DEPARTMENT OF THE INTERIOR
UNITED STATES GEOLOGICAL SURVEY

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Geochemical Symbols
(size of symbol explained on histogram)

LA Anomalous copper value (figure 1)

Anomalous lead value (figure 2)

O Anomalous barium value (figure 3)

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DISCUSSION

This map shows the distribution and abundance of
copper, lead, and barium in 296, minus 80-mesh stream-
sediment samples collected during the 1978-1979 field
seasons in the West Chichagof-Yakobi Wilderness Study
Area, Sitka quadrangle, southeastern Alaska.

The area of this project amounted to approxi-
mately 600 square miles (1800 km2). The stream
sediments were collected from active stream channels,
draining areas approximating 2 square miles (6 km2).

The preparation of the stream-sediment sample
prior to analysis consisted of sieving to minus
80-mesh (0.2 mm) and pulverizing to minus 200-mesh
(0.075 mm). The samples were analyzed by
semiquantitative emission spectroscopy (Grimes and
Marranzino, 1968).

From the analytical data the analyses were
compiled and used in preparing the histograms and
geochemical map. The histograms were used to identify
the anomalous values for each element.

A listing of results from the analysis of various
sample media, collected in this Wilderness Study Area
appears in Hessin and others, (1980).

REFERENCES CITED
Grimes, D. J., and Marranzino, A. P., 1968, Direct-
current and alternating-current spark emission
spectrographic field methods for the
semiquantitative analysis of geologic materials:
U.S. Geological Survey Circular 591, 6 p.

Hessin, T. D., Speckman, W. S., Crenshaw, G. L.,
Hoffman, J. D., and Cooley, E. F., 1980,
Analytical results of various types of samples

taken in the West Chichagof-Yakobi Wilderness

Study Area, Sitka quadrangle, southeastern Alaska,

U.S. Geological Survey Open File Report 80-905.

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Sitka; Mt. Fairweather

SCALE 1:125 000
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8 MILES

8 KILOMETERS
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Geology simplified by B. R. Johnson and S. M. Karl, 1981

GEOCHEMICAL MAP SHOWING THE DISTRIBUTION AND ABUNDANCE OF COPPER, LEAD, AND BARIUM IN STREAM-SEDIMENT SAMPLES
IN THE WEST CHICHAGOF-YAKOBI WILDERNESS STUDY AREA, SITKA QUADRANGLE, SOUTHEASTERN ALASKA

Studies Related to Wilderness

The Wilderness Act (Public Law 88-577, Sept. 3,
1964) and related Acts require the U.S. Geological
Survey to survey certain areas on Federal lands to
determine their mineral resource potential. Results
must be made available to the public and be submitted
to the President and the Congress. This report presents
the results of a geochemical survey of the West Chicagof-
Yakobi Wilderness Study Area, Sitka quadrangle, southeastern

Alaska.

By
TD. Hessin, MG. Maslowski, and G.W. Day
1981

a 16 a6 36

OPEN-FILE REPORT
81-27-Q

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Figure 1.--Histogram showing copper in 296, minus 80 mesh (0.2 mm) stream-
sediment samples in the West Chichago-Yakobi Wilderness Study Area.
Triangles indicate anomalous concentrations and class percentages computed
on total sample population. Analysis by optical emission spectroscopy
(Grimes and Marranzino, 1968).
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Figure 2.--Histogram showing lead in 296, minus 80-mesh (0.2 mm) stream-
sediment samples from the West Chichago-Yakobi Wilderness Study Area.
Squares indicate anomalous concentrations with class perecentages computed
on total sample population. Analysis by optical emission spectroscopy
(Grimes and Marranzino, 1968).
N, not detected at limit of detection
L, detected but below limit of determination
Fact opery
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Figure 3.--Histogram showing barium in 296, minus 80-mesh (0.2 mm) stream-
sediment samples in the West Chichago-Yakobi Wilderness Study Area. Circles
indicate anomalous concentrations with class percentages computed on total

sample population.
Marranzino, 1968).

Analysis by optical emission spectroscopy (Grimes and

136°40° 134°
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SITKA’
a LA,
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SUADRANGLE LOCATION INDEX SHOWING LOCATION OF STUDY AREA
CORRELATION OF MAP UNITS
Qal QUATERNARY
Tf | Tm TERTIARY (?)
Kd CRETACEOUS (?)
Ks
CRETACEOUS
Kkb
CRETACEOUS AND
KJE | Kim | f surasstc
Trw
TRIASSIC(?)
Trg
MESOZOIC AND
pereu PALEOZOTC(?)
LIST OF MAP UNITS
Qal ALLUVIAL DEPOSITS--Undivided
Tf FELSIC PLUTONIC ROCKS--Dominantly tonalitic
Tm MAFIC PLUTONIC ROCKS--Dominantly gabbroic
Kd DIORITE SILL--Extensively altered
Ks SITKA GRAYWACKE
Kkb KELP BAY GROUP--Metasediments and metavolcanics
KJ£ FELSIC PLUTONIC ROCKS--Dominantly granodiorite
KIm MAFIC PLUTONIC ROCKS--Dominantly quartz diorite, diorite, and gabbro
Trw WHITESTRIPE MARBLE
Trg GOON DIP GREENSTONE

MzPzu UNDIVIDED METASEDIMENTARY--Metavolcanic and metaplutonic rocks