Genesis of the Neogene to Quaternary volcanism in the Carpathian-Pannonian region: Role of subduction, extension, and mantle plume

Abstract

Neogene to Quaternary volcanism of the Carpathian-Pannonian region is part of the extensive volcanic activity in the Mediterranean and surrounding regions. Using the spatial and temporal distribution of the magmatic rocks, their major-and traceelement features, and Sr-Nd-Pb isotope characteristics, we suggest that lithospheric extension in the Pannonian Basin had a major role in the generation of the magmas. Dehydration of subducting slab should have resulted in thorough metasomatism in the mantle wedge during Cretaceous to early Miocene that would have lowered the melting temperature, therefore playing an indirect role in the generation of magmas later on. Mixing between mantle-derived magmas and lower-crustal melts was an important process at the fi rst stage of the silicic and calc-alkaline magmatism in the Northern Pannonian Basin. However, the crustal component gradually decreased with time, which is consistent with magmatic activity in a continuously thinning continental plate. Calc-alkaline volcanism along the Eastern Carpathians was mostly postcollisional and could have been related to slab break-off processes. However, the fairly young (<1.5 Ma) potassic magmatism at the southeasternmost segment of the Carpathian volcanic arc could be explained by lithospheric delamination under the Vrancea zone. Alkaline basaltic volcanism began at the end of rifting of the Pannonian Basin (11 Ma) and continued until recently. We suggest that a mantle plume beneath the Pannonian Basin is highly unlikely and the mafi c magmas were formed by small degree partial melting in a heterogeneous asthenospheric mantle, which has been close to the solidus temperature due to the lithospheric extension in the Miocene. Magmatism appears to have been in a waning phase for the last 2 m.y., but recent volcanic eruptions (<200 k.y.) indicate that future volcanic activity cannot be unambiguously ruled out.

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

“…Based on published reviews [3,5,24,25,[350][351][352][353] volcanic activity took place in the arc type and back-arc type geotectonic settings, both of them related to the Neogene subduction in front of the advancing Carpathian arc. The back-arc geotectonic setting changed its parameters with time.…”

“…Volcanic and/or intrusive activity took place since 21 Ma till 0.1 Ma with a distinct migration in time from west to east ( Figure 2). Volcanic forms show diverse compositions that were generated in response to complex syn-and post-collisional tectonic processes [1,2] involving subduction with roll-back, collision, slab breakoff, delamination, strike-slip tectonics and block rotations of two microplates [4][5][6][7]. Major groups of calc-alkaline rock-types (felsic, intermediate and mafic varieties) have been distinguished and several minor alkalic types also pointed out, including K-alkalic, shoshonitic, ultrapotassic and Na-alkalic.…”

“…Major groups of calc-alkaline rock-types (felsic, intermediate and mafic varieties) have been distinguished and several minor alkalic types also pointed out, including K-alkalic, shoshonitic, ultrapotassic and Na-alkalic. Geodynamic and petrological models have clarified many of the petrogenetic processes [4][5][6][7]. In most cases the geochemical fingerprint of initial contributions from different magma sources are obscured by further evolution of magmas via differentiation, assimilation and mixing processes during ascent and storage in crustal magma chambers.…”

“…Reviews have been published treating the space/time evolution of volcanic activity [1,2], geotectonic evolution [3] and petrology and geodynamic setting of volcanic activity [4][5][6][7]. That is the reason that these subjects are covered only in the extent necessary for a proper understanding of volcanic form presentation.…”

“…Attention is paid also to this aspect in discussion of volcanic forms and/or evolution of volcanic fields and sub-regions. General information concerning petrology of volcanic rocks in the CPR and their compositional variability has been widely reported recently [5][6][7][23][24][25][26][27].…”