Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/4029
AuthorsSussman, A. J.* 
Butler, R. F.* 
Dinarès-Turell, J.* 
Vergès, J.* 
TitleVertical-axis rotation of a foreland fold and implications for orogenic curvature: an example from the Southern Pyrenees, Spain
Issue Date15-Feb-2004
Series/Report no.3-4 / 218 (2004)
DOI10.1016/S0012-821X(03)00644-7
URIhttp://hdl.handle.net/2122/4029
KeywordsPyrenees
Oliana anticline
synorogenic strata
paleomagnetism
salients
Subject Classification04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism 
04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics 
04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics 
AbstractIn curved orogenic systems where thrusting and vertical-axis rotations have been documented, it is possible to determine whether the curvature is secondary or progressive based on the timing between the two motions. The South-Central Unit of the Southern Pyrenees provides an opportunity to investigate relationships between thrusting, folding, and vertical-axis rotation because of unusual preservation of Tertiary synorogenic sedimentary strata. Paleomagnetic samples were collected from 51 sites in the upper Eocene-lower Oligocene continental synorogenic strata of the Oliana anticline, a foreland fold along the eastern margin of the South-Central Unit. Site-mean characteristic remanent magnetization directions were determined from 17 sites through thermal demagnetization and principal component analysis. In addition, 72 samples were collected from 39 stratigraphic levels spanning the Upper Eocene marine marls and treated with thermal and alternating field demagnetization techniques. Of these, 53 samples yielded demagnetization trajectories that further constrained the rotation. Comparison of the observed mean paleomagnetic direction from the Oliana anticline with the expected direction indicates a counterclockwise rotation (R ± ΔR) of 20.3° ± 10.9°. Based on the stratigraphic horizons recording the rotation, the age of the rotation is younger than ~34 Ma (after deposition of Unit 3). Data covering the Upper Eocene-Lower Oligocene time interval indicate a similar magnitude of rotation, suggesting that late stage emplacement of thrust sheets hinterlandward of the Oliana anticline controlled the rotation, with rotation accommodated along regionally extensive evaporites. The well-constrained timing relationships between thrusting and rotation and the regional and local transport directions, suggest that the South-Central Unit is a progressive curve that formed through distributed shortening.
Appears in Collections:Papers Published / Papers in press

Files in This Item:
File Description SizeFormat 
EPSL_Sussman_2004.pdfmain article877.47 kBAdobe PDFView/Open    Request a copy
Show full item record

Page view(s)

76
checked on Apr 24, 2017

Download(s)

28
checked on Apr 24, 2017

Google ScholarTM

Check

Altmetric