The times dispatch. [volume] (Richmond, Va.) 1903-1914, 1913-02-16

than the valley or limestone brown
ores, and are regarded as cOncentra-
tions by meteroic water. the iron hav-
ing been derived largely. If not en-
tirely, from the everything shale and
limestone formations.
THE valley or limestone brown ores
are distributed at intervals throughout
the valley region west OF the Blue
Ridge. in association with the residual
clays derived from the limestones by
processes of decay. The principal oc-
currences of these ores is in the New
r-Crippie Creek district OF Wytho
and Pulaski Counties, in residual clays
derived from the Shady dover mem
Der Of the Shenandoah group lime
stone. A large number OF mines have
been operated in this district.
North OF Ronnoke.
In the northern and central Valley
region the limestone brown ores are
not SO abundant. there being less than
dozen deposits that have been
worked between Roanoke and the
Maryland boundary. The ores OF this
region, called the Blue Ridge belt, oc-
cur In residual clays derived from the
Natural Bridge limestone.
THE ore Is disseminated through the
residual clay in varying concentra-
tons. ranging from large. porous
masses down To pellets the size OF n
pea. The proportion of clay to ore In
the workable deposits varies consider
ably, usually from five TO one to TWEEN
,y-fve to one. The ores arc usually
richer than the mountain ores, rang
ing In iron content from so to 55 per
cent and In silica content from to
20 per cent with usually less than !
per cent of manganese and enough
phosph orous to be classed as q non
Bcssemer ore.
The valley or limestone brown ore:
are residual deposits, the iron of which
was originally disseminated through
the rocks. and. under favorable condi-
tions, has been concentrated during
the process of weathering and erosion
Most Important of All.
The Oriskany brown ores arc the
most important of the iron ores mined
at present in Virginia. The principal
district Of Orissany ores includes the
counties OF Allegheny, Botetourt and
Craig, from which nearly all the ore
mined of this type is produced. Minor
deposits occur on Draper Mountain, In
Pulaski and Wythe Counties: on
Peters Mountain, Giles County; in the
Buffalo Gap area. Augusta County; in
Mnssanuttcn Mountain. Shenandoah
County. and on North Mountain. in
Shenandoah and Frederick Counties.
These ores are limited to n definite
horizon. in the Lewiston UIelderber-
gian) limestone. Immediately below the
! Monterey tOriskany) sandstone. They
, represent requirements of the upper
| portion Of the limestone The ore was
derived from the everything Devoniar
black shales by meteoric waters
| Where the shales were of sufficient
! thickness. and the underlying Monte
rey sandstone sufficiently thin and frac'
! tured. the iron bearing solution penc'
| trated Into the underlying limestone
and. under favorable conditions. re-
| placed the calcium carbonate by iron
oxide. forming tho ore bodies.
The ore deposits are continuous To-
! considerable distances along the STRIKE
| with greater variations In thickness o
! the ore bodies ranging up to seventy
1--WE feet. with "a probable average o
| fifteen to twenty-five feet. The ore
usually fairly gold. but frequentl,
| porous with the cavities containing
clay. ranges between So and so per cen
OF metallic iron. They are usually hfgl
in silica and manganese. and. in thi
| particular, they resemble the noun
tain ores.
VarIoua Deposits.
The principal Orisknny brown or
minos In the State arc Liberty an
Van Duran Furnace mines. in Shen
andoah County: the Buffalo Gap an
JTerrol mines i'm Augusta County; tn
Victoria and LonRdale nina. north o
LonYdale. Allegheny County, the Doll
Ann, Iron Mountain and Stack mine;