DOI: 10.5880/gfz.dekorp.ktb8502.001
title: Deep seismic reflection profile KTB 1985 Line 2 in the Upper Palatinate, Southeast Germany

description: The 50 km long KTB Line 2 was recorded in 1985 as part of deep seismic reflection investigations for the DEKORP (German Continental Seismic Reflection Program) and KTB (German Continental Deep Drilling Program) projects. The network of lines consists of two DEKORP profiles, DEKORP 4N and its appendix 4Q, and six shorter KTB profiles, KTB 8501 – 8506, arranged in the form of a grid parallel and perpendicular to the main tectonic lineaments. The purpose of the investigations was to explore the planned target area for the Continental Deep Drilling Site in the Upper Palatinate with high-fold near-vertical incidence vibroseis acquisition. The main focus was on the crustal structure of the central Mid-European Variscides down to the Moho and the uppermost mantle and, in particular, on the suture between the Moldanubian Zone and the northward adjacent Saxothuringian Zone as well as on the metamorphic Zone of Erbendorf-Vohenstrauss. The array of the KTB profiles represents the pre-cursor of the 3D seismic survey ISO 1989 (Integrated Seismics Oberpfalz). Details of the experiment, first results and interpretations were published by DEKORP Research Group (1987, 1988). Results discussed together with the drilling site were presented in a number of works which can be found in Emmermann & Wohlenberg (1989). The Technical Report of KTB 8502 gives complete information about acquisition and processing parameters. The European Variscides, extending from the French Central Massif to the East European Platform, originated during the collision between Gondwana and Baltica in the Late Palaeozoic. Due to involvement of various crustal blocks in the orogenesis, the mountain belt is subdivided into distinct zones. The external fold-and-thrust belts of the Rhenohercynian and Saxothuringian as well as the predominantly crystalline body of the Moldanubian dominate the central European segment of the Variscides. Polyphase tectonic deformation, magmatism and metamorphic processes led to a complex interlinking between the units. The Saxothuringian represents the infill of a Cambro-Ordovician basin. The Moldanubian contains blocks of pre-Variscan crust and their Palaezoic cover. During the Variscan orogeny the Moldanubian crust was thrust toward the northwest over the Saxothuringian foreland. Both units were welded to one another by a low-pressure metamorphism accompanied by polyphase deformation (DEKORP Research Group, 1987, 1988). The ENE – WSW striking line KTB 8502 is located normally to the KTB lines 8504, 8505 and 8506 and to DEKORP 4N. The profile runs close to the area of the KTB drill hole, thereby crossing the DEKORP 3D survey ISO 1989. As well as the lines KTB 8501 and 8503 the profile 8502 was arranged parallel to strike, running across the NW-SE directed system of block-faults at the southwestern margin of the Bohemian Massif (DEKORP Research Group, 1988). In the southwest KTB 8502 crosses the Franconian Line, a fault zone which separates the crystalline Bohemian Massif from a foreland. Farther to the northeast KTB 8502 crosses metamorphic nappes and Variscan granites of the Erbendorf-Vohenstrauss Zone.
description: The German Continental Seismic Reflection Program DEKORP (DEutsches KOntinentales Reflexionsseismisches Programm) was carried out between 1984 – 1999 as the German national reflection seismic program funded by the Federal Ministry of Research and Technology (BMFT), Bonn [now: the Federal Ministry of Education and Research (BMBF)]. DEKORP was administrated by the former Geological Survey of Lower Saxony (NLfB), Hannover [now: the State Authority for Mining, Energy and Geology (LBEG)]. In 1994 the DEKORP management was taken over by the Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences. The aim of DEKORP was to investigate the deep crustal structure of Germany with high-resolution near-vertical incidence (mostly vibro)seismic acquisition, supplemented by wide-angle seismic and other target-oriented piggy-back experiments, all complemented by optimized methods of data processing and interpretation. The DEKORP project was closely linked with the KTB (German continental deep-drilling program) and was an equivalent to many other deep-seismic programs world-wide such as COCORP, BIRPS, LITHOPROBE, ECORS, CROP, BELCORP, IBERSEIS and many more. The DEKORP-Atlas (Meissner & Bortfeld, 1990) gives a detailed overview about most of the different campaigns and results. In sum, the resulting DEKORP database includes approximately 40 crustal-scale 2D-seismic reflection lines covering a total of ca. 4 700 km and one 3D-seismic reflection survey covering ca. 400 km². Each DEKORP survey is provided with all datasets that are necessary for either a re-processing (i.e. raw unstacked field records in SEGY) or a re-interpretation (i.e. finally processed sections in SEGY or PNG). The raw data are sorted by records or by CDPs. The final data are available as unmigrated or migrated stacks without or with coherency enhancement. Automatical line-drawings are also included. All data come with additional meta information for each domain (source, receiver, CDP) like coordinates, elevations, locations and static corrections combined in ASCII-tables for geometry assignment. Furthermore, all metadata originating from paper copies are made available as scanned files in PNG or PDF, e.g. field and observer reports, location maps in different scales, near-surface profile headers and others. The DEKORP datasets provide unique and deep insights into the subsurface below Germany covering the earth’s crust from the surface to the upper mantle and are increasingly requested by academic institutions and commercial companies. Fields of applications are geothermal development, hazard analysis, hydrocarbon/shale gas exploration, underground gas storage, tunnel construction and much more.