Canyon Lake Gorge is a

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

gorge A canyon (; archaic British English spelling: ''cañon''), gorge or chasm, is a deep cleft between escarpments or cliffs resulting from weathering and the erosion, erosive activity of a river over geologic time scales. Rivers have a natural tend ...

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

, which is around long, hundreds of yards (metres) wide, and up to or more deep, which was exposed in 2002 when extensive flooding of the Guadalupe River led to a huge amount of water going over the

spillway A spillway is a structure used to provide the controlled release of water downstream from a dam or levee, typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure tha ...

from Canyon Lake reservoir and removing the sediment from the gorge. The gorge provides a valuable exposure of rock

strata In geology and related fields, a stratum (: strata) is a layer of Rock (geology), rock or sediment characterized by certain Lithology, lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by v ...

as old as 111 million years showing fossils and a set of dinosaur tracks, and forms a new

ecosystem An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...

for wildlife with

carp The term carp (: carp) is a generic common name for numerous species of freshwater fish from the family (biology), family Cyprinidae, a very large clade of ray-finned fish mostly native to Eurasia. While carp are prized game fish, quarries and a ...

and other creatures in a series of pools fed by springs and waterfalls. The Gorge Preservation Society formed as a local citizen's group to develop long-term plans for the Gorge in partnership with the

Guadalupe-Blanco River Authority The Guadalupe-Blanco River Authority or GBRA was formed in 1933 by the Texas legislature. Its main concerns are water supply and water Conservation ethic, conservation in the Guadalupe River (Texas), Guadalupe River Basin, which includes the Blanc ...

and the

U.S. Army Corps of Engineers The United States Army Corps of Engineers (USACE) is the military engineering branch of the United States Army. A direct reporting unit (DRU), it has three primary mission areas: Engineer Regiment, military construction, and civil wor ...

. Public access to the gorge is restricted to guided tours by the Society along a designated route for a hike lasting about three hours. Availability of tours is limited, no pets are permitted and no rock or

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

collecting is allowed. Research permits can be obtained by university or scientific research groups.

July 2002 flood

In July 2002 up to of water per second flowed over the spillway of

Canyon Lake, Texas Canyon Lake is a census-designated place (CDP) in Comal County, Texas, United States. The population was 31,124 at the 2020 census. It is part of the San Antonio Metropolitan Statistical Area. The Canyon Lake CDP includes a number of small, u ...

for approximately six weeks, the first time the spillway had been in use since the reservoir dam was constructed in 1964. Normally, the flow out of the reservoir is around of water per second. The Guadalupe River basin forms a part of Flash Flood Alley which is one of the river basins most prone to

flash flood A flash flood is a rapid flooding of low-lying areas: washes, rivers, dry lakes and depressions. It may be caused by heavy rain associated with a severe thunderstorm, hurricane, or tropical storm, or by meltwater from ice and snow. Flash f ...

ing in the world. Nine people were killed by the flood over a stretch of the river, which damaged or destroyed 48,000 homes and cost around $1 billion in damages, but the Canyon Lake manager has stated that even though the floodwaters went over the spillway, the dam still prevented an estimated $38.6 million in damages downstream during the event.

Educational and natural resource

On November 29, 2005, a ceremony was held in which representatives of the

and the

signed an agreement to develop the gorge as an educational and natural resource.

Significance for geologists

The 2002 flood at Canyon Lake and subsequent rapid formation of Canyon Lake Gorge presented a unique opportunity to study the

geomorphological Geomorphology () is the scientific study of the origin and evolution of topography, topographic and bathymetry, bathymetric features generated by physical, chemical or biological processes operating at or near Earth#Surface, Earth's surface. Ge ...

power of rapidly moving water and to better understand the process of canyon formation. Canyon Lake Gorge March 2017 IMG1771

In their 2010 study, Michael Lamb of the

California Institute of Technology The California Institute of Technology (branded as Caltech) is a private research university in Pasadena, California, United States. The university is responsible for many modern scientific advancements and is among a small group of institutes ...

and Mark Fonstad of

Texas State University Texas State University (TXST) is a public university, public research university with its main campus in San Marcos, Texas, United States, and another campus in Round Rock, Texas, Round Rock. Since its establishment in 1899, the university has ...

documented the dramatic transformation of a section of the Guadalupe River Valley landscape into a steep-walled bedrock canyon in just three days.Lamb, M. P. and M. A. Fonstad. 2010. Rapid formation of a modern bedrock canyon by a single flood event. Nature Geoscience. 3 (7): 477-481. The scientists documented the excavation of bedrock limestone to an average depth of over 20 feet and average width of 130–200 feet for a distance of over one mile.Perkins, S. 2010. Even a newborn canyon is big in Texas. ScienceNews. 178 (2): 15. The “plucking” and transport of massive boulders from the site resulted in the formation of several waterfalls, inner channels, and bedrock terraces. The abrasion of rock by sediment-loaded water sculpted walls and created

plunge pool A plunge pool (or plunge basin or waterfall lake) is a deep depression in a stream bed at the base of a waterfall or Shut-in (river), shut-in. It is created by the erosion, erosional forces of cascading water on the rocks at the formation's bas ...

s and teardrop-shaped “streamlined islands”.Kathy Svitil, 06/20/10, Caltech Geologist Investigates Canyon Carved in Just Three Days in Texas Flood. Caltech Press Release. Although some of the geological formations present in the gorge are known to be associated with rapidly flowing flood water (such as the streamlined islands), other formations (such as the inner channels,

knickpoint In geomorphology, a knickpoint or nickpoint is part of a river or channel where there is a sharp change in channel bed slope, such as a waterfall or lake. Knickpoints reflect different conditions and processes on the river, often caused by pre ...

s and terraces) have traditionally been interpreted through the “long ago and very slow” paradigm of geologic time in response to shifting climate or tectonic forcing. Typically, a steep-walled narrow gorge is inferred to represent slow persistent erosion, but because many of the geological formations of Canyon Lake Gorge are virtually indistinguishable from other formations which have been attributed to long term (slower) processes, the data collected from Canyon Lake Gorge lends further credence to the

hypothesis A hypothesis (: hypotheses) is a proposed explanation for a phenomenon. A scientific hypothesis must be based on observations and make a testable and reproducible prediction about reality, in a process beginning with an educated guess o ...

that some of the most spectacular canyons on Earth may have been carved rapidly during ancient

megaflood In geomorphology, an outburst flood—a type of megaflood—is a high-magnitude, low-frequency catastrophic flood involving the sudden release of a large quantity of water. During the last deglaciation, numerous glacial lake outburst floods were ca ...

events. Additionally, because the flood conditions under which the gorge was formed are known, Canyon Lake Gorge provides a means of developing improved

computer model Computer simulation is the running of a mathematical model on a computer, the model being designed to represent the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be determin ...

reconstructions of pre-historic floods to determine water volume, flood duration and erosion rates.

References

External links

* {{coord, 29.86098, -98.19000, region:US, format=dms, display=title Canyons and gorges of Texas Protected areas of Comal County, Texas Nature reserves in Texas Landforms of Comal County, Texas United States Army Corps of Engineers Guadalupe-Blanco River Authority