시베리아 포피가이 분화구 직경 100킬로미터(62마일)의 분화구를 만들었습니다.그것은 Eocene–Oligocene 멸종 사건과 연결될 수 있습니다.

2023. 3. 13. 00:51토하라인

Popigai diamonds are about 1 mm in size and consist of  nanodiamond  agglomerates.
Landsat  image of Popigai crater

 

Popigai 충돌 구조는 러시아 시베리아 북부에 있는 충돌 분화구의 침식된 잔해입니다. 그것은 지구상에서 네 번째로 큰 확인된 충격 구조로서 Manicouagan 구조와 연결되어 있습니다.[2][3] 약 3,500만 년 전 에오세 후기(프리아보니아기)에 거대한 불화물 충돌이 직경 100킬로미터(62마일)의 분화구를 만들었습니다.[4][5] 그것은 Eocene–Oligocene 멸종 사건과 연결될 수 있습니다.[6]

구조물은 카탕가 전초기지에서 동쪽으로 300km(190마일), 아나바르 고원 북동쪽 노릴스크 시에서 북동쪽으로 880km(550마일) 떨어져 있습니다. 이곳은 유네스코에 의해 특별한 지질학적 유산인 지질공원으로 지정되었습니다.[7] Popigai 충돌 분화구가 약 3,500만 년 된 Chesapeake Bay 및 Toms Canyon 충돌 분화구와 동시에 형성되었을 가능성이 적습니다.[4]

수십 년 동안 Popigai 충격 구조물은 고생물학자와 지질학자를 매료시켰지만 그곳에서 발견된 다이아몬드 때문에 전체 지역은 완전히 출입금지였습니다. 그러나 1997년에 대대적인 조사 원정이 착수되어 구조에 대한 이해가 크게 향상되었습니다.[7] 이 사건의 충돌체는 직경 8km(5.0마일)의 콘드라이트 소행성 또는 직경 5km(3.1마일)의 돌 소행성으로 확인되었습니다.

충격으로 인한 충격 압력은 순간적으로 충격 지점의 반경 13.6km(8.5마일) 내에서 지면의 흑연을 다이아몬드로 변형시켰습니다. 이 다이아몬드는 일반적으로 직경이 0.5~2mm(0.020~0.079인치)이지만 일부 예외적인 표본은 크기가 10mm(0.39인치)입니다. 다이아몬드는 원래 흑연 입자의 판 모양과 원래 결정의 섬세한 줄무늬를 계승했습니다.[7]

다이아몬드 예금

Popigai 다이아몬드는 크기가 약 1mm이고 나노다이아몬드 덩어리로 구성됩니다.[8]
대부분의 현대 산업용 다이아몬드는 합성으로 생산됩니다. Popigai의 다이아몬드 광상은 원격 위치와 인프라 부족으로 인해 채굴되지 않았으며 합성 다이아몬드와 경쟁할 가능성이 낮습니다.[9] Popigai의 많은 다이아몬드에는 육각형 격자를 가진 탄소의 동소체인 결정질 론스달라이트가 포함되어 있습니다.[10] 순수한 실험실에서 만든 론달라이트는 일반 다이아몬드보다 최대 58% 더 단단합니다.[11][9] 이러한 유형의 다이아몬드는 운석이 흑연 침전물에 고속으로 충돌할 때 생성되는 것으로 생각되기 때문에 "임팩트 다이아몬드"로 알려져 있습니다.[10] 그들은 산업적 용도를 가질 수 있지만 보석으로는 적합하지 않습니다.[12]

또한 순수한 론스달라이트보다 더 단단한 다이아몬드와 론스달라이트의 조합인 탄소 다형체가 분화구에서 발견되었습니다.[13]

https://en.wikipedia.org/wiki/Popigai_impact_structure

The Popigai impact structure is the eroded remnant of an impact crater in northern Siberia, Russia. It is tied with the Manicouagan structure as the fourth largest verified impact structure on Earth.[2][3] A large bolide impact created the 100-kilometre (62 mi) diameter crater approximately 35 million years ago during the late Eocene epoch (Priabonian stage).[4][5] It might be linked to the Eocene–Oligocene extinction event.[6]

The structure is 300 km (190 mi) east from the outpost of Khatanga and 880 km (550 mi) northeast of the city of Norilsk, NNE of the Anabar Plateau. It is designated by UNESCO as a Geopark, a site of special geological heritage.[7] There is a small possibility that the Popigai impact crater may have formed simultaneously with the approximately 35-million-year-old Chesapeake Bay and Toms Canyon impact craters.[4]

For decades, the Popigai impact structure has fascinated paleontologists and geologists, but the entire area was completely off limits because of the diamonds found there. However, a major investigatory expedition was undertaken in 1997, which greatly advanced understanding of the structure.[7] The impactor in this event has been identified as either an 8 km (5.0 mi) diameter chondrite asteroid, or a 5 km (3.1 mi) diameter stony asteroid.

The shock pressures from the impact instantaneously transformed graphite in the ground into diamonds within a 13.6 km (8.5 mi) radius of the impact point. These diamonds are usually 0.5 to 2 mm (0.020 to 0.079 in) in diameter, though a few exceptional specimens are 10 mm (0.39 in) in size. The diamonds inherited the tabular shape of the original graphite grains and also the original crystals' delicate striations.[7]

Diamond deposits[edit]

 
Popigai diamonds are about 1 mm in size and consist of nanodiamond agglomerates.[8]

Most modern industrial diamonds are produced synthetically. The diamond deposits at Popigai have not been mined because of the remote location and lack of infrastructure, and are unlikely to be competitive with synthetic diamonds.[9] Many of the diamonds at Popigai contain crystalline lonsdaleite, an allotrope of carbon that has a hexagonal lattice.[10] Pure, laboratory-created lonsdaleite is up to 58% harder than ordinary diamonds.[11][9] These types of diamonds are known as "impact diamonds" because they are thought to be produced when a meteorite strikes a graphite deposit at high velocity.[10] They may have industrial uses but are unsuitable as gems.[12]

Additionally, carbon polymorphs, a combination of diamond and lonsdaleite even harder than pure lonsdaleite, have been discovered in the crater.[13][14]

See also[edit]

References[edit]

  1. ^ Schmitz, Birger; Boschi, Samuele; Cronholm, Anders; Heck, Philipp R.; Monechi, Simonetta; Montanari, Alessandro; Terfelt, Fredrik (2015). "Fragments of Late Eocene Earth-impacting asteroids linked to disturbance of asteroid belt"Earth and Planetary Science Letters425: 77–83. Bibcode:2015E&PSL.425...77Sdoi:10.1016/j.epsl.2015.05.041ISSN 0012-821X.
  2. ^ "Popigai"Earth Impact DatabasePlanetary and Space Science Centre University of New Brunswick Fredericton. Retrieved 2017-10-09.
  3. ^ Masaitis, Victor L. (2003). Popigai Crater: General Geology. Springer. pp. 81–85. ISBN 978-3-540-43517-4.
  4. Jump up to:a b Deutsch, Alexander; Christian Koeberl (2006). "Establishing the link between the Chesapeake Bay impact structure and the North American tektite strewn field: The Sr-Nd isotopic evidence"Meteoritics & Planetary Science41 (5): 689–703. Bibcode:2006M&PS...41..689Ddoi:10.1111/j.1945-5100.2006.tb00985.x.
  5. ^ Armstrong, Richard; S. Vishnevsky; C. Koeberl (2003). U-Pb Analysis of zircons from the Popigai impact structure, Russia: First Results. Springer. pp. 99–116. ISBN 978-3-540-43517-4.
  6. ^ "Russia's Popigai Meteor Crash Linked to Mass Extinction". June 13, 2014.
  7. Jump up to:a b c Deutsch, Alexander; V.L. Masaitis; F. Langenhorst; R.A.F. Grieve (2000). "Popigai, Siberia—well preserved giant impact structure, national treasury, and world's geological heritage"Episodes23 (1): 3–12. doi:10.18814/epiiugs/2000/v23i1/002.
  8. ^ Ohfuji, Hiroaki; Irifune, Tetsuo; Litasov, Konstantin D.; Yamashita, Tomoharu; Isobe, Futoshi; Afanasiev, Valentin P.; Pokhilenko, Nikolai P. (2015). "Natural occurrence of pure nano-polycrystalline diamond from impact crater"Scientific Reports5: 14702. Bibcode:2015NatSR...514702Odoi:10.1038/srep14702PMC 4589680PMID 26424384.
  9. Jump up to:a b "Diamonds Beneath the Popigai Crater -- Northern Russia". geology.com. 23 September 2012. Retrieved 24 September 2012.
  10. Jump up to:a b "Russia declassifies deposit of impact diamonds". ITAR-TASS. 17 September 2012. Archived from the original on 20 September 2012. Retrieved 17 September 2012.
  11. ^ Pan, Zicheng; Sun, Hong; Zhang, Yi & Chen, Changfeng (2009). "Harder than Diamond: Superior Indentation Strength of Wurtzite BN and Lonsdaleite". Physical Review Letters102 (5): 055503. Bibcode:2009PhRvL.102e5503Pdoi:10.1103/PhysRevLett.102.055503PMID 19257519.
  12. ^ Pros and cons of extraterrestrial diamonds Archived 2014-12-22 at the Wayback Machine, from "Rough&Polished–information and analytics on diamond and jewellery markets."
  13. ^ El Goresy, Ahmed; Dubrovinsky, Leonid S; Gillet, Philippe; Mostefaoui, Smail; Graup, Günther; Drakopoulos, Michael; Simionovici, Alexandre S; Swamy, Varghese; Masaitis, Victor L (2003). "A new natural, super-hard, transparent polymorph of carbon from the Popigai impact crater, Russia". Comptes Rendus Geoscience335 (12): 889. Bibcode:2003CRGeo.335..889Edoi:10.1016/j.crte.2003.07.001.
  14. ^ Baek, Woohyeon; Gromilov, Sergey A.; Kuklin, Artem V.; Kovaleva, Evgenia A.; Fedorov, Alexandr S.; Sukhikh, Alexander S.; Hanfland, Michael; Pomogaev, Vladimir A.; Melchakova, Iuliia A.; Avramov, Paul V.; Yusenko, Kirill V. (2019-03-13). "Unique Nanomechanical Properties of Diamond–Lonsdaleite Biphases: Combined Experimental and Theoretical Consideration of Popigai Impact Diamonds". Nano Letters19 (3): 1570–1576. Bibcode:2019NanoL..19.1570Bdoi:10.1021/acs.nanolett.8b04421ISSN 1530-6984PMID 30735045.

External links[edit]

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