Late-orogenic Variscan magmatism: The case of quartz monzodiorite dykes from the Blanice Graben, southern Bohemia

Abstract

Pyroxenebiotite quartz monzodiorite of the tìpánovice dyke (3 km long and up to 50 m wide), together with additional small occurrences further north, is associated with the Late Variscan Blanice Graben in the Moldanubian Zone of southern Bohemia. The texture is subophitic, fine-to medium-grained, with skeletal crystals of ilmenite and zircon. This, together with rare amygdaloidal texture, indicates a rapid cooling of the melt emplaced at shallow (subvolcanic) crustal levels.

Sr Isotope Analysis of Human Remains from Settlement Pits at Stillfried/March. Reappraising Diagenetic Changes

“…132 The bioavailable Sr signature of the Stillfried location was identified by using recent soil samples.133 The Austrian part of the Bohemian Massif shares the Moldanubian unit and the Moravian unit, which consists predominantly of granite, granulite, granitoids and gneiss:Friedl et al 2004. -The n( 87 Sr)/n( 86 Sr) ratios within this unit display values up to 0.770:Janoušek, Rogers, Bowes 1995. -Vrána, Janoušek 1999…”

Intrusive and deformation history of the Ševětín Pluton, Moldanubian Batholith: record of polyphase tectonic evolution of the Blanice Graben, Bohemian Massif

“…Overall scarcity of hydrothermal veins coupled with this tectonic phase, however, indicates only a short-lived and relatively insignificant hydrothermal activity. The magmatic activity (270 ± 2 Ma; Košler et al 2001) ascribed to this phase produced NNE-SSW to N-S trending and steeply dipping dikes of pyroxene-bearing microgranodiorite (Vrána et al 1993) and quartz monzodiorite (Vrána and Janoušek 2006).…”

“…1a; Košler et al 2001). The parental magma of this dike originated from mixing between remelted lower crustal (Moldanubian) rocks and primary magmas derived from an upper mantle source (Košler et al 2001;Vrána and Janoušek 2006).…”