 1.9 | 0.06
-48, +65 110.0 25.50 6.18 93.82 0003 3.9 +02
-65, +100 210.5 48.81 20.90 79.10 +003 12.5 +08
-100, +200 92.4 21.42 70.78 29.22 }
-200 3 107 16.67 83.33 2012 | 25.5 | 2.2
Sample 17 (panned tail)
+35 39.0 3.73 - 100.00 te) 0.7 0
-35, +48 369.3 35.30 0.08 99.92 0.003 -8 | 0
-48, +65 467.5 44.68 334 99.66 +002 1.5 | 0
-65, +100 158.7 15.17 2.58 97.42 002 3.7 @)
~200 5 3200 aor 1.06 } 33.33 66.67 -004 | 12.0] @)
1Head assay 12.5 percent TiO, , 0.04 percent ZrO, , no eU.
2 Trace.

Preliminary mineral dressing studies were made of an unweighted composite
of table concentrates from 17 samples taken between Ocean Cape and Lost Creek
(samples 1 through 17). The composite represented a bulk heavy-mineral concen-
trate such as might be obtained from a dredge or stationary washing plant. The
material tested consisted principally of ilmenite, titaniferous magnetite, and
spessartite. Some ferromagnesian minerals were present as well as small
amounts of calcite, quartz, tourmaline, apatite, and altered feldspar. The


37

Lituya Bay--La Perouse

The beaches between Grand Plateau and La Perouse Glaciers are accessible
by small plane from Yakutat or Juneau. These beaches may also be reached in a
small boat by entering Lituya Bay during calm weather at slack tide. The
sheltered deep water of Lituya Bay is also suitable for landing with
amphibious-type or pontoon-equipped aircraft. From Lituya Bay the beaches
may be reached by traveling the coast on foot.

The beach area shown (figs. 12 and 13) was sampled with 26 auger holes
and 11 shovel samples. The shovel samples collected at the head of Lituya Bay
were composed of sand from glacier moraines. The mineral constituents of non-
magnetic fractions from select samples are shown in table 20. The results of
auger-hole and shovel sampling are summarized in table 21.

A suite of specimens was collected from the moraine on La Perouse Glacier.
Samples 106 and 111 were identified as quartz diorite, altered gabbro, schist,
and altered diorite; a trace of chromium was present in the altered diorite.
Samples 125 and 127 were specimens collected from the moraines of Lituya and
Crillon Glaciers; both were diorite.

TABLE 20. - Petrographic examination of nonmagnetic fractions,
Lituya Bay--La Perouse

{Code: 1 = major constituent, 2 = small amount, 3 = trace,
and - = not detected]

Sample number
86 | 89 | 94

fond
joo
an
[-)
i
oO

Mineral constituent 8
Tlmenite......cceseee cece cece ccnececeeces
Zircon
Garnet..
Staurolite....
Augite..
Epidote...
Hypersthene
Hornblende.

PORRPNR IER IN|
INNKFWUNINWE
TWONFWNWH

'
TNPRP ter wtnlo

NNT RPNENNNE ED
WW toe ret we wl

'
'
INP RwWeEN



\ - ° ; —
\ —_— “ are >
7 \ ‘
8 So — ~~ oO LEGEND
ae \ Drill hole. °e
we So ee — — Shovel sample. oO
%° ~s, ° 60 —
2) > . yee — ee ° ! 2 3 4
=~ ee —~_ Scale in miles. a os
N TM —
oe
a
=
> is

Approximate width

of beach sands.

170 > 25 8-2 “gg

FIGURE 7. - Malaspina.


at work along the beach. Gold-bearing sands occur from 2 to 16 miles north-
west and 4 to 9 miles southeast of the entrance to Lituya Bay. An estimated
$75,000 in gold was recovered by the year 1917, but there is no record of any
substantial production since then.*

Gold was first discovered in the beach sands at Yakataga in 1897 or 1898.
Auriferous sands extend for a distance of about 18 miles along the coast from
a point 1 mile west to a point approximately one-quarter of a mile east of
Yakataga Reef. An estimated $320,000 in gold had been produced through 1930.
Mining has been carried on intermittently since 1930, but no production fig-
ures are available. © During the summers of 1955 and 1956, considerable
attention was directed toward the radioactive mineral potential of the beach
deposits near Yakataga. Several prospectors as well as two private concerns
conducted bore-hole sampling programs along the deposits fronting the tidal
zone.

During the summer of 1957, a private concern was actively engaged in
investigating the magnetite content of beach sands near Yakutat and Lituya
Bays. Work consisted of churn-drill hole sampling of deposits near Black Sand
Island and on a section of beach about 4 miles northwest of Lituya Bay.

PROPERTY AND OWNERSHIP

Beach deposits in the Yakataga, Yakutat, and Lituya Bay areas are only
partially covered by placer claims; no attempt was made by the authors to
accurately determine claim boundaries or ownership. No known patented placer-
mining claims are held in any of these areas.

In the vicinity of Cape Yakataga, 73 placer claims, each covering about
20 acres, are held and maintained by several owners. The descriptions of
these claims and the names of the claimants are on file in the recording office
at Cordova.

Beach deposits in the Yakutat area are covered by 76 placer claims on
Black Sand Island and along the estuary and lower stream course of the
Ahrnklin River. In the Lituya Bay area, the beach deposits extending from
the entrance of Lituya Bay westward to the Cape Fairweather lobe of Grand
Plateau Glacier are covered by 160 standard placer claims. Beach deposits
between the entrance to Lituya Bay and La Perouse Glacier are held with 14
placer claims. The descriptions of mining claims held in the Yakutat and
Lituya Bay areas and the names of the claimants are on file in the recording
office at Juneau.

4Mertie, J. B., Jr., Notes on the Geography and Geology of Lituya Bay, Alaska:
Geol. Survey Bull. 836, 1933, pp. 117-135.

®Maddren, A. G., Mineral Deposits of the Yakataga District: Geol. Survey
Bull. 592, 1913, pp. 119-153.

Ssmith, P. S., Past Placer-Gold Production From Alaska: Geol. Survey Bull.
857, 1933, pp. 93-98.


10

Mineral-dressing tests were conducted on samples taken in the Yakutat
area. Representative cuts of the original samples were screen-sized. Magnet-
ite was removed from each sized fraction with a hand magnet; the nonmagnetic
portions were subjected to radiometric and chemical analyses.

Sampling Methods and Equipment

Frequent moves along 247 miles of coast required the selection of light
and easily portable sampling equipment that would extract fairly representa-
tive samples from semicompacted beach sands. At most localities it was neces-
sary to back-pack equipment between boring sites, but moves from area to area
were usually made by small airplane.

Before the investigation along the Gulf of Alaska, preliminary tests were
made along readily accessible beaches of the Kenai Peninsula, Alaska, with
various types of hand-operated soil-testing equipment; an Iwan auger was
selected as best suited for the spot-sampling program. Holes to 27 feet in
depth were attained with a 3-inch Iwan auger in semicompacted beach sands.
With caution, a fairly uniform open hole (without casing) could be bored and
sampled to this depth in 1% hours. The Iwan auger is not satisfactory for use
in dry, loose, or water-saturated sands or gravel, but outside these limita-
tions, samples usually can be obtained that will be roughly representative of
the beach area. A light, compact, and readily portable bore sampling kit,
consisting of the items listed in table 1, was used during the field
investigation.

TABLE 1. - Bore sampling equipment

Quantity Size Description
1 3-inch Iwan auger.
6 l-inch x 5-foot | Aluminum pipe with coupling.
5 l-inch Pipe coupling.
2 14-inch Pipe wrench.
1 1-inch Pipe die nut.
1 - Tee-handle for auger.
3 16-inch Gold pan.
1 No. 2 Wash tub, galvanized.

Bore-hole records show the location, depth of hole, and material pene-
trated. Most of the holes were bottomed in water-saturated sands or loose
gravel. The boring or bulk sample from each hole was measured loose in a gold
pan, then reduced to a rough concentrate by panning. The rough concentrate
was shipped to the Bureau of Mines laboratory at Juneau for additional concen-
tration and analyses.

A few shovel samples were taken from natural concentrations of black
sands. They were not concentrated in the field but were shipped as bulk
samples to the laboratory.

The percentage of heavy mineral recovered in the pan concentrate was
determined by panning efficiency and by judgment in selecting the satisfactory