The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1898-02-08
IDAHO GEOLOGICAL SURVEYS.
REPORT ON THE IDAHO BASIN
QUADRANGLE.
Placer and Quartz Mines Present
Many Interesting and Complex
Features-Tintic District Surveyed
(speciaI Correspondence.l


Washington. Feb. 3.-The annual re-
port of Director Charles D. walcott
of the geological survey, which is just
from the press of the government
printing office, gives an interesting ac-
count of Waldemar Lindgren's COM
pete survey of the Boise quadrangle
and a survey of the northwest quarter
of the Idaho Basin quadrangle. A to-
tai area of 1,O96 square miles was
mapped.
The mapping of the Boise quadrangle
was begun July 1 and completed Sept.
10. This area, which is located on the
northern side of the Snake River val
ley consists geOlogically of a granite
range. against the TANKS of which rests
an extensive series of tertiary lacus-
trine and fluviatile deposits, in which,
many volcanic flows of differing nature
are embedded. These tertiary beds.
which occupy at least one-half of the
Boise quadrangle, were carefully stud
led, and they afford a key to the late
geologic history of the Snake River
valley. The oldest and most extensive
series of lake beds are of MiOcene age,
and contain in places an abundant fos-
sill fora, which has been studied by
Professor Knowlton.
Several mining districts are located
in the granite rocks OF the Boise quad
rangle. The deposits, which are, as a
rule, gold bearing assure veins, were
examined, and special attention was
given to the processes of alteration-as
metasOmatism-to which the rocks ad-
joining these deposits have been sub
jected.
The northwestern quarter of the Ida
no Basin quadrangle forms an isolated
intermontane valley. and received es-
pecial attention in view of its past
large production of precious metals and
Of its future possibilities. Both the
placer mines, which have been extern
sively exploited, and the quartz mines.
where but little work has been done,
were carefully examined and found to
present many interesting and complex
features. The placer deposits were in
ali cases traced up to the larger vein
systems.
Mr. Lindgren also wrote a special
paper on the mining districts of the
Idaho Basin and the Boise Ridge
UTAH SEEPAGE.
Director Walcott says Professor
Fortier of Logan has continued work
at the river stations, with the assist
ance of Mr.. William DOugall, and also
has conducted ,seepage measurements,
being aided in the latter by county au-
tnOflIleS ana OlHefS, dS lIle ItSullS art
of immediate practical benefit to the
inhabitants of the northern part of
Utah The results of this latter work
are given in the water supply and ir-
rigation series.
The area embracing the mining dis
trict in the vicinity of the towns of
Eureka, Mammoth, Robinson and Sill
yer City, in Juab and Utah counties.
was surveyed by Mr. I. w. Griswold
on the scale of 500 feet to the inch, with
a contour interval of 20 feet, the area
covered being u Square miles. Mr..
Griswold was engaged on this work
from Nov. to Jac. 20.
The survey of the Sawtooth quad
rangle. in Alturas county, Idaho, was
completed by Mr.. E. T. Perkins, jr..
assisted by Mr.. A. B. Searle. 525 square
miles. on the scale of 1:125000, being
surveyed. Mr.. Perkins reached the field
in the latter part of June and finished
the work assigned to him early in No
vember. In connection with this work
there were 40 miles of levels run and
% permanent bench marks established.