Montana oil and mining journal. [volume] (Great Falls, Mont.) 1931-1953, 1941-11-29
PHOTOGRAPHY
OF ARTICLES
ON CHROMITE
CONTINUED from Last week

tNpnLulncQ from LaSC week
SingewaId. Joseph T., JF. Mag
matte segregations: Ore deposits Of
the Western States Iindgren vol
umel, pp. 504-524. Am. Inst. bin.
Met. Eng fig. 1888.
Gives the general features Of mag
matte Segregations; occurrences Of
platinum. non-titaniferous, and titan
I ferrous magnetites, chromite, wolfra-
mite, nickel and copper sulfideS. In
11cnt1na ch-cs.,...e occurs II Sweet
grass and Saltwater counties in a
belt Of igneous rocks some 30 miles
long. They constitute q complex Of
about 10000 feet Of pSeudostratified
rocks ranging from peridotites and py-
SoxeniteS near the base to anorthositic
norites and anorthosites In the upper
zone. Chromite bands occur near the
center Of the peridotite-pyroxeni
zone, which is about 5000 feet thick.
In Carbon county, near Red Lodge,
chromite Is found at several places
and 80 tons have been shipped. Gneis-
ses inclose the ultra-basic rocks In
which the chromite is found. Samp-
son believes the branching chromite
veins to be Of pydrothermal origin
Five miles southeast Of Sheridan,
Madison county, chromite occurs in
lenticular segregations up to five feet
IN width in coarse-grained diorite
bikes. The occurrence is unusual be-
cause Of the acid character Of the rock
Nickel-copper -pyrrhotite deposits are
found in the Saltwater igneous COM
pick. A smelter was built at Nye in
1880 but no shipments were made. The
ore occurs along the lower margin
Of the complex in mylonitized norite I
lying below the main peridotite-py- /
roxenite belt A large body Of nom
nickeliferous pyrrhotite is found In the {
Golden Curry mine, in the Elkhorn /
district. Unusual features Of this oc-
currence are its high gold content and
its segregation from rock so siliceous
as a quartz monzonite.
Smith, Lewis A. World produce
tiOn and resources of chrOmite:
Am. Inst. Min. Met Eng. Trans,
vol SO, PIP. 376-4O2, figs, 1881
with discussiOn).
A large chromiferous serpentine area
lying in Sweetgrass and Saltwater
counties reported to contain large
tonnage of ore. Most of the area has
not been developed, but the west and
east ends were under development
during 1929. Serpentine belt is one
half to three-quarters of a mile wide
and 30 miles long and reserve Of this
area has been reported at about 300
700 tons. containing less than 40 per-
cent Cr2 O3, whereas the total Mon
ana reserve in five deposits has been
,stimated at about 100000 tons.
Smith, Lewis A. Chromium: u.
S. Bur. Mines, Inf. Giro. 6566, 81
PIP, 6 figs, 1882. IA
This circular presents summary OF
he domestic chromium industry and
discusses the salient features Of the
world situation. A chromium bearing ]
belt, one-half to three ;
quarters of a mile wide and 30 miles :
ong, has been reported in Sweetgrass !
nd Saltwater counties. The total re- J
srve for Montana is estimated at 400 T
90 to 100000 tons. y
Thorn, William T., Jr. land Field, !
Richard M. Cooperative geologic :
research near Red Lodge, Mont: .
Science, new SER. vol ~, No. 1878, 4
PIP. 655-656, 1880. h
Geological Investigators cooperating G
18th the state and federal government G
nd assisted by Red Lodge and Bill Q
ngs organizations studied a district S
T great geologic and paleontologic s
terest northeast of Yellowstone park. p
mong unusual and unique discov-
les cited are. similarity of the Bear pl
10Th chromite deposits to those Of d.
Outh Africa; finding Of dinosaur egg h