Mantle upwelling within the Pannonian Basin: evidence from xenolith lithology and mineral chemistry

Abstract

Five spinel lherzolite xenoliths hosted in Neogene alkali basalts from the marginal parts of the Pannonian Basin (Styrian Basin in Austria and Persani Mts. in the Eastern Transylvanian Basin, Romania) contain orthopyroxene–clinopyroxene–spinel clusters, which are believed to represent former garnet in lherzolitic mantle material. ‘Palaeo’ equilibrium pressure of this former garnet lherzolite was estimated to be equivalent to depths of 90–120 km using calculated garnet compositions and measured orthopyroxene compositions from the clusters. ‘Neo’ equilibrium pressures of the xenoliths indicate depths of 55–65 km, suggesting c. 50–60 km uprise of the mantle section represented by these xenoliths. This petrological result confirms the observations from previous geophysical studies that significant mantle uplift has occurred beneath the Pannonian Basin.

Neogene-Quaternary Volcanic forms in the Carpathian-Pannonian Region: a review

“…Maar volcanoes in the Pannonian Basin are common [58] due to a long lasting production of Na-alkalic mafic magmas through the Late Miocene to Pleistocene time [1,5,24,25,27,59]. Such intraplate, intracontinental magmatism released mafic magma along weakness zones (e.g.…”

“…The diatreme filling pyroclastic rocks are rich in accidental lithic fragments, rounded basaltic lapilli, cored bombs and irregularshaped mud chunks indicating active conduit processes, particle mixing and syn-volcanic mass reorganization typical for many diatremes worldwide. Diatremes in the CPR also contain exotic deep-seated crustal and upper mantle xenoliths indicating rapid ascent of magma from its heterogeneous and commonly metasomatized source [59,[196][197][198]. [192].…”

U–Th–Pb and Lu–Hf isotopic constraints on the evolution of sub-continental lithospheric mantle, French Massif Central

“…Numerous studies have investigated mantle xenoliths from these localities including the Eifel (Witt-Eickschen et al, 2003), Rhö n (Franz and Wirth, 1997;Witt-Eickschen and Kramm, 1997), the French Massif Central (Zangana et al, 1997(Zangana et al, , 1999Lenoir et al, 2000a;Downes et al, 2003), Poland (Blustztajn and Shimizu, 1994), Italy (Downes et al, 2002) and the Pannonian Basin (Downes and Vaselli, 1995;Rosenbaum and Wilson, 1997;Falus et al, 2000), mainly with respect to their geophysical, mineralogical, geochemical (major and trace element) and isotopic (Sr-Nd-Os-Pb) compositions. In general terms, European SCLM sampled by intraplate volcanism is dominated by spinel-facies lherzolites with a range of Mg numbers, Al 2 O 3 and TiO 2 contents, and which are variably and sometimes strongly enriched in incompatible and fluid-mobile trace elements such as light rare earth elements (REE) and large ion lithophile elements (LILE) (references above, Downes, 2001).…”

Geodynamic significance of ultramafic xenoliths from Eastern Serbia: Relics of sub-arc oceanic mantle?

“…In this context, it can be stressed that they are lower than those reported from xenoliths found in adjacent extensional area of the Pannonian basin (e.g. Falus et al, 2000;Embey-Isztin et al, 2001) but are more similar to recent subduction zones (e.g. Franz et al, 2002).…”