Lost River - Karst Information Portal

2007 NSS Convention Guidebook
the entire cave region.
The second continental ice sheet, the
Kansan, extended into Indiana and covered
about five-sixths of the state, but it flowed
around the southern two-thirds of the cave
region. The exact extent of the Kansan ice
sheet is uncertain because it was covered by the
following (Illinoian) glacier. The Kansan ice
sheet blocked the passage of many streams and
rivers in its path, especially those streams that
are now in the head waters of the present day
Ohio but that once flowed to the north.
These blocked streams flowed along the
front of the ice sheet, in a westerly direction,
to the headwaters of the ancient Ohio, and
thence out to the Gulf of Mexico. The streams,
surging with sediment-laden melt waters from
the ice sheet, rapidly downcut the Ohio River
bedrock channel. By the time the Wisconsinan
ice sheet ablated, the Ohio River had extended
its headwaters to their present position.
During the Illinoian glaciation, the process
was repeated. The Ohio channel was widened
in some places and perhaps deepened in a few
areas, but in general the sediment-laden melt
waters from the ice sheet tended to fill the
Ohio Valley. This fill generally lies below the
present valley fill.
The Illinoian ice sheet overrode the
Knobstone Escarpment and the Norman
Upland in northeastern Washington County.
Travel to Stop 4
We will continue east on scenic State Road
62 along the north side of the Blue River
passing though the Harrison Crawford State
Forest, portions of which were recently named
O’Bannon Woods State Park (named after
the late beloved Governor Frank O’Bannon,
a Harrison County native, cave owner, and an
active conservationist). We will travel about
13 miles from Wyandotte through historic
Corydon and past the first capital of Indiana,
and then another 5 miles north on State Road
135, crossing Interstate 64 to the Corydon
Crushed Stone Company Quarry located
on Quarry Road. See Figures 20 & 21 for
116
Melt waters from the glacier temporarily
flowed into Blue River, possibly scouring and
deepening the bedrock channel. Glacially
derived sediments have been reported preserved
as terraces within the headwater streams of Blue
River; these sediments have not been detected,
however, south of Washington County.
The Wisconsin, the 4th and last major
glaciation, did not extend into the southern
third of Indiana as did the Kansan and Illinoian
ice sheets. But melt waters from the ice sheet
did reach many of the major streams, such as the
Ohio River. The sediments deposited within the
Ohio Valley overlie those of earlier glaciations.
Blue River was a ponded stream during the
period of time while the Ohio River received
the Wisconsinan meltwater. As a result, some
sediments, those of earlier glaciations, from the
upper Ohio River were deposited at the mouth
of Blue River. Blue River was a ponded stream
during the period of time while the Ohio River
received the Wisconsinan meltwater (generally
at an elevation of 435 feet). Stream sediments
borne by the upper part of Blue River settled
out in the lake-like lower Blue River valley.
These lacustrine (lake deposited) sediments
are present today as terraces or remnants of the
former lake bottom from the mouth of Blue
River to the vicinity of Harrison Spring (these
deposits at Harrison Spring are at an elevation
of about 450 feet).
topographic maps of the area.
After leaving Wyandotte, we will continue
to pass through the heart of the Blue River karst
in more of the most heavily dissected portions
of Indiana, then pass into the Harrison Spring
area which is Indiana’s largest spring located
just north of Interstate 64 on Harrison Springs
Road in a corn field. We will also see Scout
Mountain and Greenbriar Knob, and pass by
State Road 462, off of which is the old caver
barn reconstructed by the O’Bannon family
into a rustic retreat.
The highway in this area is built on
Wisconsinan-age lake sediments derived from
late glacial back flooding of the Blue River