7 
oe 
Wisconsin and Missouri Lead Region. 67 
could get no satisfactory information, no work being now done 
there. The mine is in a dilapidated condition, and little insight 
can be obtained as to the true position of the ore. The limestone 
and red rock meet each other very confusedly, there being near 
the surface no regular line of contact. Fissures or openings ex- 
tend ‘vertically down between the rocks, and these are filled with 
a mixture of iron ore, copper ore, clay and gossan, while above, 
the surface is composed of gravel, consisting of pebbles of quartz, 
chalcedony; and jasper mixed with red and yellowish clay. :. The 
work over this small tract, which alone was found to contain the 
ore, was carried on very.badly. Instead of the whole surface 
being stripped off clean to the rock, little holes and trenches were 
dug*all over it, and where the loose ore was found most abundant, 
there the most digging was done. Sometimes the copper ore 
forms nearly the whole material from the surface down even to 
the depth of seven feet, the greatest thickness yet found to con- 
sist almost entirely of ore. It lies in irregularshaped’ masses, 
accompanied with hematite iron ore, into which it passes, and 
these masses vary from pebbles up to the weight of seventy 
pounds. They are’scattered through the clay and ’gossan, or lie 
sometimes in contact, and sometimes tending to a horizontal po- 
sition. ‘The clay and gossan are found to be worth washing for 
the ore they contain. A little spot about twenty feet square, 
where the ore was most abundant, is said to have produced as 
much as all the rest. © Little veins of ae principally car- 
a where ‘it 
thick ; and on the granite under the other ores‘is often found a 
thin plate: of oxide of copper, inerus rock but not joined 
to it. The grain of the limestone ix’here: irregular, the seams of 
stratification obliterated, and itis impossible to. determine the 
amount of disturbance it has experienced. Veins of “tiff” (calc. 
spar) are occasionally found in it, and with them: small frag- 
ments of oxide of copper a tes and 1 apd of pearl spar 
and pargasite (?) 
~ A rotten vein, a foot thick, at nbtat the poikeos contact of the 
two'rocks, consists of a’ curious altered mixture of them, with 
particles of carbonate of copper “scattered through the mass. 
This sort of breccia is considered of some importance, as indica- 
ting the proximity of ore, for almost exactly similar specimens 
