Jb. Geol. B.-A. ISSN 0016-7800 Band 134 Heft 2 S.271-297 Wien, Oktober 1991 New Middle Carnian and Rhaetian Conodonts from Hungary and the Alps. Stratigraphic Importance and Tectonic Implications for the Buda Mountains and Adjacent Areas By HEINZ KOZUR & RUDOLF MOCK') With 1 Text-Figure, 2 Tables and 7 Plates Hungary Alps Buda Mountains Conodonts Stratigraphy Contents Zusammenfassung 271 Abstract 272 1. Introduction 272 2. Taxonomic Part 273 3. Stratigraphic Evaluation of the Rhaetian Conodonts in the Alps and Hungary 277 3.1. Misikella hemsteini - Parvigondolella andrusovi Assemblage Zone 278 3.2. Misikella posthemsteini Assemblage Zone 279 3.2.1. Misikella hemsteini - Misikella posthemsteini Subzone 280 3.2.2. Misikella koessenensis Subzone 281 3.3. Misikella ultima Zone 281 3.4. Neohindeodella detrei Zone 282 4. Stratigraphic and Tectonic Implications of the New Rhaetian Conodont Data for the Investigated areas in Hungary 282 4.1. Csövar (Triassic of the Left side of Danube River) 282 4.2. Buda Mountains and Pillis Mountains 283 Acknowledgements 289 References 296 Neue mittel karnische und rhätische Conodonten aus Ungarn und den Alpen. Stratigraphische Bedeutung und tektonische Konsequenzen für die Budaer Berge und angrenzende Gebiete. Zusammenfassung Zum ersten Mal wurden mittel karnische Conodonten in den nordwestlichen Budaer Bergen und in Pilisvörösvar, beide Lokali- täten NW der Buda-Linie, gefunden. Aus diesen Schichten wird Nicoraella ? budaensis n. sp. beschrieben, die einzige darin vor- kommende Conodontenart. Ein neuer Einzahnconodont, Zieglericonus rhaeticus n. gen. n. sp., und die neuen Arten Misikel/a ultima n. sp., Neohindeodel/a detrei n. sp., N. rhaetica n.sp. und Parvigondolel/a rhaetica n. sp. werden aus rhätischen Gesteinen beschrieben. Der stratigraphische Wert rhätischer Conodonten speziell aus Ungarn und aus den Alpen wird diskutiert. Innerhalb des post- sevatischen Rhät-Abschnittes können 3 Conodontenzonen unterschieden werden. Die älteste dieser Zonen kann noch weiter in 2 Subzonen unterteilt werden. Die VÖllig neue stratigraphische Unterteilung der Trias in den Budaer Bergen (Ungarn) und die Deckenstrukturen dieses Ge- bietes werden diskutiert. Zum ersten Mal wurden rhätische Ablagerungen (Matyashegy-Kalk) in den Budaer Bergen nachgewie- sen. Der Matyashegy-Kalk, der bisher ins Unterkarn gestellt wurde, ist das Zeit- und Fazies-Äquivalent der Csövar-Kalk-For- mation s.str.; er gehört größtenteils in Rhät. Er kommt nur in der nun neu eingeführten Csövar-Decke vor, die ebenso wie die Buda-Decke s.str. zum Dinarischen Deckensystem gehört. Diese beiden Decken SE der Buda-Linie (sensu BALDI& NAGYMARO- SI, 1976) zeigen eine ganz andere spät-triadische Entwicklung als die Nagykovacsi-Decke (wird hier ebenfalls neu eingeführt) 0) Authors' addresses: Dr. sc. HEINZKOZUR,Reszü u. 83, H-1029 Budapest; RNDr. RUDOLFMOCK, Department of Geology and Paleontology, JA Comenius University, Mlynska dolina, CSFR-84215 Bratislava. 271 NW der Buda-Linie, die höchstwahrscheinlich zum Adriatischen Deckensystem gehört. Die Ansicht von BALDI & NAGYMAROSI (1976) und BALDI(1986), daß die Buda-Linie ein tektonisches Element erster Ordnung mit ausgedehnten Horizontalbewegungen im späten Miozän ist, kann durch unsere Untersuchungen bestätigt werden. Neuere paläogeographische und tektonische Re- konstruktionen, welche die Existenz dieses wichtigen tektonischen Elementes widerlegen, können nicht bestätigt werden. Abstract For the first time Middle Carnian conodonts were found in the northwestern Buda Mts and in Pilisvörösvar, both NW of the Buda Line. Nicoraella ? budaensis n. sp. is described from these beds in which it represents the only conodont species. A new single cone conodont, lieglericonus rhaeticus n. gen. n. sp., and the new species Misikella ultima n. sp., Neohindeodella detrei n. sp., N. rhaetica n.sp., and Parvigondolella rhaetica n. sp. are described from Rhaetian rocks. The stratigraphic value of the Rhaetian conodonts especially of Hungary and the Alps is discussed. 3 conodont zones can be discriminated within the post-Sevatian Rhaetian stage. The oldest of these zones can be still subdivided into 2 subzones. The quite new stratigraphic subdivision of the Triassic in the Buda Mountains (Hungary) and the nappe structures of this area are briefly discussed. For the first time Rhaetian beds (Matyashegy Limestone) were found in the Buda Mts. The Matyas- hegy Limestone, placed until now into the Lower Carnian, is the time- and facial equivalent of the Csövar Limestone Formation s.str. and it belongs to its largest part to the Rhaetian. It is only present in the Csövar Nappe (newly introduced here) that belongs, like the Buda Nappe s.str. to the Dinaric nappe system. These two nappes SE of the Buda Line (sensu BALDI& NAGY- MAROSI,1976) have a quite different Late Triassic development than the Nagykovacsi Nappe (newly introduced here) NW of the Buda Line that belongs most probably to the Adriatic nappe system. The view of BALDI& NAGYMAROSI(1976) and BALDI(1986) that the Buda Line is a first order tectonic element with large-scale horizontal movements in the Late Miocene can be confir- med by our investigations. New paleogeographic and tectonic reconstructions that reject the existence of this important tecto- nic element cannot be confirmed. 1. Introduction (e.g. KovAcs, 1982). Triassic rocks are originally wider distributed or (and) facially more differentiated than KOZUR & MOSTLER (1973) found for the first time con- older and younger rocks in most part of the Alpine odonts and holothurian sclerites in the Csövar Lime- Neoeurope. Therefore they are very useful for recon- stone Formation near Csöövar. They placed these structions of the pre-rift paleogeography. However, if beds, before regarded as Lower Carnian, into the top- the ages of the compared facial developments are not most Triassic. These data were now also confirmed by correctly determined, this method leads to consider- the discovery of Choristoceras, an exclusively Rhaetian able mistakes. ammonoid genus, found by DETRE, DOSZTALY& HERMAN The most important unit for paleogeographic consid- (1986). More detailed investigations of the conodont erations of the Buda Mountains, the so-called distribution inside the Csövar Limestone Formation Matyashegy "Formation" (HAAS & KovACS, 1985) was, s.str. in its type locality have shown that it contains all e.g., not dated by its fossil content, but placed into the 3 Rhaetian conodont zones discriminated in this paper Lower/Middle Carnian according to its assumed on the base of conodont ranges in the Alpine Triassic paleogeographic connection and correlation with the of Europe. Lower/Middle Carnian Veszpn3m Marl Formation of the No conodonts were published so far from the Buda Balaton Highland. Especially the Lower/Middle Carnian Mts and from Pilisvörösvar (between Buda Mts and cherty dolomites and cherty limestones of the borehole Pilis Mts). The first evidence of Rhaetian conodonts in Zsambek were used as "evidence" that the Matyas- the Matyashegy Limestone, regarded by all Hungarian hegy "Formation" cannot be Rhaetian in age (as shown geologists since more than 100 years as Lower Carnian by KOZUR, 1987 on the base of conodonts, holothurian or even Late Ladinian, as well as further new biostra- sclerites and radiolarians), but must be placed into the tigraphic data, resulted in a quite new stratigraphic Lower to Middle Carnian. This assumed, but not fossil- subdivision of the Triassic in the Buda Mts. This new proven Lower to Middle Carnian age of the Matyashegy subdivision in at least 3 different Late Triassic develop- "Formation" was than used as evidence for the direct ments in the Buda Mts. (instead of the hitherto as- paleogeographic connection between the Triassic of sumed one hypothetical sequence for the whole Buda the Balaton Highland and the Triassic of the whole Mts.) has considerable tectonic importance. At least 3 Buda Mts (also SE of the Buda Line) within one tec- nappes could be recognized in the Buda Mts. tonic unit. However, the Zsambek borehole lies far NW Moreover, the Buda Line sensu BALDI & NAGYMAROSI of the Buda Line in a quite different tectonic unit than (1976), that indicate large-scale Late Miocene lateral the Matyashegy Limestones SE of the Buda Line. Such movements, separates the Buda Mts. into a South Al- really Middle Carnian cherty dolomites and marly lime- pine/Dinaric southeastern part from the quite diffe- stones are known from the Buda Mts, but only NW of rently developed northwestern part that belongs to the the Buda Line (Pesthidegkut, Kalvariahegy), where the Adriatic nappe system sensu FLÜGEL, FAUPL & marly limestones yielded rich conodont faunas with MAURITSCH (1986). Nicoraella ? budaensis described in the present paper. The Triassic facial developments in Hungary, among Our paleontological investigations have shown that it the Triassic sequences of the Buda Mountains and of the Late Triassic stratigraphy of the Buda Mts. has to the Csövar area (on the left side of Danube river) are be totally revised. The only age determinations that often regarded as decisive for paleogeographic recon- could be confirmed, are the ages of the megalodontid- structions in the Alpine, Carpathian and Dinaric areas bearing rocks (V!OGH-NEUBRANDT,1974, 1982). 272 Rokohegy CD Csilloghegy Text-Fig. 1. Sampling sites in the Buda Mountains. 1 = Norian Dachstein limestone; 2 = Middle Carnian massi- 'th 'kl Matyashegy ve cherty shallow water lagoonal dolomite and marly thin- A po SZI 0 <ID t & bedded