Zacatón
Encyclopedia
Zacatón is thermal water filled sinkhole
belonging to Zacatón system - group of unusual karst
features located in Aldama Municipality in the northeastern state of Tamaulipas
, Mexico
. It is the deepest known water-filled sinkhole in the world with a total depth of 339 metres (1,112.2 ft). The 392 metres (1,286.1 ft) deep Pozzo Merro (Italy) is deeper but is rather a near-vertical cave and not sinkhole.
DEPTHX
, a NASA
funded project using an autonomous robot has measured the underwater portion of Zacatón to be 319 metres (1,046.6 ft) deep (a adj=on 20 difference between the rim of cliff and surface of water adds to the total depth). Zacatón is the only sinkhole of the five located in Rancho La Azufrosa to have any noticeable water flow.
The name Zacatón comes from the free-floating islands of zacate grass which move around on the surface with the wind.
Scrapings from the rock walls beneath the surface yielded at least 6 new phyla
of bacteria
.
Since the late 1990s, Marcus Gary, a hydrogeology graduate student at the Jackson School of Geosciences
at the University of Texas at Austin
has studied Sistema Zacatón to better understand how the sinkholes formed and how they evolve over time. During these studies, Gary made extensive use of high-end water quality monitoring instrumentation provided free of charge by (the now defunct) Hydrolab Corporation. Gary was a primary member on the DEPTHX mission, which used an autonomous underwater robot to explore the deepest parts of Zacatón for the first time.
According to Gary, these sinkholes began to form during the Pleistocene as a result of volcanic activity from below. This view differs from the classical theory of cave formation and also hypotheses about the formation of other large caves in this part of Mexico.
In this view, volcanism turned deep water slightly acidic by adding dissolved carbon dioxide and hydrogen sulfide. This water slowly dissolved the limestone above, creating porous karst. This is referred to as “hypogenic karstification.” From time to time, overlying rock collapsed into hollow chambers below, creating deep shafts. If his interpretation is correct, Sistema Zacatón has more in common with Mammoth Hot Springs
in Yellowstone than with other deep sinkholes in this same region of Mexico.
Another interesting hydrogeologic feature is that some of the sinkholes appear to be in the process of closing up at the top as crusts of travertine
(a form of calcium carbonate) form at their surfaces. Marc Airhart, a science writer at the Jackson School of Geosciences wrote:
Sinkhole
A sinkhole, also known as a sink, shake hole, swallow hole, swallet, doline or cenote, is a natural depression or hole in the Earth's surface caused by karst processes — the chemical dissolution of carbonate rocks or suffosion processes for example in sandstone...
belonging to Zacatón system - group of unusual karst
KARST
Kilometer-square Area Radio Synthesis Telescope is a Chinese telescope project to which FAST is a forerunner. KARST is a set of large spherical reflectors on karst landforms, which are bowlshaped limestone sinkholes named after the Kras region in Slovenia and Northern Italy. It will consist of...
features located in Aldama Municipality in the northeastern state of Tamaulipas
Tamaulipas
Tamaulipas officially Estado Libre y Soberano de Tamaulipas is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 43 municipalities and its capital city is Ciudad Victoria. The capital city was named after Guadalupe Victoria, the...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. It is the deepest known water-filled sinkhole in the world with a total depth of 339 metres (1,112.2 ft). The 392 metres (1,286.1 ft) deep Pozzo Merro (Italy) is deeper but is rather a near-vertical cave and not sinkhole.
DEPTHX
DEPTHX
The Deep Phreatic Thermal Explorer is an autonomous underwater vehicle, designed to explore deep underwater caves. It is purported to be the most advanced robotic vehicle of its kind on Earth. Its primary function is observation, with an array of sonar sensors all around its flattened spheroid hull...
, a NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
funded project using an autonomous robot has measured the underwater portion of Zacatón to be 319 metres (1,046.6 ft) deep (a adj=on 20 difference between the rim of cliff and surface of water adds to the total depth). Zacatón is the only sinkhole of the five located in Rancho La Azufrosa to have any noticeable water flow.
The name Zacatón comes from the free-floating islands of zacate grass which move around on the surface with the wind.
Scrapings from the rock walls beneath the surface yielded at least 6 new phyla
Phyla
Phyla, the plural of phylum, may refer to:* Phylum, a biological taxon between Kingdom and Class* Phylum , in linguistics, a large division of possibly related languagesPhyla, as a singular, may refer to:...
of bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
.
Diving
El Zacatón's depth has made it an important dive site:- Dr. Ann Kristovich set the women's world depth record of 554 feet (168.9 m) during a 1993 dive into the sinkhole.
- On April 6, 1994, explorer diver Jim BowdenJim Bowden (diver)Jim Bowden is an American SCUBA diver, and an elite technical diver, famous as a cave diver and as a deep diver. In 1994 he set a world record, since broken, by diving to . He is one of only eight people who have dived below a depth of on self contained breathing apparatus...
and cave diving pioneer Sheck ExleySheck Exley-Biography:Exley is widely regarded as one of the pioneers of cave diving, writing two major books on the subject: Basic Cave Diving: A Blueprint for Survival and Caverns Measureless to Man published by Cave Books, , and establishing many of the basic safety procedures used in cave and overhead...
plunged into El Zacatón with the intent of reaching bottom. Bowden dove to a men's world record depth of 925 feet (281.9 m), but Exley died, probably from high pressure nervous syndromeHigh pressure nervous syndromeHigh-pressure nervous syndrome is a neurological and physiological diving disorder that results when a commercial diver or scuba diver descends below about while breathing a helium–oxygen mixture. The effects depend on the rate of descent and the depth...
(HPNS) at a depth of 879 to 906 ft (267.9 to 276.1 m).
- The NASANASAThe National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
Deep Phreatic Thermal Explorer (DEPTHXDEPTHXThe Deep Phreatic Thermal Explorer is an autonomous underwater vehicle, designed to explore deep underwater caves. It is purported to be the most advanced robotic vehicle of its kind on Earth. Its primary function is observation, with an array of sonar sensors all around its flattened spheroid hull...
) project used the sinkhole as a testbed for robotic hardware being developed to explore the JovianJupiterJupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
moon of EuropaEuropa (moon)Europa Slightly smaller than Earth's Moon, Europa is primarily made of silicate rock and probably has an iron core. It has a tenuous atmosphere composed primarily of oxygen. Its surface is composed of ice and is one of the smoothest in the Solar System. This surface is striated by cracks and...
. DEPTHX was designed and integrated by NASA Principal Investigator Stone Aerospace. Additional co-investigators on the Deep Phreatic Thermal Explorer (DEPTHX) team included Carnegie Mellon UniversityCarnegie Mellon UniversityCarnegie Mellon University is a private research university in Pittsburgh, Pennsylvania, United States....
, Southwest Research InstituteSouthwest Research InstituteSouthwest Research Institute , headquartered in San Antonio, Texas, is one of the oldest and largest independent, nonprofit, applied research and development organizations in the United States...
, Colorado School of MinesColorado School of MinesThe Colorado School of Mines is a small public teaching and research university devoted to engineering and applied science, with special expertise in the development and stewardship of the Earth's natural resources. Located in Golden, Colorado, CSM was ranked 29th, in America among national...
, The University of Arizona, and the University of Texas at Austin's Jackson School of GeosciencesJackson School of GeosciencesThe Jackson School of Geosciences at The University of Texas at Austin unites the Department of Geological Sciences with two research units, the Institute for Geophysics and the Bureau of Economic Geology....
.
Hydrogeology
Zacatón is just one of the numerous sinkholes and other karst features in the region. Here are located more than 15 sinkholes, several cave systems and karst springs with caves. Several of these karst features have unusual characteristics like travertine lids over several of the sinkholes with isolated waterbodies below.Since the late 1990s, Marcus Gary, a hydrogeology graduate student at the Jackson School of Geosciences
Jackson School of Geosciences
The Jackson School of Geosciences at The University of Texas at Austin unites the Department of Geological Sciences with two research units, the Institute for Geophysics and the Bureau of Economic Geology....
at the University of Texas at Austin
University of Texas at Austin
The University of Texas at Austin is a state research university located in Austin, Texas, USA, and is the flagship institution of the The University of Texas System. Founded in 1883, its campus is located approximately from the Texas State Capitol in Austin...
has studied Sistema Zacatón to better understand how the sinkholes formed and how they evolve over time. During these studies, Gary made extensive use of high-end water quality monitoring instrumentation provided free of charge by (the now defunct) Hydrolab Corporation. Gary was a primary member on the DEPTHX mission, which used an autonomous underwater robot to explore the deepest parts of Zacatón for the first time.
According to Gary, these sinkholes began to form during the Pleistocene as a result of volcanic activity from below. This view differs from the classical theory of cave formation and also hypotheses about the formation of other large caves in this part of Mexico.
In this view, volcanism turned deep water slightly acidic by adding dissolved carbon dioxide and hydrogen sulfide. This water slowly dissolved the limestone above, creating porous karst. This is referred to as “hypogenic karstification.” From time to time, overlying rock collapsed into hollow chambers below, creating deep shafts. If his interpretation is correct, Sistema Zacatón has more in common with Mammoth Hot Springs
Mammoth Hot Springs
Mammoth Hot Springs is a large complex of hot springs on a hill of travertine in Yellowstone National Park adjacent to Fort Yellowstone and the Mammoth Hot Springs Historic District. It was created over thousands of years as hot water from the spring cooled and deposited calcium carbonate...
in Yellowstone than with other deep sinkholes in this same region of Mexico.
Another interesting hydrogeologic feature is that some of the sinkholes appear to be in the process of closing up at the top as crusts of travertine
Travertine
Travertine is a form of limestone deposited by mineral springs, especially hot springs. Travertine often has a fibrous or concentric appearance and exists in white, tan, and cream-colored varieties. It is formed by a process of rapid precipitation of calcium carbonate, often at the mouth of a hot...
(a form of calcium carbonate) form at their surfaces. Marc Airhart, a science writer at the Jackson School of Geosciences wrote:
It’s a bit like the skin on a can of paint that has been left open in the sun. For the paint, it might take a day or two. In this case, the process probably takes thousands of years. It is basically the sinkhole’s way of taking a bunch of dissolved rock floating in the water and recycling it to form new rock at the surface. At least one sinkhole (Poza Seca) appears to have closed up entirely, sealing off an underwater lake, possibly with unusual life forms. If such life forms exist, they’re likely to be bacteria that can live without oxygen and sunlight. And assuming the lake has been sealed off from the outside world for thousands and thousands of years, they might have evolved to be different from anything scientists have ever discovered and characterized before.
Further reading
- Sistema Zacatón
- Dispatches from Zacatón JSG Online, March/May 2007
- NASA-funded Robotic Sub Makes Final Dive To Reach Bottom of Earth’s Deepest Sinkhole JSG Online, May 14, 2007
- Sistema Zacatón by Wondermondo. Separate descriptions of 17 features in system.
External links
- Plan and profile view from DEPTHX (216KB PNG)
