The Mariánské-Lázně Complex, NW Bohemian Massif: development and destruction of an early Palaeozoic seaway
Published:January 01, 2002
Quentin G. Crowley, Peter A. Floyd, Veronika Štědrá, John A. Winchester, Vaclav Kachlík, J. Grenville Holland, 2002. "The Mariánské-Lázně Complex, NW Bohemian Massif: development and destruction of an early Palaeozoic seaway", Palaeozoic Amalgamation of Central Europe, J. A. Winchester, T. C. Pharaoh, J. Verniers
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The Mariánské-Lázně Complex is a Cambro-Ordovician terrane of oceanic affinity tectonically emplaced between the Saxothuringian Zone and Teplá-Barrandian Unit, NW Czech Republic. It forms a SE-dipping allochthonous body that comprises the largest contiguous exposure of metamorphosed basic and ultrabasic lithologies in the Bohemian Massif. Petrographic evidence indicates that a significant proportion of protoliths underwent eclogite facies metamorphism (570 to 720°C, 1.44 to 2.10 GPa), followed by an increase in temperature (up to around 800°C) and a subsequent widespread retrograde amphibolite facies event (550 to 680 °C, 0.75 to 1.20 GPa). New major and trace element geochemical analyses of metamorphosed basic and ultrabasic lithologies indicate that they exhibit geochemical characteristics attributable to a sea floor origin. The metabasites were generated at a spreading centre that interacted with deep-seated upwelling mantle asthenosphere. Separate, independently fractionating basic melt batches existed: these were derived from depleted and enriched asthenosphere and depleted sub-continental lithosphere sources. Geochemical correlation of the Mariánské-Lázně Complex with other early Palaeozoic metabasic provinces facilitates comparison of metabasic lithologies occurring in tectonically dislocated nappe pile thrust sheets, and allows delineation of important suture zones in the European Variscides.
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Palaeozoic Amalgamation of Central Europe
Palaeozoic Amalgamation of Central Europe summarizes recent research designed to clarify the timing, geometry and processes by which discrete terranes of Central Europe became amalgamated during the Palaeozoic Era. The area studied extends from the southern North Sea to Central Poland along the Trans-European Suture Zone, covering much of Germany, Denmark, Belgium, the Czech Republic and Poland.
The 16 papers within the volume are divided into five sections: biostratigraphic/provenance evidence; isotopic constraints; petrological and geochemical evidence; structural evolution; seismic traverses and deep crustal structure. The first section contains papers summarizing continent-specific micropalaeontological and sediment provenance information backing current debates about microcontinent derivation and timing of their accretions to the proto-European continent, Baltica. The section on isotopic constraints discusses the use of isotopic dating to constrain the timing of accretions of rock units exposed in the northern Bohemian Massif, while the following section has more detailed studies of metamorphosed ophiolitic complexes adjoining palaeosutures in the same area. The two papers on the structural evolution of the area contrast a detailed review of the structural evolution of the Sudetes, with a broader, more regionally based hypothesis for the structural evolution of all Central Europe. The final section discusses models based on extensive seismic traverses in contrasting parts of the area - Belgium, the southern North Sea and Poland. This wide-ranging study thus encapsulates the most up-to-date ideas on the Palaeozoic amalgamation of Central Europe from the leading international researchers in the field.
The volume will be of interest to those earth scientists in industry and academia with a broad-based interest in the construction of the European continent, primarily biostratigraphers, geophysicists, structural geologists and geochemists.