Ancient lake

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Lake Zaysan in Kazakhstan is one of the oldest lakes in the world. Zaysan.jpg
Lake Zaysan in Kazakhstan is one of the oldest lakes in the world.

An ancient lake is a lake that has consistently carried water for more than one million years. 12 of the 20 ancient lakes have existed for more than 2.6 million years, the full Quaternary period. Ancient lakes continue to persist due to plate tectonics in an active rift zone. This active rift zone creates lakes that are extremely deep and difficult to naturally fill with sediment. Due to the prolonged life of ancient lakes, they serve as models for isolated evolutionary traits and speciation. Most of the world's bodies of water are less than 18,000 years old. There are only 20 ancient lakes over 1 million years old. [1]

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Lake Baikal is often considered the oldest, as clear evidence shows that it is 25–30 million years old. [2] [3] Lake Zaysan may be even older, of Cretaceous origin and at least 66 million years old [4] (most likely around 70 million years [5] ), but its exact age is controversial and labeled with some uncertainty. [6] Another contender for oldest is Lake Maracaibo, estimated to be 20–36 million years old. In ancient times it was indisputably a true lake, but today it is saline and directly connected to the sea, leading many to consider it a large lagoon or bay. [7]

Ancient lakes vs. younger lakes

There are six major types of lakes (listed below). The majority of lakes dry up as the result of the filling with lacustrine deposits, sediment deposited from a river into a lake over thousands of years. Factors that influence the water level decreasing include fluvial-lacustrine sediment build-up, evaporation, natural drainage, and geophysical processes. Ancient lakes have a prolonged life when compared to younger, more ordinary lakes due to the local active rift zones and subsided sections of land called grabens.

For example, Lake Baikal in Russia, the deepest lake in the world, is an ancient lake created by the Baikal Rift Zone which is 25–30 million years old and 5,387 feet (1,642 m) deep. This is compared to the North American Great Lakes, which were formed by the last glacial period by glacial scouring and the pooling of meltwater which are 14,000 years old and have maximum depths ranging from 200–1,300 feet (60–400 m) deep.

Formation of ancient lakes

Ancient lake formation is similar to that of a rift valley. Formation occurs within a graben that is located on an active rift zone. Grabens are sections of land, formed along divergent plate boundaries, which have subsided between two parallel plates. The location of the graben above the active rift zone results in a lake bottom that is constantly dropping in-depth and walls increasing in height.

Importance to evolution

Ancient lakes allow scientists to study the mechanisms of environmental changes over glacial-interglacial timescales. Evolutionary characteristics including sexual selection, adaptive radiation and punctuated equilibrium are studied in ancient lakes due to their prolonged existence and general geographic isolation. Most of the research has been associated with the endemic fauna and diatoms that exist in these isolated lakes, concentrating on Lake Baikal, the Caspian Sea and the African Great Lakes. Information is derived from the associations of the fluvial-lacustrine, fluctuating profundal and evaporative facies.

List of ancient lakes

These are the 20 ancient lakes in the world that have existed for more than 1 million years. [1]

NameOriginTypeAgeArea
(km2)
Volume
(km3)
Depth maxDepth averageCountriesNotes
Lake Pingualuk meteor impactfresh, permanent, crater1.5 million8267 Canada
Lake Tahoe tectonicfresh, permanent1–2 million499156505313 United States
Lake Bosumtwi meteor impactsoda, permanent, crater1–2 million492.248145 Ghana
Lake Lanao volcanicfresh, permanent2 million37511260.3 Philippines
Lake Titicaca tectonicfresh, permanent3 million8372893281107 Bolivia, Peru
Lake Prespa tectonicfresh, permanent1.5-5 million2594.85418.7 Albania, Greece, North Macedonia
Lake Ohrid tectonicfresh, permanent1.5-5 million358.1853.63286.7163.71Albania North Macedonia
Lake Malawi tectonicfresh, permanent2–5 million296008400705292 Malawi, Mozambique, Tanzania
Lake Hovsgol tectonicfresh, permanent2–5 million2770381267138 Mongolia
Kati Thanda–Lake Eyre tectonicsaline, intermittent, endorheic2.5-5 million969030.163 Australia
Lake Tanganyika tectonicfresh, permanent3–6 million32000178001471572 Burundi, Congo, Tanzania, Zambia
Caspian Sea tectonicsaline, permanent, endorheic5.5 million374000782001025182 Azerbaijan, Iran, Kazakhstan, Russia, Turkmenistan
Aral Sea tectonicsaline, permanent5.5 million645006256716 Kazakhstan, Uzbekistan Formerly the fourth largest lake in the world with an area of 68,000 km2 (26,300 sq mi). By 1997, it had shrunk to 10% of its original size due to water that was diverted in the Soviet Era. It is now split into 4 smaller lakes. As of 2023, the Aral Sea has become mostly desert.
Lake Biwa tectonicfresh, permanent5–6 million67427.510441 Japan
Lake Tule tectonicfresh, permanent3–15 million5340 United States
Lake Maracaibo tectonicsaline, permanent, coastal bay20+ million130102806025.9 Venezuela Historically it was an ancient lake. Now, it is a large tidal bay/inlet rather than a lake in the traditional sense. It is saline and directly connected to the Caribbean Sea, leading many to consider it a large lagoon or bay.
Lake Baikal tectonicfresh, permanent25+ million31500230001741740 Russia
Issyk-Kul tectonicsaline, permanent25 million62361738668270 Kyrgyzstan
Lake Vostok subglacialfresh, permanent, subglacial15–35 million125005400510432 Antarctica
Lake Zaysan tectonicfresh, permanent65+ million551053105 Kazakhstan The construction of the Bukhtarma dam inundated the lake, thus, in some sources, the lake is considered a reservoir. [8]

Related Research Articles

<span class="mw-page-title-main">Lake Zaysan</span> Lake in Kazakhstan

Lake Zaysan or Zaisan, also known by other names in other languages, is a freshwater lake in Tarbagatay District, East Kazakhstan Region, Kazakhstan. It is the largest lake in the region. The lake is generally frozen from the beginning of November to the end of April, but still has an abundance of fish.

<span class="mw-page-title-main">Graben</span> Depressed block of planetary crust bordered by parallel normal faults

In geology, a graben is a depressed block of the crust of a planet or moon, bordered by parallel normal faults.

<span class="mw-page-title-main">Rift</span> Geological linear zone where the lithosphere is being pulled apart

In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben with normal faulting and rift-flank uplifts mainly on one side. Where rifts remain above sea level they form a rift valley, which may be filled by water forming a rift lake. The axis of the rift area may contain volcanic rocks, and active volcanism is a part of many, but not all, active rift systems.

<span class="mw-page-title-main">Mississippi embayment</span> Low-lying basin filled with Cretaceous to recent sediments

The Mississippi embayment is a physiographic feature in the south-central United States, part of the Mississippi Alluvial Plain. It is essentially a northward continuation of the fluvial sediments of the Mississippi River Delta to its confluence with the Ohio River at Cairo, Illinois. The current sedimentary area was formed in the Cretaceous and early Cenozoic by the filling with sediment of a pre-existing basin. An explanation for the embayment's formation was put forward by Van Arsdale and Cox in 2007: movement of the Earth's crust brought this region over a volcanic "hotspot" in the Earth's mantle causing an upthrust of magma which formed the Appalachian-Ouachita range. Subsequent erosion caused a deep trough that was flooded by the Gulf of Mexico and eventually filled with sediment from the Mississippi River.

<span class="mw-page-title-main">Maracaibo Basin</span> Foreland basin in Venezuela

The Maracaibo Basin, also known as Lake Maracaibo natural region, Lake Maracaibo depression or Lake Maracaibo Lowlands, is a foreland basin and one of the eight natural regions of Venezuela, found in the northwestern corner of Venezuela in South America. Covering over 36,657 square km, it is a hydrocarbon-rich region that has produced over 30 billion bbl of oil with an estimated 44 billion bbl yet to be recovered. The basin is characterized by a large shallow tidal estuary, Lake Maracaibo, located near its center. The Maracaibo basin has a complex tectonic history that dates back to the Jurassic period with multiple evolution stages. Despite its complexity, these major tectonic stages are well preserved within its stratigraphy. This makes The Maracaibo basin one of the most valuable basins for reconstructing South America's early tectonic history.

<span class="mw-page-title-main">Lacustrine plain</span> Lakes filled by sediment

A lacustrine plain or lake plain is a plain formed due to the past existence of a lake and its accompanying sediment accumulation. Lacustrine plains can be formed through one of three major mechanisms: glacial drainage, differential uplift, and inland lake creation and drainage. Lake plains can have various uses depending on where and how they form.

The Orcadian Basin is a sedimentary basin of Devonian age that formed mainly as a result of extensional tectonics in northeastern Scotland after the end of the Caledonian orogeny. During part of its history, the basin was filled by a lake now known as Lake Orcadie. In that lacustrine environment, a sequence of finely bedded sedimentary rocks was deposited, containing well-preserved fish fossils, with alternating layers of mudstone and coarse siltstone to very fine sandstone. These flagstones split easily along the bedding and have been used as building material for thousands of years. The deposits of the Orcadian Basin form part of the Old Red Sandstone (ORS). The lithostratigraphic terms lower, middle and upper ORS, however, do not necessarily match exactly with sediments of lower, middle and upper Devonian age, as the base of the ORS is now known to be in the Silurian and the top in the Carboniferous.

<span class="mw-page-title-main">Baikal Rift Zone</span> Part of the boundary between the Amur and Eurasian tectonic plates.

The Baikal Rift Zone is a series of continental rifts centered beneath Lake Baikal in southeastern Russia. Current strain in the rifts tends to be extending with some shear movement. A series of basins form along the zone for more than 2,000 kilometres (1,200 mi), creating a rift valley. The rifts form between the Eurasian Plate to the west and the Amur Plate to the east.

<span class="mw-page-title-main">Geology of the North Sea</span>

The geology of the North Sea describes the geological features such as channels, trenches, and ridges today and the geological history, plate tectonics, and geological events that created them.

The Aquitaine Basin is the second largest Mesozoic and Cenozoic sedimentary basin in France after the Paris Basin, occupying a large part of the country's southwestern quadrant. Its surface area covers 66,000 km2 onshore. It formed on Variscan basement which was peneplained during the Permian and then started subsiding in the early Triassic. The basement is covered in the Parentis Basin and in the Subpyrenean Basin—both sub-basins of the main Aquitaine Basin—by 11,000 m of sediment.

<span class="mw-page-title-main">Geology of Russia</span>

The geology of Russia, the world's largest country, which extends over much of northern Eurasia, consists of several stable cratons and sedimentary platforms bounded by orogenic (mountain) belts.

<span class="mw-page-title-main">Half-graben</span> Geological structure bounded by a fault along one side of its boundaries

A half-graben is a geological structure bounded by a fault along one side of its boundaries, unlike a full graben where a depressed block of land is bordered by parallel faults.

<span class="mw-page-title-main">North German basin</span> Passive-active rift basin in central and west Europe

The North German Basin is a passive-active rift basin located in central and west Europe, lying within the southeasternmost portions of the North Sea and the southwestern Baltic Sea and across terrestrial portions of northern Germany, Netherlands, and Poland. The North German Basin is a sub-basin of the Southern Permian Basin, that accounts for a composite of intra-continental basins composed of Permian to Cenozoic sediments, which have accumulated to thicknesses around 10–12 kilometres (6–7.5 mi). The complex evolution of the basin takes place from the Permian to the Cenozoic, and is largely influenced by multiple stages of rifting, subsidence, and salt tectonic events. The North German Basin also accounts for a significant amount of Western Europe's natural gas resources, including one of the world's largest natural gas reservoir, the Groningen gas field.

<span class="mw-page-title-main">Lacustrine deposits</span> Sediment deposited by a lake

Lacustrine deposits are sedimentary rock formations which formed in the bottom of ancient lakes. A common characteristic of lacustrine deposits is that a river or stream channel has carried sediment into the basin. Lacustrine deposits form in all lake types including rift graben lakes, oxbow lakes, glacial lakes, and crater lakes. Lacustrine environments, like seas, are large bodies of water. They share similar sedimentary deposits which are mainly composed of low-energy particle sizes. Lacustrine deposits are typically very well sorted with highly laminated beds of silts, clays, and occasionally carbonates. In regards to geologic time, lakes are temporary and once they no longer receive water, they dry up and leave a formation.

<span class="mw-page-title-main">Bolivar Coastal Fields</span>

The Bolivar Coastal Fields (BCF), also known as the Bolivar Coastal Complex, is located on the eastern margin of Lake Maracaibo, Venezuela. Bolivar Coastal Field is the largest oil field in South America with its 6,000-7,000 wells and forest of related derricks, stretches thirty-five miles along the north-east coast of Lake Maracaibo. They form the largest oil field outside of the Middle East and contain mostly heavy oil with a gravity less than 22 degrees API. Also known as the Eastern Coast Fields, Bolivar Coastal Oil Field consists of Tía Juana, Lagunillas, Bachaquero, Ceuta, Motatán, Barua and Ambrosio. The Bolivar Coast field lies in the Maracaibo dry forests ecoregion, which has been severely damaged by farming and ranching as well as oil exploitation. The oil field still plays an important role in production from the nation with approximately 2.6 million barrels of oil a day. It is important to note that the oil and gas industry refers to the Bolivar Coastal Complex as a single oilfield, in spite of the fact that the oilfield consists of many sub-fields as stated above.

<span class="mw-page-title-main">Geology of Ethiopia</span>

The geology of Ethiopia includes rocks of the Neoproterozoic East African Orogeny, Jurassic marine sediments and Quaternary rift-related volcanism. Events that greatly shaped Ethiopian geology is the assembly and break-up of Gondwana and the present-day rifting of Africa.

The geology of Mozambique is primarily extremely old Precambrian metamorphic and igneous crystalline basement rock, formed in the Archean and Proterozoic, in some cases more than two billion years ago. Mozambique contains greenstone belts and spans the Zimbabwe Craton, a section of ancient stable crust. The region was impacted by major tectonic events, such as the mountain building Irumide orogeny, Pan-African orogeny and the Snowball Earth glaciation. Large basins that formed in the last half-billion years have filled with extensive continental and marine sedimentary rocks, including rocks of the extensive Karoo Supergroup which exist across Southern Africa. In some cases these units are capped by volcanic rocks. As a result of its complex and ancient geology, Mozambique has deposits of iron, coal, gold, mineral sands, bauxite, copper and other natural resources.

The geology of Uganda extends back to the Archean and Proterozoic eons of the Precambrian, and much of the country is underlain by gneiss, argillite and other metamorphic rocks that are sometimes over 2.5 billion years old. Sedimentary rocks and new igneous and metamorphic units formed throughout the Proterozoic and the region was partially affected by the Pan-African orogeny and Snowball Earth events. Through the Mesozoic and Cenozoic, ancient basement rock has weathered into water-bearing saprolite and the region has experienced periods of volcanism and rift valley formation. The East Africa Rift gives rise to thick, more geologically recent sediment sequences and the country's numerous lakes. Uganda has extensive natural resources, particularly gold.

The geology of Argentina includes ancient Precambrian basement rock affected by the Grenville orogeny, sediment filled basins from the Mesozoic and Cenozoic as well as newly uplifted areas in the Andes.

<span class="mw-page-title-main">Espanola basin</span> Structural basin in northern New Mexico, US

The Espanola basin is a structural basin in northern New Mexico. It is located in the Rio Grande watershed and is part of the Rio Grande rift. The definition of its boundaries is not fully settled, but the basin is usually defined such that it includes the cities of Santa Fe, Los Alamos, and Espanola.

References

  1. 1 2 Free, Christopher (April 23, 2016). "Ancient lakes of the world". Christopher M. Free. Archived from the original (website) on February 9, 2020. Retrieved 20 January 2024. Most of the hundreds of thousands of inland water bodies on our planet are less than 18,000 years old, but a few lakes and inland seas have existed continuously for more than 1 million years. I present a database of the 20 ancient lakes of the world.
  2. "Lake Baikal – UNESCO World Heritage Centre". 1992–2024. Retrieved 20 January 2024. Situated in south-east Siberia, the 3.15-million-ha Lake Baikal is the oldest (25 million years) and deepest (1,700 m) lake in the world. It contains 20% of the world's total unfrozen freshwater reserve.
  3. "Lake Baikal: Protection of a unique ecosystem". ScienceDaily. 26 July 2017. Retrieved 8 March 2018.
  4. Lucas; Bray; Emry; Hirsch (2012). "Dinosaur eggshell and Cretaceous-Paleogene Boundary in the Zaysan Basin, eastern Kazakhstan". Journal of Stratigraphy. 36 (2): 1376–1382. doi: 10.1016/j.proenv.2011.09.220 .
  5. Dorfman, B.F. (2011). "Zaysan-the Only Surviving Cretaceous Lake-May be Lost". Procedia Environmental Sciences. 10 (B): 1376–1382. Bibcode:2011PrEnS..10.1376D. doi: 10.1016/j.proenv.2011.09.220 .
  6. "The Oldest Lakes in the World". World Atlas. 25 August 2017. Retrieved 8 March 2018.
  7. "Lake Maracaibo – Lakes of the World". World Atlas. Retrieved 8 March 2018.
  8. Soviet Encyclopedic Dictionary, Moscow, 1980, p. 451.