A Lower Silurian (Aeronian) radiolarian assemblage from black cherts of the Armorican Massif (France) - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles Comptes Rendus. Palevol Year : 2014

A Lower Silurian (Aeronian) radiolarian assemblage from black cherts of the Armorican Massif (France)

Marie-Pierre Dabard
  • Function : Author
  • PersonId : 840697

Abstract

The Chalonnes-sur-Loire outcrop is the most complete Llandovery section in the Ligerian domain (Armorican Massif, NW France); it displays a ca. 10 m-thick sequence of organic-rich black bedded cherts alternating with black graptolitic shales, which were deposited above glaciomarine diamictites of the Hirnantian glaciation. It is likely the black cherts accumulated under eutrophic waters, on the outer shelf part (distal offshore) of a Gondwanan margin, situated at intermediate to high latitudes of the Southern hemisphere. Hydrofluoric acid processing allowed the extraction of radiolarians; seven species are identified in the best preserved sample discovered so far. All seven are common species in tropical assemblages known from Alaska and Nevada, which are characteristic of the Orbiculopylorum assemblage, of Aeronian to early Telychian age. This age is in good agreement with independent age control from graptolites in the Chalonnes section, suggestive of an Aeronian age for the radiolarian-yielding level.
Fichier principal
Vignette du fichier
MS_Tetard_et_al_revised_clean_.pdf (168.32 Ko) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

insu-01022529 , version 1 (04-09-2014)

Identifiers

Cite

Martin Tetard, Taniel Danelian, Jean-François Ghienne, Marie-Pierre Dabard. A Lower Silurian (Aeronian) radiolarian assemblage from black cherts of the Armorican Massif (France). Comptes Rendus. Palevol, 2014, 13 (6), pp.483-488. ⟨10.1016/j.crpv.2014.01.001⟩. ⟨insu-01022529⟩
231 View
260 Download

Altmetric

Share

Gmail Facebook X LinkedIn More