Geologica Hungarica - Series Geologica 25.

Fülszöveg

lArgon forwedions m -Hungary Wi+k special ^eference ío íke (Sas+em ;A!ps, tke Western ^pa+k ians cmd fhe ,Apwsewi A^oun+ains The flrst chapters of this volume outline: (1) history of the term Urgon, (2) fundamental changes in and reinterpretation ofthe term, and (3) its application in Hungary. The main aim is to introduce major occurrences of the Urgon-type formations of Hungary based on field observation, measurements, for microfacies and depositional environment studies in thin-sections and other lab investigations. Two Urgon-type formations are known in the Tisza Unit. The Nagyharsány Limestone was developed in a double lagoon environment in the Valanginian Early Albian. Theformation (retrogradation) ofthis carbonate platform ceased because of a flexural basin provoked by compressional (nappe-type) tectonism. Basalt volcanoes grew above the sea level in the rifted Mecsek Zone which had a thinned Continental crust. In the lack ofintensive subsidence ofthe zone instead of Darwin 's... Tovább

Fülszöveg

lArgon forwedions m -Hungary Wi+k special ^eference ío íke (Sas+em ;A!ps, tke Western ^pa+k ians cmd fhe ,Apwsewi A^oun+ains The flrst chapters of this volume outline: (1) history of the term Urgon, (2) fundamental changes in and reinterpretation ofthe term, and (3) its application in Hungary. The main aim is to introduce major occurrences of the Urgon-type formations of Hungary based on field observation, measurements, for microfacies and depositional environment studies in thin-sections and other lab investigations. Two Urgon-type formations are known in the Tisza Unit. The Nagyharsány Limestone was developed in a double lagoon environment in the Valanginian Early Albian. Theformation (retrogradation) ofthis carbonate platform ceased because of a flexural basin provoked by compressional (nappe-type) tectonism. Basalt volcanoes grew above the sea level in the rifted Mecsek Zone which had a thinned Continental crust. In the lack ofintensive subsidence ofthe zone instead of Darwin 's atoll a new type has been developed. After its occurrence it is called as Mecsek-type atoll. The age of the Mag)>aregregy Conglomerate which preserved vestiges of the atoll ring is ValanginianA Ibian. Three Urgon formations of Albian age are förmed in the Pelso Unit. Rudistid and coral-bearing limestone cobbles and boulders are constituents ofthe olisthostrome bodies of the Köszörűkőbánya Conglomerat on a steep slope which was connected the carbonate platform-rimmed island arc and the foreland basin. It had a direct relation to the Vardar (Halstatt) Ocean. In the foreland of the Vértes and Gerecse Mountains an allochtonous and an autochtonous type Urgon limestone (Környe Fm) as heteropic facies extended between a semi-restricted, hemipelagic basinal and a fluvial to paludal environments. It is alsó known as basin floor fan. Zirc Limestone manifests itself as an extended carbonate platform developed on the terrestrial formation above. Sequence stratigraphic analysis concluded that a short-time sea level drop preceded the global sea level rise ofat least 150 m amplitude in the Stoliczkaia disparZone in the Transdanubian Rangé andprobably alsó in the Mecsek Zone. Afewpages are dedicated to survey the Urgon type formations in somé neighbouring tectoniczones, namely in the Helvetic Zone, the Eastern Alps, the Western Carpathians and the Apuseni Mountains. The age of the Urgon facies ofthis region is gettingyoungerfrom the north to the soüth, while the tirne span of theirformation usually has no significant diff 'erences. Independent chapters deal with (1) distribution ofcarbon andoxygen isotopes, (2) naturalprotection ofkey andreference sections of the Urgon formation. Harsány Hill, Villány Hills Vissza