Table 6 - uploaded by Uli Schuessler
Content may be subject to copyright.
(Gabbro~)amphibolites of the BHitterberg-Hoher Sogen area 

(Gabbro~)amphibolites of the BHitterberg-Hoher Sogen area 

Source publication
Article
Full-text available
Various amphibolites, metagabbros and eclogitic relics of the Mariimske Lazne complex, and amphibolites from the Cerna Hora Massif exhibit an uniform geochemical character which compares well with modern mid-ocean ridge basalts. Geochemically these metabasites are similar to the amphibolites of the My to area and to schistose. partly striped amphib...

Similar publications

Chapter
Full-text available
ABSTRACT In Chapter 2, we showed that the eclogite-facies metamorphism within the Mesoarchean–Neoarchean Belomorian eclogite province can be correlated with “hot” subduction. However, was such a thermal regime specifi c to the Archean? Comparison of pressure-temperature-time paths and data for peak metamorphic parameters demonstrates the general si...
Article
Full-text available
Serpentinites are widespread in the Arabian-Nubian Shield (ANS) of the Eastern Desert of Egypt and usually enclose a tremendous carbonate alteration. Combined investigation of the stable isotope compositions of both O-H in serpentines and O-C in the whole-rock and the chemistry of the fluid-mobile elements (FMEs) in whole-rock serpentinites from Wa...
Article
Full-text available
Abstract The composition of the intrusive gabbroic lower oceanic crust remains poorly characterized in comparison to the extrusive portion of the oceanic crust, especially for intermediate-fast spreading mid-ocean ridges. This is a consequence of limited exposures of extant lower oceanic crust or ophiolites similar to mid-ocean ridge crust. One of...
Article
Full-text available
Various studies of geochemistry, mineral chemistry and petrogenesis of part of the Mawat ophiolite complex (NE Iraq) show its affinity to mid-oceanic ridge basalt (MORB). The complex is characterized by mineral assemblages belonging to low-grade amphibolite facies with non lineated fabric, low glaucophane content in hornblende, and oligoclase compo...
Article
Full-text available
The metamorphic complex from the Mt. Tenzan area in northern Kyushu consists mainly of mafic rocks with small amounts of siliceous, calc–silicate, and ultramafic rocks. These lithofacies can be recognized as an ophiolitic complex. Metamorphosed mafic rocks are divided into two types, amphibolites I and II, which are probably derived from supracrust...

Citations

Article
As laid out in Chapters V.B.1 and V.B.2, the parautochthonous Thuringian fades of the Saxothuringian Belt has been overthrust from the SE by nappes, which have survived in the core of the Vogtland Synform. These are the tectonic klippen of Münchberg, Wildenfels, and Frankenberg (in order from W to E; see Fig. 1). The klippen represent, in fact, erosional remnants of one or several nappe piles, which were originally more extensive, and possibly laterally continuous with each other. The tectonic sequence in each of these klippen is characterized by inversion of the stratigraphy and of the metamorphic grades. The lower nappes comprise (in order from bottom to top): proximal Early Carboniferous flysch, Silurian/Devonian bedded chert, and a volcanosedimentary sequence of largely Ordovician age. These very-low-grade, fossiliferous sequences are overlain by a number of metamorphic thrust sheets. This chapter describes the lithology, tectonic sequence, and internal structure of the metamorphic nappes in the klippen, and of their probable equivalents at the northwestern margin of the Moldanubian Region, from which they are derived. We set out from the Münchberg klippe, which is the largest, most differentiated and best studied example of its kind, and then briefly discuss the closely related units. Details on the metamorphic evolution are available in the contribution by Blümel (Chap. V.C.2)
Full-text available
Article
Bodies of coronitic metagabbro occur in the SW Mariánské Lázně Complex (MLC) and the adjacent Teplá Crystalline Unit (TCU) on the western margin of the Teplá-Barrandian Unit (TBU), Bohemian Massif. The characteristic structural, geochemical, petrographic, and metamorphic features of five groups of metagabbros and related rocks are presented, compared with other metabasites of the MLC and Zone of Erbendorff-Vohenstrauss (ZEV), and used to constrain the tectonometamorphic evolution of the western part of the TBU. The metagabbros are considered to be a younger intrusive member of the complicated lower crustal tectonic stack of Upper Proterozoic to Early Palaeozoic age which is formed by the Mariánské Lázně Complex and the Teplá Crystalline Unit together. It is proposed that a significant part of the metamorphic evolution of some parts of these units took place before the emplacement of metagabbros and granitoids at around 496-516 Ma. The sequence of metamorphic events is interpreted to have been as follows. Deep burial of primitive MORB type tholeiitic rocks (a) metamorphosed up to eclogite facies, followed by (b) uplift to lower crustal levels so that the partially exhumed rocks were juxtaposed with other lower/middle crustal rocks. Thermal relaxation (c) followed, with an episode of extension recorded in L-tectonites of amphibolite facies. Once this lithologically variegated stack was welded together, it was intruded by the Upper Cambrian-Lower Ordovician granitoids and gabbros (d). This pre-Variscan metamorphic event may be expressed at the supracrustal level by an unconformity between Upper Cambrian and Lower Ordovician rocks in the Barrandian. The final configuration of the units was established during the Variscan collision of the Teplá Barrandian terrane with Saxothuringia (e) in which the rocks of the MLC and TCU were thrust to the NW over the Saxothuringian para-autochthon. The accompanying metamorphic event reached upper amphibolite facies. The thermally relaxed rocks cooled rapidly, and pre-existing thrust planes were re-activated during the final extensional collapse.
At its southern margin along the Hoher Bogen mountain, the Tepl-Barrandian (Bohemian massif, Central Europe) is made up of a 1- to 4-km wide belt of amphibolites. An upper amphibolite/lower granulite facies Variscan metamorphism has brought forth coarse-grained, weakly foliated rocks with hbl+pl&#45cpx&#45opx&#45grt parageneses. Since the beginning of this century, these rocks, together with fine-grained or mylonitized amphibolites, have been regarded as metamorphic gabbros (gabbro amphibolites) of the Neukirchen-Kdyne igneous complex. Relics of magmatic textures, however, cannot be found anywhere. The amphibolites are therefore reinterpreted as metamorphic basalts. The Hoher Bogen amphibolites (HBA) derive from N-type MORB. The most primitive samples have Mg#s between 60 and 65. Locally occurring (garnet-)hornblendites and leucodioritic mobilisates are the products of partial melting of amphibolites during the Variscan metamorphism and do not belong to the primary magmatic rock association. Ultramafic rocks are tectonically emplaced between the HBA belt and the metapelitic rocks of the Moldanubian. At the very least, the metapyroxenites among them seem to have a cumulus origin. Together with the ultramafic rocks, the HBA belt may be regarded as a metaophiolite, comparable to the Marinsk Lazne complex. The reinterpretation of the former "gabbro amphibolites" as a metaophiolite has consequences for the geology of the Tepl-Barrandian: the size of the Neukirchen-Kdyne igneous complex is reduced. The HBA belt is a piece of oceanic crust which is possibly younger than the Precambrian metasedimentary/metavolcanic country rock of the Neukirchen-Kdyne igneous complex.