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Convener: Manuel Díaz-Azpiroz (Universidad Pablo de Olavide, Seville, Spain)
Co-conveners: Dyanna M. Czeck (University of Wisconsin-Milwakee, USA), Carlos Fernández (Universidad de Huelva, Spain), Karen Leever (GFZ Potsdam, Germany)
In plate tectonics,
the rotational relative displacements of lithospheric plates
imply that oblique plate boundaries must be the norm, rather
than the exception. Oblique displacement includes a lateral and
an orthogonal component, which can be convergent (Transpression)
or divergent (Transtension). Therefore, a better understanding
on the kinematics and the mechanics involved in transpressional
and transtensional deformation is crucial to the knowledge of
the processes that take place at plate tectonic boundaries.
Transpression was first modeled by Sanderson and Marchini in
what has become one of the most cited papers in Structural
Geology. Now, thirty years after its publication, their proposal
is still current, and many Structural Geology and Tectonic
studies are partly based on it. Subsequent kinematic models have
become progressively more complex, including transtension
(kinematically equivalent to transpression but with a divergent,
rather than convergent orthogonal strain component), triclinic
symmetries arising from oblique simple shear and/or coaxial
extrusion, general coaxial strain, deformation zones with
migrating limits, etc. These have helped to understand many
natural deformation zones, at different tectonic settings, that
could not be explained by more simple models. Still, there are
several aspects, some of them currently ongoing, that will
improve our knowledge of deformation at oblique tectonic
settings, such as heterogeneous deformation, non-steady strain
rates or the consideration of mechanical aspects. We pretend to
acknowledge Sanderson and Marchini’s contribution, by proposing
a broad session covering different topics related to oblique
tectonics: studies on natural cases of deformation at oblique
tectonic settings, including oblique convergent orogens, lateral
branches of orogenic arcs, strike-slip settings or
transtensional tectonics; as well as innovative approaches on
numerical (kinematical and mechanical) and analogue modeling of
transpressional/transtensional deformation. Our aim is provoke
wide discussion that would include (1) heterogeneous
distribution of simple shear and coaxial components of
deformation, (2) transpressional/transtensional zones showing
strain partitioning at multiple scales, (3) upper crustal
heterogeneous transpression/transtension or (4) tectonic uplift
and basin development related to transpression/transtension.
Best regards,
Manuel, Dyanna,
Carlos and Karen
-- ----------------------------------------- Manuel Díaz Azpiroz Dpt. Sistemas físicos, químicos y naturales Universidad Pablo de Olavide Crtra. Utrera, km 1 41013 Sevilla Tf: +34 954 348351 Fax: 954349814 [log in to unmask] -----------------------------------------