Discover Kentucky and Explore the Geodiversity and Fossils of Abraham Lincoln Birthplace National Historical Park
- Wayne Munday
- Apr 1
- 3 min read
Sip back and discover the Abraham Lincoln Birthplace National Historical Park established as a National Park in 1916 to celebrate the sixteenth President's early years of life. Only a 2 hour drive north on the I-65 from Nashville or slightly long southwards on the I-71 & I-65 from Cincinnati we explore its geodiversity and fossils across its two main locations: Abraham Lincoln's Birthplace and his Boyhood Home. At the Birthplace is the historic memorial and surrounding cultural landscape, Sinking Spring, an old-growth forest, and the historic Boundary Oak site. The Boyhood Home encompasses a three-hectare field, a preserved rural 19th-century landscape, Knob Creek and its tributaries and rare limestone glades. The Abraham Lincoln Birthplace National Historical Park lays upon the Borden Formation a fossiliferous rock unit found in north eastern Kentucky dating to the Mississippian between 358.9 - 323.2 years ago a subperiod of the Lower Carboniferous. The Borden Formation is considered a marine deposit and more specifically a delta platform deposit of the Borden delta consisting of mudstones, carbonates and siltstone. The dominant fossil groups include crinoids, brachiopods and rugose corals.
The park holds a fossil record in the Mississippian aged Borden Formation including crinoids with potential colour banding preservation, brachiopods, bryozoans, and corals. The Borden Formation is widespread in the region and generally does not contain any rare fossils. Fossils eroded from bedrock can accumulate in alluvial and colluvial deposits as loose and unconsolidated sediments that have been deposited at the base of hillslopes further enriching the park’s geological history. All fossils at the park are protected under the Paleontological Resources Preservation Act of 2009.
Geologically the park is part of the Interior Low Plateaus Physiographic Province a region including the the Ohio, Cumberland, and lower Tennessee River drainage systems and encompassing parts of six states including central Kentucky and Tennessee, with smaller areas in Alabama, Illinois, Indiana, and Ohio.
The park lies on the Mississippian Age limestone karst plain of central Kentucky known as the Pennyroyal Plateau which forms part of the ancient Illinois Basin. This basin, an asymmetrical depression trending northwest-southeast through Kentucky, Indiana, and Illinois, is filled with over 4,300 meters of Paleozoic marine sediments. It is surrounded by the structural highs of the Wisconsin Arch to the north, the Cincinnati Arch to the east, and the Ozark and Nashville Domes to the southwest and southeast, respectively.
The park sits on the basin’s eastern flank, where depositional and erosional processes have shaped the landscape over time. Throughout the Paleozoic the Illinois Basin experienced repeated uplift, subsidence, faulting, and folding, contributing to the accumulation of hydrocarbons and shaping its complex geologic history.
The crinoid (Sea Lilly) shown above is a species of Platycrinites hemisphericus on public display at the Geology Department of Wittenberg University in Springfield,
The park also features notable karst topography, which has played a significant role in the area’s settlement and natural history. One of its most significant karst features is Sinking Spring a perennial spring that emerges from a small cave. This reliable water source was a key factor in Thomas Lincoln’s decision to settle at the site in 1808. The Pennyroyal Plateau has relatively scarce surface water resources making karst springs essential.
Additionally, all caves within National Park Service lands, including those in the Abraham Lincoln Birthplace National Historical Park, are protected under the Federal Cave Resources Protection Act of 1988. This ensures the preservation of significant geological and hydrological features critical to both the park’s natural history and its role in commemorating Abraham Lincoln’s early life.
