LHISTORY OF GREEN COUNTY. 
 
CHAPTER II. 
TOPOGRAPHY AND GEOLOGY. 
 
Lead has been found so far east in Green 
county that we may consider the whole of it as 
lying in the "Lead Region."  It will be profit- 
able, in this chapter, to begin with 
I.-TOPOGRAPHY. 
Unlike most regions which nature has selected 
for the reception of metallic ores and useful 
minerals, the Lead Region bears no evidences of 
any sudden disturbancesor violent action of phys- 
ical laws. The effects produced by igneous and 
eruptive agencies are wanting. Faults and dis- 
location of strata are nowhere found. The only 
irregularities are slight upheavals, or bending 
of the strata (and these never of great extent) 
producing changes of but a few feet from the 
normal dip. 
Between the geological condition and thu 
general surface contour of the country, there is 
no direct correlation. The existence of a hill 
or valley on the surface is not due to a subter- 
ranean elevation or depression of the surface, 
as is by many supposed; and whatever irregu- 
larities exist, must be chiefly attributed to the 
milder natural agencies now constantly at work, 
-such as running water, frost, winds, etc., 
acting through an immensely long period of time. 
_Drainage.-The most marked and persistent 
feature of the Lead Region is the long dividing 
ridge, or water-shed, which, commencing near 
Madison, in Dane county, continues almost di- 
rectly west to the Blue Mounds, a distance of 
about twenty miles. Here it takes a slight bend 
to the southwest for fifteen miles until it reaches 
Dodgeville, where it resumes its westerly coutse 
until it terminators in th  bluffs at thb conflu- 
 
ence of the Wisconsin and Mississippi rivers. 
Its total length is about eighty-five miles. Two 
points are noticeable: one is, its gentle uniform 
directness of outline (it being subject to but few 
and unimportant flexures); and the other is its 
parallelism with the Wisconsin river so long as 
the latter holds an approximately westerly course 
--the summit of the ridge being always about 
fifteen miles from the river. 
The divide maintains an average elevation of 
about 600 feet above Lake Michigan and is sel- 
dom less than 500, or more than 700, except at 
the Blue Mounds, where it gradually rises east 
and west for several miles, until it attains an 
elevation at the west mound of 1,151 feet. This, 
however, is an extreme case, and in fact, the 
only marked exception to its general level. In 
the town of Mount Hope, Grant county, a slight 
decrease of elevation commences and contin- 
ues to the western end of the divide, where the 
elevation is about 430 feet, at a point within a 
mile of both the Mississippi andWisconsin rivers. 
There are two main branches or sub-divisions 
of the water-shed. Of these, the western is the 
ridge which separates the waters that flow into 
the Platte and Fever rivers from those which 
flow into the Pecatonica. It leaves the main 
divide in the town of Wingville, Grant county, 
and passing through the towns of Belmont 
and Shullsburg, in Iowa county, in a southeast- 
erly direction, passes out of the State in the 
town of Monticello, in the same county. This 
ridge is not so conspicuous as the main water- 
shed either for the directness of its course or 
the uniformity Of its levation. The most &in- 
 
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