Mesozoic igneous rocks occur in various tectonic units of the Intra-Carpathian Area
of Eastern Europe. These rocks were situated several hundred km apart from one another
during their formation, and subsequent large lateral displacements resulted in their
present positions. They formed during a relatively wide temporal range (Middle Triassic
to Late Cretaceous) through different petrogenetic processes associated with the Mesozoic
evolution of the northwestern part of Tethys. In the Transdanubian subunit of the
Alcapa block, Middle Triassic calc-alkaline, intermediateto-acidic, and potassic rocks
occur as pyroclastics, lava flows, and dikes in the Bakony and Buda mountains. The
Gemer-Bükk subunit of the Alcapa block comprises two different igneous series: (1)
slightly metamorphosed Middle Triassic volcanic rocks of the Eastern Bükk Mountains,
which can be divided into an older (Anisian-Early Ladinian) calc-alkaline, intermediateto-acidic
volcanic series and a younger (Late Ladinian) alkaline basaltic series; and (2) two
series of the Middle Triassic to Middle Jurassic ophiolite complex (Bódva Magmatic
Series and Darnó-Szarvaskö Magmatic Series), embedded in a tectonic mélange and in
an olistostrome suite along a SW-NE-oriented zone. The Tisza block contains Early
Cretaceous alkaline volcanic rocks in the Mecsek-Alföld subunit. Strong temporal and
geochemical correlations have been observed between the Middle Triassic volcanic rocks
of the Bakony and Buda mountains and the Southern Alps, and those of the Eastern Bükk
Mountains and the Outer Dinarides. We propose that all these rocks were formed during
the same extension-related volcanic activity along the Southern Alps-Bakony and Buda
mountains-Eastern Bükk Mountains-Dinarides region. The Middle Triassic-Middle Jurassic
ultramafic-mafic igneous rocks of the Gemer-Bükk subunit can be correlated with the
ophiolites of the Inner Dinarides. Geochemistry of the mafic rocks is consistent with
an origin from an N-MORB and E-MORB source mantle. The Middle to Late Triassic ultramafic
and mafic rocks of the Bódva and Darnó-Szarvaskö series could have originated along
the mid-oceanic ridge system of the northwestern segment of the Vardar ocean (Meliaticum).
The Middle Jurassic igneous rocks of the Darnó-Szarvaskö series could have corresponded
to the opening of a backarc basin. Early Cretaceous alkaline volcanic rocks of the
Mecsek-Alföld zone in the Tisza block formed as a result of continental rifting along
the southern margin of the European plate. Two volcanic series - a mafic and a sodic
group - were generated from an OIB-like asthenospheric mantle. Separation of the Tisza
block from the European plate occurred contemporaneously with volcanic activity during
the late Early Cretaceous.
