HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
The GEORIFT 2013 (GR'13) WARR (wide-angle reflection and refraction) experiment was carried out in 2013 on the territory of Belarus and Ukraine in wide international cooperation. The aim of the work is to study basin architecture and deep structure of the Pripyat-Dnieper-Donets Basin (PDDB), which is the deepest and best studied Palaeozoic rift basin in Europe. The PDDB is located in the southern part of the East European Craton (EEC) and crosses the Sarmatia-one of the three segments of the EEC. The PDDB was formed by Late Devonian rifting, associated with domal basement uplift and magmatism. The GR'13 runs in NW-SE direction along the PDDB strike and crosses the Pripyat Trough (PT) and Dnieper Graben (DG) separated by Bragin Uplift of the basement. The field acquisition along the GR'13, of 670 km total length, involved 14 shots and recorders every ~2.2 km. The good quality of the data, with first arrivals visible up to 670 km, permitted to construct the velocity model (to 80 km depth) using the ray-tracing modelling. The thickness of the sediments (Vp<6.0 km s-1) changes from 1-4 km in the PT, through ~5 km in the NW part of the DG, to 10-13 km in the SE part of the profile. Below the DG, at ~330-530 km distance, we observed an updoming of the lower crust (with Vp of ~7.1 km s-1) to ~25 km depth that represents a rift pillow or mantle underplate. The Moho shallows southeastwards from ~47 km in the PT to 40-38 km in the DG with mantle velocities of 8.35 and ~8.25 km s-1 in the PT and DG, respectively. A near-horizontal mantle discontinuity was found beneath Bragin Uplift (a transition zone from the PT to the DG) at the depth of 50-47 km. It dips to the depth of ~60 km at distances of 360-405 km, similarly to intersecting EUROBRIDGE'97 profile. The crust and upper mantle structure on the GR'13 may reflect varying intensity of rifting in the PDDB-from passive stage in the PT to active rifting in the DG. The absence of the Moho uplift and relatively thick crystalline crust under the PT is explained by its tectonic position as a closing unit of the PDDB, with a gradual attenuation of rifting from the southeast to the northwest. Active stage of rifting is evidenced in the DG by a shallower Moho and by a presence of a rift pillow caused by mafic and ultramafic intrusions during the active phase. The junction of the PT and the DG (the Bragin Uplift) locates just at its intersection with the NS regional tectonic zone Odessa-Gomel. Most likely, the "blocking" effect of this zone did not allow for further propagation of active rifting to the NW.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.