Delineating tectonic units beneath the Donbas Fold Belt using scale lengths estimated from DOBRE 2000/2001 deep reflection data

Abstract

A novel statistical analysis, which augments conventional interpretation of deep seismic reflection/refraction data, is applied to the DOBRE 2000/2001 reflection profile. The goal is to improve delineation of the lithosphere in terms of lithotectonic units and to compare these to existing interpretations. After a successful validation of the method using synthetic data, stochastic parameters estimated from windowed average lateral autocorrelations in the DOBRE data are compiled in a two‐dimensional profile of von Karman‐type causative reflectivity. These estimates in terms of lateral correlation lengths and power law exponents are accompanied by associated uncertainties. Given its low uncertainties, the lateral correlation length ax turns out to be a robust delineator. The profile of ax reveals systematic spatial variations in the lithospheric fabric below the Donbas Fold Belt. As in earlier interpretations based upon conventional processing of reflection/refraction data, both the sedimentary basin and Moho discontinuity stand out clearly, as well as a region indicating massive vertical intrusion in the crust from upper mantle sills and ultramafic underplating of the lower crust. Notable differences with conventional interpretations include the number and extent of supra‐Moho rift pillow structures, the lack of imaging a crust‐cutting dislocation feature and a laterally disturbed uppermost mantle. Von Karman lateral correlation length provides new independent information at a scale between velocity models from wide‐angle reflection/refraction data and line drawings from near vertical reflections and provides new insights and understanding of lithospheric evolution.

Conservation of lateral stochastic structure of a medium in its simulated seismic response

“…In spite of some of the limitations encountered, the results in this study appear to validate estimates of lateral correlation lengths in crustal heterogeneity from deep seismic reflection data, which is the subject of the companion paper by Carpentier et al [2009].…”

“…The wavefield was recorded for 3000 ms with sampling interval Δ t = 4 ms, long enough to record all single reflected events and the most important multiply reflected ones, yet keeping the computation time reasonable. We have chosen this near‐vertical setup because we are interested in applying our method to near‐vertical lower crustal reflection seismic data [see Carpentier et al , 2009]. Apart from a bandpass filter plus top mute to remove surface generated Rayleigh waves and a gain function, no further processing is done.…”

Late Cretaceous-Cenozoic basin inversion and palaeostress fields in the North Atlantic-western Alpine-Tethys realm: Implications for intraplate tectonics

“…Recently, in this regard, Bezada and Smale (2019) have argued that lithospheric mantle structure may be strongly involved in the localisation of intraplate seismicity based from studies of the attenuation of teleseismic earthquake phases. Carpentier et al (2009) presented evidence from stochastic attributes of controlled-source deep seismic reflection profiling that suggests sub-crustal lithosphere structure beneath an old rift zone is more chaotic, hence potentially more attenuating to teleseismic waves, than away from the rift zone.…”

Lithospheric structure along wide-angle seismic profile GEORIFT 2013 in Pripyat–Dnieper–Donets Basin (Belarus and Ukraine)

“…9) indicate heterogeneous inner structure of the HVB -its NW part is characterized by strong reflectivity, while in the SE portion a body with higher velocities (up to 7.30 km s -1 ) has been distinguished. Reflective HVB has been indicated in the Donbas segment (DF) of the PDDB from recent studies on the lower crustal reflectivity (Lyngsie et al 2007;Carpentier et al 2009). They have shown that the HVB includes a series of high-velocity layers with individual thickness of the order 400-700 m and strong seismic velocity contrast (Lyngsie et al 2007).…”