New aspects on the tectonic of the Alps and the Apennines revealed by ERTS-1 data

An analysis of the tectonic situation in the Alps and Apennine Mountains based on ERTS-1 imagery is presented. It is stated that the ERTS-1 imagery reveals connections between shearing systems of more than regional importance which could not be determined previously. The tracing of locally known fault distances by ERTS-1 imagery is discussed

The birth of the Alps: Ediacaran to Paleozoic accretionary processes and crustal growth along the northern Gondwana margin

New whole-rock geochemical and coupled U–Pb and Lu–Hf LA-ICP-MS zircon data of metasedimentary rocks of the Austroalpine, South Alpine and Penninic basement domains are presented, to disentangle the pre-Variscan tectonic evolution of the proto-Alps. The studied units seem to record distinct stages of protracted Late Ediacaran to Carboniferous tectonosedimentary processes prior to the Variscan collision. In the case of Austroalpine and South Alpine units, nevertheless, no major differences in terms of provenance are observed, since most detrital zircon samples are characterized by a major Pan-African peak. Their detrital zircon spectra record a provenance from the northeastern Saharan Metacraton and the Sinai basement at the northern Arabian-Nubian Shield, being thus located along the eastern Early Paleozoic northern Gondwana margin, whereas sources located further west are inferred for the Penninic Unit, which might have been placed close to the Moldanubian Unit of the Bohemian Massif. In any case, it is thus clear that the Alpine basement remained in a close position to the Gondwana mainland at least during the Early Paleozoic. The Late Ediacaran to Silurian tectonic evolution, which includes Cadomian and Cenerian tectonometamorphic and magmatic processes, seem thus to record a continuum related to a retreating-mode accretionary orogen, with diachronous back-arc basin opening and possibly discrete compressional/transpressional pulses linked to changes in subduction zone dynamics. On the other hand, it is inferred that the Alpine basement essentially comprises Pan-African metasedimentary and subordinate metaigneous rocks, possibly with very few Early Neoproterozoic relics. This basement was significantly reworked during the protracted Paleozoic orogenic evolution, due to anatexis and/or assimilation by mantle-derived juvenile magmatism.Georg-August-Universität Göttingen (1018

First deep seismic reflection images of the Eastern Alps reveal giant crustal wedges and transcrustal ramps

The Alps are considered as a classical example for an orogen created by continental plate collision. In this study we present new images obtained from deep seismic reflection profiling in the Eastern Alps between Munich and Venice which give rise to examine and revise existing concepts. The seismic sections exhibit a prominent bi-verging reflection pattern at crustal scale. A major ramp-like structure, outcropping at the Inn-Valley fault, can be traced southward over 80 km into the mountain root where relics of the subducted Penninic ocean are expected. New models of the evolution of the Eastern Alps show an upper/lower crustal decoupling along transcrustal thrust faults with opposite thrust directions of both the European and the Adriatic-African continents

Geology and evolution of the Northern Adriatic structural triangle between Alps and Apennine

The basic kinematic evolution leading to the present tectonic setting of the Northern Adriatic zone is here synthetically outlined. The Adriatic domain is the structural area progressively invaded by neighboring orogenic chains. The evolution of the Southern Alps and of the Northern Apennines from the beginning of the Neogene time onward is here summarized. Orogenic processes due to plate convergence or to orogenic and magmatic arc evolution are here compared and discussed in the frame of Western Mediterranean genesis