From continental platform towards rifting of the Tisza Unit in the Late Triassic to Early Cretaceous

Abstract

Abstract:The Upper Triassic-Lower Cretaceous successions of the Transdanubian part of the Mecsek and Villány-Bihor Zones of the Tisza Unit have been studied from the lithological, lithostratigraphical, sedimentological, microfossil and microfacies points of view in order to correlate and interpret the significant differences between them and to draw a conclusion about their geological and paleogeographical history. After an overview of the paleogeographical reconstructions of the broader area, the succession of the Mecsek and Villány-Bihor Zones and the debated Máriakéménd-Bár Range are introduced. Until the end of the Middle Triassic the study area acted as an entity. The first fundamental difference between the two zones can be recognized in the Late Triassic when marine carbonates were replaced by thick fluvial siliciclastics in the Mecsek Zone, while it is represented only by small, local lenses with a few and thin dolostone intercalations in the Villány Zone. The Mecsek Zone is bordered southward by one of the large listric faults to the north of which very thick siliciclastics developed in the Early to Middle Jurassic, whereas it is highly lacunose in the larger western part of the Villány-Bihor Zone. The break at the base is subaerial, higher in the succession it is shallow submarine. The sediment is silty, occasionally sandy crinoidal limestone of late Early Jurassic or even Middle Jurassic in age. The Upper Jurassic in the Mecsek Zone is composed of deep-water cherty limestone while in the Villány Zone it became a thick, shallowing pelagic limestone with reworked patch reef fragments. It is clear evidence that the Mecsek Zone had a thinned continental crust thanks to the nearby rift zone while in the Villány Zone the crust remained thick. The actualized version of the Plašienka's paleogeographical model (Plašienka 2000) is introduced.

Continuity and Episodicity in the Early Alpine Tectonic Evolution of the Western Carpathians: How Large‐Scale Processes Are Expressed by the Orogenic Architecture and Rock Record Data

“…The southern boundary of the Transdanubian Superunit is formed by the Balaton Line, the northern branch of the complex Mid-Hungarian Fault Zone (e.g., Csontos & Nagymarosy, 1998), which is a major wrench zone that juxtaposes the IWC against the Tisia terrane (Figure 1; e.g., Császár et al, 2013;Haas et al, 1995;Haas & Péró, 2004;Kovács, 1992). According to borehole data, the broad Mid-Hungarian Fault Zone is composed of various dismembered units of the Austroalpine, Southalpine, or Dinaric provenance, including ophiolite complexes of the Sava Belt (Schmid et al, 2008), as well as Oligocene granitoid intrusions that are correlative to the intrusions along the Periadriatic Line separating the Western and Eastern Alps from the Southern Alps (Haas et al, 2000).…”

Oxfordian brachiopods from the ammonitico rosso-type Fonyászó Limestone formation at Zengővárkony, Mecsek Mountains, Hungary and their palaeoecological, palaeobiogeographical and palaeopathological significance

“…According to Géczy, this significant change in the faunal composition is related to continuous subsidence, sealevel change and the formation of a pelagic basin that was invaded by the bathypelagic ammonites in the Middle Jurassic. This scenario is widely accepted by Hungarian geologists (Császár et al 2013;Csontos and Vörös 2004;Galácz 2015;Haas and Péró 2004;Vörös 1993Vörös , 1995, however, the ammonite faunas of the Mecsek Mountains were neglected for decades with no primary ammonite faunal data available to support this approach. Although upper Jurassic ammonite bearing strata are known in the Mecsek Mountains for more than 150 years, systematic descriptions and quantitative analysis has just started (Bujtor et al subm.).…”

A Kelet-Mecsek kora-kréta vulkanizmusához kapcsolódó hidrotermális folyamatok és ércindikációk

“…A bányászattörténeti részben bemutatott Pusztakisfalu-i hematitos ércesedés a hozzávetőlegesen 50 m-es vastagságúra becsült aaleni Pusztakisfalui Mészkő Formáció (Császár et al, 2013) szublitorális, krinoideás, brachiopodás képződményében található meg.…”