The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1913-09-25
ECONOMIC GEOLOGY0F REGION AROUND
MULLAN, IDAHO, AND SA[TEsE, MONT.
ALeoNklAN BELT SERIES RAvALL' GROUP
Explanations or VARIOUS FORMATIONS IN THE cosuR
pALENEs-ossvRN FAULT.

IHTtHeI tdSt' liz uPpSs" 1850 =
1.-THE formation are certainly paler neal
Borax, ON the st. Regis, than they are
on Mill creek and near Saltese the pur.
ple tint Of these beds Is SO faint tina
there IL real difficulty In fixing I
boundary between them and the states
OF the Newland formation. The col
grafton Of the lower beds is still more
indefinite; they are In general green
ish and thicker bedded than the upper
beds and therefore approach the upper
Reyett rocks In character. The rail-
way section between Saltese and De
borgia and still farther east expose
so great thickness Of these dull
greenish impure quartzites as to glvs
the impression that any distinction
here between the st. Regis and tn
Revett would probably be impossible
TO the north Of the old valley, how
ever, the Revett quartzitc and tn
Burke formation are extensively ex
posed, each with lithologic characte'
that is typical and fairly distinct from
that Of the ST Regis. The thickness O.
the ST. Regis near the northeast corner
of the area described Is about 1907
feet It's thickness farther south i
parently greater, but Is difficult Y
measure owing to the indeiiniteness o
: the lower limit.
MAINLAND (WaIjace) Formation.
The Newland Is the thlckest forlna-
tion In this area and occupies tn,
greatest portion Of It's surface beihs
the principal country rock south o.
the Occur d'Alene and st. Regis rivers
4 In the original reports on the Coeul
dAlene district 1t was mapped and de-
scribed as the Wallace formation, but
1t has since been related with the New
land formation to the east and the To-
cal name (Wallace formation) Is M
longer used.
The formation as whole consists O.
thin bedded rocks which are for tn.
most part calcareous. The rocks con
tain carbonates Of magnesium an
iron as well as OF calcium, but the ca.
cium seems the most abundant. In
formation comprises three member
which are fairly distinct in genera
character, but which grade into on.
another and are not distinguished q
1.-The map.
The lowest member is characterized
by the prevailing green color Of y
rocks. The strata Immediately abov
the ST. Regis consist of obscurel,
banded states, of rather bright ap
ple- green color, which are very slight
~ calcareous, their separation from
the st. Regis being determined rattle
by convenience than by strict logic
Higher in the formation the proper
ton OF limy material is greater, as J
indicated by the yellow color assume
by the rocks when weathered; numer
Gus bands of whitish calcareous sand
stone and few strata OF blue an
white argillite make their appearance
The part Of the formation in which tn
green color is strongly preponderan
constitutes what may conveniently b
called the lower member.
The middle member contains green
jsh beds but is characterized more es
pecially by blue and white banded ar
4 gillite and an abundance of calcareou
sandstone or quartzite, together wit
some impure limestone. In its uppe
portion the limy and sandy layers dim
inish In quantity and finally 1t passe