66 Wisconsin and Missouri Lead Region. 



On the Current and Jack's Fork, (a branch of it,) the banks 

 are generally precipitous, the hmestone forming steep bluffs 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, 

 with a 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 above, a 

 few imperfect encrinites were met with. 



A range of igneous rock — a red compact siliceous rock, close 

 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. S. 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 miles, and it or similar par- 

 allel ridges of red rock extend across the line into Arkansas. It 

 crosses Jack's Fork in town xxix, range'4. In town xxix, range 

 3, farther north in the township, another ridge of red rock is to 

 be seen, which will be more particularly noticed when describing 

 " Yallee's diggings." 



At the contact of the first range with the limestone 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 (?) with a little sulphuret forms a considerable 

 part of the whole. This has been dug over to the extent of 

 about three fourths of 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 



