DEPARTMENT OF THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

/

Geochemical Symbols
(size of symbol explained

Anomalous sulfate value

C)anomal ous fluoride value

on histogram)
(fig. 1)
(fig. 2)

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DISCUSSION

This geochemical map shows the distribution and
abundance of sulfate and fluoride in 359, unfiltered
water 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 is about 600 square miles (1800 km).

Acid-rinsed, 8-0z (250 mL) plastic bottles were
used for collecting the water samples. They were
rinsed again in the stream or lake, prior to filling
the bottle with the water sample.

At the laboratory, the sulfate and fluoride *
analyses were completed by ion chromotography (Fishman iit
and Pyen, 1979).

The histograms were used to identify the
anomalous values for each anion.

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

REFERENCES CITED

Fishman, M. J., and Pyen, G., 1979, Determination of
selected anions in water by ion chromotography:
U.S. Geological Survey, Water Resources
Investigations Report 79-101.

Hessin, T. D., Spectman, W. S., Crenshaw, G. L.,
Hoffman, J. D., and Cooley, E. F., 1980,
Analytical results of various types of samples
taken in the West Chicagof-Yakobi Wilderness
Study Area, Sitka quadrangle, southeastern
Alaska, Open-File Report 80-905.

OPEN-FILE REPORT

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Figure 1.--Histogram showing sulfate in 359, unfiltered water samples from the

West Chichagof-Yakobi Wilderness Study Area. Analysis by ion
chromotography, (Fishman and Pyen, 1979). Circles indicate anomalous

concentrations and class percentages computed on total sample population.

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Figure 2.--Histogram showing fluoride in 359, unfiltered water samples from
the West Chichagof-Yakobi Wilderness Study Area. Analysis by ion
chromotography (Fishman and Pyen, 1979). Squares indicate anomalous
concentrations and class percentages computed on total sample population.

CORRELATION OF MAP UNITS

92%

3% O

NI
O

aie
\

~ NFS
~. Sao)
Salisteey. Sound R26.

~e
Sata eee

Qal
Tf

Kd

Ks
Kkb
KJE
KJm
Trw
Trg
MzPzu

gal QUATERNARY
Tf | Tm TERTIARY (?)
Kd CRETACEOUS (?)
Ks
CRETACEOUS
Kkb
CRETACEOUS AND
Kuf | KJm | ¢ jurassic
Trw
TRIASSIC(?)
Trg
MESOZOIC AND
zP2ul Ff pALEOZOTC(?)

LIST OF MAP UNITS

ALLUVIAL DEPOSITS--Undivided

FELSIC PLUTONIC ROCKS--Dominantly tonalitic

MAFIC PLUTONIC ROCKS--Dominantly gabbroic

DIORITE SILL--Extensively altered

SITKA GRAYWACKE

KELP BAY GROUP--Metasediments and metavolcanics

FELSIC PLUTONIC ROCKS--Dominantly granodiorite

MAFIC PLUTONIC ROCKS--Dominantly quartz diorite, diorite, and gabbro
WHITESTRIPE MARBLE

GOON DIP GREENSTONE

UNDIVIDED METASEDIMENTARY--Metavolcanic and metaplutonic rocks

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.

QUADRANGLE LOCATION

INDEX SHOWING LOCATION OF STUDY AREA |
if

2

—

4 ®
Ried
ae

Sinitsin

uitzen

Base from U. S. Geological Survey 1:250,000, 1951
Sitka; Mt. Fairweather

SCALE 1:125000
2 ° 2 4 6

8

2

4

6

8

10 KILOMETERS

a=

10 MILES

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

GEOCHEMICAL MAP SHOWING THE DISTRIBUTION AND ABUNDANCE OF SULFATE AND FLUORIDE IN UNFILTERED WATER SAMPLES IN THE
WEST CHICHAGOF-YAKOBI WILDERNESS STUDY AREA, SITKA QUADRANGLE, SOUTHEASTERN ALASKA
By
TD. Hessin and GL. Crenshaw
1981