TY - JOUR
T1 - Recumbent folding in the Upper Cretaceous Eaux-Chaudes massif
T2 - A Helvetic-type nappe in the Pyrenees?
AU - Caldera, Norbert
AU - Teixell, Antonio
AU - Griera, Albert
AU - Labaume, Pierre
AU - Lahfid, Abdeltif
N1 - Funding Information:
This work was supported by the Spanish MINECO/MCIU projects CGL2014‐54180 and PGC2018‐093903‐B‐C21. We thank the OROGEN project for enabling the acquisition of RSCM data, cofounded by Total S.A., BRGM and Institut national de sciences de l'Univers (INSU). Fabrice Barou is thanked for EBSD acquisition assistance and data treatment at Géosciences Montpellier. We thank T. Dumont, D. Westerman, B. Cochelin and anonymous reviewers for comments that helped to improve the original manuscript.
Publisher Copyright:
© 2020 John Wiley & Sons Ltd
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2020
Y1 - 2020
N2 - We describe a singular structure in Upper Cretaceous rocks of the Eaux-Chaudes massif of the western Pyrenees, consisting of a kilometre-scale fold nappe with a sheared overturned limb. High ductile strain attests a deformation style rarely reported for the alpine Pyrenees, and peak temperature in Upper Cretaceous carbonates is estimated by Raman spectroscopy of carbonaceous material palaeothermometry in the lower greenschist facies (>300°C). The normal fold limb retains the original sedimentary textures, while the overturned limb shows calcite crystal-plastic deformation and dynamic recrystallization, with crystallographic preferred orientation. The observed ductility and metamorphic temperature bear similarities with the lower Helvetic nappes of the Alps, suggesting deep burial and/or possibly high geothermal gradient in this part of the Pyrenees.
AB - We describe a singular structure in Upper Cretaceous rocks of the Eaux-Chaudes massif of the western Pyrenees, consisting of a kilometre-scale fold nappe with a sheared overturned limb. High ductile strain attests a deformation style rarely reported for the alpine Pyrenees, and peak temperature in Upper Cretaceous carbonates is estimated by Raman spectroscopy of carbonaceous material palaeothermometry in the lower greenschist facies (>300°C). The normal fold limb retains the original sedimentary textures, while the overturned limb shows calcite crystal-plastic deformation and dynamic recrystallization, with crystallographic preferred orientation. The observed ductility and metamorphic temperature bear similarities with the lower Helvetic nappes of the Alps, suggesting deep burial and/or possibly high geothermal gradient in this part of the Pyrenees.
UR - http://www.scopus.com/inward/record.url?scp=85099107569&partnerID=8YFLogxK
U2 - https://doi.org/10.1111/ter.12517
DO - https://doi.org/10.1111/ter.12517
M3 - Article
AN - SCOPUS:85099107569
SN - 0954-4879
JO - Terra Nova
JF - Terra Nova
ER -