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From spatial variation of fracture patterns to fold kinematics: A geomechanical approach
Author(s) -
Bellahsen N.,
Fiore P. E.,
Pollard D. D.
Publication year - 2006
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 - 10.1029/2005gl024189
Subject(s) - geology , anticline , forelimb , kinematics , fold (higher order function) , hinge , thrust , slip (aerodynamics) , seismology , stress field , fold and thrust belt , petrology , paleontology , tectonics , structural engineering , finite element method , foreland basin , mechanical engineering , physics , classical mechanics , engineering , thermodynamics
A vertical, compression‐parallel joint set apparently formed at Sheep Mountain Anticline (SMA) during the early Laramide orogeny, prior to significant folding. Field data indicate that these joints occur in fewer locations in the forelimb than in the hinge and backlimb. Using three‐dimensional elastic dislocation models, we show that early slip along an underlying thrust fault can locally perturb the surrounding stress field, inhibiting joint formation above the fault. Thus, we are able to constrain the forelimb kinematics finding that the forelimb was originally located in the hangingwall, above the thrust fault. Furthermore the mode of folding at SMA is constrained: the anticline developed with a fixed hinge and rotating limbs, while the underlying basement rocks deformed internally.