View in EDS

The Red Beds series in the Erta Ale segment, North Afar. Evidence for a 6 Ma-old post-rift basin prior to continental rupturing.

Saved in:
Bibliographic Details
Title: The Red Beds series in the Erta Ale segment, North Afar. Evidence for a 6 Ma-old post-rift basin prior to continental rupturing.
Authors: Le Gall, B.1 bernard.legall@univ-brest.fr, Leleu, S.1, Pik, R.1, Jourdan, F.1, Chazot, G.1, Ayalew, D.1, Yirgu, G.1, Cloquet, C.1, Chauvet, F.1
Source: Tectonophysics. Nov2018, Vol. 747/748, p373-389. 17p.
Subjects: Magmatism, Volcanology, Sedimentology, Geological basins, Rock deformation
Abstract: Abstract The Erta Ale rift segment, North Afar, is regarded as the most mature rift part within the entire Afar rift system. Very little is known about its deformation history because of limited exposures of geological records in its inner floor, except volcanics of the Erta Ale chain, and the poorly-known Red Beds series along the flanks of the depression. An integrated study, combining sedimentological, geochemical, 40Ar-39Ar radiometric and tectonic approaches, has been devoted to Red Beds series flanking the depression to the SW. Our new results allow to argue that (1) the >300 m-thick Red Beds exposed section comprises alluvial deposits that enclose (2) basaltic lavas and related sill intrusions that both yield ~6 Ma 40Ar-39Ar ages and display similar geochemical affinities, (3) the Red Beds series locally overlap unconformably basement bounding terrains, and (4) are involved in a limited number of low-displacement normal faults that recorded a modest amount of extension (<6%), (5) isotope contents of Red Beds volcanics indicate crustal contamination, without any contribution of the Afar plume, by contrast to the younger Erta Ale magmatism which represents the more recent Afar-plume related event in the Erta Ale segment. Combining these results leads us to regard the Red Beds series as part of an alluvial basin that post-dated a major rift event to which are attributed to (1) the present-day Ethiopian fault-scarp, (2) a concealed sedimentary depocenter at depth in its hanging wall, and (3) prominent crustal thinning. Riftward migration and axial focusing of strain during Miocene-Present times is also argued, while later flexuring of the entire Red Beds basin is assigned to magmatic loading during the axial emplacement of the Erta Ale volcanic chain. Lastly, emphasis is put on the large-scale segmentation of the Afar system into the tectonically-accreted Erta Ale rift segment to the north, and the magmatically-accreted Central segment to the south. Highlights • The Red Beds series, North Afar, are mainly composed of aerial clastic sediments. • They host basaltic lavas and a feeder sill network that both yield 6 Ma 40Ar-39Ar ages. • Red Beds magmas show a crustal contamination, by contrast to the near-by Erta Ale volcanics. • Red Beds series recorded little extension that post-dated a major synrift event. • The Erta Ale segment experienced a dominantly tectonic extension during the last 25 Ma. [ABSTRACT FROM AUTHOR]
Copyright of Tectonophysics is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
FullText Text:
  Availability: 0
Header DbId: egs
DbLabel: Engineering Source
An: 133215331
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: The Red Beds series in the Erta Ale segment, North Afar. Evidence for a 6 Ma-old post-rift basin prior to continental rupturing.
– Name: Author
  Label: Authors
  Group: Au
  Data: &lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Le+Gall%2C+B%2E%22&quot;&gt;Le Gall, B.&lt;/searchLink&gt;&lt;relatesTo&gt;1&lt;/relatesTo&gt;&lt;i&gt; bernard.legall@univ-brest.fr&lt;/i&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Leleu%2C+S%2E%22&quot;&gt;Leleu, S.&lt;/searchLink&gt;&lt;relatesTo&gt;1&lt;/relatesTo&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Pik%2C+R%2E%22&quot;&gt;Pik, R.&lt;/searchLink&gt;&lt;relatesTo&gt;1&lt;/relatesTo&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Jourdan%2C+F%2E%22&quot;&gt;Jourdan, F.&lt;/searchLink&gt;&lt;relatesTo&gt;1&lt;/relatesTo&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Chazot%2C+G%2E%22&quot;&gt;Chazot, G.&lt;/searchLink&gt;&lt;relatesTo&gt;1&lt;/relatesTo&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Ayalew%2C+D%2E%22&quot;&gt;Ayalew, D.&lt;/searchLink&gt;&lt;relatesTo&gt;1&lt;/relatesTo&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Yirgu%2C+G%2E%22&quot;&gt;Yirgu, G.&lt;/searchLink&gt;&lt;relatesTo&gt;1&lt;/relatesTo&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Cloquet%2C+C%2E%22&quot;&gt;Cloquet, C.&lt;/searchLink&gt;&lt;relatesTo&gt;1&lt;/relatesTo&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Chauvet%2C+F%2E%22&quot;&gt;Chauvet, F.&lt;/searchLink&gt;&lt;relatesTo&gt;1&lt;/relatesTo&gt;
– Name: TitleSource
  Label: Source
  Group: Src
  Data: &lt;searchLink fieldCode=&quot;JN&quot; term=&quot;%22Tectonophysics%22&quot;&gt;Tectonophysics&lt;/searchLink&gt;. Nov2018, Vol. 747/748, p373-389. 17p.
– Name: Subject
  Label: Subjects
  Group: Su
  Data: &lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Magmatism%22&quot;&gt;Magmatism&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Volcanology%22&quot;&gt;Volcanology&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Sedimentology%22&quot;&gt;Sedimentology&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Geological+basins%22&quot;&gt;Geological basins&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Rock+deformation%22&quot;&gt;Rock deformation&lt;/searchLink&gt;
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: Abstract The Erta Ale rift segment, North Afar, is regarded as the most mature rift part within the entire Afar rift system. Very little is known about its deformation history because of limited exposures of geological records in its inner floor, except volcanics of the Erta Ale chain, and the poorly-known Red Beds series along the flanks of the depression. An integrated study, combining sedimentological, geochemical, 40Ar-39Ar radiometric and tectonic approaches, has been devoted to Red Beds series flanking the depression to the SW. Our new results allow to argue that (1) the &gt;300 m-thick Red Beds exposed section comprises alluvial deposits that enclose (2) basaltic lavas and related sill intrusions that both yield ~6 Ma 40Ar-39Ar ages and display similar geochemical affinities, (3) the Red Beds series locally overlap unconformably basement bounding terrains, and (4) are involved in a limited number of low-displacement normal faults that recorded a modest amount of extension (&lt;6%), (5) isotope contents of Red Beds volcanics indicate crustal contamination, without any contribution of the Afar plume, by contrast to the younger Erta Ale magmatism which represents the more recent Afar-plume related event in the Erta Ale segment. Combining these results leads us to regard the Red Beds series as part of an alluvial basin that post-dated a major rift event to which are attributed to (1) the present-day Ethiopian fault-scarp, (2) a concealed sedimentary depocenter at depth in its hanging wall, and (3) prominent crustal thinning. Riftward migration and axial focusing of strain during Miocene-Present times is also argued, while later flexuring of the entire Red Beds basin is assigned to magmatic loading during the axial emplacement of the Erta Ale volcanic chain. Lastly, emphasis is put on the large-scale segmentation of the Afar system into the tectonically-accreted Erta Ale rift segment to the north, and the magmatically-accreted Central segment to the south. Highlights • The Red Beds series, North Afar, are mainly composed of aerial clastic sediments. • They host basaltic lavas and a feeder sill network that both yield 6 Ma 40Ar-39Ar ages. • Red Beds magmas show a crustal contamination, by contrast to the near-by Erta Ale volcanics. • Red Beds series recorded little extension that post-dated a major synrift event. • The Erta Ale segment experienced a dominantly tectonic extension during the last 25 Ma. [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: &lt;i&gt;Copyright of Tectonophysics is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder&#39;s express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.&lt;/i&gt; (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=133215331
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1016/j.tecto.2018.10.002
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 17
        StartPage: 373
    Subjects:
      – SubjectFull: Magmatism
        Type: general
      – SubjectFull: Volcanology
        Type: general
      – SubjectFull: Sedimentology
        Type: general
      – SubjectFull: Geological basins
        Type: general
      – SubjectFull: Rock deformation
        Type: general
    Titles:
      – TitleFull: The Red Beds series in the Erta Ale segment, North Afar. Evidence for a 6 Ma-old post-rift basin prior to continental rupturing.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Le Gall, B.
      – PersonEntity:
          Name:
            NameFull: Leleu, S.
      – PersonEntity:
          Name:
            NameFull: Pik, R.
      – PersonEntity:
          Name:
            NameFull: Jourdan, F.
      – PersonEntity:
          Name:
            NameFull: Chazot, G.
      – PersonEntity:
          Name:
            NameFull: Ayalew, D.
      – PersonEntity:
          Name:
            NameFull: Yirgu, G.
      – PersonEntity:
          Name:
            NameFull: Cloquet, C.
      – PersonEntity:
          Name:
            NameFull: Chauvet, F.
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 13
              M: 11
              Text: Nov2018
              Type: published
              Y: 2018
          Identifiers:
            – Type: issn-print
              Value: 00401951
          Numbering:
            – Type: volume
              Value: 747/748
          Titles:
            – TitleFull: Tectonophysics
              Type: main
ResultId 1