Eureka daily sentinel. [volume] (Eureka, Nev.) 1871-1887, 1881-12-07
SCIENTIFIC INVESTIGATION.
Explanatory Letter on Scientific
Explorations of the Pacific

objects and utility of the U. 8. Geological
Survey, but many circumstances have pre-
vented my doing so up to the present time.
The Geolo gical Survey was organized
under an Act Of Congress OF March 8,
1879, for the purpose of classifying the
public lands and Of determining the geo.
logical structure, mineral resources, and
products OF the national domain.
The Hon. Clarence King was appointed
Director and 500, 900 appropriated by
Congress to meet the expenses of the first
year. Since then Mr.. King has resigned
and Major Powell has been appointed in
his place.
A competent corps OF biologists and en-
gineers was appointed by the Director,
and field work was begun at Leadville,
Colorado ; in the Great Salt Lake Basin,
Utah in Southern Utah and Northern
Arizona in Eureka District, and at Virgil
mia City, Nevada.
From the work done in the above named
places the following publications will re-
suit: Geology and Mining Industry OF
Leadville, Col, by s. F. Emmons; Geology
IAo iCbt wv ny hIHOtu hague,
The Copper Rocks of Lake Superior, by
Professor Irving. History of the Comstock
Mines, by Eliot Lord; The Comstock Lode,
by G. +. Becker; Mechanical Appliances
used in Mining and Milling on the Com
stock Lode, by W. r. Eckart, @. E.; Coal
OF the United States, by Raphael Pumpelly;
Iron in the United States, by the same:
The Precious Metals, by Clarence King,
Director; Lesser Metals and General Min
eral Resources, by Raphael Pumpelly;
Uinkaret Plateau, by Capt. @. E. Dutton;
Ordinance Corps, Lake Bonneville, by G..
X. Gilbert; Dinocerata, q monograph, bv
Professor Marsh.
AT present there is no field work in pro-
gress except in Eureka, owing to the failure
OF Congress to appropriate money for the
above mentioned works, and the necessity
OF deyoting the larger part of the appro-
priation for the present fiscal year 70 that
purpose. That a larger amount OF money
may be allotted by Congress to the survey
during the coming session is much to be
desired, as l shall endeavor to show. l
will explain as near as possible the work OF
the Geological Survey as regards mining.
In completing the geology OF a district
the work is usually divided into three
branches--the typographical survey, the
determination OF the surface geology and
hthology, and the study OF the under
ground formations. The first consists in
making a careful and complete surface
map which shows the canyons and r~avines,
mountains and hills, with the relative ele-
vations and depressions Of each, so that
by glancing at the map the hight and po-
sition OF any point in reference to others
above or below it can easily be seen. This
is accomplished by determining the posi-
ton Of the principal prominent points by
triangulation and by running what are
called contour lines, at a vertical distance
apart of from so to 100 feet. These lines
are run on a level and follow the sinuos-
tiles OF the hills and ~rsvines.
In order to complete the surface geology
1t is necessary to study the Theological
character Of the various rocks which COM
pose the formations, determine the lines
of contact between them. their relative
ages and position, the fossils, il there are
any contained in them, and the manner in
which they got into their present position.
In completing the map the position and
extent of the different formations are
shown by colors. and the elevations and
depressions by contour lines.
The underground mining work consists
in tracing the different formations from
the surface down, and studying their rela-
tons TO the lode, in fully examining the
lode itself-its situation, Its ore bodies,
and their relation to the country rock. In
fact, investigating everything which may
be Of interest in regard to the vein. Also
q chemical examination Of the minerals
rocks is made.
In order TO make the structure OF the
lode plain to the eye, maps and diagrams
IRE needed. In the first place q surface
map, showing the ore formation and the
Of the mines in it, then one or
longitudinal vertical sections, to-
sether with numerous cross sections,
chosen at such points as will best show the
structure of the vein, and, finally, one or
more horizontal sections.
In order to discover the action which
has caused the deposition Of the ore, it is
to examine chemically the coun-
Try rock, vein matter, minerals. and all
materials which have any bearing upon
The formation Of the lode.
Should tho theories formed by q geolo-
yist in regard to the formation Of q given
ode prove to be incorrect it would not de-
tract from the importance OF such geologi-
,al investigation in general. 1t Is only
By the long and persistent study OF ore
loROeitsr WIN "A oAa Va o'cAy MNhae ~
our power, that we can arrive at any con-
,lusion in regard to the method OF their
'ormation.
The maps Of the United States Geolog-
cal Survey will be Of the greatest impor-
iance to mining men, as well as the analy-
lis OF rocks, minerals and ores. The large
mount OF careful Investigations which are
being made cannot fail to be OF benefit in
but they will also aid in bring
ng the prominent features Of any mining
before the public Of the United
States.
In conclusion, I would state that 1t is
,nly by the courtesy and good will OF the
public that anything can be done
n this direction. This has been most
universally accorded.
The Investigations Of the survey are
made for the people ct large, and not for
he benefit Of any corporation.
For that reason its members are strictly
,njoined from working for or receiving pay
rom private parties or corporations, and
ire obliged to regard as strictly conAden-
ial any information which they may OBJ
unless permitted to make 1t public;
llso, they are not allowed to be interested
n any manner in any mining property in
The domain under investigation. Very re-
,pectfully, j. s. CURTIS, Geologist.