Lonar crater lake
Encyclopedia
Maharashtra
Maharashtra is a state located in India. It is the second most populous after Uttar Pradesh and third largest state by area in India...
, India, which was created by a meteor
METEOR
METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...
hitting the Earth during the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
Epoch. The impact crater thereby formed is the only hypervelocity
Hypervelocity
The term hypervelocity usually refers to a very high velocity, approximately over 3,000 meters per second . In particular, it refers to velocities so high that the strength of materials upon impact is very small compared to inertial stresses. Thus, even metals behave like fluids under hypervelocity...
meteoritic impact crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
on basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
rock. A lake that evolved in the resulting basaltic rock formation
Rock formation
This is a list of rock formations that include isolated, scenic, or spectacular surface rock outcrops. These formations are usually the result of weathering and erosion sculpting the existing rock...
, is both saline
Saline water
Saline water is a general term for water that contains a significant concentration of dissolved salts . The concentration is usually expressed in parts per million of salt....
and alkaline in nature. Geologists, ecologists, archaeologists, naturalists and astronomers have reported several studies on the various aspects of this crater lake ecosystem. Lonar Lake has a mean diameter of 1.2 kilometres (3,937 ft) and is about 137 metres (449.5 ft) below the crater rim. The meteor crater rim is about 1.8 kilometres (5,905.5 ft) in diameter. The circular depression bears a saline water lake in its central portion. The crater's age is usually estimated to be 52,000 ± 6,000 years (Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
), although a study published in 2010 gives an age of 656,000 ± 81,000 years.
The Smithsonian Institution
Smithsonian Institution
The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...
, the United States Geological Survey
United States Geological Survey
The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...
, Geological Society of India
Geological Society of India
The Geological Society of India is based in Bangalore, India. Its flagship product is the Journal of the Geological Society of India .-Establishment:...
, and University of Sagar
University of Sagar
Dr. Hari Singh Gour University |Central University]] in Sagar, Madhya Pradesh, India. It was founded Sir Hari Singh Gour on 18 July 1946, during the British Raj and is the oldest university in the state.-Campus:...
and the Physical Research Laboratory
Physical Research Laboratory
The Physical Research Laboratory is a national Research Institute for space and allied sciences, supported mainly by Department of Space, Government of India. This research laboratory has ongoing research programmes in Astronomy and Astrophysics, Atmospheric Sciences and Aeronomy, Earth Sciences,...
have conducted extensive studies about the site.
Biological nitrogen fixation
Nitrogen fixation
Nitrogen fixation is the natural process, either biological or abiotic, by which nitrogen in the atmosphere is converted into ammonia . This process is essential for life because fixed nitrogen is required to biosynthesize the basic building blocks of life, e.g., nucleotides for DNA and RNA and...
has been discovered in this lake in the year 2007.
Geographical features
A series of low hills surround the basin which has an oval shape (almost round) with circumference at top of about 8 km (five miles). The sides of the basin rises abruptly at an angle of about 75°. At the base, the lake has a circumference of about 4.8 km (three miles). The slopes are covered with jungle interspersed with teakTeak
Teak is the common name for the tropical hardwood tree species Tectona grandis and its wood products. Tectona grandis is native to south and southeast Asia, mainly India, Indonesia, Malaysia, and Burma, but is naturalized and cultivated in many countries, including those in Africa and the...
tree. A belt of large trees about a mile broad runs all round the basin; belt is formed of concentric rings of different species of trees. A ring of date-palms followed by a ring of tamarind
Tamarind
Tamarind is a tree in the family Fabaceae. The genus Tamarindus is monotypic .-Origin:...
trees (nearly 1.6 km or a mile broad) leads to a ring of babul
Babul
Babul or is a 1950 Bollywood film directed by S.U. Sunny produced and with music direction by Naushad. The film stars Dilip Kumar, Munawar Sultana and Nargis. A box-office success, the film became the second highest earning film of 1950, earning an approximate gross of Rs. 1,25,00,000 and a nett...
trees, bounded on the inside by a belt of bare muddy space; mud space is several hundred metres/yards broad, devoid of all vegetation (due to soda content in the water) and covered with a whitish slimy soil, and leads to the lake water. During the rainy season, the drainage into the lake covers the muddy space. The water of the lake contains various salts or sodas. During the dry weather, as the water level reduces with evaporation, large quantities of sodas are collected. A well of sweet water is also located on the southern side of the lake, close to lake's water edge Two small streams drain into the lake.
The historical document called the Ain-i-Akbari (written about A.D. 1600) states:
These mountains produce all the requisites for making glass and soap. And here are saltpetre works which yield a considerable revenue to the State, from the duties collected. On these mountains is a spring of salt water, but the water from the centre and the edges is perfectly fresh.
Geological origin
The lake is said to be the only crater in the great basaltic formation of India. The lake was initially believed to be of volcanicVolcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
origin, but now it is recognized as an impact crater created by the hypervelocity impact of either a comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
or a meteorite
Meteorite
A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...
. The presence of plagioclase
Plagioclase
Plagioclase is an important series of tectosilicate minerals within the feldspar family. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a solid solution series, more properly known as the plagioclase feldspar series...
that has been either converted into maskelynite
Maskelynite
Maskelynite is a glassy phase found in some meteorites and meteorite impact craters. Typical samples are similar in composition to plagioclase feldspar, and revert to that mineral when melted and recrystallized. It was named after British geologist M.H.N...
or contains planar deformation features
Planar deformation features
Planar deformation features, or PDFs, are optically recognizable microscopic features in grains of silicate minerals , consisting of very narrow planes of glassy material arranged in parallel sets that have distinct orientations with respect to the grain's crystal structure.PDFs are only produced...
(PDFs) has confirmed the impact origin of this crater. It is argued that only shock metamorphism
Shock metamorphism
Shock metamorphism or impact metamorphism describes the effects of shock-wave related deformation and heating during impact events. The formation of similar features during explosive volcanism is generally discounted due to the lack of metamorphic effects unequivocally associated with explosions...
caused by hypervelocity impact can transform plagioclase into maskelynite or create PDFs. The presence of shatter cone
Shatter cone
Shatter cones are rare geological features that are only known to form in the bedrock beneath meteorite impact craters or underground nuclear explosions...
s, impact deformation of basalt layers comprising its rim, shocked breccia
Breccia
Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....
inside the crater, and non-volcanic ejecta blanket
Ejecta blanket
An ejecta blanket is a generally symmetrical apron of ejecta that surrounds crater; it is layered thickly at the crater’s rim and thin to discontinuous at the blanket’s outer edge....
surrounding the crater are further proof of the impact origin of Lonar crater. As a result of the studies, broadly, the geological features of the Lonar crater has been marked under five distinguishable zones, exhibiting distinct geomorphic characteristics.
The five zones are:
- The outermost ejecta blanket
- The crater rim
- The slopes of the crater
- The crater basin, excluding lake
- The crater lake
Historicity
The lake was first mentioned in ancient scriptures such as the Skanda PuranaSkanda Purana
The Skanda Purana is the largest Mahapurana, a genre of eighteen Hindu religious texts. The text is devoted mainly to the lilas of Kartikeya , a son of Shiva and Parvati. It also contains a number of legends about Shiva, and the holy places associated with him...
, the Padma Puran and the Aaina-i-Akbari The first European to visit the lake was British officer, J.E. Alexander in 1823.
Buldhana district
Buldhana district
-Buldhana district is a district in the Amravati division of Maharashtra state in western India. It is situated at the westernmost border of Vidarbha region of Maharashtra and is 500 km from the state capital, Mumbai...
in Maharashtra where the lake is located was once part of Ashoka
Ashoka
Ashok Maurya or Ashoka , popularly known as Ashoka the Great, was an Indian emperor of the Maurya Dynasty who ruled almost all of the Indian subcontinent from ca. 269 BC to 232 BC. One of India's greatest emperors, Ashoka reigned over most of present-day India after a number of military conquests...
's empire and then of Satavahana
Satavahana
The Sātavāhana Empire or Andhra Empire, was a royal Indian dynasty based from Dharanikota and Amaravati in Andhra Pradesh as well as Junnar and Prathisthan in Maharashtra. The territory of the empire covered much of India from 230 BCE onward...
s. The Chalukyas and Rashtrakutas also ruled this area. During the period of the Mughals, Yadavas
Seuna
The Seuna, Sevuna or Yadavas of Devagiri was an Indian dynasty, which at its peak ruled a kingdom stretching from the Tungabhadra to the Narmada rivers, including present-day Maharashtra, north Karnataka and parts of Madhya Pradesh, from its capital at Devagiri...
, Nizam
Nizam
Nizam-ul-Mulk of Hyderabad popularly known as Nizams of Hyderabad was a former monarchy of the Hyderabad State, now in the states of Andhra Pradesh , Karnataka , and Maharashtra in India...
and the British, trade prospered in this area. Several temples found in the periphery of the Lake are known as Yadava temples and also as Hemadpanti temples (named after Hemadri Ramgaya).
Local legend
A legend given in the Gazetteer of talukas, towns, important villages, rivers and hills published by the Gazeteers department of Government of Maharashtra states:
As per Skanda PuranaSkanda PuranaThe Skanda Purana is the largest Mahapurana, a genre of eighteen Hindu religious texts. The text is devoted mainly to the lilas of Kartikeya , a son of Shiva and Parvati. It also contains a number of legends about Shiva, and the holy places associated with him...
, a demon named Lonasura who lived in a subterranean abode used to devastate the surrounding country and even challenge Gods. Lord VishnuVishnuVishnu is the Supreme god in the Vaishnavite tradition of Hinduism. Smarta followers of Adi Shankara, among others, venerate Vishnu as one of the five primary forms of God....
, on an appeal by the people of the region, assumed the form of a handsome youth named Daitya-sudan, charmed the giant's two sisters and discovered the giant's abode and then removed the lid of the den where he was hiding and destroyed the giant. The present lake is claimed to be the den of the giant, and a conical hill near the village Datephal, some 36 miles to the south-west, is said to be the lid of the giant's den. The water of the lake is likened to the blood of the giant and the salts that it contains as the decomposed flesh of the giant. It is also believed that a perennial spring, at the head of the path which leads down to the lake is linked to the Ganges river.
Religious setting
Numerous temples surround the lake, most of which are in ruins, except for the temple of Daityasudan, at the centre of the Lonar town, which was built in honour of Vishnu's victory over the giant Lonasur. It is a fine specimen of early Hindu architecture. Vishnumandir, Wagh Mahadev, Mora Mahadev, Munglyacha Mandir and Goddess Kamalaja Devia are the other temples found inside the crater.
Daitya Sudan temple
Daitya Sudan Temple has beautiful carvings similar to what is seen at KhajurahoKhajuraho
The Khajuraho Group of Monuments in Khajuraho , a town in the Indian state of Madhya Pradesh, located in Chhatarpur District, about southeast of New Delhi, are one of the most popular tourist destinations in India. Khajuraho has the largest group of medieval Hindu and Jain temples, famous for...
temples. The idol of this temple is made of an ore with high metal content and looks like stone. Area out-side the sanctum is dark and the ceiling reveals beautiful carvings under a torch light. It is a Vishnu temple dated to the Chalukya Dynasty
Chalukya dynasty
The Chalukya dynasty was an Indian royal dynasty that ruled large parts of southern and central India between the 6th and the 12th centuries. During this period, they ruled as three related yet individual dynasties. The earliest dynasty, known as the "Badami Chalukyas", ruled from Vatapi from the...
which ruled Central and Southern India between the 6th and 12th centuries. It belongs to the Hemadpanthi
Hemadpanthi
Hemadpanthi Sculpture is an architectural form or a style, which is named after its introducer and founder, the prime minister named Hemadpant in the court of Seuna Yadavas of Devagiri. The period of discovery was during the 13th Century in Maharashtra. Main ingredients in the construction include...
class and is built in the form of an irregular star. The exterior walls are covered with carved figurnes. The plinth of the temple is about 1.5 m in height, and the unfinished roof suggests an intended pyramidal form for the tower.
Gomukh Temple, is located along the rim of the crater. A perennial stream emerges from here and pilgrims visiting the temple bathe in the stream.
By-products of the lake
The Gazetteer chronicles the findings of the British administrators and scientists, notably, Colonel Mackenzie, Scientist Dr. I. B. Lyon, Mr. J. O. Malcolmson and Mr. Plymen, Agricultural Chemist. Some extracts from Mr Plymen's report, given in quotes, are informative.
The saline deposits obtained from the lake are rather of an exceptional nature. Compared with the most famous salt lake in India, the Sambhar Lake in Rajputana, it will be seen that whereas at Lonar the carbonates of soda are the most important, in the case of the Sambhar Lake the deposits of sodium chloride or common salt give the lake its value. The modes of formation are also entirely different and it is practically certain that the Lonar salts are derived from an unknown source in the bed of the lake. It is true that water is continually flowing into the lake and that except by evaporation there is no loss. The main feeder stream could not however supply this amount of alkali nor could the other smaller supplies coming in during the rains, for on all sides of the lake vegetation is abundant, particularly where the main stream flows in continuously. Were any quantity of alkali present in this water, vegetation would suffer considerably and, with exception of a few varieties of plants, eventually die out entirely.
The salts collected from this lake vary in their nature and composition and from their-appearance are easily separated by men accustomed to handling them. Various names are given to some five or six main varieties, but there is no fixed line between one salt and another, their compositions depending upon the period and condition of crystallization. At the present time large quantities of these salts are lying on the shores of the lake...
With the process of crystallization, sodium chloride or common salt is formed along with the carbonates of soda resulting in a number of products, as explained below.
Dalla Nimak and Nimak Dalla are found in white crystalline masses.
Khuppal is obtained in solid compact lumps and consists of a mixture of carbonates and chlorides in roughly equal proportions.
Pipadi or Papri, which has a similar chemical composition, is very different in appearance. It is frequently tinged, slightly pink in colour and hollow air spaces are found between the crystalline masses which are formed in flakes or layers.
Bhuski has no definite structure but consists of a soft flaky powder mixed with a quantity of impurity.
All the salts are not obtained in the same way or at the same period of the year.
Pipadi and Bhuski are deposited on the shores of the lake as the water dries up in the hot weather, Pipadi being the upper layer and therefore the purer.
Except for Bhuski the salts are in a fairly pure state and contain only small proportions of earthy matter. Their further purification is not considered difficult.
Commercial exploitation of the salts from the lake, is recorded from 1842 including the period of Government of His Highness Nizam, and till 1903. Presently, there is only a very small local demand for the Lonar Lake products.
Lake ecosystem
The chemical characteristics of the lake shows two distinct regions that don’t mix - an outer neutral (pHPH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
7) and an inner alkaline (pH 11) each with its own flora and fauna.
The lake is a haven for a wide range of plant and animal life. Resident and migratory birds such as black-winged stilts, brahminy ducks, grebes, shell-ducks (European migrants), shovellers, teals, herons, red-wattled lapwings, rollers or blue jays, baya weavers, parakeet hoopoes, larks, tailorbirds, magpies and robins and swallows are found on the lake. Among reptiles, the monitor lizard is reported to be prominent. The lake is also home to thousands of pea fowls, chinkara and gazelles. Plea to declare Lonar lake a protected wetland.
Nitrogen fixing microorganisms
Nonsymbiotic nitrogen fixing microorganismNitrogen fixation
Nitrogen fixation is the natural process, either biological or abiotic, by which nitrogen in the atmosphere is converted into ammonia . This process is essential for life because fixed nitrogen is required to biosynthesize the basic building blocks of life, e.g., nucleotides for DNA and RNA and...
s such as Halomonas sp., Paracoccus sp. Klebsiella sp., Slackia sp. Actinopolyspora sp. have been reported from this lake. All the nitrogen fixers are haloalkaliphilic in nature as they can grow only at pH-11. Some of the 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...
and actinomycetes isolated from this lake are able to grow on some components of inorganic medium containing martian soil simulant components.
Threats to Lonar lake
Lonar lake of faces anthropological and environmental problems as listed below:- Use of fertilizers, pesticides and toxic materials in the agriculture field around the lake results in pollution lake water.
- One of the water sources for the lake is small river stream Dhara, Sita Nhani. The household effluents containing detergents are regularly disposed of here.
- Deforestation is illegally carried out in the surrounding and cattle grazing inside or near the rim of crater creates fecal pollution.
- During local festival such as Kamala Devi festival, large number of pilgrims enter the crater. Small shops, food-stalls are often established near the crater or along its rim.
- Excavation activities are often carried out illegally thus disturbing the lake's underground water source.
- The government is unable to raise funds needed for preserving this crater and often tourist activities continue to cause environmental damage to nearby land.
External links
- Lonar crater, India: an analog for martian impact craters, Lunar and Planetary Science XXXVIII abstracts.
- Lonar, A Gem of Craters SPARK Volume 2, K-12 outreach, Space Science and Engineering Centre, University of Wisc-Madison.
- http://picasaweb.google.com/GuNsOnPicasa/Lonar?feat=directlink Pictures from the Lonar crater taken in 2010.