Deep seismic investigations in Southern Germany/Oberpfalz
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 (RH) and Saxothuringian (ST) as well as the predominantly crystalline body of the Moldanubian (MN) dominate the central European segment of the Variscides. Polyphase tectonic deformation, magmatism and metamorphic processes led to a complex interlinking between the units.
The Oberpfalz area in NE Bavaria is located in the transition zone between the Moldanubian (MN) and Saxothuringian (ST) units of the Variscan orogen.
The seismic surveys of DEKORP 4 and KTB 8501- KTB 8506 aimed
- to investigate crustal structure in the transition region between MN and ST,
- to understand the nature of the metamorphic Erbendorf body,
- to select a suitable site for the KTB drill hole.
In 1985 the seismic experiments of DEKORP 4, consisting of lines DEKORP 4N and 4Q, and KTB 8501 - KTB 8506 were performed by the DEKORP Research Group. The network of lines consisted of a long, NW-SE trending profile (4N) and a short cross-line at its southern end (4Q) as well as an array of shorter KTB-lines around the pre-selected drilling site (KTB 8501 - KTB 8506) (see location map). Wide-angle seismic observations along the long DEKORP 4 profile completed the survey.
Experiments
DEKORP 4N/4Q
The 187 km long, NW-SE trending DEKORP 4N line provides a cross-section from the Saxothuringian Teuschnitz synform in the north to the Moldanubian crystalline massif in the south. Line 4Q crosses line 4N perpendicularly at its southern end and runs across the shear zones of the "Bavarian Pfahl" to the metamorphic massif "Hoher Bogen".
KTB 8501- KTB 8506
The KTB lines 8501-8506 were arranged as a grid covering the ST/MN boundary region and the metamorphic unit of the "Zone of Erbendorf-Vohenstrauss". This array was the pre-cursor of the 3-D survey ISO '89.
long (start) lat (start) long (end) lat (end)
DEKORP 4N 11.35621 50.52041 12.98438 49.24944
DEKORP 4Q 12.67380 49.07117 12.96251 49.33574
KTB 8501 11.77771 49.81097 12.31433 50.05408
KTB 8502 11.88920 49.73925 12.47617 49.98173
KTB 8503 11.98314 49.57611 12.53159 49.92421
KTB 8504 11.66798 49.91544 12.10616 49.56983
KTB 8505 11.95515 50.12612 12.38429 49.72417
KTB 8506 12.19312 50.11964 12.45743 49.78461
