論文

査読有り
2019年1月1日

Further evidence for an impact origin of the Tsenkher structure in the Gobi-Altai, Mongolia: Geology of a 3.7 km crater with a well-preserved ejecta blanket

Geological Magazine
  • Goro Komatsu
  • Jens Ormö
  • Togookhuu Bayaraa
  • Tomoko Arai
  • Keisuke Nagao
  • Yoshihiro Hidaka
  • Naoki Shirai
  • Mitsuru Ebihara
  • Carl Alwmark
  • Lkhagva Gereltsetseg
  • Shoovdor Tserendug
  • Kazuhisa Goto
  • Takafumi Matsui
  • Sodnomsambuu Demberel
  • 全て表示

156
1
開始ページ
1
終了ページ
24
記述言語
英語
掲載種別
DOI
10.1017/S0016756817000620
出版者・発行元
CAMBRIDGE UNIV PRESS

© 2017 Cambridge University Press. The Tsenkher structure in the Gobi-Altai, Mongolia is a c. 3.7 km diameter crater with a well-preserved ejecta blanket. It has been hypothesized to be either of impact or volcanic origin in our previous work. Observations during our 2007 expedition and related sample analyses give further support for an impact origin. The evidence includes the presence of a structurally uplifted near-circular rim surrounded by an ejecta blanket, and abundant breccias, some of which are melt- A nd millimetre-scale spherule-bearing. Planar deformation features (PDFs) were found in one quartz grain in a breccia sample. Fe-rich grains are found in a vesicular melt sample that is also characterized by elevated platinum group element (PGE) abundances with respect to the sedimentary bedrock of the area (approximately an order of magnitude). Noble gas analysis of one breccia sample yielded an elevated 3 He/ 4 He value of (5.0±0.2) × 10 -6 . Although not conclusive alone, these geochemical results are consistent with a contribution of meteoritic components. A volcanic origin, in particular a maar formation, would require explanations for the unusual conditions associated with Tsenkher, including its large size occurring in isolation, the structurally uplifted rim and the lack of a bedded base surge deposit. A pronounced rampart structure observed at the eastern ejecta is also unusual for any volcanic origin. 40 Ar- 39 Ar dating of a vesicular melt sample gives an age of the Tsenkher structure of 4.9±0.9 Ma. The rampart structure could provide insights into the formation of similar ejecta morphologies associated with numerous impact craters on Mars.

リンク情報
DOI
https://doi.org/10.1017/S0016756817000620
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000454499600001&DestApp=WOS_CPL
Scopus
https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85059911695&origin=inward
Scopus Citedby
https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85059911695&origin=inward
ID情報
  • DOI : 10.1017/S0016756817000620
  • ISSN : 0016-7568
  • eISSN : 1469-5081
  • SCOPUS ID : 85059911695
  • Web of Science ID : WOS:000454499600001

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