Multidetachment analogue models of fold reactivation in transpression: The NW Persian Gulf
Keywords:Analogue modelling, Reactivation, Multi detachment, Compression, Transpression, Persian Gulf
Two deformation events have been documented in the NW Persian Gulf during the Late Cretaceous and the Late Cenozoic. The most distinctive feature in this part of the Persian Gulf is the reactivation of the Late Cretaceous NNE-SSW Arabian trending folds by NE-SW shortening during the Late Cenozoic Zagros orogeny. In general, if a set of folds with horizontal axes is shortened roughly parallel to its fold axis, a dome-basin fold interference pattern is produced. In the NW Persian Gulf, reactivation of some old folds occurred instead of a fold interference pattern. Reactivation may be influenced by the following factors: i) the presence of incompetent layers (i.e. evaporites), ii) a variable overburden, iii) basement faults, and iv) obliquity between the younger deformation shortening axis and fold axis. It is this last factor that we investigated by means of analogue modelling. The experimental apparatus is similar to that commonly used for experiments with brittle-ductile systems at the Laboratory of Experimental Tectonics of Géosciences Rennes. The model consisted of an alternation of ductile and brittle horizontal layers with a stratigraphy similar to the one found in the NW Persian Gulf. The model was deformed by two deformation events with an angle α between the two directions of shortening. After deformation, the resulting structure resembled a fold facing the static wall with internal thrust faults and detachment faults arranged into a geometry similar to a fish tail. In the second shortening event, the fold was reactivated without formation of an interference pattern. Moreover, the displacement on both the reactivated and newly formed faults varied between almost pure thrust faults for low α and oblique thrust faults with a strike-slip component for high α. The models suggest that the presence of incompetent layers plays an important role in fold reactivation and confirm that basement faults are not necessary.
Copyright (c) 2023 B. SOLEIMANY, T. NALPAS, F. SÀBAT
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Geologica Acta is the property of the UB, GEO3BCN, IDAEA and UAB. Geologica Acta must be cited for any partial or full reproduction. Papers are distributed under the Attribution-Share Alike Creative Commons License. This license allows anyone to reproduce and disseminate the content of the journal and even make derivative works crediting authorship and provenance and distributing possible derivative works under the same or an equivalent license.
Authors retain the copyright on their papers and are authorized to post them on their own web pages or institutional repositories. The copyright was retained by the journal from the year 2003 until 2009. In all cases, the complete citation and a link to the Digital Object Identifier (DOI) of the article must be included.
The authors can use excerpts or reproduce illustrations of their papers in other works without prior permission from Geologica Acta provided the source of the paper including the complete citation is fully acknowledged.