@article{fdi:010092566,
  title = {{T}iming of syn-orogenic extension in the {W}estern {A}lps revealed by calcite {U}-{P}b and hematite ({U}-{T}h)/{H}e dating},
  author = {{B}ilau, {A}. and {R}olland, {Y}. and {S}chwartz, {S}. and {G}autheron, {C}. and {D}umontb, {T}. and {B}ienveignant, {D}. and {B}rigaud, {B}. and {G}odeau, {N}. and {G}uihou, {A}. and {D}eschamps, {P}ierre and {M}angenot, {X}. and {C}orre, {M}. and {P}inna-{J}amme, {R}. and {F}indling, {N}.},
  editor = {},
  language = {{ENG}},
  abstract = {{U}nderstanding fault activity over time provides valuable insights for reconstructing the tectonic history of an orogen, assessing seismological risks and understanding mineralization processes. {I}n the {W}estern {A}lps, one of the main controversies in existing tectonic models is the understanding of syn-orogenic extension. {S}eismological evidence shows widespread extensional deformation related to the reactivation of major lithospheric structures, such as the {P}enninic {F}rontal {T}hrust ({PFT}). {H}owever, the onset age and origin of extension are still debated due to the lack of suitable geochronological data. {F}ault hematite and calcite geochronology as well as clumped isotope data can be used to relate fluid regimes to fault activity. {T}he analysis of calcite brecciae from extensional faults above the {PFT} shows that two distinct fluid regimes were present. {T}he first regime, occurring before 2 {M}a is associated with upwelling of deep fluids and is recorded by fault calcite at a temperature > 110 degrees {C}. {T}he second fluid regime is characterized by a meteoric signature and temperatures around 36 degrees {C}, representing crystallization since 2 {M}a. {T}his study presents a new model for the {M}iocene tectonic history of the {W}estern {A}lps that combines ({U}-{T}h)/{H}e and {U}-{P}b geochronology on fault hematite (13.3 +/- 0.8 to < 0.8 {M}a) and calcite (5.3 +/- 0.6 {M}a). {R}esults demonstrate a progression of extensional fault activity from east to west, from the {M}iddle {M}iocene (ca. 13 {M}a) to the {Q}uaternary. {T}he onset of extension in the inner part of the belt coincides with the development of the fold and thrust belt in the western {A}lpine foreland. {O}ur new model proposes that extension occurs in the hanging wall of a large top-to-the-west thrust, known as the {A}lpine {F}rontal {T}hrust. {T}his thrust, located to the west of the {E}xternal {C}rystalline {M}assifs gives rise to their uplifting and extension at the rear.},
  keywords = {{W}estern {A}lps ; {B}rian{\c{c}}onnais zone ; {H}ematite ({U}-{T}h)/{H}e ; {U}-{P}b calcite ; {C}lumped isotopes ; {S}yn-orogenic extension ; {FRANCE} ; {ALPES}},
  booktitle = {},
  journal = {{G}eoscience {F}rontiers},
  volume = {16},
  numero = {2},
  pages = {101969 [17 p.]},
  ISSN = {1674-9871},
  year = {2025},
  DOI = {10.1016/j.gsf.2024.101969},
  URL = {https://www.documentation.ird.fr/hor/fdi:010092566},
}