The karstification of a landscape may result in a variety of large or small scale features both on the surface and beneath. On exposed surfaces, small features may include flutes, runnels, clints and grikes. Medium-sized surface features may include sinkholes or cenotes (closed basins), disappearing streams, and reappearing springs.
Large-scale features may include limestone pavements, poljes and blind valleys. Mature karst landscapes, where more bedrock has been removed than remains, may result in karst towers or haystack/eggbox landscapes. Beneath the surface, complex underground drainage systems (such as karst aquifers) and extensive caves and cavern systems may form.
The formation and development of caves is known as speleogenesis. This is where we derive the word “Spelunker” for one who explores caves. Caves are formed by various geologic processes. These may involve a combination of chemical processes, erosion from water, tectonic forces, microorganisms, pressure, atmospheric influences, and even digging.Most caves are formed in limestone by dissolution. Solutional caves are the most frequently occurring caves and such caves form in rock that is soluble, such as limestone, but can also form in other rocks, including chalk, dolomite, marble, salt, and gypsum. Rock is dissolved by natural acid in groundwater that seeps through bedding-planes, faults, joints etc. Over geological epochs cracks expand to become caves or cave systems
The largest and most abundant solutional caves are located in limestone. Limestone dissolves under the action of rainwater and groundwater charged with H2CO3 (carbonic acid) and naturally occurring organic acids. The dissolution process produces a distinctive landform known as karst, characterized by sinkholes, and underground drainage. Limestone caves are often adorned with calcium carbonate formations produced through slow precipitation. These include: flowstones, stalactites, stalagmites, helictites, soda straws and columns. These secondary mineral deposits in caves are called speleothems.
The portions of a solutional cave that are below the water table or the local level of the groundwater will be flooded.
Corrasional or erosional caves are those that form entirely by erosion by flowing streams carrying rocks and other sediments. These can form in any type of rock, including hard rocks such as granite. Generally there must be some zone of weakness to guide the water, such as a fault or joint. A subtype of the erosional cave is the wind or aeolian cave, carved by wind-borne sediments. Note that many caves formed initially by solutional processes often undergo a subsequent phase of erosional or vadose enlargement where active streams or rivers pass through them.
Morrell Cave is located in Sullivan County. It has more than 37,000 feet of mapped passages on two levels. Morril’s Cave is commonly called Worley’s Cave locally and is known for its voluminous size with rooms more than 75 feet wide and 250 feet long with high ceilings that often exceeds 100 feet. It is noted for its beautiful formations within its eight to ten miles of passages. The lower level of the cave contains a perennial creek complete with various fishes, white crayfish, and salamanders.
An unearthed prehistoric stonewall some six feet high, built of rocks of various sizes, is evidence that the cave was likely inhabited by aboriginal people. It is unknown when the first settler entered Morril’s Cave, although it has been written that settlers surely would have encountered the cave by the beginning of the 1800’s. Nothing is known of the cave until it became the property of Elias S. Worley. Locally, the cavern is often still referred to as Worley’s Cave. A large amount of saltpeter was mined from the cave early in the Civil War. A mill was operated in the early 1900’s where the stream exits at the lower entrance of the cave. It was said that the stream’s volume was “sufficient, even in severest drought, to turn the undershot wheel of a large mill.&rdquo
A local resident John Morril, led many explorations of the cavern “near the turn of the century.” Much confusion has arisen over the years about the proper spelling of the name. It has been called Morrell, Morrill, Morrils, Morrels, Mirrells, Worley’s and even Worlie’s Cave. The issue was resolved in 1980 by the U.S. Board on Geographical Names when it approved the name Morrell Cave. The Natural Areas Preservation Act, however has not been amended to change it from Morril’s Cave since it was designated in 1973.
The site is privately owned. Visitors must follow the directions provided below to the landowner's house. (Jeff Watson, 449 Timber Ridge Road)
DIRECTIONS: From Elizabethton take U.S. Highway 19E/State Route 37 north toward Bunker Hill and Bluff City. Turn right on Chinquapin Grove Road. Stay on this road and travel north toward the South Fork of the Holston River. Turn left, heading west on Dry Branch Road, paralleling the South Fork of the Holston River. Turn left on Timber Ridge Road. Go about one mile. Entrance to the property is on the left.
Upon arriving, go to the front porch of the landowner's house where the sign-in sheet and the cave gate keys are kept. Sign in and obtain a key to the cave gate. Lock the gate behind you after entering the cave and secure the key where it will not be lost. Lock the gate after you leave the cave and return the key to the porch before leaving the site. You may go into the cave even if the landowner is not home.
In order to log your find, you must.
- Post a picture of you and your GPSr at any formation inside the cave.
- Estimate the height of the wall at the cave entrance.
- From the cave entrance estimate the distance to the water below
- What is the predominant type of stone in the area of the cavern?