Lost River - Karst Information Portal

2007 NSS Convention Guidebook
calcareous quartz and chert sandstone that is
markedly cross bedded, is in lenses of small areal
extent, and is as much as 40 feet thick (Shaver, et
al, 1986, p 129).
The Levias Member is a gray to light-gray,
thin- to medium-bedded limestone that is up
to 60 feet thick in outcrop. Much of it is dense
and calcarenitic but thin beds of lithographic
limestone are commonly found separated by
thin shales. Argillaceous dolomite beds are not
uncommon. The uppermost part of the member
commonly consists of a limestone breccia called
the Bryantsville Breccia Bed, but there are other
thinner, less persistent breccias.
The Ste. Genevieve Limestone probably
contains the greatest number of large caves of
any rock body in Indiana. Its vertical variations in
lithology show up again and again as variations
in passage size, shape, and orientation. It is
overlain and underlain by formations particularly
conducive to the localization of caverns and,
as a part of the greatest continuous section of
carbonate rocks exposed in the state, it is involved
in almost all of the deeper pit caves. Many of the
largest caves in the Crawford Upland are partially
or totally developed in the Ste. Genevieve. In
particular Wyandotte, Sullivan, Blair, Buckner,
and Wayne caves, as well as many of the caves
and features in the Lost River area. The unit is
extensively quarried for crushed stone aggregates,
and is a prolific Illinois Basin oil producer. The
Ste. Genevieve grades conformably into the Paoli
Limestone.
Paoli Limestone – Much of the Paoli
Limestone is characterized by four principal
lithologies, in ascending order: (1) gray to
light-gray, dense, thin- to thick-bedded, skeletal
or oolitic limestone; (2) gray or greenish-gray
calcareous shale in the middle of the formation
called the middle shale break; (3) gray to
greenish-gray, dense to lithographic limestones,
that tend to be thinner bedded and less pure than
the limestone above the shale break and that in
places are replaced by calcareous shale that grades
upward through argillaceous limestone into
the middle shale break; and (4) gray calcareous
sandstones, dark shales, and impure limestone
which at times have been called the Popcorn
100
Member at the outcrop and the Aux Vases in
the subsurface (Shaver, et al, 1986, p 6 and p
108). The Paoli averages about 20 to 35 feet in
thickness, but reaches as much as 40 feet on the
outcrop (for example at the Orleans Quarry)
At the top of a thick limestone sequence and
beneath the impermeable shales and insoluble
sandstones of the Bethel and other Chesterian
formations, the Paoli is often involved in cave
formation. Upper levels of the ridge caves
mentioned under the discussion of the Ste.
Genevieve, above, are frequently formed in the
Paoli, as are prominent hillside sinks and the
tops of many pits. Of exceptional importance are
the calcareous shales and argillaceous limestones
of the middle shale break and the Aux Vases.
Extensive passage development has occurred in
these easily eroded, soluble rocks to form major
portions of Wildcat, Joy, Connerly, Sullivan,
Batey, and Popcorn Spring caves.
The Chesterian Series: West Baden, Stephensport,
and Buffalo Wallow Groups
The Chesterian Series consist in ascending
order of the West Baden, Stephensport, and
Buffalo Wallow groups. They all consist of
thinner, interbedded sandstone, shales, and
limestones, with some thin coals. Rocks that
are now considered to belong to the Chesterian
Series in Indiana previously went by a variety
of names, most of which originated elsewhere.
Among these names are Ferruginous Sandstone,
Kaskaskia Limestone, Archimedes Limestone,
Pentremital Limestone, and Chester Limestone,
most of which were originally used in early
reports on the geology of the region surrounding
Ste. Genevieve, Missouri, and Chester, Illinois.
Hopkins (1902, 1904) first applied an
indigenous name to these rocks in Indiana. He
included in his Huron Group, named for a village
in southwestern Lawrence County, all rocks
from the top of the Mitchell Limestone (see the
discussion under “Blue River Group”) to the base
of the Mansfield Formation. The name Huron was
used for a time, but it was preoccupied, and when
equivalence to the Chester Group of southern
Illinois became clear, Greene (1911, p 269)
suggested that the name Chester be substituted.