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Paleostress magnitudes in folded sedimentary rocks
Author(s) -
Amrouch Khalid,
Beaudoin Nicolas,
Lacombe Olivier,
Bellahsen Nicolas,
Daniel JeanMarc
Publication year - 2011
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl048649
Subject(s) - geology , differential stress , anticline , fold (higher order function) , principal stress , seismology , calcite , sedimentary rock , crust , crystal twinning , deformation (meteorology) , petrology , mineralogy , paleontology , microstructure , mechanical engineering , oceanography , materials science , engineering , metallurgy , shear (geology) , tectonics
Using Sheep Mountain Anticline (Wyoming, USA) as a case study, we propose a new approach to quantify effective paleo‐principal stress magnitudes in the uppermost crust. The proposed mechanical scenario relies on a well‐documented kinematic and chronological sequence of development of faults, fractures and microstructures in the folded strata. Paleostress orientations and regimes as well as differential stress magnitudes based on calcite twinning paleopiezometry are combined with rock mechanics data in a Mohr construction to derive principal stress magnitudes related to the successive steps of layer‐parallel shortening and to late stage fold tightening. Such quantification also provides original insights into the evolution of the fluid (over)pressure and amount of syn‐folding erosion.