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{{Short description|Alleged impact crater west of India}} |
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{{Unreferenced|date=February 2008}} |
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{{Infobox terrestrial impact site |
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| name = Shiva crater |
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| other_name = |
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| photo = |
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| photo_size = |
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| map = India |
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| map_alt = |
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| map_caption = Location of the proposed crater offshore India |
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| map_size = |
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| location = [[Mumbai]] Offshore Basin |
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| label = |
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| label_position = |
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| coordinates = {{coord|18|40|N|70|14|E|type:landmark_region:IN_scale:10000000|display=inline,title}} |
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| coordinates_ref = |
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| confidence =Dubious |
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| diameter = {{convert|500|km|mi|abbr=on}} |
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| depth = |
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| rise = |
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| imp_size = |
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| age = Claimed to be ~66 million years<ref>{{cite journal |last1=Renne |first1=Paul R. |last2=Deino |first2=Alan L. |last3=Hilgen |first3=Frederik J. |last4=Kuiper |first4=Klaudia F. |last5=Mark |first5=Darren F. |last6=Mitchell |first6=William S. |last7=Morgan |first7=Leah E. |last8=Mundil |first8=Roland |last9=Smit |first9=Jan |title=Time Scales of Critical Events Around the Cretaceous–Paleogene Boundary |journal=Science |date=7 February 2013 |volume=339 |issue=6120 |pages=684–687 |doi=10.1126/science.1230492 |pmid=23393261 |bibcode=2013Sci...339..684R|s2cid=6112274 }}</ref><br/>[[Cretaceous–Paleogene boundary]] |
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| exposed = No |
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| drilled = No |
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| bolide = |
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| translation = |
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| language = |
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| pronunciation = |
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| topo = |
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| access = |
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| country = [[India]] |
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}} |
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The '''Shiva crater''' is the claim by [[Paleontology|paleontologist]] [[Sankar Chatterjee]]<ref name="chatterjee 1997">{{cite book|last=Chatterjee|first=S.|title=Comparative Planetology, Geological Education, History of Geology: Proceedings of the 30th International Geological Congress, Beijing, China, 4–14 August 1996|chapter-url=https://books.google.com/books?id=3IORF1Ei3LIC&pg=PA31|year=1997|publisher=VSP|isbn=978-90-6764-254-5|pages=31–54|chapter='Multiple impacts at the KT boundary and the death of the dinosaurs}}</ref> and colleagues that the [[Bombay High]] and [[Surat]] Depression on the Indian continental shelf west of [[Mumbai]], [[India]] represent a {{convert|500|km|mi|adj=on}} impact crater, that formed around the [[Cretaceous-Paleogene boundary]]. Chatterjee and colleagues have claimed that this could have contributed to the [[K-Pg extinction event]]. Other scholars have questioned the claims, finding that there is no evidence of an impact structure. |
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The '''Shiva crater''' is a sea floor structure, thought by some to be an [[impact crater]] ([[astrobleme]]), located beneath the [[Indian Ocean]] west of [[Mumbai]] on the west coast of [[India]]. It was named by the paleontologist [[Sankar Chatterjee]] after [[Shiva]], the Hindu god of destruction and renewal. |
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== Arguments == |
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According to the impact hypothesis, it formed around 65 million years ago, at about the same time as a number of other impact craters and the [[Cretaceous-Tertiary extinction event]] (K-T boundary). Although the site has shifted since its formation because of [[sea floor spreading]], it has been suggested that when pieced together the putative crater would have been about 600 km by 400 km across and 12 km deep (and may be just part of a larger crater). It is estimated that a crater of that size would have been made by an [[asteroid]] or [[comet]] 40 km in diameter. |
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Chatterjee argues that the Shiva crater was formed around 65<!--Chatterjee claims the structure is around 65 million years old partly based on radiometric analysis of rocks. Changing it to 66 simply because the K/T boundary moved is potential WP:SYN. That requires a reference more recent than 1997.--> million years ago, about the same time as a number of other impact craters<!--This is no longer technically true except for Chicxulub. Silverpit is no longer considered an impact crater and Boltysh has been re-dated.--> and the [[Cretaceous–Paleogene extinction event]] ([[Cretaceous–Paleogene boundary]] / K-Pg boundary). Although the site has shifted since its formation because of [[sea floor spreading]], the formation is approximately {{convert|600|km|abbr=off}} long by {{convert|400|km|abbr=on}} wide. If its status as an impact crater is ever confirmed, the Shiva crater would be the largest known impact crater on Earth. It is estimated that this proposed crater would have been made by an [[asteroid]] or [[comet]] approximately {{convert|40|km|abbr=on}} in diameter.<ref name="chatterjee 1997"/><ref name="chatterjee 5">Chatterjee, S., N. Guven, A. Yoshinobu, and R. Donofrio. (2006) ''Shiva Structure: a possible KT boundary impact crater on the western shelf of India.'' Museum of Texas Tech University Special Publications. 50, 39pp.</ref> |
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At the time of the |
At the time of the Cretaceous–Paleogene extinction, India was located over the [[Réunion hotspot]] of the Indian Ocean. Hot material rising from the [[Mantle (geology)|mantle]] flooded portions of India with a vast amount of [[flood basalt|lava]], creating a plateau known as the [[Deccan Traps]]. It has been hypothesized that either the crater or the Deccan Traps associated with the area is the reason for the high level of oil and natural gas reserves in the region.<ref>{{cite journal |author=Agrawal, P., Pandey, O. |date=November 2000 |title= Thermal regime, hydrocarbon maturation and geodynamic events along the western margin of India since late Cretaceous|journal= Journal of Geodynamics|volume= 30|issue=4 |pages=439–459 |doi= 10.1016/S0264-3707(00)00002-8 |bibcode = 2000JGeo...30..439P }}</ref> |
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=== Geology and morphology === |
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==Discovery== |
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Unlike typical known extraterrestrial impact structures, Shiva is teardrop shaped, roughly {{convert|600|x|400|km|abbr=on}}. It is also unusually rectangular. Chatterjee argues that the low angle of an impact combined with boundary fault lines and unstable rock led to this unusual formation.<ref name="chatterjee 5"/> The age of the structure is inferred from the [[Deccan Traps]] which overlie part of it.<ref name="chatterjee 5"/> |
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{{section-stub}} |
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==Impact specifics== |
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{{section-stub}} |
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===Geology and morphology=== |
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===Shiva and mass extinction=== |
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{{main|Cretaceous–Tertiary extinction event}} |
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The discovery of Shiva and other craters like those found at [[Chicxulub crater|Chicxulub]] and other places has led to the hypothesis that there were in fact multiple impacts which caused the massive extinction event at the end of the Cretaceous period. Other theories have argued that since the Chicxulub impact was in fact ''earlier'' than the extinction of the dinosaurs, Shiva's impact was enough cause the mass extinction.<ref name="texas tech">{{cite web|author=Davis, John W|date=2006-11-15|url=http://www.depts.ttu.edu/communications/news/stories/06-11-dinosaur.php|title=Texas Tech Paleontologist Finds Evidence That Meteorite Strike Near Bombay May Have Wiped Out Dinosaurs|work=[[Texas Tech University]]|accessdate=2008-02-12}}</ref> |
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=== Shiva and mass extinction === |
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==References== |
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{{Main|Cretaceous–Paleogene extinction event}} |
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{{reflist}} |
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The proposed Shiva crater and other possible impact craters along with the [[Chicxulub crater]] have led to the hypothesis that multiple impacts caused the massive extinction event at the end of the Cretaceous period. Chatterjee is confident that Shiva was one of many impacts, stating that "the K-T extinction was definitely a multiple-impact scenario."<ref name= Rampino>Rampino, M. R., and B. M. Haggerty (1996) ''The “Shiva Hypothesis”: Impacts, mass extinctions, and the galaxy.'' Earth, Moon, and Planets. 72(1–3):441–460.</ref> Other theories have argued that since the Chicxulub impact is believed by some researchers to have occurred ''earlier'' than the extinction of the non-avian dinosaurs, Shiva's impact was enough to cause the mass extinction by itself.<ref name="Davis2004a">Davis, J. W. (2006) |
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==External links== |
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[https://web.archive.org/web/20070505021703/http://www.depts.ttu.edu/communications/news/stories/06-11-dinosaur.php archived copy] of [http://www.depts.ttu.edu/communications/news/stories/06-11-dinosaur.php ''Texas Tech Paleontologist Finds Evidence That Meteorite Strike Near Bombay May Have Wiped Out Dinosaurs.''] Texas Tech Today, Texas Tech University, Lubbock, Texas.</ref> An article published in ''[[Science (journal)|Science]]'' 2013 by [[Paul Renne|Paul R. Renne]] at the University of California at Berkeley suggests that the Chicxulub crater is in fact within the time frame of when the mass extinction occurred.<ref>{{cite journal|last1=Renne|first1=Paul|url=https://eps.harvard.edu/files/eps/files/renne.kt_.science.2013.pdf|title=Time Scales of Critical Events Around the Cretaceous-Paleogene Boundary|journal=Science|date=8 February 2013|volume=339|issue=6120|pages=684–7|bibcode=2013Sci...339..684R|doi=10.1126/science.1230492|pmid=23393261|s2cid=6112274}}</ref> |
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*[http://gsa.confex.com/gsa/2003AM/finalprogram/abstract_58126.htm The Shiva Crater: Implications for Deccan Volcanism, India-seychelles Rifting, Dinosaur Extinction, and Petroleum Entrapment at the Kt Boundary] by Chatterjee, Sankar; Guven, Necip; Yoshinobu, Aaaron; and Donofrio, Richard; Paper No. 60-8, 2003 Seattle Annual Meeting of Geological Society of America (November 2–5, 2003). |
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*[http://www.spacedaily.com/news/deepimpact-04r.html Deep Impact - Shiva: Another K-T Impact?] by Leslie Mullen for Astrobiology Magazine (Nov. 2004). |
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=== Criticism === |
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{{Coor title dm|18|40|N|70|14|E|type:landmark_region:IN:landmark_scale:10000000}} |
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The claims of an impact crater have been criticised. [[Christian Koeberl]], a Professor of Geology at the [[University of Vienna]] and a specialist on impact craters, described the claims in 2004 as "a figment of imagination", stating that the claims were "inconsistent not only with the regional geology and geophysics, but also with anything we know about impact cratering."<ref>{{Cite web|last=Mullen|first=Leslie|date=7 November 2004|title=Shiva: Another K-T Impact?|url=https://www.spacedaily.com/news/deepimpact-04r.html|access-date=2022-01-16|website=Astrobiology Magazine|via=www.spacedaily.com}}</ref> American geologist [[Gerta Keller]] stated in 2007, "We have worked extensively throughout India and investigated a number of the localities where Sankar Chatterjee claims to have evidence of a large impact he calls Shiva crater... Unfortunately, we have found no evidence to support his claims. Sorry to say, this is all nonsense." Geophysicist Steve Gulick stated in the same year, "There's a bunch of problems to say the least. There is no evidence that [Chatterjee is] presenting of it actually being a crater", and described the oval shape of the structure as unlikely for an impact crater.<ref>{{Cite web|last=Moskowitz|first=Clara|date=2009-10-18|title=New Dino-destroying Theory Fuels Hot Debate|url=https://www.space.com/7413-dino-destroying-theory-fuels-hot-debate.html|access-date=2022-01-16|website=Space.com|language=en}}</ref> In the chapter "Impact Cratering from an Indian Perspective", from the 2013 book ''Earth System Processes and Disaster Management'', geologists Jayanta K. Pati and Puniti Pati write that "...the proposed Shiva structure in the Arabian Sea to the southwest of the Indian subcontinent (Chatterjee et al. 2006) have also been suggested to be of possible impact origin. However, Chatterjee et al. (2006) do not provide any substantial evidence for the existence of a crater structure and certainly not for the existence of an impact structure at Shiva."<ref>{{Citation|last1=Pati|first1=Jayanta K.|title=Impact Cratering from an Indian Perspective|date=2013|url=https://doi.org/10.1007/978-3-642-28845-6_15|work=Earth System Processes and Disaster Management|pages=213–229|editor-last=Sinha|editor-first=Rajiv|series=Society of Earth Scientists Series|place=Berlin, Heidelberg|publisher=Springer|language=en|doi=10.1007/978-3-642-28845-6_15|isbn=978-3-642-28845-6|access-date=2022-01-16|last2=Pati|first2=Puniti|editor2-last=Ravindra|editor2-first=Rasik}}</ref> |
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== See also == |
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{{geol-stub}} |
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{{Portal|Astronomy|India}} |
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{{KT_boundary}} |
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; Impact craters in India |
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[[Category:Craters of India]] |
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* [[Lonar lake|Lonar crater]] at [[Lonar]] in [[Buldhana district]] of Maharashtra |
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[[Category:Astroblemes]] |
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* [[Luna crater]] at [[Kutch district]] of Gujarat |
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[[Category:Extinction events]] |
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* [[Ramgarh crater|Ramgarh Crater]] in [[Mangrol, Rajasthan|Mangrol]] tehsil of [[Baran district]] of Rajasthan |
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; Other related topics |
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* [[List of impact craters on Earth]] |
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* [[List of possible impact structures on Earth]] |
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; Indian Ocean submerged features |
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[[da:Shiva krateret]] |
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* [[Central Indian Ridge]] |
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[[fi:Shiva-kraatteri]] |
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* [[Southeast Indian Ridge]] |
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* [[Southwest Indian Ridge]] |
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* [[Rodrigues triple junction]] |
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== References == |
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{{Reflist}} |
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== External links == |
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* [http://gsa.confex.com/gsa/2003AM/finalprogram/abstract_58126.htm The Shiva Crater: Implications for Deccan Volcanism, India-seychelles Rifting, Dinosaur Extinction, and Petroleum Entrapment at the Kt Boundary] {{Webarchive|url=https://web.archive.org/web/20081012085555/http://gsa.confex.com/gsa/2003AM/finalprogram/abstract_58126.htm |date=2008-10-12 }} by Chatterjee, Sankar; Guven, Necip; Yoshinobu, Aaaron; and Donofrio, Richard; Paper No. 60-8, 2003 Seattle Annual Meeting of Geological Society of America (November 2–5, 2003). |
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* [http://www.spacedaily.com/news/deepimpact-04r.html Deep Impact - Shiva: Another K-T Impact?] by Leslie Mullen for Astrobiology Magazine (Nov. 2004). |
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* [http://labmpg.sscc.ru/impact/index1.html The Complete Catalog of the Earth's Impact structures] |
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* [http://www.depts.ttu.edu/gesc/Fac_pages/Yoshinobu/Published_pdfs/Chatterjee%20et%20al.%202006.pdf Shiva Structure: A Possible KT Boundary Impact Crater on the Western Shelf of India] |
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{{KT boundary}} |
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{{Impact cratering on Earth}} |
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{{Authority control}} |
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[[Category:Impact craters of India]] |
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[[Category:Possible impact craters on Earth]] |
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[[Category:Cretaceous impact craters]] |
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[[Category:Cretaceous–Paleogene boundary]] |
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[[Category:Geology of the Indian Ocean]] |
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Latest revision as of 04:40, 12 November 2024
| Shiva crater | |
|---|---|
  Location of the proposed crater offshore India | |
| Impact crater/structure | |
| Confidence | Dubious |
| Diameter | 500 km (310 mi) |
| Age | Claimed to be ~66 million years[1] Cretaceous–Paleogene boundary |
| Exposed | No |
| Drilled | No |
| Location | |
| Location | Mumbai Offshore Basin |
| Coordinates | 18°40′N 70°14′E / 18.667°N 70.233°E |
| Country | India |
The Shiva crater is the claim by paleontologist Sankar Chatterjee[2] and colleagues that the Bombay High and Surat Depression on the Indian continental shelf west of Mumbai, India represent a 500-kilometre (310 mi) impact crater, that formed around the Cretaceous-Paleogene boundary. Chatterjee and colleagues have claimed that this could have contributed to the K-Pg extinction event. Other scholars have questioned the claims, finding that there is no evidence of an impact structure.
Arguments
[edit]Chatterjee argues that the Shiva crater was formed around 65 million years ago, about the same time as a number of other impact craters and the Cretaceous–Paleogene extinction event (Cretaceous–Paleogene boundary / K-Pg boundary). Although the site has shifted since its formation because of sea floor spreading, the formation is approximately 600 kilometres (370 miles) long by 400 km (250 mi) wide. If its status as an impact crater is ever confirmed, the Shiva crater would be the largest known impact crater on Earth. It is estimated that this proposed crater would have been made by an asteroid or comet approximately 40 km (25 mi) in diameter.[2][3]
At the time of the Cretaceous–Paleogene extinction, India was located over the Réunion hotspot of the Indian Ocean. Hot material rising from the mantle flooded portions of India with a vast amount of lava, creating a plateau known as the Deccan Traps. It has been hypothesized that either the crater or the Deccan Traps associated with the area is the reason for the high level of oil and natural gas reserves in the region.[4]
Geology and morphology
[edit]Unlike typical known extraterrestrial impact structures, Shiva is teardrop shaped, roughly 600 km × 400 km (370 mi × 250 mi). It is also unusually rectangular. Chatterjee argues that the low angle of an impact combined with boundary fault lines and unstable rock led to this unusual formation.[3] The age of the structure is inferred from the Deccan Traps which overlie part of it.[3]
Shiva and mass extinction
[edit]The proposed Shiva crater and other possible impact craters along with the Chicxulub crater have led to the hypothesis that multiple impacts caused the massive extinction event at the end of the Cretaceous period. Chatterjee is confident that Shiva was one of many impacts, stating that "the K-T extinction was definitely a multiple-impact scenario."[5] Other theories have argued that since the Chicxulub impact is believed by some researchers to have occurred earlier than the extinction of the non-avian dinosaurs, Shiva's impact was enough to cause the mass extinction by itself.[6] An article published in Science 2013 by Paul R. Renne at the University of California at Berkeley suggests that the Chicxulub crater is in fact within the time frame of when the mass extinction occurred.[7]
Criticism
[edit]The claims of an impact crater have been criticised. Christian Koeberl, a Professor of Geology at the University of Vienna and a specialist on impact craters, described the claims in 2004 as "a figment of imagination", stating that the claims were "inconsistent not only with the regional geology and geophysics, but also with anything we know about impact cratering."[8] American geologist Gerta Keller stated in 2007, "We have worked extensively throughout India and investigated a number of the localities where Sankar Chatterjee claims to have evidence of a large impact he calls Shiva crater... Unfortunately, we have found no evidence to support his claims. Sorry to say, this is all nonsense." Geophysicist Steve Gulick stated in the same year, "There's a bunch of problems to say the least. There is no evidence that [Chatterjee is] presenting of it actually being a crater", and described the oval shape of the structure as unlikely for an impact crater.[9] In the chapter "Impact Cratering from an Indian Perspective", from the 2013 book Earth System Processes and Disaster Management, geologists Jayanta K. Pati and Puniti Pati write that "...the proposed Shiva structure in the Arabian Sea to the southwest of the Indian subcontinent (Chatterjee et al. 2006) have also been suggested to be of possible impact origin. However, Chatterjee et al. (2006) do not provide any substantial evidence for the existence of a crater structure and certainly not for the existence of an impact structure at Shiva."[10]
See also
[edit]
- Impact craters in India
- Lonar crater at Lonar in Buldhana district of Maharashtra
- Luna crater at Kutch district of Gujarat
- Ramgarh Crater in Mangrol tehsil of Baran district of Rajasthan
- Other related topics
- Indian Ocean submerged features
References
[edit]- ^ Renne, Paul R.; Deino, Alan L.; Hilgen, Frederik J.; Kuiper, Klaudia F.; Mark, Darren F.; Mitchell, William S.; Morgan, Leah E.; Mundil, Roland; Smit, Jan (7 February 2013). "Time Scales of Critical Events Around the Cretaceous–Paleogene Boundary". Science. 339 (6120): 684–687. Bibcode:2013Sci...339..684R. doi:10.1126/science.1230492. PMID 23393261. S2CID 6112274.
- ^ a b Chatterjee, S. (1997). "'Multiple impacts at the KT boundary and the death of the dinosaurs". Comparative Planetology, Geological Education, History of Geology: Proceedings of the 30th International Geological Congress, Beijing, China, 4–14 August 1996. VSP. pp. 31–54. ISBN 978-90-6764-254-5.
- ^ a b c Chatterjee, S., N. Guven, A. Yoshinobu, and R. Donofrio. (2006) Shiva Structure: a possible KT boundary impact crater on the western shelf of India. Museum of Texas Tech University Special Publications. 50, 39pp.
- ^ Agrawal, P., Pandey, O. (November 2000). "Thermal regime, hydrocarbon maturation and geodynamic events along the western margin of India since late Cretaceous". Journal of Geodynamics. 30 (4): 439–459. Bibcode:2000JGeo...30..439P. doi:10.1016/S0264-3707(00)00002-8.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Rampino, M. R., and B. M. Haggerty (1996) The “Shiva Hypothesis”: Impacts, mass extinctions, and the galaxy. Earth, Moon, and Planets. 72(1–3):441–460.
- ^ Davis, J. W. (2006) archived copy of Texas Tech Paleontologist Finds Evidence That Meteorite Strike Near Bombay May Have Wiped Out Dinosaurs. Texas Tech Today, Texas Tech University, Lubbock, Texas.
- ^ Renne, Paul (8 February 2013). "Time Scales of Critical Events Around the Cretaceous-Paleogene Boundary" (PDF). Science. 339 (6120): 684–7. Bibcode:2013Sci...339..684R. doi:10.1126/science.1230492. PMID 23393261. S2CID 6112274.
- ^ Mullen, Leslie (7 November 2004). "Shiva: Another K-T Impact?". Astrobiology Magazine. Retrieved 2022-01-16 – via www.spacedaily.com.
- ^ Moskowitz, Clara (2009-10-18). "New Dino-destroying Theory Fuels Hot Debate". Space.com. Retrieved 2022-01-16.
- ^ Pati, Jayanta K.; Pati, Puniti (2013), Sinha, Rajiv; Ravindra, Rasik (eds.), "Impact Cratering from an Indian Perspective", Earth System Processes and Disaster Management, Society of Earth Scientists Series, Berlin, Heidelberg: Springer, pp. 213–229, doi:10.1007/978-3-642-28845-6_15, ISBN 978-3-642-28845-6, retrieved 2022-01-16
External links
[edit]- The Shiva Crater: Implications for Deccan Volcanism, India-seychelles Rifting, Dinosaur Extinction, and Petroleum Entrapment at the Kt Boundary Archived 2008-10-12 at the Wayback Machine by Chatterjee, Sankar; Guven, Necip; Yoshinobu, Aaaron; and Donofrio, Richard; Paper No. 60-8, 2003 Seattle Annual Meeting of Geological Society of America (November 2–5, 2003).
- Deep Impact - Shiva: Another K-T Impact? by Leslie Mullen for Astrobiology Magazine (Nov. 2004).
- The Complete Catalog of the Earth's Impact structures
- Shiva Structure: A Possible KT Boundary Impact Crater on the Western Shelf of India
