The Ossa-Morena Zone (SW Iberian Massif)
was affected by continuous orogen-parallel transcurrent
continental tectonics from the Neoproterozoic to the
Carboniferous times, involving transtension (TT) and
transpression (TP) processes that co-existed together,
occurred separately in neighbouring regions by the means
of strain partitioning or even worked diachronically. A
first stage of transpression TP1 took place during the Late
Neoproterozoic–Lower Cambrian as a result of Cadomian
arc-continent collisional processes. Structures generated
by transtension TT1 from Cambrian to Lower Devonian
were related to strong lithosphere stretching responsible
for the development of basins controlled by major detachments,
tilting, rifting and important tectono–thermal
diachronic processes. Denudation phenomena and inhibition
of sedimentation related with thermal uplift
(asthenosphere upwelling) and consequent subsidence
caused by isostatic equilibrium, involving generalized
transgressions, were processes responsible for major unconformities.
The Variscan TP2-TT2 episodes that followed
diachronically TP1-TT1, by maintaining the orogen-
parallel transport direction, were concomitant with
syntectonic deposition of continental basins in the OMZ
and foreland basins in the SPZ. TT2 local transtension
and tectonic exhumation of deep crustal rocks along
major shear zones, favoured the opening of tectonic
troughs filled up by sediments and volcanism. TP2
shortening have generated fold axes parallel to the orogen-
strike and composite dissymmetric flower structures
