Sunbury American. [volume] (Sunbury, Pa.) 1848-1879, 1850-06-08
Iflilu1esota Gerritorp.
[From the Pennsylvania Telegraph
ORIGINAL SKETCH
OF THE
HISTORY AND GEOGRAPHY
OF
MINNESOTA TERRITORY.
BY DE-. THOMAS FOSTER.
Number 2.
BY DR.. THOMAS FOSTER.

THE GEOLOGY OF THE TERRITORY.
The immediate valley of the Upper Missis-
sippi 10 some distance above the Falls OF ST.
Anthony, has been explored within the last
few years, by the United States Corps of Geo.
logists, under the direction of DR.. David D.
Owen The bluffs or hills al Prairie du Chen,
! the old French and Indian town above the
Wisconsin river, on the Mississippi, he pre-
sents as type of the rock stIaliicatiOn of
the whole valley north of that place; and
the different strata are found 10 range in this
order:
lst. Near the level of the bed o: the Mis-
sissipp is soft ,ohite quartose sandstone.
End Next above this is an unslralifed
limestone, styled The lower magnetism lime
stone, abou, 200 feet thick.
3D. Next over this is a soft sandstone be-
tween 40 and so feet in thickness.
4th. Lying Immediately above the last, is
the buf.colored, blue and gray fossiliterous
limestone, upwards of 100 fee, in thickness
5th, Gaping the whole at the summit, is
the upper magnetism limestone, or lead bearing
rock of the Mineral Point and Dubuque dis
tric,s Of Wisconsin and Iowa.
On ascending the river above Prairie Du
Chen, or going North, the rocks constituting
The base of the hills at the Prairie are seen
higher up on the sides of The bluffs, though
the hills themselves retain nearly the same
elevation; The consequence is that, one after
another, the upper rocks thin out and disap-
pear; and before proceeding many miles, The
lo0er magnetism limestone first found at the
bottom Of the hills is seen extending even
TO their highest SUBMITS, while The quartoze
sandstone next below it, gradually rises, and
al last constitutes principal portion of their
base.
This general tendency of the qualification
TO rise going North, or rather Northeast, is
interrupted occasionally by local pitches of
the strata, by which the beds that have been
observed higher on the hill.sides, as one as
cends The river, dip down again; and the
upper beds of rock which had nearly run out,
again thicken, and constitute as before, the
principal part of The hills.
But aside from these local irregularities,
or pitches the lower rocks continue to rise
up as we proceed North, until at Mountain
Island the sandstone that lies beneath the
lower magnetism limestone, is observed to
form the great body of that hill to the height
of 42s feet
About this part of the Mississippi, or few
miles below, we have, in fact, the COM
mencement of what, in the language of the
Geologisi, is termed the principal aris of the
Upper Mississippi, or geological backbone,
from whence the different rock strata decline
each way--to the South towards the Gulf of
Mexico, and 10 The North, (still with OCCASION
al local undulations or Irregularities as before
mentioned,) toward the Falls of st. Anthony
That is to say, that as you proceed in either
direction, North or South from the rocky back
bone, the rocky strata nearest the surface of
the country, and highest in the bluffs, sink
deeper and deeper and are replaced by