56 GEOLOGICAL RECONNOISSANCE 
it is true, contains a higher percentage of metal than the carbonate; but it 
is much more difficult and expensive to work, and hence a less profitable 
ore to mine than the carbonates, with a less per centage of zinc in their 
composition. 
The higher points of the hills in this part of Marion county, are capped 
with cherty rocks of subcarboniferous date, but the lower part of the hills 
belongs to the same age as the members exhibited in the geological section 
on Sugar-loaf creek, previously given. 
The pine and other timber on the high ridge, mentioned as intervening 
between the head of Sugar-loaf creek and the waters of George’s creek, 
will afford good coaling grounds for the use of zinc furnaces, which might 
be located some where in the vicinity of these zinc mines, as well as for 
the reduction of the lead ore that may be raised towards the head of 
Sugar-loaf creek. 
, CARROLL COUNTY. 
As yet, only the eastern portion of this county has been examined. 
The lead ore of this county, occurs in the cotemporaneous formations of 
magnesian limestones, with occasional interstratification of sandstone and 
siliceous limestones, overlaid, towards the summits of the hills, by the en- 
crinital limestones and marble rock, capped with chert. The diggings 
have been somewhat deeper in Carroll than in Marion county, but still 
quite limited, consisting of a few shallow trenches on the hill-side, and 
one shaft of 40 feet. These have exposed several lead-bearing crevices in 
the rocks, sometimes expanded into cavernous spaces forming occasional 
“ pockets” filled with lead ore; at other times compressed in the joints of 
of the wall-rock, almost in contact, or only affording space enough for 
small “ strings,” and thin “ sheets” of ore, irregularly distributed along its 
course. 
In sinking the main shaft, the first layer of rock passed through, beneath 
the subsoil and under-clay, was: 
Light grey shale. +... ee cecees sees cece ence eveeseeee 4 feet 
Dark “ BOO gare whale tesa Gee ee ore a eae 8 « 
Magnesian lead-bearing limestone: +++ +++. eee ee eeee 28 
Total depth sunk... -+-seeeceeeeees +» 40 « 
A hole carried a few feet further, by means of a “ churn auger,” passed 
mostly through good solid galena disseminated in the adjacent magnesian 
limestone. 
