1st datings of ammonite-bearing Bajocian suites from Caucasus (Georgia) - K-Ar ages of volcanic hornblendes

Détails

ID Serval
serval:BIB_832FE98C9FB2
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
1st datings of ammonite-bearing Bajocian suites from Caucasus (Georgia) - K-Ar ages of volcanic hornblendes
Périodique
Comptes Rendus de l'Académie des Sciences - Série II
Auteur(s)
Odin G.S., Gillot P.Y., Lordkipanidze M., Hernandez J., Dercourt J.
ISSN-L
1251-8069
Statut éditorial
Publié
Date de publication
1993
Peer-reviewed
Oui
Volume
317
Pages
629-638
Langue
anglais
Notes
ISI:A1993LY80700011
Résumé
Volcanic flows and tuffs interbedded with ammonite-bearing sediments
directly correlatable with the stratotype section of the Bajocian stage
have been dated for the first time within the Caucasus area. Three
samples, each from a different section, allowed separation of
well-preserved brown hornblende; these are considered reliable
geochronometers in a region where subsequent volcanic activity occurred.
The dated separates are V139: a volcanic layer probably near the base,
V142 another layer near the top of the Lower Bajocian substage; V141 a
boulder from a latest Bajocian volcanic conglomerate. From bottom to
top, apparent ages at 173.5 +/- 2.6, 164.8 +/- 2.5 and 167.1 +/- 1.9 Ma
(analytical uncertainty, 95% confidence level) respectively, can be
calculated. The consistency of the results is obtained if the dated
boulder is interpreted as derived from an underlying layer, The
Bajocian-Bathonian boundary is much younger than commonly accepted and
younger than 164 Ma.
Création de la notice
11/12/2012 16:25
Dernière modification de la notice
03/03/2018 18:52
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