Pre-Late Carboniferous geology along the contact of the Saxothuringian and Teplá-Barrandian zones in the area covered by younger sediments and volcanics (western Bohemian Massif, Czech Republic)

Abstract

The boundary between the Saxothuringian and the Tepla–Barrandian zones at the western margin of the Bohemian Massif represents an important tectonic suture of the Central European Variscides. However, most of this boundary is covered by Late Carboniferous and younger sedimentary and volcanic rocks, which prevent direct observation of particular geological units. We present a compilation of geological and depth measurement data from 12,134 exploration boreholes that reached the basement of the volcanic and sedimentary infill in the area of the Eger Graben in the north-western Bohemia, and correlate covered geological units with those exposed on the present-day surface. The resulting compilation reveals the relief of the sedimentary basins basement and interprets the real extent of the basement geological units in the western part of the Bohemian Massif. It also shows the position of the contact between units with the Saxothuringian and the Tepla–Barrandian affinities and suggests the boundary between rocks with Devonian metamorphic record and those metamorphosed during the Early Carboniferous period of the Variscan tectonometamorphic cycle.