Quaternary deformation and stress perturbations along the Digne thrust front, Southwestern Alps
- 作者：Jean-Claude Hippolyte ; hippolyte@cerege.fr ; Olivier Bellier ; Nicolas Espurt
- 关键词：Paleostresses ; Stress perturbations ; Quaternary tectonics ; Messinian event ; Canyons ; Digne thrust ; Southwestern Alps
- 刊名：Comptes Rendus Geoscience
- 出版年：2012
- 期刊代码：87_16310713
- 类别：ear
- 出版时间：March-April, 2012
- 卷：344
- 期：3-4
- 页码：205-213
- 文件大小：2548 K
摘要
In the southwestern Alps, the retrogradation of the continental sedimentary wedge that infilled the Valensole foreland basin after the Messinian event, resulted in the deposition of recent (3.4 to 2 Ma) and thick (up to 100 m) conglomerates within canyons in the Digne thrust sheet. Paleostress analysis, in these Upper Pliocene-Quaternary sediments and in a Quaternary terrace, allows characterizing the local Quaternary stress field. This stress field displays typical stress perturbations (deviation of 蟽1 of up to 53掳) along a main dextral fault (B猫s fault, 0.7 mm/yr) of the strike-slip edge of the Digne south-verging thrust sheet. We propose a structural model that explains the highest tectonic uplift recorded by the paleo-drainage network (345 m; 0.1 mm/yr) at the northern tip of this dextral fault. We conclude that Messinian-Zanclean canyons allow one to characterize Quaternary geodynamics for deformation rates as low as 0.1 mm/yr.