Magmenentwicklung und Dioritbildung im synorogen konsolidierten Grundgebirge des Bergsträßer Odenwaldes

The genesis of synorogeneous, variscian magmatites from the Bergsträsser Odenwald is explained. They are alternating with steep, old metamorphic rocks (schists and schisteous gneisses, partly transformed to plagioclase-blastites). The magmatites are differentiated into an early-orogenic hornblende-basiteseries (gabbro → diorite) and a high-orogenic biotite-flasermagmatite-series (diorite → granite). The hornblende-basite-series is “normally intrusive” with differentiated syntectic members; the biotite-flasermagmatite-series is lithogenic and has been formed by plagioclase-blastesis and anatexis. At the transition to the high-orogenic phase the rocks develop a strong gneissose foliation (due to movements during the emplacement). The structures assimilate, and a protoclastic to primary-gneissic texture is formed. We name the crystalline in this periode of formation briefly “Synorogen”. The diorites from the two series, as well as the dioritoids and aorites (products of “dioritisation”) show converging structures within the Synorogen. The mobile (ultrametamorphic) stage during the dioritisation and granitisation is discussed.