Karst Topography: Karst topography is any landscape that owes its topography to sinkholes.

Karst topography often appears in rock formations that are easily susceptible to dissolution. Evaporitic rocks like the Eagle Valley Evaporites which contain halite and gypsum, are prone to dissolution and the creation of caverns resulting in sinkholes. Limestone is one other rock formation that is slowly dissolved, creating voids that either become caves or sinkholes

Subsidence is when underlying layers of rock are dissolved which causes the overlying land to subside. This process of subsidence can be both gradual and spontaneous. In gradual subsidence, the overlying land subsides at an even pace with the dissolution. Spontaneous subsidence occurs on behalf of solution caverns, voids left when layers of rock formations, once under the water table, had been dissolved. While these caverns are slowly hallowed out, the overlying land remains at the same level until the force of gravity causes the surface layers to implode into the void.

Eagle Valley Evaportie Subsidence (EVE):

The EVE is made up predominantly of Halite, Gypsum and Anhydrite. As the Eagle Basin Seaway evaporated during the Pennsylvanian period, these formations were deposited in a series of cycles. Because these formations were deposited as evaporates, they are easily affected when re-hydrated.

Because the EVE’s vulnerability to dissolution is so high, human behavior such as irrigation can often induce and expedite these processes. Water used to irrigate farm pastures sinks down through the ground to these layers of EVE where they are dissolved, and in turn, sinkholes are created. On account of the increased amounts of water that reach the EVE, sinkholes occur quite frequently in the Roaring Fork Valley, on average four per square mile. A perfect example of this process is the spontaneous sinkhole located at the Colorado Mountain College soccer field. The constant water that the fields receive via sprinkler system created a solution cavern which then collapsed fairly recently. This natural process of subsidence has also affected CRMS soccer fields in identical fashions. At one point, CRMS’s soccer field was located across the river, behind Jim Gaw’s house. Over the years, numerous sinkholes occurred and eventually rendered the field unusable.

Although illusive at times, sinkholes amidst the Roaring Fork Valley are extremely numerous. The back road that runs from Glenwood to Carbondale has many dips that have been created on account of subsidence. These dips in the road are constantly being repaired for the cycle of dissolution is never ending. The abstractly placed bodies of water located in Coryell Ranch that you thought were lakes, aren’t! Mother nature has actually been the landscaper for this luxurious golf club neighborhood, for these ponds are all sinkholes that have been lined (to stop the process of dissolution) and filled with water rather than refilled. The ‘big dip’ located on highway 82 before the senic overlook is yet another fascinating creation of dissolution that is constantly repaired.

Solution Caverns of the Leadville Limestone:

Leadville Limestone and White River Uplift:

A warm shallow sea deposited the Leadville Limestone in the Mississippian period (360-320 M.Y.A.). After many hundreds of thousands of years, a regional uplift occurred that resulted in a monocline. This uplift is called the White River Uplift and is responsible for the monocline located on the northern slopes of Glenwood Springs. While the topography south of Glenwood remained at a static level of altitude, northern areas were uplifted. This caused the layers of strata to be bent, creating an incline that connects the Flat Tops to the bottom of the Roaring Fork Valley.

An additional affect that this uplift had was that the solution caverns of the Leadville Limestone were uplifted above the water table. Now separated from its previous erosional environment, the cave systems now lie in open-air environments (the area once flustered with water has now been replaced with air) where the growth of cave formations is now possible. The curved and bent nature of a monocline has created the cavern systems in the Leadville limestone to lie in this curved fashion.

Dissolution of Limestone:

When ground water flows through ground soil, carbonic acid is created. Moderate levels of carbon dioxide (CO₂) that exists within the soil from dead plant and animal matter mingle with the water molecules and create this low pH acid. This process is defined by this formula: H₂O + CO₂ ⇐ H₂CO₃ ⇐ H⁺+HCO^–₃. After flowing through these layers of soil, the carbonic acid flows through the layers of Leadville limestone. Limestone, which is dissolved by acids, is slowly chemically weathered as the acid dissolves small amounts of calcite that become ionized in the water. This dissolution occurs below the water table as the carbonic acid rushes past and through exposed limestone formations. Creating huge solution caverns, the dissolution of limestone occurs at a rate of 10cm per 1,000 years.

The rates of dissolution, however, can be accelerated by means of increased temperatures of the dissolvent, as it has in the Glenwood Springs area. Before the White River Uplift, Limestone cavern systems were exposed to hot geothermal water sources that came up from within the earth. This hot sulfuric acid mixed with the carbonic acid from above sped up the rates of dissolution of the Limestone.

Precipitation of Calcite and Cave Formations:

Suspended calcite is commonly precipitated on to walls of solution caverns. This process, however, can only occur in open-air caverns, above the water table, as the ground water travels down to it. The products of this precipitation are called speleothems, which literally translates to cave formations. Such formations include: stalactites, stalagmites, cave bacon, flowstone, soda straws, cave popcorn and columns. The chemical processes of precipitation, however is quite complex, more so than simple deposition.

The CO₂ levels in the atmosphere within open solution caverns are substantially lower than within the carbonic acid. Due to the chemical process of diffusion (tendency for molecules to travel from an area of higher to lower concentration), carbon dioxide molecules within a water droplet diffuse out into the atmosphere of the cavern. The result of this loss of CO₂ molecules is precipitation, for water molecules are no longer able to keep calcite in solution. This water droplet process of calcite precipitation occurs frequently in cavernous settings and is often the process that produces stalactites, a carrot shaped cone that hangs from the ceiling. In their premature states, stalactites are referred to as soda straws, and have small openings through the middle, through which water slowly flows. At a certain point in the growth of a soda straw, this small channel is blocked by precipitate, and the flowing water is forced to flow on the outside causing lateral growth.

A similar process involving water drops produces stalagmites, formations similar to stalactites, but rising from the ground. As calcite-bearing water droplets fall from the cave ceiling, precipitation occurs as the drop lands and builds upon itself. Because the point from which water drips often becomes a stalactite, a column can be formed over time which bridges the gap between a stalactite and a stalagmite.

Flowstone, another speleothem, is created when water flows over ledges and surfaces. This process of precipitation creates smooth, rounded, flowing formations that represent the flow of the thin layers of water that deposited it. Cave bacon is found hanging from cavern walls that are sloped at an angle. The angled ceiling allows water to flow down the roof of the cave slowly while calcite precipitates. As the water trickles in lines, calcite is deposited in these paths, which, over time, form sheets that hang from the ceiling. One reason that this type of speleothem is called cave bacon is due to its color. Red streaks often stripe these sheets giving it and even more appetizing appearance. This red coloration is the product of Iron molecules mixed within the calcite and can appear in all speleothems.

Our last speleothem is called Cave Popcorn. Cave Popcorn, resembles popcorn, small to medium sized bubble-like formations that are found on the walls and floors of caves. There are several hypothesized possibilities of deposition of this speleothem, but not one has been scientifically proven. One such theory is that the popcorn is precipitated below the water table. In this theory, pressure from cavern walls causes gas to be released, which, in turn simultaneously precipitates calcite. This precipitation, however, would require an environment where the water is calm or moving at a slow speed.

Aragonites, crystal-like formations, are the product of depositions of moving air with in open caverns. Rushing air is common in cavern systems and often collects and deposits molecules, which produce these formations.

In Conclusion:

The cave systems and speleothems that we are able to observe present day, are the product of millions of years of deposition, dissolution, uplift and precipitation. Incomprehensible amounts of geologic time have formed these priceless formations. These formations are the product of Mother Nature’s everlasting care and a great example of the true immorality of the Earth in comparison with our lives. Her artwork is to be cherished and protect for all to see and learn from.

An Amendment:

The Carbondale Collapse Theory:

The Carbondale Collapse Center Theory states that the Carbondale area is the result of numerous sinkholes and events of subsidence. The fact that Mt. Sopris is not a volcano proves the idea that the Carbondale area was once level with the base of the mountain. Lower levels of elevation and the relief of Mt. Sopris are the results of hundreds of thousands of years of dissolution and subsidence. The Eagle Valley has a similar history of such subsidence.

An Amendment:

The Water Tower and The Dissolution Induced Slurry Flow:

Seven years ago, on the Crystal River Terrace, a mass wasting event (any huge event of erosion) occurred on account of a wet summer and agricultural irrigation. The pressure created by the excess water pushed the clasts apart resulting in a flow. When saturated, the gypsum of the EVE expands back to anhydrite, breaking up soil and rock formations. The sediment was so saturated that a slurry flow occurred simultaneously with a sinkhole. As the area spontaneously subsided, the sediment flowed down through the nearby valley due to its wet consistency. This site is an on going problem now, for the sinkhole drainage will continue to slowly erode encroaching on the nearby pastures and the area is much more prone to additional evaporitic collapses.