AUTHORS:

Grad M.

ABSTRACT:

In the area of the Central Europe three large continental scale tectonic units meet together, namely Precambrian East European Craton (EEC) to the northeast, Variscan West European Platform (WEP) terranes to the southwest, and younger Alpine Carpathian arc in the south. The reference structure of the Central Europe is a sharp edge of the East European Craton. In the area of Poland the south-western margin of the EEC is marked as Teisseyre–Tornquist Zone (TTZ), which continues to the north as Sorgenfrei–Tornquist Zone (STZ). Teisseyre–Tornquist Zone (TTZ) — earlier Teisseyre Line, Tornquist Line or Teisseyre–Tornquist Line (TTL), is a term created in commemoration of Polish geologist Wawrzyniec Teisseyre and German geologist and paleontologist Alexander Tornquist. At the turn of XIX and XX century, they noticed a fundamental difference in the geology of platform cover between the rigid East European Platform and its more mobile southwestern forefield (Teisseyre, 1893, 1903; Tornquist, 1908, 1910). From the very beginning the TTL was conceived as a linear feature (fault or fault zone) marking the southwestern boundary of the EEC. Contrarily, the Trans–European Suture Zone (TESZ) is a term coined by Asger Berthelsen for an assemblage of suspect terranes boarded by the East European Craton and the Variscan orogeny. It is not a linear structure, but a terrane accretion zone, 100–200 km wide. Both terms, TTL and TESZ, should not be mistaken, as is the case on many maps concerning the problem (Dadlez et al., 2005). The edge of the craton is a major lithospheric structure, which appears to be a deep-seated boundary reaching at least down to a depth of about 200 km as shown by tomographic analysis of shear wave velocity structure of the mantle under Europe. Another indication of the deep-seated nature of this zone was obtained from observations of earthquakes and explosions located in Europe. To explain the observed blockage of energy from regional seismic events by TTZ, the structural anomaly between eastern and western Europe must reach at least down to a depth of about 200 km. Continental scale tectonic units of the Central Europe are clearly visible in the crustal structure, Moho depth map, and also gravity, magnetic and heat flow maps.

Geochemistry, 2019, vol. 79(3), pp. 422-433, doi: 10.1016/j.chemer.2019.03.002