Title :

A source-to-sink model for Upper Paleozoicsandstones from Armenia: new insights into theevolution of the northern margin ofGondwana

Author(s) :

Witt, César [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Poujol, Marc [Auteur]
Géosciences Rennes [GR]
Bruguier, Olivier [Auteur]
Géosciences Montpellier
Chiaradia, Massimo [Auteur]
Université de Genève = University of Geneva [UNIGE]
Traore, Sakina [Auteur]
Serobyan, Vahram [Auteur]
Évolution, Écologie et Paléontologie (Evo-Eco-Paleo) - UMR 8198 [Evo-Eco-Paléo (EEP)]
Crônier, Catherine [Auteur]
Évolution, Écologie et Paléontologie (Evo-Eco-Paleo) - UMR 8198 [Evo-Eco-Paléo (EEP)]
Seyler, Monique [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Danelian, Taniel [Auteur]
Évolution, Écologie et Paléontologie (Evo-Eco-Paleo) - UMR 8198 [Evo-Eco-Paléo (EEP)]

Conference title :

19 ème Congrès français de sédimentologie (ASF 2024)

City :

Villeneuve d'Ascq (Lille)

Country :

France

Start date of the conference :

2024-11-26

Book title :

Livre des résumés, Publication ASF

Publication date :

2024

HAL domain(s) :

Planète et Univers [physics]/Sciences de la Terre/Stratigraphie

English abstract : [en]

The South Armenian Block (SAB) is a peri-Gondwana block that was part of the Cimmeriansuper-terrain, located in northeastern Gondwana during most of the Paleozoic. Very well preservedmature to ultra-mature siliciclastic ...
Show more >The South Armenian Block (SAB) is a peri-Gondwana block that was part of the Cimmeriansuper-terrain, located in northeastern Gondwana during most of the Paleozoic. Very well preservedmature to ultra-mature siliciclastic sediments are documented in three Upper Devonian -Carboniferous stratigraphic sections in the SAB. These sections are crucial for understanding thegeodynamic evolution of the block, as they provide a unique opportunity to obtain zirconpetrochronological constraints (i.e., U-Pb age, Hf, d18O and trace elements) that can be furthertranslated into models constraining the sediment provenance, the nature of magmatic reservoirs,the crustal thickness evolution, among others.Approximately 240 detrital zircons from two late Devonian and one early Carboniferoussedimentary sections in the SAB were subjected to U-Pb dating, and Lu-Hf and O isotopic andtrace element analysis. The sandstones are very mature and contain at least 90% quartz, indicatingsignificant sedimentary transport. The detrital zircon record of the Devonian and Carboniferoussandstones of the SAB is dominated by Paleozoic (18%), Neoproterozoic (~63%) andMesoproterozoic and older ages (~19%), with the greatest concentration of ages peaking at ~600Ma, ~890-900 Ma and ~2.5 Ga. These ages are typical for northern Gondwana settings. Thus,the wealth of data indicates that the SAB sandstones were sourced from distal pan-African basementsrelated to the Saharan craton, with only minor (more proximal) contributions from the Arabian-Nubian shield and the Cadomian arc.Several zircon markers (e.g., U/Yb, L/H REE and Ce/Y) define a bell-shaped distributionwith higher values between 700 and 500 Ma. This suggests greater continental affinities, and mostlikely thick crustal settings, for this interval. All of these ratios decrease significantly at ~500Ma, indicating a marked reduction in the continental signature and the early rifting of thenorthern Gondwana terrains.Because of: 1) its peripheral position with respect to Gondwana; 2) its general stratigraphicfacies; 3) its U-Pb age spectra; and 4) its general Neoproterozoic zircon TE continental signature,the sandstones of the SAB may represent very distal exposures of the Super Gondwana FanSystem, thus extending the life of the supercontinental-scale fluvial and alluvial fan system into theLower Carboniferous.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Nationale

Popular science :

Non

Collections :

• Évolution, Écologie et Paléontologie (Evo Eco Paleo) - UMR 8198

Source :

Harvested from HAL