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New constraints on the geochronology and Sm-Nd isotopic characteristics of Bas-Drâa mafic dykes, Anti-Atlas of Morocco

El Bahat, Abdelhakim; Ikenne, Moha; Cousens, Brian; Söderlund, Ulf LU ; Ernst, Richard; Klausen, Martin B. and Youbi, Nasrrddine (2017) In Journal of African Earth Sciences 127. p.77-87
Abstract

The Precambrian inliers of the Anti-Atlas belt across the southern part of Morocco contain numerous mafic dyke and sill swarms, which are thought to represent the erosional remnants of Proterozoic Large Igneous Provinces (LIPs). As part of an extended research campaign to date and characterize these LIPs, two amphiboles from one dyke within the Bas-Drâa inlier (western Anti-Atlas) yielded consistent 40Ar-39Ar ages of 611 Ma ± 1.3; i.e., evidence of magmatic activity during the Ediacaran (635-542 Ma). Furthermore, Nd isotope ratios and model ages identifies four groups of dykes within the Bas-Drâa inlier, all of which were derived from a previously enriched mantle reservoir with very low... (More)

The Precambrian inliers of the Anti-Atlas belt across the southern part of Morocco contain numerous mafic dyke and sill swarms, which are thought to represent the erosional remnants of Proterozoic Large Igneous Provinces (LIPs). As part of an extended research campaign to date and characterize these LIPs, two amphiboles from one dyke within the Bas-Drâa inlier (western Anti-Atlas) yielded consistent 40Ar-39Ar ages of 611 Ma ± 1.3; i.e., evidence of magmatic activity during the Ediacaran (635-542 Ma). Furthermore, Nd isotope ratios and model ages identifies four groups of dykes within the Bas-Drâa inlier, all of which were derived from a previously enriched mantle reservoir with very low 143Nd/144Nd ratios (0.51065–0.51170) and corresponding εNd(t) values (−16.44 to −2.45). Such low Nd-ratios arguably reflect either a contribution of crustal components, such as the Paleoproterozoïc schisto-granitic basement, or metasomatic modification of the sub-continental lithospheric mantle.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Anti-Atlas, Ar–Ar geochronology, Bas-Drâa, Mafic dykes, Model age, Sm-Nd, West African Craton
in
Journal of African Earth Sciences
volume
127
pages
11 pages
publisher
Elsevier
external identifiers
  • scopus:85007496800
  • wos:000395223700006
ISSN
1464-343X
DOI
10.1016/j.jafrearsci.2016.09.003
language
English
LU publication?
yes
id
be21aa11-e8d7-47f0-b56f-254c5b8610d4
date added to LUP
2017-02-20 09:02:56
date last changed
2018-01-07 11:51:01
@article{be21aa11-e8d7-47f0-b56f-254c5b8610d4,
  abstract     = {<p>The Precambrian inliers of the Anti-Atlas belt across the southern part of Morocco contain numerous mafic dyke and sill swarms, which are thought to represent the erosional remnants of Proterozoic Large Igneous Provinces (LIPs). As part of an extended research campaign to date and characterize these LIPs, two amphiboles from one dyke within the Bas-Drâa inlier (western Anti-Atlas) yielded consistent <sup>40</sup>Ar-<sup>39</sup>Ar ages of 611 Ma ± 1.3; i.e., evidence of magmatic activity during the Ediacaran (635-542 Ma). Furthermore, Nd isotope ratios and model ages identifies four groups of dykes within the Bas-Drâa inlier, all of which were derived from a previously enriched mantle reservoir with very low <sup>143</sup>Nd/<sup>144</sup>Nd ratios (0.51065–0.51170) and corresponding εNd(t) values (−16.44 to −2.45). Such low Nd-ratios arguably reflect either a contribution of crustal components, such as the Paleoproterozoïc schisto-granitic basement, or metasomatic modification of the sub-continental lithospheric mantle.</p>},
  author       = {El Bahat, Abdelhakim and Ikenne, Moha and Cousens, Brian and Söderlund, Ulf and Ernst, Richard and Klausen, Martin B. and Youbi, Nasrrddine},
  issn         = {1464-343X},
  keyword      = {Anti-Atlas,Ar–Ar geochronology,Bas-Drâa,Mafic dykes,Model age,Sm-Nd,West African Craton},
  language     = {eng},
  month        = {03},
  pages        = {77--87},
  publisher    = {Elsevier},
  series       = {Journal of African Earth Sciences},
  title        = {New constraints on the geochronology and Sm-Nd isotopic characteristics of Bas-Drâa mafic dykes, Anti-Atlas of Morocco},
  url          = {http://dx.doi.org/10.1016/j.jafrearsci.2016.09.003},
  volume       = {127},
  year         = {2017},
}