Over
500 million years ago, grain by grain
, rock
was eroded and washed down into the lowlands of what is now Lake
Superior. Sometimes it was laid down slowly in clay or into sand of
a lakebed or from rivers swollen by storm
run-off. There is no
record of life existing in these sediments, but they hold evidence
of rain, and of an atmosphere with enough oxygen to form the iron
oxides that coat and cement together each quartz grain with the
rust color characteristic of brownstone.
These layers
of sediment were laid down year after
year.
Today, hints of this past can be seen along
the southern shore
of Lake Superior in a
narrow belt six to eight miles along Chequamegon Bay and the South
Shore to Port Wing and on several of the Apostle Islands, this is
called the Keweenaw strata.
The names of these sedimentary rock formations come from their
locations: the Fond du Lac formation in Minnesota, The Bayfield or
Lake Superior sandstones (brownstone) along the south shore in
Wisconsin and the Jacobsville sandstone in the Upper Peninsula of
Michigan. The hardness of the brownstone, and thus suitability for
building, is determined by how fast or slow the stone can be sawed.
For example, sandstone from a quarry in Michigan sawed at a rate of
28 inches per hour. The Lake Superior sandstone sawed at a rate of
4 inches per hour!
The quarrying of brownstone became
an important local industry in the late 1800's with several
quarries operating between Washburn and Bayfield along the
sandstone outcrops. At the height of the industry, seven
quarries were operating in Bayfield County. One such quarry can be
seen just off of Highway 13 (see waypoint). The first brownstone
was quarried on Basswood Island in 1869 . By 1871 brownstone
was being shipped down the lakes to Chicago to rebuild that city
after its devastating fire. Lake vessels, docked alongside
many of the quarries, loaded and shipped cargoes of up to 600 tons
of undressed stone.
In 1892 Frederick Prentice, president of the
Prentice Brownstone Co., offered to supply a huge brownstone
monolith for the Wisconsin Exhibit at the 1893 World’s Fair in
Chicago. He proposed to furnish this impressive one piece structure
at a size of 110 feet high, 10 feet wide at the base and coming to
an apex of 2.5 feet, which, according to Mr. Prentice, would
eclipse the Egyptian Obelisk that measured 105 feet, 7 inches high.
The Houghton quarry was selected because it had the best brownstone
for the purpose, i.e., free from clay pockets, tints and streaks.
Unfortunately, the cut stone never left the quarry because it
became too expensive. Mr. Prentice withdrew his offer and the huge
stone was cut and reshaped for use in other buildings. In 1893
Prentice cut 750,000 cubic feet of sandstone and by 1903 the
industry all but died, having been replaced by concrete and other
building materials.
The building in front of you is one of the finest examples
of a brownstone building anywhere. It was built in 1890 as a bank
and now houses the Washburn Historical Society and Museum. Go
inside and further examine some of the history related to the
industry.
***
Washburn
Brownstone
Building
Tour***
So from the bosom of darkness our days come roaring and gleaming,
Chafe and break into foam, sink into darkness again.
But on the shores of Time each leaves some trace of its passage,
Though the succeeding wave washes it out from the sand.
-Henry Wadsworth
Longfellow
TO LOG THIS CACHE:
1) How tall is
this brownstone object?
2) Upon
close examination of the brownstone, do you see any quartz grains
without any of the iron oxide coating?
3) Who
erected this particular brownstone object?
To log this cache e-mail me
the
answer
HERE
.
Sources:
-
Dott, R.H. and J.W. Attig (2004). Roadside
Geology of Wisconsin. 400 p.
-
Washburn Historical Society and
Museum