DOI: 10.5880/gfz.dekorp-3a.002
title: Reprocessed deep seismic reflection profile DEKORP 1990-3A (including cross-profiles Q12-Q16) across the Hessian Depression, Northwest Germany

description: The profile 3A was recorded in 1990 as part of the DEKORP project, the German deep seismic reflection program. The focus of the DEKORP project was on deep crustal and lithospheric structures and therefore originally not on structures at shallower depths. From today's perspective, however, this depth range is of great interest for a wide range of possible technical applications (including medium-depth and deep geothermal projects). The original data is published by Stiller et al. (2021). On behalf of the Hessian Agency of Nature Conservation, Environment and Geology (HLNUG). From the 128 km long profile 3A the southernmost 104 km (plus additional 9 km northwards with decreasing CDP coverage to avoid boundary effects during migration) were reprocessed. As a particularity, also a set of 6 cross-lines, each ca. 9.6 km in length and perpendicular to the main line, were surveyed along DEKORP 3A to get information about possible cross-dips. Five of those short cross-lines (Q12-Q16) were reprocessed in 2D and 3D as well. The focus of reprocessing of the old data was on improving the resolution / mapping of geological structures down to a depth of 6 km (approx. 3 s TWT) to describe the prolongation of faults and geological structures in more detail than in previous studies. In order to achieve these goals and in view of the fact that today's processing and evaluation methods have been improved considerably compared to the 1990‘s, a state-of-the-art reprocessing was implemented. In comparison with the original processing (Stiller et al. (2021)), more sophisticated processing steps like CRS (Common Reflection Surface) instead of CDP (Common Depth Point) stacking, turning-ray tomography and prestack time and depth migration were carried out. The reprocessing results of the DEKORP 3A survey comprise all datasets newly achieved in addition to the datasets from the original processing (Stiller et al. (2021)), i.e. (1) the migrated CRS image gathers as unstacked data, and (2) the pure CRS stack, the poststack-time as well as prestack-time and prestack-depth migrated sections as stacked data. Moreover, (3) all velocity models used for the different versions including (4) the separate first-break tomography inversion, are contained. Additionally, the results of the 2D- and 3D-reprocessing of cross-lines Q12-Q16 are included. All reprocessed data come in SEGY trace format, the final sections additionally in PDF graphic format. A reprocessing report is included as well as again all meta information for each domain (source, receiver, CDP) like coordinates, elevations, locations and static corrections combined in ASCII-tables for geometry assignment purposes. Detailed information about acquisition and reprocessing parameters can be found in the accompanying Technical Report (Stiller & Agafonova, 2022). The DEKORP 3 survey was a combined seismic survey investigating the Variscan structures of the Rhenohercynian and the Saxothuringian. Consisting of three seismic lines it starts in the Rhenohercynian Hessian Depression (DEKORP 3A), crosses the Saxothuringian Mid-German Crystalline High (DEKORP 3B/MVE (West)) and runs parallel to the northern margin of the Moldanubian (DEKORP 3B/MVE (East)). The 128 km long DEKORP 3A profile runs N-S within the Hessian Depression from the Solling Dome in the Rhenohercynian to the Vogelsberg Volcano of the Saxothuringian Mid-German Crystalline High. The middle part of the profile crosses the "Northern Phyllite Zone". The reprocessed datasets contain a sub-section of the entire profile with a total length of 104.1 km of full CDP coverage, covering the territory of the state of Hesse. The reprocessed part of 3A is intersected by five short cross-lines along the profile at km 31.75, 53.55, 73.75, 89.85, 109.85 and by DEKORP 3B/MVE (West) at km 120.75 at its southern end. The DEKORP '90-3A profile is of particular interest to investigate the seismic resolution of the crust beneath the Permo-Mesozoic to Tertiary Hessian depression, the Kassel graben structure, as well as the tertiary volcanic fields of the Reinhardswald, Habichtswald, Knüll, Söhrewald and stopping just north of the large Cenozoic Vogelsberg complex.
description: The German Continental Seismic Reflection Program DEKORP (DEutsches KOntinentales Reflexionsseismisches Programm) was carried out between 1984 - 1997 and funded by the Federal Ministry of Education, Science and Technology (BMFT), now Federal Ministry of Education and Science (BMBF). The data was originally processed in the DEKORP Processing Centre (DPC) at the Institute of Geophysics of the Technical University Clausthal. DEKORP was founded in 1983 with the aim to investigate the deep crustal structure of Germany with high-resolution near-vertical incidence seismic methods. It was closely associated with the deep drilling project KTB (German continental deep-drilling program). One of the main research topics of DEKORP were deep seismic studies to investigate the lithospheric structure beneath Germany. The DEKORP profiles cover approx. 450 km in the state of Hesse and mostly cross areas for which there is only insufficient geological data (i.e. only few deep boreholes). As a governmental agency the HLNUG archives and publishes the data for future applications and usages, such as the search for a repository for nuclear waste in Germany, an expansion of the geophysical database, possibilities for modelling using gravimetric and magnetic data as well as an improvement of the 3D underground model of the state of Hesse. Therefore, the results are directly linked to the new geological 3D model of the state of Hesse, developed by the Technical University of Darmstadt (Hessen3D 2.0 project, BMWi-FKZ: 0325944). The reprocessed DEKORP datasets provide up-to-date unique and deep insights into the subsurface below Germany covering the earth’s crust from the surface to the upper mantle. Fields of applications are geothermal development, hazard analysis, hydrocarbon/shale gas exploration, underground gas storage, tunnel construction and much more.