The Caves of Onondaga State Park
Onondaga Cave State Park is one of the state parks of Missouri. It is located in Leasburg, Missouri and was established in 1982. The park is named after the Onondaga Nation, who were the original inhabitants of the area.
The park is situated in the Ozarks region of Missouri and covers an area of 3,752 acres (15.19 km2). The park features two caves, Onondaga Cave and Cathedral Cave. Both of these caves are open to the public for tours.
Onondaga Cave is the more popular of the two caves, and is known for its large chambers and beautiful formations. Cathedral Cave is smaller, but is known for its delicate formations.
The caves of Onondaga State Park are formed in rocks that date back to the Cambrian Period, which began 541 million years ago. These rocks were originally deposited as sediments at the bottom of a shallow sea.
Over time, these sediments were buried deeper and deeper under subsequent layers of sediment. The weight of these layers caused the sediments to compact and harden into rock.
The process of lithification continued until the rocks were buried several miles deep. This deep burial caused the rocks to heat up and deform. This heating and deformation caused the rocks to break apart and form fractures.
Water percolating through these fractures widened them into caves. The caves were further enlarged by the chemical weathering of the rock by carbon dioxide-rich water. This water dissolves limestone and creates stalactites, stalagmites, and other cave formations.
The Rubidoux Sandstones are the oldest rocks in Onondaga Cave State Park and date back to the Early Cambrian Period, which began 541 million years ago. The Rubidoux Sandstones are a red sandstone that was deposited as desert sand dunes in a hot, arid climate.
The Upper Cambrian Dolomites are a white to gray limestone that was deposited in a shallow marine environment. These rocks date back to 485 million years ago and are interbedded with shales and sandstones.
The Mississippian Period began 329 million years ago with the deposition of the Osagean Series, which consists of limestones, dolomites, shales, and sandstones that were deposited in a shallow marine environment.
The Pennsylvanian Period began 298 million years ago with the deposition of the Meramecian Series, which consists of limestones, shales, sandstones, coals, and ironstones that were deposited in a variety of environments including shallow marine, deltaic, fluvial, and swampy environments.
The Permian Period began 251 million years ago with the deposition of the Roubidoux Formation, which consists of red beds that were deposited in a hot desert climate. The Triassic Period began 252 million years ago with the deposition of the Sudbury Formation, which consists of red beds that were deposited in a hot desert climate.
The Cenozoic Era began 66 million years ago with the deposition of the Tertiary Period Sediments, which consist of sandstones, gravels, and clays that were deposited by rivers and lakes in a variety of environments. The Quaternary Period began 2.6 million years ago with the deposition of glacial till that was deposited by glaciers.
The caves of Onondaga State Park are a product of the geological history of the Ozarks. The rocks that make up the caves date back to the Cambrian Period and have been through a variety of heating and deforming processes. Water has dissolved the limestone and created stalactites, stalagmites, and other cave formations.