[1] Detailed geological mapping, structural investigation and amphibole chemistry analyses in southern Evia (Aegean Sea, Greece) allow us to place new constraints on the internal structural architecture and tectonic evolution of the Cycladic Blueschists. We show that the early deformation history was related to ESE directed thrusting resulting in the stacking of the Styra and Ochi nappes, which constitute the Cycladic Blueschist unit in Evia. These early thrust movements initiated just before and proceeded at peak conditions of the Eocene high-pressure metamorphism. Subsequent constrictional deformation gave rise to E-W trending upright folding accomplished at the early exhumation stage. The main ductile-stage exhumation occurred during a single deformation phase associated with the decompression of blueschist rocks from the stability field of crossite to that of actinolite. This phase was characterized by localization of ductile deformation into a series of major, tens of meters thick, ENE directed shear zones, which cut up-section in their transport direction and restack the early thrust and fold sequence, locally bringing the structurally lower Styra nappe over the higher Ochi nappe. It is suggested that these zones operated as thrusts rather than normal sense shear zones as has been previously argued and were possibly formed during the Oligocene ENE-ward extrusion of the blueschists. Brittle-ductile NE dipping normal faulting of post-early Miocene age was probably responsible for the final exhumation of rocks.Citation: Xypolias, P., I. Iliopoulos, V. Chatzaras, and S. Kokkalas (2012), Subduction-and exhumation-related structures in the Cycladic Blueschists:
post-orogenic extension. Our new kinematic results in combination with previous works in the Cyclades area reveal a regional scale change in tectonic transport direction from (W)NW-(E)SE at Late Cretaceous-middle Eocene to (E) NE-(W)SW at late Eocene-Oligocene times. The observed change in transport direction may be governed by the relative motion of Africa with respect to Europe during Alpine orogeny.
Chemical analysis is a well-established procedure for provenancing of were carried out and the results were statistically evaluated. An attempt is also made towards the establishment of calibration factors between pairs of analytical set-ups in order to smooth the systematic differences among the results.
Samples of Roman thin‐walled ware from Segesta (northwestern Sicily), dating back to the early Imperial period, were studied by optical microscopy (OM) and Neutron Activation Analysis (NAA). Up to now, this class of Roman fine tableware has only occasionally been evaluated archaeometrically. Nevertheless, numerous production centres are believed to have been simultaneously active in the western Mediterranean area. Petrographic and chemical data seem to be in agreement with the archaeological hypothesis of local manufacture in Segesta for most of the analysed samples, through a comparison with kiln wasters and local raw materials. The effectiveness of thin‐section petrography for determining the provenance of such a tiny tempered class of pottery and the integrated use of two different grouping procedures (petrography and chemistry) were also tested.
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