UNITED STATES DEPARTMENT OF THE INTERIOR f. BULLETIN 1058
GEOLOGICAL SURVEY r] s PLATE 33

132°%40° yf 132"20° EXPLANATION

55%5"

Recent

Beach deposits
In large part wave-reworked glacial deposits

Qal

Post-Eocene(?) Pleistocene(?)

Alluvium and reworked glacial deposits

Glacial deposits
Includes till and outwash gravels; locally contains some
alluvium ; and along streams may grade to alluvium

Diabase

faa

Coarse cobble conglomerate

Tse

glomerate

40

Limestone
In part massive and in part thin bed-
ded with shaly partings

Middle Devonian

NORTHEASTERN
PART OF MAP AREA

Graywacke, tuff, agglomerate,
‘conglomerate, and lavas

Lower Silurian
y
>
5

* codtree-cobble
cobbles of gray or a chert, rhyolite,

rhyolite ar

Scg; and then lenses of impure and

35’ often schistose marble, Sis. Each map
‘unit contains varying amounts of

‘material mapped other units,

and contacts between many wnits are

highly gradational

36’

where inferred;

SILURIAN

Middle Ordovician to Lower Silurian(?)

Contact

Dashed where approximately located or infer-
red; dotted where concealed

Sandstone, graywacke sandstone, and con-
glomeratie sandstone with local coarse con-

Gneissic quartz diorite
In part altered to quartz-monzonite and alkalic granite

Quartz diorite porphyry
| 40" Contains large feldspar phenocrysts

Quartz diorite

Diorite

Gabbro

Pyroxenite, with some gabbro and diorite

Rhyolite and andesite with
marked flow foliation

SOUTHWESTERN:
PART OF MAP AREA

Graywacke, taf, agglomerate,

conglomerate, and lavas
Volcanic povasels, conglomeratic
con.

glomerate and agglomerate, and
andesitic lava, SOg; includes slaty
argillite, graywacke, and minor
black-matriz fine conglomerate, SOsg;

ree a charac-

facies comprising chert, argillite,
‘slaty argillte, feldspathic graywacke,
‘and tuf, SOfg; andathick, relatively
continuous unit of slate, slaty argil-
lite, aud minor fine conglomerate and
graywacke, SOsl; beds of reerystal-
lized limestone, SOls

Approximate boundary between
subdivisions of major rock units
__ Queried where boundary is inferred

Fault, showing dip and relative
movement
Dashed where approrimately located; queried

‘where concealed. U,
side

Anticline
Showing trace of axial plane ; dashed where
approximately located ; dotted where concealed

ine
Showing trace of axial plane; dashed where
concealed

approximately located ; dotted where

Strike and dip of bedding
Strike and dip of erenulated beds
55° 30’ 57°30" 7
¥ Strike and dip of foliation or schistosity
. .
a Strike of vertical foliation
a
Bedded rocks characterized by notable
addition of alkalic feldspar
ea C)
ES EER Mines and prospects
CHC iy
v Sys =
‘ ow /- VY ee ‘a -_
“ & NX Gaps F Copper or copper-magnetite mine
a J wa
L ne 13220° *
Base from U. S. Geological Survey topographic maps, Craig B-1, B-2, Geology by C. L. Sainsbury, 1954-55; Copper or sulfide-magnetite prospect
B-3, C-2, C-3, and D-2 (1:63 360 scale), Topographic Series of Alaska assisted by G. W. Herreid, 1955 3
os Gold quartz mine
i 100° e
‘SEA LEVEL ‘SEA LEVEL Gold quartz prospect
1000 1000

2000 2000°

1000"
+ SEA LEVEL
1000"
2000°

GEOLOGIC MAP OF PART OF THE CRAIG C-2 QUADRANGLE AND ADJOINING AREAS
PRINCE OF WALES ISLAND, SOUTHEASTERN ALASKA

SCALE 1:63 360

1 0 1 2 3 4 5 MILES

=o
CONTOUR INTERVAL 100 FEET
DATUM IS MEAN SEA LEVEL

QUATERNARY

TERTIARY

CRETACEOUS

DEVONIAN

ORDOVICIAN AND SILURIAN