Philip Heckel characterized the geology of eastern Kansas and western Missouri:
Bedrock geology of eastern Kansas is characterized by an alternation of laterally persistent Middle and Upper Pennsylvanian sandy shales from 3 to 30 m thick and containing local sandstones, with laterally persistent limestones from 3 to 15 m thick and containing thin shale beds. These rocks strike generally north-northeast to south-southwest . . . and dip gently westward about 30 feet per mile (approximately 5.5 m/km). South of the limit of thin glacial cover, the more resistant thicker limestone and sandstone units are cut by rivers and streams to form low, irregular, eastward-facing escarpments, prongs, and flat-topped hills that break the otherwise nearly flat plain and allow lateral tracing of major units with ease.[5]
Richard Gentile adds:
Of most importance economically are the beds of limestone, in particular, the Bethany Falls. The industrial development of Kansas City is closely related to the exploitation of the 20-24 ft (6-7 m) thick “ledge” of Bethany Falls Limestone in quarrying and mining operations. . . .
The Bethany Falls has been extensively quarried and mined throughout the Kansas City area since the 1880s. . . . [It is] informally called the “Bethany Ledge” by quarrymen. Almost all of the underground space left after mining operations in metropolitan Kansas City is in the Bethany Falls Limestone.
This underground space is extensively used throughout the Kansas City area, for example, in the 55 million square foot SubTropolis underground business complex, the largest such underground complex in the United States - and just one of many such underground operations in the Kansas City metro area.
The Missourian Series is the third of four stages the Pennsylvanianperiod and is considered Late Pennsylvanian. The Pennsylvanian, also known as the Late Carboniferous, approximately covers the years 323.4 million years ago to 298.9 million years ago.
At this time, the area that is now the Kansas City Group was periodically covered in low-lying seas, along the seashore, or in wet and swampy areas along the seashore. As the climate changed over hundreds of thousands to millions of years, the varying sea levels created a fairly predictable sequence of strata that became the modern-day limestone, shale, and occasional sandstone formations.
As common for strata in the Carboniferous period, the Kansas City Group held commercially exploitable reserves of oil that have been tapped in both Missouri and Kansas; coal has been mined in some locations as well.
This image illustrates the first three stages of a typical cyclothem as found in eastern Kansas and western Missouri. **Stage 1, Outside Shale (non-marine). **Stage 2, Middle Limestone (fast-rising seawater). **Stage 3, Core Shale (deep seawater). **In situ, shale layers are often seen as slumping hillside. As the Hushpuckney Shale layer in this photo, the shale is covered with soil and not seen. **Middle Limestone often has beds separated by a thin shale layer - as we see here with the Middle Creek Limestone's two relatively thin beds of limestone separated by a very thin layer of shale. The two limestone beds range from 0.5 to 1.5 ft in thickness, and the thin shale layer is just a fraction of an inch. Here, you see the effects of water erosion on the two separated layers of limestone. (Bed of Cedar Creek in Lees Summit, Missouri)
Upper Pennsylvanian Cyclothems as seen in the Kansas City Group
Simplified outline of a basic cyclothem as found in the geology of eastern Kansas, northwest Missouri, and southwest Iowa. After "Field Guide to Upper Pennsylvanian Cyclothemic Limestone Facies in Eastern Kansas", figure 4.[5]Click to view at full size.
The cyclothems in the Kansas City Group are fairly predictable, repeating layers of limestone-shale-limestone-shale created as the sea level rose and fell:
Outside Shale. At the lowest sea level, the area was a non-marine environment adjacent to the nearby sea. The area may have been low-lying and swampy, receiving outflows of detritus and, sometimes, sand from streams and downwash from adjacent land. The result is a gray to brown sandy shale with local coal and sandstone deposits. As the sea level begins to rise slightly, this turns to sandy shale with marine biota.
Middle Limestone. Sea levels begin to rise, typically due to melting of ice sheets. Because the melting process and resulting rise in sea level is typically quite fast-moving, this phase is shorter than the later regressive phase of the sea levels - and thus creates a thinner, denser, and more uniform limestone layer. This phase begins when the sea level is deep enough that the layer was below the wave base, allowing calcium carbonate deposits to accumulate steadily, undisturbed by wave action. Invertebrate marine fossils are present as are preserved algae - the primary biological driver of the calcium carbonate deposits. Thin layers of shale between thicker section of limestone are often present, and may represent a layer of detritus from flooding or some other major outflow event or some other relatively brief change in conditions.
Core Shale. As the sea level continues to rise, the sea depth reaches a limit beyond which the algae can no longer create calcium carbonate. Accumulation of calcium carbonate - and thus limestone - ends. The deep-water conditions create a thin, gray layer of marine shale - typically 0.3 to 2 meters thick - lacking sand and holding only fossils of organisms known to frequent deep water areas. These layers were created by very slow process of sedimentation in deep water under anoxic (very low oxygen) conditions. The deposits are rich in heavy metals and phosphate, which was created by the slow decay of immense blooms of plankton, which slowly settled to the sea floor.
Cliffside exposure of the Kansas City Group showing a full cyclothem from Upper Limestone through Outer Shale, Middle Limestone, Core Shale, and back to Upper Limestone. **Red Arrow: Note chunks of thin-layered, dark-gray shale, which have dropped down from the Elm Branch/Ladore Shale layer just above. **Blue Arrow: Note the two relatively thin sections of Middle Creek Limestone parted by a very thin shale layer, seen here as a narrow crack. (Blue River, Kansas City, Missouri)Upper Limestone. As ice sheets slowly grow again, the sea levels slowly decline. As soon as sea depth in this area becomes shallow enough that algae can once again resume the production of calcium carbonate, the accumulation of limestone formations begins again. Because the decline in sea levels is far slower than the rise was - typically taking around three times as long - this layer of limestone is far thicker and also, typically, more varied than was the Middle Limestone. This layer can be 3–9 meters in thickness. Again, preserved algae, marine invertebrates, and conodonts such as Ozarkodina - eel-like marine creatures lacking jaws but with numerous sharp teeth - are present. The lower part of this limestone typically consists of wavy-bedded limestone with a large number of fossils of many marine species. Thin layers of shale often separate the wavy-bedded limestone layers. The upper section of the Upper Limestone formation is often more varied from place to place - representing the disproportionate effect minor differences in topography can have in shallow waters, and in some cases reefs or shoals that accumulated atop the other layers. The limestone created under shallower seas reflects the greater agitation due to wave action and penetration of light expected at those shallower depths.
Outside Shale again. As sea levels continue to decrease, we finally reach the stage where shale accumulates in very shallow seas, along the seashore, and then in drier areas just above sea level - as in the beginning (Stage 1). Some areas were ancient stream or river deltas, with deposits of material weathered from rocks in present-day Oklahoma. In these areas we may see shale deposits interspersed with lenses of sandstone, siltstone, or other sedimentary rock. And, again, we may find local coal deposits created in more substantial swamps or marshy areas.[5]
1929 view of Signboard Hill, Main Street, Kansas City, showing more than two and a half cyclothems in the geological strata of the Kansas City Group.**1. Wea Shale (Core Shale) **2. Cement City Limestone (Upper Limestone) **3. Chanute Shale (Outer Shale) **4. Iola Group (thin layers Paola Limestone [Middle LS] and Muncie Creek Shale [Core Shale] below thicker Raytown Sandstone [Upper LS]) **5. Liberty Memorial Shale (Outer Shale) **6. Wyandotte Formation (thin layers Frisbie Limestone [Middle LS] and Quindaro Shale [Core Shale] below much thicker Argentine Limestone [Upper LS])
Kansas City Group Examples - Lowest to Highest Strata
Outcrop showing Elm Branch Shale (lowest, undercut), Middle Creek Limestone, Hushpuckney Shale (slumping hillside), and Bethany Falls Limestone (highest cliff). Note soft, eroded shale undercutting Middle Creek Limestone and slumped slope representing Hushpuckney Shale, with little or no shale visible on the surface - both typical of shale members of the Kansas City Group in many outcrops and road cuts. Knobtown, Missouri.
Railroad cut showing Winterset Limestone, Dennis Formation, Upper Bronson Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Note thin horizontal partings - very thin layers of shale separating the limestone periodically - a characteristic of many Kansas City Group limestone members. The thin shale layers represent a short period of time under different environmental conditions, or perhaps even a single catastrophic or large-scale event. Raytown, Missouri.
Railroad cut showing Winterset Limestone, Dennis Formation, Upper Bronson Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Note the Stark Shale Member beneath the limestone - the softer shale has eroded and undercut the limestone above. Raytown, Missouri.
Railroad cut showing new rockfall Winterset Limestone next to older cliffs. Note the gray color of the weathered limestone vs the buff color of the new rockfall. Raytown, Missouri.
Detail of Winterset Limestone, Dennis Formation, Upper Bronson Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Raytown, Missouri.
Block Limestone is typically a relatively thin, fine-grained, well consolidated limestone in a single even bed, broken into near-rectangular blocks by vertical joints at roughly 90 degrees to each other. Created in moderately deep seas while seawater was quickly rising, it represents the "Middle Limestone" of a cyclothem. The slabs here are 6-8 inches thick. (Round Grove Creek, Raytown, Missouri.)
The mound of gray Wea Shale was excavated by a burrowing rodent, about 6 feet above the level of the Block Limestone formation. Wea Shale represents the "Core Shale" of the cylothem, laid down in deep marine waters.
Wea Shale, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group. Wea Shale is gray shale between Block Limestone and Westerville Limestone. This sample was found just below Westerville Limestone. The shale was created in a deep marine environment. Note the thin, delicate, perfectly parallel and horizontal flakes.
Westerville Limestone at a railroad cut, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Raytown, Missouri.
Railroad cut showing Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Note irregular and wavey-bedded strata, signs of wave action and other disturbance as water levels became very shallow. Raytown, Missouri.
Outcrop of Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group. The limestone overlays much softer Wea Shale, which quickly erodes leaving a characteristic overhang. Raytown, Missouri.
Crinoid fossil in Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Raytown, Missouri.
Brachiopod and crinoid fossils in Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Raytown, Missouri.
Crinoid fossils in Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Note irregular and wavey-bedded strata. Raytown, Missouri.
Marine fossils in the upper portion of an outcrop of Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group. Raytown, MO.
Invertebrate marine fossils in Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group. Raytown, Missouri.
Numerous invertebrate marine fossils in the upper portion of Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group. Raytown, Missouri.
Cement City Limestone, Dewey Formation, Upper Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Also known as Drum Limestone. Note irregular wavy-bedded upper layers - common in the upper portions of Middle Limestone formations. As sea levels slowly decline, they reach a level where the seabed is sometimes and then continually disturbed by waves, before transitioning to a tidal and then non-marine environment where limestone is no longer produced. Thus, the common transition from regular limestone layers to wavy-bedded and more disturbed layers, and finally a transition to a shale formation.
Chert nodules and a fossil imprint in Cement City Limestone, Dewey Formation, Upper Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Several of the limestone formations in the Kansas City Group are cherty.
Invertebrate marine fossil in Cement City Limestone, Dewey Formation, Upper Linn Subgroup, Kansas City Group. Raytown, Missouri.
Detail of Cement City Limestone, Kansas City Group
Raytown Limestone Formation and underlying Muncie Creek Shale, Iola Formation, Upper Zarah Subgroup, Kansas City Group. Note the softer shale layer has eroded and undercut the limestone formation. (Railroad cut in Raytown, Missouri.)
Raytown Limestone outcrop, showing undercutting by the underlying Muncie Creek Limestone. Note more uniform lower layers and more variable and disjointed upper layers. (Truman Sports Complex, Kansas City)
Crinoid fossils in a sample of Raytown Limestone. (Truman Sports Complex, Kansas City)
Brachiopod fossils in a sample of Raytown Limestone. (Truman Sports Complex, Kansas City)
Outcrop of Argentine Limestone, Wyandotte Formation, near Shawnee Mission Lake, Johnson County, Kansas.
Invertebrate marine fossils in Argentine Limestone, Wyandotte Formation, Middle Zarah Subgroup, Kansas City Group. Near Shawnee Mission Lake, Johnson County, Kansas.
Detail of Argentine Limestone showing marine fossils, Wyandotte Formation, Middle Zarah Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System showing fossil fragments. Taken at an outcrop near Shawnee Mission Lake, Johnson County, Kansas
^D.L. Baars, W. Lynn Watney, Don W. Steeples, and Erling A. Brostuen (1993). "Petroleum: a primer for Kansas". Educational Series (7): 9. Retrieved 2023-10-24.{{cite journal}}: CS1 maint: multiple names: authors list (link)
Outcrop showing Elm Branch Shale (lowest, undercut), Middle Creek Limestone, Hushpuckney Shale (slumping hillside), and Bethany Falls Limestone (highest cliff). Note soft, eroded shale undercutting Middle Creek Limestone and slumped slope representing Hushpuckney Shale, with little or no shale visible on the surface - both typical of shale members of the Kansas City Group in many outcrops and road cuts. Knobtown, Missouri.
Railroad cut showing Winterset Limestone, Dennis Formation, Upper Bronson Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Note thin horizontal partings - very thin layers of shale separating the limestone periodically - a characteristic of many Kansas City Group limestone members. The thin shale layers represent a short period of time under different environmental conditions, or perhaps even a single catastrophic or large-scale event. Raytown, Missouri.
Railroad cut showing Winterset Limestone, Dennis Formation, Upper Bronson Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Note the Stark Shale Member beneath the limestone - the softer shale has eroded and undercut the limestone above. Raytown, Missouri.
Railroad cut showing new rockfall Winterset Limestone next to older cliffs. Note the gray color of the weathered limestone vs the buff color of the new rockfall. Raytown, Missouri.
Detail of Winterset Limestone, Dennis Formation, Upper Bronson Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Raytown, Missouri.
Block Limestone is typically a relatively thin, fine-grained, well consolidated limestone in a single even bed, broken into near-rectangular blocks by vertical joints at roughly 90 degrees to each other. Created in moderately deep seas while seawater was quickly rising, it represents the "Middle Limestone" of a cyclothem. The slabs here are 6-8 inches thick. (Round Grove Creek, Raytown, Missouri.)
The mound of gray Wea Shale was excavated by a burrowing rodent, about 6 feet above the level of the Block Limestone formation. Wea Shale represents the "Core Shale" of the cylothem, laid down in deep marine waters.
Wea Shale, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group. Wea Shale is gray shale between Block Limestone and Westerville Limestone. This sample was found just below Westerville Limestone. The shale was created in a deep marine environment. Note the thin, delicate, perfectly parallel and horizontal flakes.
Westerville Limestone at a railroad cut, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Raytown, Missouri.
Railroad cut showing Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Note irregular and wavey-bedded strata, signs of wave action and other disturbance as water levels became very shallow. Raytown, Missouri.
Outcrop of Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group. The limestone overlays much softer Wea Shale, which quickly erodes leaving a characteristic overhang. Raytown, Missouri.
Crinoid fossil in Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Raytown, Missouri.
Brachiopod and crinoid fossils in Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Raytown, Missouri.
Crinoid fossils in Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Note irregular and wavey-bedded strata. Raytown, Missouri.
Marine fossils in the upper portion of an outcrop of Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group. Raytown, MO.
Invertebrate marine fossils in Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group. Raytown, Missouri.
Numerous invertebrate marine fossils in the upper portion of Westerville Limestone, Cherryvale Formation, Lower Linn Subgroup, Kansas City Group. Raytown, Missouri.
Cement City Limestone, Dewey Formation, Upper Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Also known as Drum Limestone. Note irregular wavy-bedded upper layers - common in the upper portions of Middle Limestone formations. As sea levels slowly decline, they reach a level where the seabed is sometimes and then continually disturbed by waves, before transitioning to a tidal and then non-marine environment where limestone is no longer produced. Thus, the common transition from regular limestone layers to wavy-bedded and more disturbed layers, and finally a transition to a shale formation.
Chert nodules and a fossil imprint in Cement City Limestone, Dewey Formation, Upper Linn Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Several of the limestone formations in the Kansas City Group are cherty.
Invertebrate marine fossil in Cement City Limestone, Dewey Formation, Upper Linn Subgroup, Kansas City Group. Raytown, Missouri.
Detail of Cement City Limestone, Kansas City Group
Raytown Limestone Formation and underlying Muncie Creek Shale, Iola Formation, Upper Zarah Subgroup, Kansas City Group. Note the softer shale layer has eroded and undercut the limestone formation. (Railroad cut in Raytown, Missouri.)
Raytown Limestone outcrop, showing undercutting by the underlying Muncie Creek Limestone. Note more uniform lower layers and more variable and disjointed upper layers. (Truman Sports Complex, Kansas City)
Crinoid fossils in a sample of Raytown Limestone. (Truman Sports Complex, Kansas City)
Brachiopod fossils in a sample of Raytown Limestone. (Truman Sports Complex, Kansas City)
Outcrop of Argentine Limestone, Wyandotte Formation, near Shawnee Mission Lake, Johnson County, Kansas.
Invertebrate marine fossils in Argentine Limestone, Wyandotte Formation, Middle Zarah Subgroup, Kansas City Group. Near Shawnee Mission Lake, Johnson County, Kansas.
Detail of Argentine Limestone showing marine fossils, Wyandotte Formation, Middle Zarah Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System showing fossil fragments. Taken at an outcrop near Shawnee Mission Lake, Johnson County, Kansas
