A Rough Excursion
Field Inspection of the Caseyville Sandstone,
the Pennsylvanian-Mississippian Unconformity
and the Middle Chester Series.
21 and 22 November 2008
The Kentucky Society of Professional
Geologists
Annual Field Conference
Rough River State Park
Ken Kuehn
Mike May
Scott Waninger
David Williams
Chesterian Rocks of the Rough River Area
The subject of this field conference is a section of rocks comprising the middle part of the Chesterian Series
of Missippian Age and the Sub-Pennsylvanian unconformity. The area of the field conference lies in the
triangle between Rough River State Park, Caneyville, and Leitchfield, Kentucky. There are an abundance
of exposures along roads, particularly along the Western Kentucky Parkway but also in quarries, natural
outcrops, and the lake shore of Rough River Lake. The Caseyville Sandstone of basal Pennsylvanian Age is
the youngest rock exposed at locations that will be visited by this field conference. We will have a couple
of opportunities to observe the actual contact at the Sub-Pennsylvanian unconformity. The Missippian
Chester rocks that are part of the field area start at the Big Cliffy Sandstone the oldest rock unit to the to be
visited to the Kinkaid Limestone which is the youngest rock unit other than the Caseyville Sandstone.
The field area lies south of the Rough Creek Fault Zone (RCFZ) the major tectonic feature of Western
Kentucky and overlies a part of the Rough Creek Graben that is bounded on the north by the RCFZ and the
Pennyrile Fault Zone to the south. The Rough Creek Graben contains the deepest sedimentary rocks in
Kentucky and these deeply buried rocks have been the target of two of the deepest petroleum tests in
Kentucky, the Texas Gas Transmission Corp. #1 Herman Shain drilled to a depth of 13,551 feet in the and
the Conoco Inc. #1 Isaac Shain drilled to a depth of 12,622 feet; both wells penetrated into the Cambrian
Eau Claire Formation.
The field area lies on the eastern flank of the Illinois Basin and the regional dips reflect the western flank of
the Cincinnati Arch. The positive area of the arch caused a thinning of the rock section through the thinning
of individual rock formations and allowed the Pre-Pennsylvanian erosion surface to cut down and remove
the upper Chester Rocks above the level of the Kincaid Limestone and allowed for very deep incensement
of paleovalleys into the Middle Chester Rocks.
This field conference will make available for study the sedimentology and stratigraphy of the Chesterian
Rocks exposed at various locations within the field area as well as paleoslumps, petroleum traps, asphaltic
sandstone, and the opportunity to sample fossils and coal.
Falls of Rough – A Brief History
The small community of Falls of Rough, Kentucky was established as a milling community associated with a falls or
cascade on the Rough River located at the present Breckinridge and Grayson county line. The falls are near the
contact between the Hardinsburg Sandstone with and the Haney Limestone Member of the Golconda Formation.
The Hardinsburg forms a relatively resistant layer at this location creating the falls. The Rough River valley at Falls
of Rough provides several examples of entrenched meanders as well as meander cut-offs. The falls location was
used by the Green family who established the Green Mill in 1823.
Willis Green was the first of the family to settle at Falls of Rough having purchased the land in 1821. He was a
member of the Kentucky state legislature from 1836 to 1837 and was a U.S. Congressman from 1839 to 1845. The
Green Mill was the center of activity for a 6,000-acre agricultural-timber complex that supported a number of
family-owned enterprises. Grain was brought from seven surrounding counties by farmers who needed it milled into
wheat flour and corn meal.
In addition to the mill, the Green mansion and a few old houses and stores remain in the community today. One
other notable structure, spanning the river at the mill site, is an arcuate iron bridge. The bridge dates to 1877 and
was built by the King Iron Bridge & Manufacturing Company out of Cleveland, Ohio. This bridge is chronicled in
the Great American Bridges and Dams – A National Trust Guide by Donald Jackson (1984).
Green Mill at Falls of Rough
1877 Arch Bridge above falls and mill dam
General Stratigraphy in vicinity of Hwy 79 Salvage (Abandoned Quarry)
Approximately two miles north of Caneyville, KY, a small creek valley (Jarrett Fork) has incised through the
Pennsylvanian Caseyville (or Caseyville-Tradewater – Ptc), the Mississippian Kincaid Limestone Member of the
Buffalo Wallow Formation (Mbk) and the Lower part of the Buffalo Wallow Formation just above the Menard
Limestone marker bed (Mbw). The Kincaid Limestone can be examined in an abandoned quarry on the salvage
yard property and the basal Caseyville can be seen as unconformably overlying this limestone at the top of the
quarry walls. We will examine both the Kincaid Limestone and the basal Pennsylvanian in detail and collect in this
quarry. In this region the Buffalo Wallow and Tar Springs Formations have been mapped by Gildersleeve (1978) as
stratigraphic equivalents to the Leitchfield Formation in the Leitchfield, KY, quadrangle located to the east of this
quarry.
Mbk
Ptc
Quarry
Quarry
Aerial view of Hwy 79 Salvage Yard and Quarry in Kincaid Limestone.
Basemaps modified from Kentucky Geological Survey.
There is some minor relief observable in the quarry at the Mississippian-Pennsylvanian unconformity marked by
scours and backfills typical of pre-Pennsylvanian surfaces in the region. In the Caneyville Quadrangle, mapped
relief on the unconformity surface is quite variable (Gildersleeve and Johnson, 1978). The southern part of the
quadrangle for example has much of the Menard Limestone missing, being cut out along pre-Pennsylvanian
paleovalley that was subsequently filled with Caseyville Sandstone. Pennsylvanian rocks even locally cut down as
far as the Tar Springs Formation in the subsurface but channeling is minimal in the northern portion of the
quadrangle.
Kincaid Limestone
The Kincaid Limestone in the quarry is typically a light- to dark gray, muddy limestone with brown and yellowish
brown mottles. There are some grainy or skeletal intervals and some shaley interbeds. Many of the limestone slabs
are mudstones or wackestones and these fracture much like lithographic limestone possessing a spally or conchoidal
nature. The grainier intervals are generally packstones with only minor grainstones and are typified as being rich in
horn corals, crinoid stems (columnals), bryozoans, gastropods, brachiopods and small masses of spongiostromatoid
algae (Gildersleeve and Johnson, 1978).
This quarry was one of four developed in the Kincaid Limestone in the Jarrett Fork area. The limestone was used
for road metal and limestone aggregate and was reportedly quarried by the Works Progress Administration (WPA)
during the 1930s in a quarry located just south of our stop along highway 79. At the time of mapping the Caneyville
Quadrangle (approximately 30 years ago) there were two active quarries in the area that supplied riprap for roads
and for lining on earthen dams in the Caney Creek watershed (Gildersleeve and Johnson, 1978).
Lithologic variation in the mottled Kincaid Limestone. View on left shows
grainy or skeletal intervals and right view shows muddier or less grainy interval.
Caseyville Formation
ville Ss
Casey
id Ls
Kinca
Mudstone lag or rip-up clasts below
rippled interval near base of Caseyville
Ripple Laminated Caseyville
The original mapping in the vicinity of the quarry denotes this unit as Caseyville-Tradewater but the lowermost
portion as is exposed in the quarry is thought to represent the Caseyville based on recent mapping and palynology
studies by the Kentucky Geological Survey (Eble, pers. comm. 2008). The sandstone portion of the Caseyville
exposed in the quarry on fresh surfaces is a white, very fine to medium grained quartz arenite with some localized
coarse-grained intervals at the base. This sandstone weathers as brown, yellowish brown and reddish brown with
myriad Fe-oxide stained intervals throughout. In the quarry walls some sole marks such as load casts and flute casts
are visible (look closely at contact between the sandstone and the limestone) as is cross bedding. There are also a
few interbedded shales and siltstone in the Caseyville interval.
CSVL. SS
Coal
Seat Rock
Detail of the Base of the Caseyville Formation just above the Kinkaid Limestone
Paleoslump Feature
Caseyville Formation-Pennsylvanian
Colloquially known among the older geologists at the Western Kentucky Office of KGS as “Mile Post 99” this is a
good exposure of an ancient slump event. Located just above the Mississippian-Pennsylvanian contact, the slump is
composed mainly of fluvial sandstones, shale and coal.
Thick, gnarled sandstone capped by planar-bedded sandstone and possible rhythmic (tidal) bedding with
abundant plant casts, this unit has an unconformable base which stops at the top of an underlying coal.
The coal is approximately one foot thick, bright, and well banded. Present beneath the coal is a zoned
paleosol or ‘seat earth’; the first zone is light gray, semi-plastic, sulfurous, rooted and carbonaceous. The
second zone is hard, non-plastic clay, with abundant iron nodules.
Approximately four feet beneath the claystone is a carbonaceous shaley bed which caps a lower coal.
This coal is up to two feet thick and is horizontal to a thin coal 30 feet to the west. The west boundary of
the thick coal is terminated by a sharp edge with slickensides and upturned banding in the coal that
indicates a slump face. Beneath the coal is a rooted shaley unit and a gnarly well-cemented, fine-grained
shaley sandstone with plant casts. This seems to form an unconformable base with the Mississippian
Buffalo Wallow Formation below.
On the west end of the cut, the Menard Limestone drops off with a slickensided sandstone above. John
Nelson (Illinois State Geological Survey) interprets this exposure as a paleovalley which formed to the
west of the cut removing the Menard; later Pennsylvanian sediments slumped into the paleovalley
leaving the slickensides.
There are several slump features in this cut and the Menard seems to have been lithified prior to any
slumping. The Pennsylvanian sediments are represented by the flat lying coal and sandstone. The top of
the cut does not seem to be involved in the slump events. Movement on the east end of the cut seems to
be to the east causing a compressional fold near the top of the road grade. A second possible slump
involving the thick coal appears to have rotated to the west. The east-moving slump involves possible
Palestine Sandstone whereas the west-moving slumps involve Pennsylvanian rocks.
Compression Fold Involving Paleoslumped Caseyville Rocks near Mile Post 99 Western Kentucky Parkway
There many small slump structures exposed along the Kentucky Parkways; one of the other better exposures of a
large slump event can be found in the south exit ramp off the Pennyrile Parkway at Sebree. Slump events have also
been identified in drill holes and underground mines.
Mile Post 100
Caseyville and Menard Formations
Here is exposed what is believed to be a contact between the Pennsylvanian Caseyville Formation and the
Mississippian Menard Formation along the systemic unconformity. The road cut consists of flat-lying, mediumbedded Caseyville Sandstone near the top of the cut in unconformable contact with the shale and limestone of the
Menard Formation. The Menard consists of thin- to medium-bedded shale and limestone. The limestone is a
medium gray, fossiliferous wackestone representing a mud-dominated shallow marine environment. Contained
within the Menard are small cut and fill structures (filled with limestone) that represent small channels. At the top of
the road cut there is a thick, cross-bedded sandstone incised into the flat-lying sandstone. The flat-lying Caseyville
strata are interpreted as offshore deposits incised by an outward building stream channel depositing the cross-bedded
sandstone.
A short distance east of this exposure is another road cut exposing a somewhat different section. Here more of the
Menard Formation is exposed in contact across the unconformity with a thin unit of distal ripple-bedded sandstone
of the Caseyville. That unit is overlain by a cross-bedded, channel phase of the Caseyville Formation.
Caseyville-Menard Contact at Mile Post 100 on Western Kentucky Parkway
CASEYVILLE FORMATION (from USGS PP 1151-H )
Primary Lithology: Quartzose sandstone, shale, limestone
and coal The Caseyville Formation was named for exposures
of massive cliff-forming, crossbedded, pebbly sandstone on
the Ohio River near Caseyville, just north of the mouth of the
Tradewater River (Owen, 1856). At the type locality, the
Caseyville is a channel deposit that occupies the broad
Evansville paleovalley of Potter and Desborough (1965). The
valley, which is as much as 15 mi wide and 250 ft deep, has
been traced in the subsurface by Bristol and Howard (1971,
fig. 4) for about 130 mi across Kentucky and Indiana. At the
type section, about 10 mi northwest of Caseyville, Lee (1916)
described the Caseyville as a formation about 500 ft thick that
includes pebbly quartzose sandstone, carbonaceous and
calcareous shale, limestone, and coal. Lee placed the top of
the Caseyville at the top of a massive pebbly to
conglomeratic sandstone that is about 80ft thick.
None of the sandstone units of the Caseyville Formation are
persistent: some sandstone units are terminated at the walls
of the paleovalleys, and others pinch out or grade into
siltstone (Potter and Desborough, 1965, fig. 6). As a result,
the Caseyville varies greatly in thickness and lithology from
place to place. Thus, the top of the Caseyville is mapped
locally in the western part of the western Kentucky coal field
at the base of the Bell (or No. lb) coal bed because that coal
is in places only a few tens of feet above pebbly Caseyville
sandstone, but in most other parts of the basin where the Bell
coal bed does not persist or cannot be identified owing to
poor exposures, the Caseyville has been combined on the
quadrangle maps with the overlying Tradewater Formation.
On the State geologic map, the contact at the top of the
Caseyville in most areas of the western Kentucky coal field is
approximately located by projection of the horizon of the Bell
coal bed from overlying and underlying units, such as the
Lead Creek or Curlew Limestone Members of the Tradewater
Formation or the top of the Mississippian, all of which were
identified in drill hole logs by T.M. Kehn and J.G. Beard.
Buffalo Wallow Formation
(Upper Mississippian - Upper Mississippian)
USGS Unit Info: GEOLEX (id: 706)
Mapped or described as these unit(s) on the original GQ:
BUFFALO WALLOW FORMATION
USGS Unit Info: GEOLEX (id: 706)
Primary Lithology: Shale, siltstone, sandstone, and coal
Above Menard Limestone
Shale, siltstone, sandstone, and coal: Shale, grayish-green, moderate- to
dark-greenish-gray, medium-gray, and locally dark-reddish-brown and
grayish-red in lower part, weathers light to moderate olive gray, medium
gray, and grayish green; clayey to silty; locally underlies nearly bare slopes.
Siltstone, light- to medium-light-gray and light-olive-gray to light-yellowishgray, weathers to conspicuous light- to dark-yellowish-brown angular to
subrounded chips; laminated, generally in beds less than 2 feet thick;
calcareous, locally slightly sandy. Sandstone, light-gray, weathers brown,
iron stained; very fine to fine grained; thin to very thick bedded, in part
crossbedded. Locally along east side of Bennett Fork upstream from
Caneyville Reservoir, a 3-foot-thick bed of sandstone, light-gray, very
Buffalo Wallow Formation (GQ-1472):
calcareous, thin-bedded to platy, slightly crossbedded, occurs in basal part of
unit; it weathers dark yellowish brown and at places contains many dense
granules and pebbles as much as 0.15 foot in diameter of limestone and
siltstone. The sandstone seemingly is in an intraformational channel that
locally has eroded out the Menard limestone marker bed. Coal, coaly shale,
and shaly coal as much as 10 inches thick occur locally near top of unit near
west quadrangle border at two localities less than 1,600 feet generally north
of Lake No. 6, and along a road about 1,100 feet northeast of Caneyville
Reservoir.
Below Menard Limestone:
Shale, siltstone, and sandstone: Shale, medium-gray to olive-gray, weathers
light to moderate olive gray and light to medium gray, locally light yellowish
brown where slightly calcareous; clayey to finely sandy. Siltstone, very light
to light-gray and very light brownish gray, weathers light gray to light olive
gray and light to moderate yellowish brown; calcareous; platy to very thin
bedded, in layers less than 5 feet thick; generally hard and forms
conspicuous light-colored ledges on steep slopes, particularly in upper 25
feet of unit. Sandstone, olive-gray to light-gray, weathers to dense light-olivegray and light- to dark-yellowish-brown rectangular fragments; very fine
grained, platy to thin bedded, in part quartzitic; locally ripple marked; occurs
near middle of unit, generally in northwestern part of quadrangle. Unit not
well exposed.?p??p? Buffalo Wallow and Tar Springs Formations are
equivalent to Leitchfield Formation as mapped in Leitchfield quadrangle
(Gildersleeve, 1978) to east.
BUFFALO WALLOW FORMATION
USGS Unit Info: GEOLEX (id: 706)
Primary Lithology: Limestone and shale
Kinkaid Limestone Member
Limestone and shale: Limestone, light- to medium-light-gray and mediumdark-gray, weathers mottled brown, yellowish brown, light gray, and brownish
gray; very finely crystalline, in part dense, with subconchoidal to conchoidal
fracture; thin to very thick bedded; weathers to spalls and irregular thin slabs;
abundant fossils include horn corals, bryozoans, crinoid columnals,
gastropods, brachiopods, and very small masses of spongiostromatoid
algae. Locally near west border of quadrangle, 10 to 15 feet of gray,
fossiliferous shale containing a few thin beds of limestone occurs above thick
limestone beds and is overlain uncomformably by Pennsylvanian rocks. At
some localities unit is represented by reddish-brown clay residuum
containing scattered fossils. Buffalo Wallow and Tar Springs Formations are
equivalent to Leitchfield Formation as mapped in Leitchfield quadrangle
(Gildersleeve, 1978) to east.
Shale, siltstone, sandstone, and coal: Shale, grayish-green, moderate- to
dark-greenish-gray, medium-gray, and locally dark-reddish-brown and
grayish-red in lower part, weathers light to moderate olive gray, medium
gray, and grayish green; clayey to silty; locally underlies nearly bare slopes.
Siltstone, light- to medium-light-gray and light-olive-gray to light-yellowishgray, weathers to conspicuous light- to dark-yellowish-brown angular to
subrounded chips; laminated, generally in beds less than 2 feet thick;
calcareous, locally slightly sandy. Sandstone, light-gray, weathers brown,
iron stained; very fine to fine grained; thin to very thick bedded, in part
crossbedded. Locally along east side of Bennett Fork upstream from
Caneyville Reservoir, a 3-foot-thick bed of sandstone, light-gray, very
calcareous, thin-bedded to platy, slightly crossbedded, occurs in basal part of
unit; it weathers dark yellowish brown and at places contains many dense
granules and pebbles as much as 0.15 foot in diameter of limestone and
siltstone. The sandstone seemingly is in an intraformational channel that
locally has eroded out the Menard limestone marker bed. Coal, coaly shale,
and shaly coal as much as 10 inches thick occur locally near top of unit near
west quadrangle border at two localities less than 1,600 feet generally north
of Lake No. 6, and along a road about 1,100 feet northeast of Caneyville
Reservoir.
Menard Limestone marker bed:
Limestone, light- to medium-dark-gray and brownish-gray, weathers light to
medium gray, light brownish gray, light yellowish gray and moderate to dark
yellowish brown, commonly mottled; very finely crystalline, locally coarsely
crystalline, and very fine grained fossil-fragmental texture; hard, dense;
abundant small crinoid columnals and calyx plates, horn corals, and
brachiopods; generally a single vertically joined bed, but locally two beds;
weathers to large smooth rectangular blocks, the upper surfaces of which
break into small irregular plates and chips. Forms narrow ledge over much of
outcrop area but is missing along Bennett Fork upstream from Caneyville
Reservoir, seemingly due to intraformational channeling. This unit is
generally missing in the subsurface due to pre-Pennsylvanian erosion over
much of southern one-third of quadrangle.
Shale, siltstone, and sandstone: Shale, medium-gray to olive-gray, weathers
light to moderate olive gray and light to medium gray, locally light yellowish
brown where slightly calcareous; clayey to finely sandy. Siltstone, very light
to light-gray and very light brownish gray, weathers light gray to light olive
gray and light to moderate yellowish brown; calcareous; platy to very thin
bedded, in layers less than 5 feet thick; generally hard and forms
conspicuous light-colored ledges on steep slopes, particularly in upper 25
feet of unit. Sandstone, olive-gray to light-gray, weathers to dense light-olivegray and light- to dark-yellowish-brown rectangular fragments; very fine
grained, platy to thin bedded, in part quartzitic; locally ripple marked; occurs
near middle of unit, generally in northwestern part of quadrangle. Unit not
well exposed.
Viennna Limestone Member:
Limestone, very light to medium-gray and brownish-gray, weathers light gray,
light yellowish brown and light brownish gray, commonly mottled; very finely
crystalline to very fine grained, fossil fragmental, dense, platy to thin bedded;
argillaceous on bedding planes commonly in lower half and at few places in
upper half. Abundant lenses and masses as much as 0.8 foot long, 0.3 foot
wide and 0.1 foot thick of grayish-black fossiliferous chert that weathers to
porous white to brownish-gray and yellowish- to dark-brown angular
fragments that litter the outcrop. Commonly forms narrow ledge along
streams; top is well exposed locally along bottoms of North Fork and its
tributaries in northeast quadrant of quadrangle. At many places only chart
residuum marks position of unit.
Mile Post 105
Caseyville Formation
Asphaltic Sandstone and Petroleum Trap
This road cut is an exposure of the Caseyville Sandstone. The unit is coarse grained and orthoquartzitic, massive
with cross bedding. The exposure is cut by a north-south trending fault across which there is a distinct change in the
rocks. The sandstone is asphaltic over much of the road cut but all asphalt terminates against the fault. The asphalt is
truncated within the sandstone by a thick shale layer that separates the lower asphaltic sandstone from the upper
sandstone along the top of the road cut. Asphalt also seems to be limited by small shale ripple beds within the
sandstone but this is not common. The fault is expressed by drag folds in the sandstone and by an upturned coal bed
found in a ditch on the north side of the road.
Asphaltic Sandstone
Asphaltic Caseyville Sandstone near Mile Post 105 of the Western Kentucky Parkway
Leitchfield Exit Mile 106 to 107 Western Kentucky Parkway
Glen Dean Limestone to Palestine Sandstone
Mississippian Chester, Leitchfield Formation
The Western Kentucky Parkway passes eastward down through a long road cut toward Exit 107 at Leitchfield,
Kentucky. Starting near Mile Post 106 is a well exposed bench of the Palestine Sandstone about midway of the road
grade west of Leitchfield. The section as exposed along the road grade is described below: These rocks are mapped
as the Leitchfield Formation by the USGS mappers during the Kentucky Geologic Mapping Program but are broken
out here into the more individual units that are found westward within the Illinois Basin.
Mile Post 106 Western Kentucky Parkway
Palestine Sandstone
+3 feet
Sandy-Shaley unit with lycopod casts
+/- 3 feet
Shale, medium gray, poorly exposed
3 feet
Sandstone, light gray, fine grained, argillaceous, thick to medium bedded. Joe Devera (Illinois
State Geological Survey) identified Riezocorellium and Zoophycus trace fossils. The top of the
unit is rooted and bone material was also identified at this site.
Palestine-Menard Contact
1 foot
Shale, weathered, reddish brown, calcareous, with odd concretions, appears to be a
paleoexposure surface that forms a continuous band across the exposure.
+10 feet
Shale, light medium gray, flakey calcareous
Just west of the exit ramp at high cut: Approximately mile 106.5
Palestine?
+4 feet
Sandstone, weathered, red, disaggregated, fine grained shaley
1 foot
Shale, medium gray, flakey
1.5 feet
Sandstone, light brown, fine grained, well cemented, non-calcareous, thin bedded with no
internal structures. Bed thickness decreases upward from 0.5 feet to 0.1 feet. Rare large
horizontal traces, no great abundance but unit does appear to be bioturbated, Riezocorellium
+/-10 feet
Covered shale slope. Basal three feet there is a light green silty shale weathering out
Menard?
1.5 feet
Limestone, very thin bedded, dense calcilutite
+/-4 feet
Shale, light greenish gray, weathered, light gray to beige, flakey, scattered large light gray
limestone weathers beige, concretions, no fossils
Break in Slope
+/-7 feet
Shale, light greenish gray, soft, flakey, with zone of thin bedded dark gray limestone
(calcilutite) with greenish gray shale interbedded in center of exposure
1 foot
Limestone, dark gray, dense, calcilutite, weathers a musky yellow
1 foot
Shale, medium gray, hard, flakey
0.4 feet
limestone, dark gray, dense, calcilutite, weathers a musky yellow
+/-18 feet
Shale, medium gray, flakey, Spirifer.increbesus; disarticulated
+/-2.5 feet
Limestone, medium gray, dense, fossiliferous (crinoids, brachiopods, bryzoans); fossiliferous
calcilutite, thick blocky bedding
1 foot
Shale, light greenish gray, calcareous, small light gray limestone concretions, powdery
+/-1 foot
Limestone, medium gray with light brown speckled appearance, biorudite
1 foot
Limestone, medium gray, weathers light tan, calcilutite, curved fracture; abundant small
Productids
1 foot
Shale, light greenish gray, silty, blocky to flakey, calcareous, sparse Productids
+/-1 foot
Limestone, medium bray, weathers light tan, calcilutite, curved fracture, no Productids
Menard Fossil Suite
Spirifer.increbesence
Brachiopod.debria
Brachiopod.composita
Waltersburg?
0.8 feet
0.3 feet
1.5 feet
2 feet
+/-2.5 feet
Shale, medium gray, large tube burrow, calcareous
Zone of limestone concretions, light green very argillaceous
Shale, light green with red mottling, hard, blocky, calcareous, stands out in greater relief
Shale, dark green with red mottling, calcareous, flakey
Shale, red, hard, blocky
3 feet
Shale, medium green, blocky, calcareous
Vienna?
6 feet
+/-10feet
Tar Springs?
3 feet
4 feet
+/-2 feet
Covered
Limestone, light brown, chalky appearance, blocky, contains thin shale beds
Covered shale slope
Sandstone, light gray, fine grained, well cemented, thin tabular bedded
Covered
Shale, medium gray, flakey
At base of hill under overpass the Glen Dean is exposed
Description Source:
Geologic map of the Leitchfield quadrangle, Grayson County, Kentucky
Leitchfield Formation
(Upper Mississippian - Upper Mississippian)
Mapped or described as these unit(s) on the original GQ:
LEITCHFIELD FORMATION
USGS Unit Info: GEOLEX (id: 2440)
Primary Lithology: Shale, siltstone, limestone, and limestone conglomerate
Shale, siltstone, limestone, and limestone conglomerate: Shale, gray, green, gray-ish green, and
grayish-red; in part interbedded with siltstone and limestone. Siltstone, light-to medium-gray, weathers
yellowish gray; laminated to very thin bedded. Limestone, light- to medium-dark-gray, very fine to
coarsely crystalline, very thin to thick-bedded. Limestone marker bed, light- to dark-gray, dominantly
dense but coarsely crystalline locally, medium- to thick-bedded; contains thin shale split at some places;
weathered surfaces are characteristically smooth and brown; upper part of bed yields small chip-like
spalls whereas lower part yields large spalls; best exposed near heads of small draws and as isolated
outcrops on hillsides; persistent though not continuously exposed, and is cut out at many places by prePennsylvanian channeling. Limestone marker bed is equivalent to apart of the Menard Limestone. It
was mapped at places in the Clarkson quadrangle (Glick, 1963) as the probable equivalent of the Clore
Limestone. Intraformational limestone conglomerate, composed of subrounded to well-rounded
limestone pebbles averaging less than 3 inches in diameter (maximum 6 inches) cemented by very fine
limy sand, crops out at three places: 1) about 21/2 miles southwest of the Leitchfield interchange of
Western Kentucky Parkway, where it is approximately 100 feet above the base of the Vienna Limestone
Member of the Leitchfield Formation and is 2 to 3 feet thick; 2) about 11/2 miles south of the
interchange, where it is about 65 feet above the base of the Vienna and is 4 feet thick; 3) about 5 miles
south-southwest of the interchange, where it is about 45 feet above the base of the Vienna and is 1 to
11/2 feet thick.
VIENNA LIMESTONE MEMBER
USGS Unit Info: GEOLEX (id: 4243)
Primary Lithology: Limestone
Limestone, light-gray to medium-dark-gray, very fine to coarse grained, thick- to very thick bedded;
locally contains stringers of dense black chart; sparse fragments of crinoid columnals, brachiopods, and
bryozoans; weathered surfaces are smooth and brown. Probably persistent where not eroded, but not
mapped in northwestern part of quadrangle due to inadequate exposures.
TAR SPRINGS SANDSTONE EQUIVALENTS
USGS Unit Info: GEOLEX (id: 4068)
Primary Lithology: Shale, sandstone, siltstone, limestone, and limestone conglomerate
Shale, sandstone, siltstone, limestone, and limestone conglomerate: Shale, dark-gray to olive-gray,
yellowish-green, and grayish-red; clayey to sandy; grades laterally into sandstone and calcareous
sandstone at some localities; locally interbedded with siltstone, thin beds of sandstone and limestone.
Sandstone, light-gray to yellowish-brown, very fine to fine grained, very thin to thick-bedded, locally
calcareous. Limestone, light- to medium-gray, very fine to medium grained. In bed of Helm Fork, 2.2
miles east-southeast of the Leitchfield interchange of Western Kentucky Parkway, a limestone
conglomerate about 30 feet below the base of the Vienna is 6 to 10 inches thick. The conglomerate
contains fragments of fossil invertebrates and plants associated with vertebrate bones and teeth
(written communication, J. R. Jennings, December 1973). Unit equivalent to shaly upper part of Glen
Dean Limestone in Big Clifty quadrangle (Swadley, 1962) to the northeast; unit in most places includes
shale member of Glen Dean Limestone as mapped in Clarkson quadrangle (Glick, 1963) to the east.
Leitchfield Formation (GQ1316):
LEITCHFIELD FORMATION
USGS Unit Info: GEOLEX (id: 2440)
Primary Lithology: Shale, siltstone, limestone, and limestone conglomerate
Limestone marker bed
Shale, siltstone, limestone, and limestone conglomerate: Shale, gray, green, gray-ish green, and
grayish-red; in part interbedded with siltstone and limestone. Siltstone, light-to medium-gray, weathers
yellowish gray; laminated to very thin bedded. Limestone, light- to medium-dark-gray, very fine to
coarsely crystalline, very thin to thick-bedded. Limestone marker bed, light- to dark-gray, dominantly
dense but coarsely crystalline locally, medium- to thick-bedded; contains thin shale split at some places;
weathered surfaces are characteristically smooth and brown; upper part of bed yields small chip-like
spalls whereas lower part yields large spalls; best exposed near heads of small draws and as isolated
outcrops on hillsides; persistent though not continuously exposed, and is cut out at many places by prePennsylvanian channeling. Limestone marker bed is equivalent to apart of the Menard Limestone. It
was mapped at places in the Clarkson quadrangle (Glick, 1963) as the probable equivalent of the Clore
Limestone. Intraformational limestone conglomerate, composed of subrounded to well-rounded
limestone pebbles averaging less than 3 inches in diameter (maximum 6 inches) cemented by very fine
limy sand, crops out at three places: 1) about 21/2 miles southwest of the Leitchfield interchange of
Western Kentucky Parkway, where it is approximately 100 feet above the base of the Vienna Limestone
Member of the Leitchfield Formation and is 2 to 3 feet thick; 2) about 11/2 miles south of the
interchange, where it is about 65 feet above the base of the Vienna and is 4 feet thick; 3) about 5 miles
south-southwest of the interchange, where it is about 45 feet above the base of the Vienna and is 1 to
11/2 feet thick.
Vienna Limestone Member:
Limestone, light-gray to medium-dark-gray, very fine to coarse grained, thick- to very thick bedded;
locally contains stringers of dense black chart; sparse fragments of crinoid columnals, brachiopods, and
bryozoans; weathered surfaces are smooth and brown. Probably persistent where not eroded, but not
mapped in northwestern part of quadrangle due to inadequate exposures.
Tar Springs Sandstone equivalents:
Shale, sandstone, siltstone, limestone, and limestone conglomerate: Shale, dark-gray to olive-gray,
yellowish-green, and grayish-red; clayey to sandy; grades laterally into sandstone and calcareous
sandstone at some localities; locally interbedded with siltstone, thin beds of sandstone and limestone.
Sandstone, light-gray to yellowish-brown, very fine to fine grained, very thin to thick-bedded, locally
calcareous. Limestone, light- to medium-gray, very fine to medium grained. In bed of Helm Fork, 2.2
miles east-southeast of the Leitchfield interchange of Western Kentucky Parkway, a limestone
conglomerate about 30 feet below the base of the Vienna is 6 to 10 inches thick. The conglomerate
contains fragments of fossil invertebrates and plants associated with vertebrate bones and teeth
(written communication, J. R. Jennings, December 1973). Unit equivalent to shaly upper part of Glen
Dean Limestone in Big Clifty quadrangle (Swadley, 1962) to the northeast; unit in most places includes
shale member of Glen Dean Limestone as mapped in Clarkson quadrangle (Glick, 1963) to the east.
Boat Shop Renegade Marine
Tar Springs Formation—Mississippian
Tar Springs Formation as exposed behind Renegade Marine Boat Shop
Vienna Limestone Member:
Limestone, light-gray to medium-dark-gray, very fine to coarse grained, thick- to very thick bedded; locally contains stringers of
dense black chart; sparse fragments of crinoid columnals, brachiopods, and bryozoans; weathered surfaces are smooth and
brown. Probably persistent where not eroded, but not mapped in northwestern part of quadrangle due to inadequate exposures.
Tar Springs Sandstone equivalents:
Shale, sandstone, siltstone, limestone, and limestone conglomerate: Shale, dark-gray to olive-gray, yellowish-green, and
grayish-red; clayey to sandy; grades laterally into sandstone and calcareous sandstone at some localities; locally interbedded
with siltstone, thin beds of sandstone and limestone. Sandstone, light-gray to yellowish-brown, very fine to fine grained, very thin
to thick-bedded, locally calcareous. Limestone, light- to medium-gray, very fine to medium grained. In bed of Helm Fork, 2.2
miles east-southeast of the Leitchfield interchange of Western Kentucky Parkway, a limestone conglomerate about 30 feet below
the base of the Vienna is 6 to 10 inches thick. The conglomerate contains fragments of fossil invertebrates and plants associated
with vertebrate bones and teeth (written communication, J. R. Jennings, December 1973). Unit equivalent to shaly upper part of
Glen Dean Limestone in Big Clifty quadrangle (Swadley, 1962) to the northeast; unit in most places includes shale member of
Glen Dean Limestone as mapped in Clarkson quadrangle (Glick, 1963) to the east.
Glen Dean Limestone:
Limestone, light-gray, bluish-gray, and medium-dark to dark-gray, fine-grained to coarse-crystal line, thin- to very thick bedded;
upper beds commonly argillaceous and weather to rubble and thin slabs; scraggly chart on some weathered surfaces; locally
abundant bryozoans, crinoid stems, blastoid horn corals, and brachiopods; diagnostic fossils Pterotocrinus acutus Wetherby and
Prismopora serrulata Ulrich identified at several localities. Shale, greenish- to dark-gray, weathers gray; occurs as partings and
beds of' variable thickness interbedded with thin beds of limestone in upper part.
Tar Springs Exposure
Mississippian System
Chester Series
37.46592 N
86.28363W
NAD 83
The Tar Springs Formation is generally referred to as the “Tar Springs Sands” or “1st and 2nd Jett
sandstones” by oil drillers. The Tar Springs is the lower most unit of the Upper Chester Series of the
Mississippian System. The Tar Springs Section is mapped as between 25 – 40 feet in the Leitchfield
Geologic Quadrangle (Gildersleeve, 1978). The general appearance is of a shallowing upward sequence
before return to the offshore deposition of the Vienna Limestone. This transition from marine to
shallowing before returning to marine is characteristic of the Chester series. The base may be difficult to
determine at times due to possible facies relationship with the underling Upper Glen Dean Limestone
(Jacobs,1961). Sand to silty shale is the dominate lithology in the lower Tar Springs section. Gildersleeve
(1978) reported the occurrence of invertebrate, plant, and vertebrate bones and teeth fossils associated with
a 6-10 inch limestone conglomerate “about 30 feet below the base of the Vienna Limestone”. Shale to silty
shale is dominate in the upper Tar Springs. The contact with the overlying Vienna Limestone is thought to
be comfortable occasionally displaying a thin calcareous shale that is believed to be transitional zone
(McCreary, 1957).
The exposure displays about 30 feet of the Tar Springs Formation. The contact with the overlying
Vienna Limestone is displayed by red staining and weathered chert residuum in the upper portion of the
exposure. Looking west (down the hill) the Vienna Limestone is exposed in the valley wall along KY S.R.
259. The upper Tar Springs at this exposure displayed variegated silty shale. The red color indicates
oxidizing conditions, while the green, reduction. A blackish band midway through this section suggests
high organic content possibly equivalent with coal that occurs in other areas.
Separating the upper and lower Tar Springs is a concretion/burrowed zone. These concretions are
rounded and up to 4 inches in diameter usually displaying an indentation in the one, or both ends. Below
this zone, laminated to thin bedded couplets of carbonate cemented sandy shale dominate with minor thin
limestone beds near the concretion/burrowed zone. Invertebrate shells, molds and feeding traces can be
found in the limestone. The couplets form rhythmites, though no work has been done to determine if they
are tidal in nature. These rhythmites are best exposed where they are weathering out in the NE corner of
the exposure.
No longer exposed is an apparently comfortable contact with an underlying dark gray shale. This
shale is exposed in a 6 inch drainage ditch that was recently cut near the gravel parking lot. Ripples and
rhythmic bedding are visible. This shale likely represents the upper portion of the Glen Dean Limestone, or
the transitional facies from Glen Dean to Tar Springs.
References:
Gildersleeve, Benjamin, 1978, Geologic map of the Leitchfield quadrangle, Grayson County, Kentucky;
US Geological Survey. Reston, VA, United States. GQ-1316
McCreary, Gary B., 1957, A subsurface study of the Tar Springs Sandstone bodies in a portion of Webster
County, Kentucky; Masters Thesis University of Kentucky
Jacobs, Charles M., 1961, A subsurface study of Tar Springs Sandstone in Hopkins County, Kentucky;
Masters Thesis University of Kentucky
Glen Dean Limestone
Interchange of US 62 and State Road 1365
This location provides an excellent new exposure of the Glen Dean Limestone. Starting at road level there
is a massive, medium gray, fossiliferous wackestone that shoals upward becoming thin to medium bedded.
Cutting into the upper part of the lower limestone, a channel phase with cut and fill structures is present.
Truncating the channel phase is a thick dark medium gray, fossiliferous shale with thin limestone beds
interspersed. The shale abruptly terminates beneath another massive, medium gray fossiliferous wackestone
that again shoals upward to thinly bedded limestone. There is a preponderance of brachiopods, crinoids,
and bryzoans representing a rich photiczone environment. At the top of the cut on the east side the Tar
Springs Sandstone is present. Southward on SR 1365 there is a cut containing the Hardinsburg Sandstone.
The Students will be given the opportunity to inspect this road cut and tell us what you think.
Panoramic Photograph of the Glen Dean the intersection of US 62 and SR 1365
Units of the Glen Dean Limestone as Exposed at the Intersection of US 60 and SR 1365
Steeply dipping beds of yellow, micritic limestone are exposed in the northwest quadrant
of the intersection just beyond the railroad trestle. No determination of the stratigraphic
position of these beds is available at this time however the steep dip toward the southwest
seems to define the location of a northwest trending fault that is not mapped.
Glen Dean Limestone
(Upper Mississippian - Upper Mississippian)
USGS Unit Info: GEOLEX (id: 1808)
Mapped or described as these unit(s) on the original GQ:
Glen Dean Limestone (GQ-386):
GLEN DEAN LIMESTONE
USGS Unit Info: GEOLEX (id: 1808)
Primary Lithology: Limestone and shale
Limestone and shale: Limestone, light-gray to medium-dark-gray; contains
lenses of greenish-gray calcareous shale; in part fossil fragmental; thin
bedded to very thick bedded. Medial bed of greenish-gray calcareous shale,
10 to 15 feet thick, interbedded with siltstone and dark-gray shale, divides
limestone into upper and lower massive units. Greenish-gray calcareous
shale, as much as 15 feet thick, containing thin beds, lenses, and laminae
of limestone locally overlies upper massive limestone.
Description Source:
Hardinsburg Sandstone
(Upper Mississippian - Upper Mississippian
USGS Unit Info: GEOLEX (id: 1972)
Mapped or described as these unit(s) on the original GQ:
HARDINSBURG SANDSTONE
USGS Unit Info: GEOLEX (id: 1972)
Primary Lithology: Sandstone
Sandstone, yellowish-gray, white, and yellowish-brown, limonitic,
medium-bedded to very thick bedded, slabby to massive; weakly
crossbedded in part. Upper 5 feet locally is laminated light-gray
siltstone. Basal 10 feet locally is medium-gray shale interlaminated
with siltstone; rarely it is white clay shale. Forms wide benches on
many divides in northern half of quadrangle. Along sides of
benches large blocks of Hardinsburg Sandstone locally have false
dips of 20 ft to 60 ft because of tilting or collapse resulting from
dissolution of underlying Haney Limestone Member of Golconda
Formation.
HARDINSBURG SANDSTONE
USGS Unit Info: GEOLEX (id: 1972)
Primary Lithology: Sandstone
Sandstone, yellowish-gray, white, and yellowish-brown, limonitic,
medium-bedded to very thick bedded, slabby to massive; weakly
crossbedded in part. Upper 5 feet locally is laminated light-gray
siltstone. Basal 10 feet locally is medium-gray shale interlaminated
with siltstone; rarely it is white clay shale. Forms wide benches on
many divides in northern half of quadrangle. Along sides of
benches large blocks of Hardinsburg Sandstone locally have false
dips of 20 to 60 degrees because of tilting or collapse resulting
from dissolution of underlying Haney Limestone Member of
Golconda Formation.
Hardinsburg Sandstone (GQ-386):
General Stratigraphy at Rough River Dam
In the vicinity of the Corps of Engineer’s Office at the Rough River Dam State Resort Park we can observe
the Big Clifty Sandstone Member of the Golconda Formation (Mgb) near the shoreline (normal pool
elevation of 495 feet) followed upslope by the Haney Limestone Member of the Golconda (Mgh) and
eventually the Hardinsburg Sandstone (Mh). Away from the edge of the lake some ridges become broader
and the Glen Dean Limestone lies above the steeper terrain marked by the Haney and Hardinsburg intervals
Only locally atop the broader ridges can one find small outcrops of the Tar Springs Sandstone with even
smaller patches of the Buffalo Wallow Formation (with basal Vienna Limestone Member). In our visit
around the dam and the lake lodge we will be able to closely examine the Big Clifty (at the Lake edge), the
Haney (best exposed in the emergency spillway) and the Hardinsburg (capping Haney in the emergency
spill cut). Local relief associated with the exposure of the uppermost Big Clifty, Haney and Hardinsburg
that we will traverse ranges from 80 to 90 feet.
Haney Limestone Member
(Upper Mississippian - Upper Mississippian)
USGS Unit Info: GEOLEX (id: 1961)
Mapped or described as these unit(s) on the original GQ:
HANEY LIMESTONE MEMBER, GOLCONDA FORMATION
USGS Unit Info: GEOLEX (id: 1961)
Primary Lithology: Limestone
Limestone, medium-gray, siliceous, cherty; in part oolitic; thin
to thick bedded. Bed of dark-yellowish-orange silty limestone or
silty limestone breccia, 5 feet thick, locally present in upper
part. Forms steep slopes or cliffs with springs at base along
sides of main valleys. On gentle slopes in divide areas, and on
the sides of many tributary streams the member is mostly
dissolved, and it has yielded a residual red clay soil, 5 to 10
feet thick, containing abundant chert and silicified-fossil
fragments and scattered blocks of unweathered limestone.
Haney Limestone Member (GQ-386):
Dam
Lodge
F
lt Z
au
e
on
Note dendritic drainage pattern of Rough River Dam area suggesting nearly flatlying strata and also note fault zone. Lodge & Dam shown on KGS geology map.
Haney Limestone in Emergency Spillway
According to Johnson (1977) the Haney is a light gray to light brownish gray to light yellowish brown,
fine-to-medium crystalline and locally coarsely crystalline and medium grained fossiliferous limestone.
Some of the Haney in the region can be quite oolitic and these beds are typically packstone-grainstone
intervals. The beds are thin to thick and contain some chert nodules approaching 50 cm in diameter.
Cherts in the Haney are fossiliferous and are gray or grayish black. Fossils in both chert-rich and nonsilicified intervals include fenestral and associated Archimedes bryozoans, solitary (horn) corals, and
blastoids (Pentremities) along with various crinoid and brachiopods. The Haney is mapped in the Falls of
Rough Quadrangle as being approximately 50 feet thick but in some area of the subsurface in the region it
may exceed 70 feet.
Spillway
Dam
Emergency
Spillway
Corp of Engineers Office
Detailed aerial photo with basic geology in vicinity of Corp of Engineers Office
located between Emergency Spillway and Dam (from KY Geol Survey website)
Hardinsburg Sandstone in Emergency Spillway
Sandstone, shale, siltstone and limestone comprise the Hardinsburg in the Falls of Rough Quadrangle
(Johnson, 1977). In the vicinity of the spillway the basal Hardinsburg Sandstone is very thin to thin bedded
possessing some crossbeds and ripple-laminated beds with shale interbeds. In some locations here there are
intercalated siltstones in the shale intervals. The sandstone is calcareous at the base and contains lenticular
limestones. Some well defined sole marks can be seen in the micaceous silty beds of the Hardinsburg in
the spillway cut. Various clinoforms and truncation surfaces can also be noted in the exposure.
Hardin
sburg
Ss
Haney L
s
Hardinsburg Ss
Haney Ls
Emergency Spillway Cut – Rough River Dam – Haney & Hardinsburg Contact
Medium to Thickly Bedded Haney Limestone in Spillway Cut
Setting of Rough River State Resort Park Lodge
The Lodge at Rough River Dam State Resort Park is situated on a bluff of Hardinsburg Sandstone that caps
the Haney Limestone slope above the lake. At low water a significant portion of the Big Clifty Sandstone
is beautifully exposed approximately at lake level, down slope from the Haney Limestone. Taking a short
trail down behind the lodge provides one with a location to study myriad ripple-laminated bedding along
with other sedimentary structures. How many different types of ripples and other sedimentary structures
and trace fossils can be identified at this location? Below is a list of just a few interesting features visible in
the Big Clifty.
Select Big Clifty Sandstone Member Features down slope from the Lodge
 Straight Crested Ripples
 Curved to Sigmoid Crested Ripples
 Mud cracks (Desiccation Cracks)
 Planar and Trough Cross beds
 Various Emergent features (e.g. varied current directions shown by ripple-laminated strata with varied
crest orientations)
 Feeding traces and burrows
 Others-
For students (aren’t we all?) on the trip see what the grain size is for the Big Clifty Sandstone and how
many different types of sedimentary structures you can observe. Also observe the bedding thickness,
changes in paleocurrent direction and try your hand at interpreting a specific environment of deposition (or
more than one) for this sandstone. Below are some photos of some of the bulleted features above. Can you
observe and properly identify these features? As an exercise make a list of the lettered photos and record
the salient features for each and we can discuss these images at he lake-side location.
The Big Clifty is not sandstone throughout the Rough River Dam and Lodge area as there are commonly
shale and siltstone intervals (Johnson, 1977). Many of the coarse clastic intervals have carbonaceous
material (from plants) and iron-staining along bedding planes. The Big Clifty Sandstone Member ranges
from 35 to 80 feet in thickness in the Falls of Rough Quadrangle.
Lodge
Big Clifty Exposure
Detailed aerial photo with KGS geology base map showing location of
Lodge and Big Clifty Sandstone examined.
A
B
C
D
Sedimentary Structures in Big Clifty A-D (scale is 6 inches in length)
E
F
G
H
Sedimentary Structures in Big Clifty E-H (Scale is 6 inches long)
Big Clifty Sandstone Member
(Upper Mississippian - Upper Mississippian)
USGS Unit Info: GEOLEX (id: 455)
Mapped or described as these unit(s) on
the original GQ:
BIG CLIFTY SANDSTONE MEMBER (from
GQ-446) |
Map Link: Geologic Map (highlight unit)
USGS Unit Info: GEOLEX (id: 455)
Primary Lithology: Sandstone, siltstone,
and shale
Sandstone, siltstone, and shale: Sandstone
is light tan to brown, thin bedded to
massive, in part crossbedded; some thin
beds ripple-marked, very fine to fine
grained; thick beds of moderately hard
quartz sandstone have minor amounts of
silica and iron-oxide cement; thin beds are
generally argillaceous. Siltstone and shale
are light brownish gray, greenish gray and
medium gray; locally thin beds of red shale.