Lost River - Karst Information Portal

Regional and Karst Geology
of the Ohio River Fringe and South-Central Indiana
Featuring the Lost River, and Carbonate and
Clastic Rocks of the Mississippian and Devonian (with some
historical and cultural notes)
Many portions of the text and road log were
taken from previously published papers
and field trips written and/or organized by:
Blatchely, Malott, Powell, Bassett, Armstrong,
Art and Peggy Palmer, Hobbs, Moore, Krothe,
Deebel, Johnson, and many others. We wish
to thank them for their previous work and
their interest in, and dedication to, Indiana
speleology. In recent years, Special Report
61 (Gray, 2000) of the Indiana Geological
Survey has promoted changing the name of
the Mitchell Plain to the “Mitchell Plateau,”
and that of the Chester Escarpment to the
“Springville Escarpment.” This paper continues
the long-standing, widely recognized, and
typically current useage of the Mitchell Plain
and Chester Escarpment to be consistent with
over 150 years of geologic and karst literature
in Indiana and globally.
Summary of the Major Stops on
the Field Trip
Stop 1: The Crawford County
Fairgrounds is on top of the Crawford Upland,
a loess and sandstone-capped, dissected
plateau and regional erosional feature with
up to 500 feet of local relief. Wyandotte and
other large caves are within this area. Within
the Crawford Upland, the limestones exposed
in the Mitchell Plain to the east, are protected
by a veneer of Mississippian-aged interbedded
sandstone and shales of the Chester Group,
resulting in the picturesque upland topography.
The eastern edge of the Upland is the Chester
Escarpment, the prominent erosion, structural,
and topographical transition with the
carbonate floored and heavily karsted Mitchell
Edited, updated, and partially written by
Kevin Strunk, MS, LPG, NSS 16267
Plain. Classic karst features are associated
with subsurface drainage of the sinkhole plain
and the uplands under the control of massive
regional down cutting of the base level Blue
River and Ohio River. The Upland also has
sandstone-capped and dominated erosional
“buttes” and many sandstone shelter caves.
Travel to Stop 2: We will go south on
State Road 66 and travel past Pilot Knob, an
erosional remnant and topographical feature
sitting on top of the Upland that is capped by
likely the eastern-most outcrop of the lowermost
Pennsylvanian-aged strata, the Mansfield
Sandstone.
Stop 2: Tower Quarry has excellent
exposures of the lower Chester Series sandstones
and limestones and the main cave bearing
units, the Ste. Genevieve Limestone and
other Blue River Group rocks. We will see an
approximately 150-foot-tall highwall in a brief
stop which will begin our exploration of the
Indiana stratigraphic column from the Chester
Series in the west to Devonian limestones in
the east. This will also show the rocks which are
at the Upland’s surface locally.
Travel to Stop 3: We will travel east on
scenic State Road 62 to Leavenworth and
then along the Ohio River scenic overlook
at Horseshoe Bend, and then cross and
pass through the heavily karsted and deeply
dissected Blue River Valley on the way to
Wyandotte Cave.
Stop 3: Wyandotte Cave is perhaps
Indiana’s most famous cave with a combination
of history, geology, exploration challenges, and
management issues making for a unique spot
in Indiana speleology. We will visit the historic
73