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The orogenic peridotite body Mohelno represents an ultramafic igneous rock of asthenospheric origin located in the Moldanubian Zone (the eastern margin of the Bohemian Massif, Czech Republic), which is interpreted as a deep part of the thickened orogenic root developed during Variscan continental convergence. The Mohelno body represents a large scale fold structure that underwent a complex tectonic and metamorphic history. It records deformation in mantle, emplacement into lower orogenic crust and exhumation within granulite complex to middle crustal levels. The oldest part of the evolution is partially recorded by the crystallographic preferred orientation of olivine and orthopyroxene preserved in coarse-grained relics of the Mohelno peridotite. This original structure is reworked by pervasive deformation resulting in ultramylonitic fabric. Later in the middle crustal conditions, the peridotite is affected by the serpentinization to various degree, thus original anisotropy of magnetic susceptibility (AMS) record is disturbed and difficult to interpret. Modeling of AMS using the topotactic relationships between olivine and orthopyroxene and newly growing serpentine minerals + magnetite helped us to understand the AMS evolution during the serpentinization process. This enables us to relate distinct AMS fabrics to original mantle structure of olivine and pyroxenes and to late deformation evolution of already serpentinized peridotite., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

The geological structure of the Central Apennines along a section line across the Lazio-Abruzzi carbonate plat- form has traditionally been interpreted using a thin-skinned thrust tectonic model, in which the sedimentary cover has been detached from an undeformed basement below. Such models have been used to predict that very large amounts of crustal shortening (e.g. 172 km over a section 173 km long) have occurred. Alternatively, in this paper we reinterpret the surface geology and well data along the same section line us- ing a thick-skinned thrust tectonic model. Restoration of this section shows that the amount of shortening (37 km over a section 158 km long) is considerably lower than previously predicted; this is accomplished by open buckling of the car- bonate platform, tighter folding of the basin scarp stratig- raphy, and reactivation of pre-existing extensional faults. Age bracketing on thrust fault movement allows shortening rates for the two different models to be calculated; these are < 6 mm yr 1 for the new interpretation, but over 24 mm yr 1 for the equivalent thin-skinned model. This latter value is significantly greater than shortening rates reported for most other thrust belts, suggesting that thick-skinned tectonics is a more satisfactory explanation for the structure of this area. The two most important implications of this are that sub- thrust hydrocarbon plays are largely absent in the area, and Neogene contractional deformation in this part of the Apen- nines resulted in much less crustal shortening than previously predicted.