Selected limestone caves recognized as exhibiting hypogene origin

 

Carlsbad Caverns (New Mexico)

Carlsbad Caverns National Park has 119 caves, all formed by sulfuric acid rather than carbonic acid. [53] Most famous of these caves are the Big Room and Lechuguilla Cave.

Research shows that hydrogen sulfide from local oil deposits and various newly identified microbes interacted with oxygen in the underground water table producing sulfuric acid. This process led to aggressive dissolution of passageways at the water table level along cracks, fractures, and faults in the limestone. [54]

Big Room

Carlsbad Caverns' Big    Room is the largest single cave chamber in North America, with “an area equivalent to 14 football fields and a height enough to accommodate the U.S. Capital Building.” [55] Large gypsum blocks, created by sulfuric acid dissolving limestone, remain on Big Room’s floor. [56]

 

 

 

 

 

 

 

 

Big Room, Carlsbad Caverns (b)

 

Lechuguilla Cave

Lechuguilla Cave stretches more than 150 miles and reaches a depth of 1,604 feet.[57] This cave ranks as the deepest and third longest in the United States. [58] While it features numerous spacious chambers, none are as large as Carlsbad's Big Room. It features rare speleothems such as lemon-yellow sulfur deposits, 20-foot gypsum chandeliers, hairs, and beards. [59]

 Frasassi Caves (Italy)

The Frasassi Caves prove ongoing hypogenic karst development through active sulfuric acid formation. [60] The interaction between tectonic uplift and river downcutting has resulted in a series of horizontal passage levels interconnected by vertical shafts, with older cave systems found at higher elevations. [61]

 

 

 

 

 

 

 

 

 

Frasassi Caves (c)

 

Krubera-Voronya Cave (Arabika Massif of the Western Caucasus, Georgia)

Once the deepest cave known, at approximately 2,197 meters (7,208 ft), its entrance sits around 2,240 meters (7,349 ft) above sea level. [62] “The cave is characterized by vertical shafts, narrow passages, and large chambers.” [63] These are good indications of hypogenesis. [b]  

Cave of the Crystals(Nacia Mine, Chihuahua, Mexico)

The upward movement of magma led to the development of a mountain in the vicinity of Naica. In the process hot, mineral-laden waters forced through fissures subsequently created caverns and voids within the limestone bedrock. [64][65] The water that formed this cave likely was saturated with sulfide ions. [66] This cave is situated approximately 300 meters (980 ft) beneath the present ground level and has a maximum volume of 6,000 cubic meters (210,000 cu ft). [67] The site features large selenite (gypsum) crystals, including one that is 11.4 meters (37.4 ft) long and about 5 cubic meters (180 cu ft) in volume. [68]

 

 

 

 

 

 

 

 

Cave of the Crystals (d)

 

Gouffre Berger Cave (French Alps)

Descends from the Vercors Plateau to about 1,271 meters (4,170 ft) below the surface. [69]

 

Selected limestone caves recognized as exhibiting epigenesis origin

 

Mammoth Caves

“The Mammoth Cave system is the most extensive in the world, with more than 557 kilometers (345 miles) of interconnected passages.” [70]

 

 

 

 

 

 

 

 

Mammoth Cave (e)

 

Bystrianska Cave (Slovak Republic)

This cave is not classified as hypogenic. It consists primarily of dark limestone rocks and is 2,637 meters (8,652 ft) in long and 95 meters (312 ft) in depth. [71] It was formed from tectonic cracks that were enlarged by water corrosion, demolition of parts of the ceiling and enlargement by the underground river Bystra. [72] Morphology includes flowstone fills. [73]

 

 

 

 

 

 

 

 

 

Bystrianska Cave (f)

 

Cave of the Mounds (Wisconsin)

This cave features soda straws, flowstones, curtains, lily pads, helictites, and rare oolites. [74] “In total, Cave of the Mounds measures 1,692 ft including all rooms, cracks, and crevices.” [75] It is roughly fifteen meters (50 ft) below the ground surface.

 

 

 

 

 

 

 

 

Cave of the Mounds (g)

 

Luray Cave (Luray, Virginia)

This cavern features columns, stalactites, stalagmites, flowstone, and mirrored pools. [76]

 

Notes:

[a] “Many caves contain large amounts of clay, gravel, cobbles, and boulders which could not have been dissolved from the limestone. Instead, the cave-filling material appears to have been transported by moving water from a sediment source outside the cave.” [77]

[b] Vertical caves can develop when fluids move upward through the Earth's crust and fault zones. These caves may join with horizontal caverns, resulting in extensive cave systems. [78]

[c] RATE is an acronym for Radioisotopes and the Age of the Earth. The Institute for Creation Research sponsored this project which ran from 1997 to 2005. RATE scientists included two geologists, a geophysicist, three physicists, and a meteorologist, all with earned doctorates. [79]

 

Photos:

(a)      Dave Bunnell, CC BY-SA 2.5, via Wikimedia Commons

(b)       CarlsbadCavernsNPS, Public domain, via Wikimedia Commons

(c)       Accurimbono, CC BY-SA 4.0, via Wikimedia Commons

(d)      Alexander Van Driessche, CC BY 3.0, via Wikimedia Commons

(e)       Daniel Schwen, CC BY-SA 4.0, via Wikimedia Commons

(f)     Pe3kZA, CC BY-SA 3.0, via Wikimedia Commons

(g)      Yinan Chen, Public Domain, via Wikimedia Commons

References:

[1] Austin, S, “Origin of Limestone Caves,” Acts & Facts, January 1, 1980, The Institute for Creation Research, internet

[2] Lutgens, F, Tarbuck, J, “Essentials of Geology,” Ninth Edition, (Upper Saddle River, NJ: Pearson, Prentice Hall, 2006), 144

[3] Prothero, D, Schwab, F, “Sedimentary Geology,” Second Edition, (New York, NY: W. H. Freeman and Company, 2004), 212

[4] “Cave Formations,” Wonders of Geology, August 14, 2008, Answers in Genesis, internet

[5] Matthews, M, “Caves – Underground and Upside Down,” Answers Magazine, May 1, 2018, Answers in Genesis, internet

[6] “How Does CO2 Affect pH in Water?” Atlas Scientific, viewed internet September 10, 2025

[7] Dave, “Discovering How Many Limestone Caves Are There in the World: A Global Exploration, Limestone Legend, viewed internet August 18, 2025

[8] “Hypogene,” Wikipedia, viewed internet September 8, 2025

[9] “Unearthing the Sources of Cave-Forming Sulfuric Acid,” journal Geology, The Geological Society of America, viewed internet October 7, 2025

[10] Ibid.

[11] “pH of Sulfuric Acid,” whatistheph.com, viewed internet September 10, 2025

[12] Kempe, S, “Hypogene Limestone Caves in Germany: Geochemical Background and Regionality,” Hypogene Cave Morphologies, Special Publication 18, Karst Waters Institute

[13] Ibid.

[14] De Waele, J, Plan, L, et al., “Sulfuric Acid Water Table Caves (Grotte Du Chat/Acqua Fitusa/Bad Deutsch Altenburg + Kraushohle,” Hypogene Cave Morphologies, Special Publication 18, Karst Waters Institute

[15] Austin

[16] Salzwedel, M, “How Does Salt Affect the pH Of Water?” Sciencing, March 24, 2022, viewed internet

[17] Omni Calculator

[18] “Will Limestone Dissolve in Water? Understanding Its Chemical Interactions and Environmental Impact,” Limestone Legend, viewed internet September 29, 2025

[19] “Examples of Temperature Effects in Real Chemical Reactions,” Solubility of Things, viewed internet October 24, 2025

[20] “Effect of Salts on pH,” Pathways to Chemistry, viewed internet October 9, 2025       

[21] Will Limestone Dissolve in Water?

[22] Oard, 51

[23] “Cave-Forming Processes,” Kentucky Geological Survey, Special Publication 7, University of Kentucky, viewed internet October 3, 2025

[24] “Effect of Salts on pH,” Pathways to Chemistry, viewed internet October 9, 2025       

[25] Sulfuric Acid Water Table Caves

[26] Leet, L, Judson, S, “Physical Geology,” Third Edition, (Engelwood Cliffs, NJ: Prentice-Hall, Inc., 1965), 172

[27] Lutgens, 236

[28] “Hypogenic karst of the Great Basin,” USGS, September 2021, viewed internet October 14, 2025.

[29] Audra, P, Palmer, A, “The pattern of caves: controls of epigenic speleogenesis,” Géo morphologie, Volume 17, No. 4, 2011

[30] Klimchouk, A.B., “Hypogene Speleogenesis,” Treatise on Geomorphology, Volume 6, March 2013, Pages 220-240, viewed internet

[31] Palmer, A, “Sulfuric Acid vs. Epigenic Carbonic Acid in Cave Origin and Morphology,” March 2013, DeepKarst, 2016

[32] Earle, S, “Origin and Genesis of Caves,” Vancouver Island University, geo.libretexts, viewed internet September 27, 2025

[33] “Evidence of a Sulfuric Acid Origin for Lehman Caves,” U.S. National Park Service, viewed internet July 14, 2025

[34] Kempe

[35] Kempe

[36] Sulfuric Acid Water Table Caves

[37] “Hypogene Speleogenesis”

[38] Klimchouk, A, “Speleogenesis – Hypogene, Meso-morphology features,” Chapter 114, Encyclopedia of Caves, Third Edition, 2019, viewed internet October 22, 2025

[39] Matthews, M, “Caves – Underground and Upside Down,” Answers Magazine, May 1, 2018, Answers in Genesis, internet

[40] “Hypogenic karst of the Great Basin,” USGS, September 24, 2021, viewed internet October 14, 2025

[41] Borges, S, Casarin, C, et al., “Preliminary Considerations on Hypogene Morphology in Toca Da Boa Boa Vista E Toca Da Barriguda Caves, Northeastern Brazil,” Hypogene Cave Morphologies, Special Publication 18, Karst Waters Institute

[42] Macalady, J, Galassi, D, “The Frasassi Caves, Italy, Morphology and genesis,” Chapter 52, Encyclopedia of Caves, Third Edition, 2019, viewed internet October 22, 2025

[43] De Waele, J, Audra, P, et al., “Kraushohle (Austria): morphology and mineralogy of an alpine sulfuric acid cave, 2009 ICS Proceedings, viewed internet October 21, 2025

[44] De Waele, J, Galenzi, S, et al., “A Review on Hypogene Caves in Italy,” Hypogene Cave Morphologies, Special Publication 18, Karst Waters Institute

[45] Palmer, A, “Sulfuric Acid vs. Epigenic Carbonic Acid in Cave Origin and Morphology,” March 2013, DeepKarst, 2016

[46] Audra, P, et al, “Hypogenic caves in France, Speleogenesis and morphology of cave systems,” Abstract, Bulletin de la Societe Geologique de France (2010) 181 (4); 327-335, viewed internet October 14, 2025

[47] “Hypogenic karst of the Great Basin”

[48] Audra

[49] “A Review on Hypogene Caves in Italy”

[50] Snelling, 978

[51] “Cave-Forming Processes,” Kentucky Geological Survey, Special Publication 7, University of Kentucky, viewed internet October 3, 2025

[52 “Effect of Salts on pH,” Pathways to Chemistry, viewed internet October 9, 2025       

[53] “Carlsbad Caverns,” National Park Service, viewed internet May 19, 2025

[54] Ibid.

[55] Lutgens, 236

[56] Carlsbad

[57] “Lechuguilla Cave,” Wikipedia, viewed internet August 20, 2025

[58] “Geology of Carlsbad Caverns National Park,” USGS, viewed internet October 8, 2025

[59] Lechuguilla Cave

[60] “The Frasassi Caves, Italy,” Chapter 53, Encyclopedia of Caves, 2019, viewed internet September 29, 2025

[61] Ibid.

[62] “The World’s Deepest Cave Known As ‘Everest of the Caves’,” Geology, viewed on internet July 21, 2025

[63] Ibid.

[64] Hiolski, E, “Naica’s crystal cave captivates chemist’s,” C&EN, February 8, 2029, viewed internet

[65] Pare, S, “Cave of Crystals: The deadly cavern in Mexico dubbed ’the Sistine Chapel of Crystals’,” Live Science, May 3, 2024

[66] “Cave of the Crystals,” Wikipedia, viewed internet August 25, 2025

[67] Pare, S, “Cave of Crystals: The deadly cavern in Mexico dubbed ’the Sistine Chapel of Crystals’,” Live Science, May 3, 2024

[68] “Cave of the Crystals”

[69] “Gouffre Berger,” Wikipedia, viewed internet August 1, 2025

[70] Lutgens, 236

[71] “Bystrianska Cave,” Wikipedia, viewed internet September 29, 2025

[72] Ibid.

[73] “Bystrianska Cave,” International Show Caves Association, viewed internet September 29, 2025

[74] “Cave of the Mounds,” Wikipedia, viewed internet October 23, 2025

[75] “Our Geology,” Cave of the Mounds, viewed internet October 23, 2025

[76] “Luray Caverns,” Wikipedia, viewed internet October 4, 2025

[77] Austin

[78] “Unearthing the Sources of Cave-Forming Sulfuric Acid,” journal Geology, The Geological Society of America, viewed internet October 7, 2025

[79] DeYoung, D., Thousands...Not Billions, (Green Forest, AR: Master Books, 2005),18

 

 

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