66 Wisconsin and Missouri Lead Region. 
~» On the Current and Jack’s Fork, (a branch of it,) the banks 
are generally precipitous, the limestone forming steep blufis.of 
great height, above which, in the hill-tops, the quartzose rock is 
often seen cropping out. 'This limestone is of a light gray color, 
witha crystalline texture, and lies in nearly horizontal. strata. 
The rock is full of quartz veins, which run generally with the 
stratification, and should rather therefore be called beds of quartz. 
They are intimately mixed with the limestone, so that it appears 
sometimes to pass into quartz rock, the two not being easily 
distinguished, and sometimes the quartz predominates over the 
limestone in relative proportion. Little nests and bunches of 
quartz crystals frequently occur, both in the quartz beds and in 
the limestone. Excepting these, and the calcareous spar in veins, 
and pearl spar, no minerals were observed. Stains of a greenish 
hue, like those of carbonate of copper, may be noticed almost 
every where, on and through pieces of the limestone. I found 
no fossil shells in the limestone; in the siliceous rock sibling a 
few imperfect encrinites were met with. 
A range of igneous rock—a red compact ; ‘siighoam iia cm 
grain, flinty fracture, porphyritic near the limestone, crosses Jack’s 
Fork in a direction west of north, east of south, about-five miles 
above its.confluence with the Current. A mile or two above this 
ridge, the limestone is seen dipping about 10° W. 8. W., and a 
mile below, the dip is about as much E. N. E. The ridge 
formed by this range of igneous rock is about three hundred feet 
at the highest elevation above the river ; it has been traced, it is 
said, in a north course ten or twelve sien and it or similar par- 
allel ridges of red rock extend across the line into Arkansas. It 
erosses Jack’s Fork in town xxrx, range 4. . In town xxzx, range 
3; farther north in the township, another ridge of red.rock is to 
be-seen, which will be more ens masions when describing 
* Valleé’s diggings.” 
_ At the contact of the first range Sisk the i contane on the 
south side of Jack’s Fork, five miles up it, and a mile back, is a 
deposit of copper ore in the soil, principally a green. carbonate, 
but the black oxide — alittle sulphuret forms a considerable 
part of the whole. is has been dug over to the extent of 
about three fourths “3 an acre since 1839, when it was discover- 
ed. The diggings extended to the depth of about ten feet aver- 
age, the deepest hole being eighteen feet; but concerning this I 
