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Tectonic analysis in conjunction with the microtectonic study of Mesozoic–Cenozoic series of the Central Constantinois of Algeria are used to reconstruct the sequence of tectonic phases since Cretaceous times. The retrotectonic method used to marshal the microtectonic data makes it possible to distinguish deformations related to Mesozoic tectonic phases from those associated with Cenozoic pre- and post-thrust sheet phases. A N120°E extensional and a N180°E compressional phase are highlighted in Albian–Cenomanian and latest Maastrichtian times, respectively. The Cenozoic era is marked by a series of three compressional phases oriented N90°–120°E in the Late Eocene, and N20°–30°E and N170°E in the Late Miocene. The first Late Miocene compressional phase related to the emplacement of Numidian flysch thrust sheets was followed by N–S compression affecting the overriding thrust sheets and their substratum. During latest Miocene–Pliocene and Quaternary times the tectonic pattern changed with NE–SW regional extension giving way in Quaternary and present-day times to a N130°–150°E compressional episode. The characteristics of the palaeostress fields and the regional structures are specified for the different phases defined.

The Upper Benue Basin (northeastern Nigeria) is interpreted as a complex strike-slip basin which consists of a set of sub-basins controlled by synsedimentary N60°C E-trending, strike-slip faults which were active during Early Cretaceous times. The oblique planar cross-beds made of the medium- to fine-grained sandstones of the upper member of the Bima Sandstone Formation are affected by various soft-sediment i.e., early diagenetic but soft-sediment deformational structures. These are present not only close to the synsedimentary faults but also on a larger regional scale. Three main types of structures (undulated and recumbent-folded cross-bedded lamination, dislocated convolutions and concordant microbreccias, discordant fluidised intrusions) are described. These are related to processes of sediment deformation favored by sand hydroplasticity, liquefaction and fluidization. The local organization of these soft-sediment intrastratal deformational structures, their spatial distribution with respect to synsedimentary faults, and their independance with respect to marginal paleoslopes, suggest that they cannot be explained by slumping or current drag. All the deformations are related to pore water expulsion and it is proposed that the required sand reorganization was triggered by seismic waves. The spatial and chronologic distribution and intensity of the various types of deformation structures suggest that they were produced around different epicenters repeated by earthquakes of varying magnitudes associated with the synsedimentary strike-slip tectonics.

Metamorphism in the Vosges massif is characterized by rocks formed under a wide range of pressures and temperatures: high-pressure rocks (garnet peridotites and eclogites facies rocks) are found together with low-pressure rocks (garnetcordierite stability field). Hitherto, metamorphism has been interpreted within the framework of an identical P-T evolution for all rock types corresponding to either two separate geotectonic events or a unique P-T evolution from high-pressure to low-pressure conditions. We studied gneisses from the Vosges massif in order to constrain the P-T-t path they followed. P-T estimation indicates that gneisses equilibrated between 5 and 7 kbar during peak metamorphism time. Rocks later experienced cooling from temperatures above 650°C down to 550°C. It is possible that the entire P-T evolution of the gneisses took place within the lower part of the amphibolite facies; which is inconsistent with the P-T evolution of the high-pressure rocks. The noteworthy absence of muscovite + staurolite assemblages is attributed to conditions of low H2O and low O2 activity. The consequences for the geodynamics in the Vosges massif are that at least two separate geotectonic events are required in order to explain the juxtaposition of high-pressure rocks with low-pressure amphibolite facies rocks.