Rifting and lower crustal reflectivity: A case study of the intracratonic Dniepr‐Donets rift zone, Ukraine

摘要: [1] Intracratonic rifting, caused by late Devonian extensional stresses in the East European Craton, created largest rift zone Europe, Pripyat-Dniepr-Donets (southeast Ukraine). The basin is approximately 2000 km long, up to 170 wide, and 22 deep. Wide-angle refraction reflection seismic data from Donbas Basin deep Refraction Reflection Experiments (DOBRE'99) project together with gravity magnetic are analyzed for structure evolution of Fold Belt, which uplifted deformed part Dniepr-Donets Basin. used identification large-scale crustal structures modeling velocities crust uppermost mantle. A ray-trace-based velocity density model derived joint inversion traveltime data. result reveals a high beneath at middle lower levels, slightly offset NE axis. Full waveform synthetic seismograms, matching observed data, show high-amplitude low-frequency arrivals this high-density body as well Moho. We interpret high-amplitude, signals reflections layered magmatic rocks, intruded into ductile during main phase subsequently were sorted fractional crystallization. intrusive material thickened 50%. This may explain enigmatic flat Moho topography across has been significantly stretched (β = 1.3). rifting initiated (Frasnien) consequence back-arc extension relation subduction Paleo-Tethys Ocean. subducting oceanic slab have enriched mantle volatiles convection, leading strong partial melting, upwelling, continued Famennien. asymmetrical geometry combination pure simple shear tectonic processes.