fr
Article scientifique
Anglais

The Antimonio ramp in Sonora, Mexico

Contributeurs/tricesHeerwagen, Eric; Martini, Rossanaorcid
Publié dansFacies, vol. 64, no. 6
Date de publication2018
Résumé

The Upper Permian to Lower Jurassic El Antimonio Group has been considered as part of the NW–SE-trending tectonostratigraphic Antimonio terrane in Sonora, Mexico. The Upper Triassic Rio Asunción Formation of the El Antimonio Group comprises a shallow-marine detrital-carbonate succession at three major localities near Caborca and Hermosillo. Previous reconstructions have proposed differing depositional environments for the Rio Asunción Formation (e.g., carbonate platform, carbonate ramp) and remained therefore nonconsensual. The present study has its focus on the Rio Asunción Formation and includes the analyses of 129 thin-sections of carbonate and mixed siliciclastic–carbonate rocks from three localities (Barra los Tanques, Sierra del Álamo, and Sierra Santa Teresa). In Sierra del Álamo, ammonite findings allowed us to confirm the position of the Triassic–Jurassic boundary. Considering the lack of biostratigraphic markers and the clastic nature of the samples, a statistical approach was used to propose a depositional model that can provide more detailed insights into this sedimentary succession. Hierarchical cluster analyses were performed on the gathered abundance data to identify microfacies and to compare the results for each outcrop. Through these analyses, 22 microfacies were defined, which describe the depositional environments of the two main localities. Furthermore, it could be demonstrated through this approach that not only the localities of Barra los Tanques and Sierra del Álamo but also the outcrops near Sierra Santa Teresa belong to the Antimonio depositional system. To gain insights into the relative depositional conditions among the microfacies, non-metric multidimensional scaling was performed. The resulting trends of water energy and proximity to the shoreline of Laurentia were then used to propose a depositional model for the mixed siliciclastic–carbonate Antimonio ramp system.

Mots-clés
  • Antimonio
  • Sonora
  • Mexico
  • Upper Triassic
  • Multivariate analysis
  • Microfacies
  • Carbonate ramp
  • Biostratigraphy
Citation (format ISO)
HEERWAGEN, Eric, MARTINI, Rossana. The Antimonio ramp in Sonora, Mexico. In: Facies, 2018, vol. 64, n° 6. doi: 10.1007/s10347-018-0519-2
Fichiers principaux (1)
Article (Published version)
accessLevelRestricted
Identifiants
ISSN du journal0172-9179
435vues
4téléchargements

Informations techniques

Création29.04.2018 20:03:00
Première validation29.04.2018 20:03:00
Heure de mise à jour15.03.2023 08:11:22
Changement de statut15.03.2023 08:11:21
Dernière indexation17.01.2024 02:46:29
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack