Deep reflection seismic imaging in SE Poland using extended correlation method applied to PolandSPAN™ data

- Record lengths of the Vibroseis data are extended from 12 to 22 s.
- Reflection imaging of the lower crust and Moho in SE Poland
- Smooth basement observed across the Teisseyre-Tornquist Zone
- Reflection Moho coincident with the refraction Moho

Here I apply the extended correlation technique to a 156-km long regional seismic profile, PL1-5100, from the PolandSPAN™ survey located in SE Poland. This method allows the extension of the nominal record length of the survey (12 s in this case) to much longer times (22 s tested here), given that in the field the raw uncorrelated data were stored and a broadband sweep was used. Processing of the ground force correlated data compared to pilot sweep correlated one produced qualitatively similar results. Based on the consistency of the ground force measured along the profile, data were correlated with the mean of the ground force estimates. Results of the processing were validated against the coincident wide-angle reflection/refraction (WARR) profile (CELEBRATION 2000 CEL05 profile) and a deep reflection profile located further to the SE (POLCRUST-01 profile). I found a good correspondence between the wide-angle Moho signature and the near-vertical incidence (NVI) Moho reflectivity, both in terms of the depth and the reflection strength, with the exception of the area of the crustal keel (Moho > 50 km) interpreted from the WARR data, where the NVI reflectivity is observed at depth ca. 47 km. Similarly to POLCRUST-01, line PL1-5100 is portraying the attenuated crust of the East European Platform margin with the dipping crystalline basement down to ca. 20 km depth and the reflective lower crust. Two important fault zones: Izbica-Zamość Fault and Wilczopole Fault Zone are interpreted as the deeply-rooted crustal features, but there is no evidence for the Teisseyre-Tornquist Zone itself.