%0 Journal Article
%A Gutiérrez Alonso, Gabriel
%A Fernández Suárez, Javier
%A Pastor Galán, D.
%A Johnston, S. T.
%A Linnemann, U.
%A Hofmann, M.
%A Shaw, J.
%A Colmenero, J. R.
%A Hernández, P.
%T Significance of detrital zircons in Siluro-Devonian rocks from Iberia
%D 2015
%@ 0016-7649
%U https://hdl.handle.net/20.500.14352/34250
%X Seven samples of Siluro-Devonian sedimentary rocks from the Cantabrian and Central Iberian zones of the IberianVariscan belt have been investigated for provenance and contain four main age populations in variable relative proportion:Ediacaran–Cryogenian (c. 0.55–0.8Ga), Tonian–Stenian (0.85–1.2Ga), Palaeoproterozoic (c. 1.8–2.2Ga) and Archaean (c.2.5–3.3Ga). Five samples contain very minor Palaeozoic (Cambrian) zircons and six samples contain minor but significantzircons of Middle and Early Mesoproterozoic (Ectasian–Calymmian, 1.6–1.8) age. These data highlight the transition froman arc environment to a stable platform following the opening of the Rheic Ocean. Variations in detrital zircon populationsin Middle–Late Devonian times reflect the onset of Variscan convergence between Laurussia and Gondwana. The presenceof a high proportion of zircons of Tonian–Stenian age in Devonian sedimentary rocks may be interpreted as (1) the existenceof a large Tonian–Stenian arc terrane exposed in the NE African realm (in or around the Arabian–Nubian Shield), (2) theparticipation, from the Ordovician time, of a more easterly alongshore provenance of Tonian–Stenian zircons, and (3) anincrease in the relative proportion of Tonian–Stenian zircons with respect to the Ediacaran–Cryogenian population owing tothe drift of the Avalonian–Cadomian ribbon continent, or the progressive burial of Ediacaran–Cryogenian rocks coeval withthe denudation of older source rocks from the craton interior.
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