Gwénaël Caravaca PhD thesis

Thumbnail imageDepositional environments and bioconstructions in the Early Triassic of western USA

funding: Agence nationale de la recherche ("After" project)

supervisors: Arnaud Brayard and Christophe Thomazo

beginning of the thesis: octobre 2014

 

Abstract

The Sonoma Foreland Basin (SFB, western USA) presents an excellent fossil and sedimentary record of the Early Triassic (~252-248 Ma), a critical period in the biotic recovery in the aftermath of the end-Permian amss extinction. Whilst the understanding of the paleogeographical framework of this basin is of prime importance in reconstructing then ecosystems, this latter is still poorly constrained up to now.

An original integrative study has therefore been done to characterize the controlling factors and the spatio-temporal evolution of the depositional settings present in the SFB. For that, a multi-scale and multidisciplinary approach was performed, using sedimentological, paleontological, geochemical, structural and geodynamical data.

Thumbnail imageIntegration of this diverse data allows to get a better understanding of the paleogeography of the SFB, which appears to be composed by two distinct sub-basins rather than one whole basin as previsouly thought. Also, this work hightlights multi-scale controlling factors (acting from local- to basin-scale) over the 4D evolution of the depositional settings, which in turn acts over the geobiological evolution of the basin.

 

Keywords

Early Triassic, post-crisis recovery, Sonoma Foreland Basin, western USA, paleoenvironmental reconstructions, palinspastic reconstructions, structural evolution

 

Jury

A. Brayard, université de Bourgogne - supervisor
C. Thomazo, université de Bourgogne - supervisor
S. Bourquin, université de Rennes 1 - abstracter
F. Boulvain, université de Liège (Belgique) - abstracter
E. Vennin, université de Bourgogne - examiner
G. Escarguel, université Claude Bernard Lyon1 - examiner
M. Guiraud, université de Bourgogne - invited