ILONA BODROGI. Hungarian Geological Survey Budapest, Stefánia út. 14. H-1143

Átírás

1 A REVISION OF STRATOTYPE SECTIONS OF THE ZIRC LIMESTONE FORMATION WITH THEIR STRATIGRAPHIC DIVISION ON THE BASIS OF FORAMINIFERS AND CALCAREOUS ALGAE (UPPER ALBIAN, N BAKONY MTS, HUNGARY) by ILONA BODROGI Hungarian Geological Survey Budapest, Stefánia út. 4. H-43 UDC: ( ) 563.2( ) K e y w o r d s : Foraminifera, calcareous alga, N Bakony Mts, Upper Albian, Zirc Limestone Formation The Zirci Limestone Fm. of the Northern Bakony, developed in Urgonian facies, belongs to the Upper Albian.'Stratotype sections of its three members Eperkéshegy Member, Mesterhajag Member, Gajavölgy Member can be studied at the Eperkés-hegy and in the Jásd 2 and Bakonynána outcrops. ln^ the present paper the first occurrence of the Salpingoporella hasi CONRAD, RADOICIC & REY species in Hungary is identified from the Eperkés-hegy Member. The Orbitolina assemblage consists of Orbitolina (M.) gr. subconcava LEYMERIE, Orbitolina (M.) aperta (ERMAN). The Mesterhajag Member is characterized by the prasence of Orbitolina (C.) conica (D ARCHIAC), while the youngest Gajavölgy Member contains Rotalipora appenninica (RENZ) Planomalina buxtorfi and Coskinolinella n.sp. The Salpingoporella species are missing from both of them. The Vimportalgae (Paraphyllum primaevum LEMOINE), Kymalithon belgicum (FOSLIE), Archaeolithothamnium rude LEMOINE are considered as new elements. The Upper Albian index fossil of the southern margin of the Tethys, the Salpingoporella dinarica RADOICIC is lacking either in the Northern Bakony and the Villány platform fragments or in the Apátvarasd Limestone Fm, outcropping in allochtonous position inside the Vékény volcanosedimentary sequence of the Mecsek. On the contrary the Coskinolinella n.sp. is present in each of the three area mentioned above. Its description is under way. Introduction A study for revising the foraminiferal and calcareous-algal associations encountered in the rocks of surface geological sections representing stratotype (Olaszfalu, Eperkés-hegy, Jásd 2, Bakonynána ) of the Zirc Limestone Forma

2 tion and a field trip for demonstration were done at the request of the Hungarian Geological Society on the occasion of the XXIth European Colloquium on Micropaleontology held in 989 in Hungary. A brief review of the history of research F. H a u e r (86) was the first to identify this rock unit in the N Bakony Mountains near Bakonybél and Zirc, describing them as Zirc Beds and Lókút Beds of reef limestone facies assignable to the Gault. Their South-Alpine facies was first stated by G. S t a c h e (88 82), classifying the Caprotina-bearing limestone to the Neocomian. He also said this unit to be similar to the Schrattenkalk in Voralberg, near Geneve. The latest paper dealing in detail with the history of research of this formation, including its comprehensive description has been made by C s á s z á r G. (986). The location of profiles is shown in Fig.. Description of profiles The visual, lithological description of each section and the geological columns concerned as well as the related system of symbols applied have been taken over from C s á s z á r G. (986). No continuous stratotype sections of member rank of the Zirc Limestone Formation can be studied along the section lines concerned. The limiting superficial stratotype between the Zirc Limestone F ig.. Localities of investigated profiles. á b r a. A vizsgált szelvények helye l. Olaszfalu, Eperkés-hegy; 2. Jásd; 3. Bakonynána; 4. Hárskút

3 Formation and the underlying Tés Claymarl Formation has not been marked out yet. O laszfalu, E p erk és-h eg y (E perkés-h egy M em b er) The stratotype profile of the lower member, referred to as Eperkés-hegy Member, of the Zirc Limestone Formation is exposed in a cliff atop the hill including its karstified continuation recovered (Fig. 3). For the site of the exposure, see Fig. 2. F ig. 2. Site of the exposure of Eperkés-hegy Member, Upper Zirc Limestone Formation, at Eperkés-hegy near Olaszfalu 2. á b ra. A Zirci Mészkő Formáció alsó, Eperkés-hegyi Tagozatának helye az olaszfalui Eperkéshegyen D e scrip tio n A 26-m-thick unit of bioclast-bearing limestone with frequent rudistids (mainly Agriopleura species) is concerned here. The lower part of the rock is thick-bedded, whereas in the upper part the thick beds-are intercalated by thin ones. In its upper part comprising the lower portion of the Mesterhajag Member, its transition into microfaunal limestone is also visible. As shown by thin section studies, a strongly homogenized, lithified cryptalgal material derivable from Rhodophyta being, in addition to rudistids, a main reef-building one is frequently encountered in almost all samples. The results of microfaunal and the floral examination are shown in Fig. 4. F oram in ifers Benthonic forms, large or of differentiated test, are prevailing. Involutina hungarica (S ld Ô ), N ezza za tin ella p ica rd i ( H e n s o n ), N e zza za ta sim p lex O m a r a and D o b ro g elin a? a n g u la ta C A L V E Z are noteworthy.

4 F ig. 3. The stratotype profile of Eperkés-hegy Member, Zirc Limestone Formation, on the h illside of Eperkés-hegy near Olaszfalu 3. á b ra. A Zirci Mészkő Formáció Eperkés-hegyi Tagozatának sztratotípus szelvénye az Olaszfalu melleti Eperkés-hegyen Planktonic elements are sporadical with presence restricted to the two lower samples (samples and 4) and sample 9. They are represented by H edb erg ella sp. and P raeglobotru n can a sp. The greatest number of specimens is exhibited by Textulariidae and C harentia cu villieri N e u m a n n, with their frequency maxima coinciding, in the lower part of the sequence, with the occurrences of the large D icyclin a sch lu m bergeri M U N IE R C h a l m a s,? C h offatella sp. N a u tilo cu lin a cf. bronnim anni PEYBER N ES of differentiated makeup as well as the primitive Orbitolina-related taxa (Cuneolina, Sabaudia, Vercorsella). Orbitolina are encountered in the upper part of the sequence. Of them, O rbitolin a (M ) su bcon cava (L E Y M E R IE ) specimens have been identified (Plate V, Fig. 0). The following taxa are not indicated in the microfaunal profile: C yclo g yra? sp., P seu d o trilo cu lin a sp., H a p lo p h ra g m o id es sp., G lo m o sp irella sp., R eo p h a x sp.,? F labelam m in a sp., Lenticulina sp. and N u b ecu la ria reich eli R a t. Of them, the first taxon occurs in almost every sample, whereas the rest are sporadical and can only be observed as encrustiqg the rounded and corroded shells of rudistids in a few of the last samples (samples 5, 5 and 2b). They all are transient forms.

5 Fig. 4. Results of microfaunal study of the lower interval of the Zirc Limestone Formation in Eperkés-hegy at Olaszfalu Geological log: I. Rudista, 2. small rudistids in clusters, 3. other bivalves, 4. gastropods, 5. sea urchinns, 6. Orbitolina, 7. corals, 8. Archaeolithothamnium, 9. oncoids, 0. oöids,. clay film; 0 25: number of strata; frequency:. sparse, 2. few, 3. mean, 4. frequent, 5. abundant 4. ábra. A Zirci Mészkő alsó szakaszának (Eperkés-hegyi Tagozat) mikrofauna vizsgálatának eredménye Rétegoszlop:. Rudista, 2. aprótermetű Rudista-kolónia, 3. egyéb kagyló, 4. csiga, 5. tengeri síin, 6. Orbitolina, 7. korall, 8. Archaeolithothamnium, 9. onkoid, 0. ooid,. agyagfilm; 0 25: rétegszám; gyakoriság:. szórványos, 2. kevés, 3. közepes, 4. gyakori, 5. tömeges C a lca reo u s a lg a e S a lp in g o p o re lla. hasi C o n r a d, R a d o ic ic & R e y including its fragments are observed in the lower part of the sequence (samples 0 through 5) and in samples 0 through 6 (Plate, Fig. and Plate II, Fig. 2). Fragments of Salpingoporella observed in samples 0 through 5 is also likely to correspond to this species identified for the first time Hungary. Additional calcareous algal

6 taxa occurring sporadically and in small amounts are E th elia a lb a P f e n d e r, D iv e rso c a llis undulatus DRAGASTAN, A cicu la ria sp. and A rch aeolith oth am n iu m sp. The last two taxa occur in the upper part of the sequence (samples 22 and 23), and their quantity is fair. The greater part of the lithified red algal derivatives are likely to have originated from Archeolithothamnium. In certa e sed is It is represented by C adosin a sp., P ith o n ella o v á lis K a u f m a n n, P ith o n ella cf. trejoi B o n é t sporadically, as well as B a cin ella irreg u la ris R a d o i c i c and L ith ocodiu m sp. In a single sample (sample 5) C ercid in a su p ra c re ta c e a V o g - ler (Det. R a d o ic ic ) is observed (Plate 7, Fig. 3). M eta zo a Pachyodonta shells and other bivalves are frequent or abundant, whereas gastropods and crinoids are only observed here and there. P ien in ia o b lo n g a M isik which is, according to R. Radoicic, an A lcyo n a ria sp icu le, non-algal remain (pers. comm.) is also sporadically observed. S tra tig ra p h y In regard to stratigraphy, the noteworthy species include In volu tin a hunga- rica SIDÓ and species of Nezzazatidae: N e zza za tin ella p ic a rd i (HENSON), N ez- za za ta sim p lex OMARA, D o b ro g elin a (?) an g u la ta CALVEZ, C u n eolin a p a v o n ia ( d O r b i g n y ), O rbitolin a su bcon cava (LEYMERIE) and S a b a u d ia ca p ita ta A r - n a u d - V a n n e a u. For their greater part, the occurrences are shown in Fig. 5. The author describing S a bau dia ca p ita ta A r n a u d - V a n n e a e deems that this species disappears from rocks of the Vercors platform in France in the Middle Albian ( A r n a u d - V a n n e a u 978). In disfavour of the disappearing species, the appearing ones such as N ezza za tin ella p ic a rd i (HENSON) and N e zza za ta sim plex O m a r a entering in the Late Albian (Fig. 5) should be preferred. O rb ito lin a (M ) su b co n ca va ( L e y m e r i e ) is a species of long range (Late Aptian-Late Albian). The a g e o f the m em ber B. P e y b e r n e s (979) has identified O rb ito lin a (O ) co n ca va ( L a m a r c k ) and O rb ito lin a (M ) ap erta ( E r m a n ) species from the locality Eperkés-hegy, without giving a sketch of profile or sampling site. K. M é h e s (in C s á s z á r, G. 986, a reference to pers. comm.) also deems that an occurrence of O rb i tolina ( 0 ) co n ca va and O rbitolin a (M ) a p erta is concerned. According to S c h r o e d e r and N e u m a n n (985) O rbitolin a (O ) co n ca va is a species appearing in the Early Cenomanian. However we have no evidence proving that the member in concern would be younger than the latest Albian. This is also supported by the appearing Praeglobotruncana. O rb ito lin a (M ) a p erta E r m a n species has recently been identified by Görög, Á. (990) in the youngest part of the sequence (bed 27, Mesterhajag Member). This also backs up our opinion.

7 Rotalipora ticinensis (GANDOLFI) Rotalipora appenninica (RENZ) L. ALBIi\N M. U. Vr CEN OMANIAN L. M. U. Q) Planomalina buxtorfi (GANDOLFI) E Favusella washitensis (CARSEY) V > Globigerinelloides bentonensir(morrow) : 0 > Coskinolinella sp. nov. a s Nezzazata cónica (SMOUTH) Paraphyllum primaevum (LEMOINE) Kymalithon bejgicum CFOSLIE) a>. co ro a> z r Orbitolina (M.) aperta (ERMAN) Orbitolina (C.) cónica (D'ARHIAC) Dobrogelina (?) angulata CALVEZ Involutina hungarica (SIDO) E Dicyclina schlombergeri (MUN.-CH.) Cuneolina pavonia (D'ORBIGNY) cn. e CD L. a> C l UJ Nezzazata simplex (OMARA) Nezzazatinella picardi (HENSON) Orbitolina (M.) subconcava (LEYMERIE) Sabaudia capitata ARN.-VANN. Salpingoporella hasi CONR., RAD. &REY F ig. 5. The chronological distribution of the major foraminiferal and calcareous algal species of the Zirc Limestone Formation 5. á b ra. A Zirci Mészkő Formáció fontosabb foraminifera és mészalga fajainak időbeni elteijedése - P rofile J d sd J 2 (M esterhajag M em b er) The Mesterhajag Member, of the Zirc Limestone Formation is exposed in the quarry of Jdsd (section marked J 2, Fig. 6). The middle member of the Zirc Limestone Formation, referred to as Mesterhajag Member, includes Orbitolina-bearing limestone, the lower fossiliferous horizon and the upper part of the microfaunal limestone. The lower part of the upper member (Gajavblgy Member) of the formation in concern can be

8 seen even today in the exposure. Rocks included in the Mesterhajag Member are rather difficult to separate, either macroscopically or microscopically, in the profile (Fig. 7, beds 0 through 0). The light brown or grey, small-grained or, less frequently medium-grained limestone contains, in addition to small forams and Orbitolinae, only a few bivalves. The approx. 2-m-thick, so called lower fossiliferous level is a yellowish-brown or greyish-brown, bioclast-bearing limestone consisting of beds 20 to 50 cm thick. Rynchostreon occurs in mass in them. Worm tubes (S e r p u la sp.) and bivalves are also frequent. In addition, gastropods, enchinoids, corals and Orbitolinae can also be observed. B e n th o n ic f o r a m in ife r s Out of the 36 taxa shown in the microfauna table (Fig. 7), one-third of the taxa can be identified to the level of species. They are well preserved. The fauna features the dominance of arenaceous benthos (8 taxa, of which 8 can be determinded to the level of species). Included in them are Orbitolinae which are of greatest importance for stratigraphy. They are as follows: O r b ito lin a (C o n ic o r b ito lin a ) c o n ic a (D ARCHIAC) O r b ito lin a (M.) a p e r ta (Erman) O r b ito lin a (M.) cf. s u b c o n c a v a (LEYMERIE) Accessorial ones are as follows: N e z z a z a t a s im p le x Omara V e r c o s e lla cf. s c a r s e lla i Arnaud-V anneau D o b r o g e lin a (? ) a n g u la ta Calvez Textulariidae have the greatest number of specimens which is, in the lower part of the sequence, parallel with the poorly-preserved, fragmental, rounded O r b ito lin a sp. and the maximum number of individuals of Miliolina. P la n k to n ic f o r a m in if e r s They are represented by transient-type H e d b e r g e lla div. sp., G lo b ig e r in e l- lo id e s sp., and F a v u s e lla w a s h ite n s is (Carsey). It is only the species of the Hedbergella genus that have a comparatively great number of specimens. C a lc a r e o u s a lg a e They are represented by C o r a llin a c e a e o f V im p o r t f a c i e s : A c h a e o lith o th a m n iu m r u d e (Lemoine) K y m a lith o n b e lg ic u m FOSLIE P a r a p h y llu m p r im a e v u m (LEMOINE) T h e a g e o f th e M e s te r h a ja g M e m b e r B. PEYBERNES (977, 979) has assigned this member to the O r b ito lin a ( 0. ) c o n c a v a Z o n e, dating its age as Late Albian (Vraconian). However, according to M. N eumann and R. Schroeder (98), and R. Schroeder and M. Neumann (985) O r b ito lin a ( 0. ) c o n c a v a appeared not in the Late Albian but

9 Fig. 6. The site of profile Jásd 2 of the middle Mesterhajag Member of Zirc Limestone Formation 6. ábra. A Zirci Mészkő Formáció középső, Mesterhajagi Tagozatának helye a Jásd 2 szelvényben later in Early Cenomanian time. The combined occurrence of O r b ito lin a (M.) a p e r t a a n d O r b ito lin a ( C.) c o n ic a indicates a Vraconian age (BODROGI, I. 989). This is also supported by the presence of R o ta lip o r a sp. and P r a e g lo - b o tr u n c a n a sp. in the Gajavölgy Member (in the lower part of the member) of the profile as well as by R o ta lip o r a a p p e n in ic a (R e n z) (B o d r o g i, I. 989) identified in the upper part of the member, in the adjacent profile Bakonynána, which gives an Early Vraconian date to the member (Plate VII, Fig. ). K. M é h e s (964) has described a new subspecies from an exposure of Orbitolina-bearing Limestone around Hárskút, referring to it as O r b ito lin a te x a n a la ta MÉHES, 964. After studying the thin section Inv. No. K. 443 guarded in the Collection of the Hungarian Geological Survey, the holotype has been reassigned to O r b ito lin a (M.) a p e r ta (E r m a n ) species a photo of which is enclosed in this paper (Plate IV, Fig. 3). P a r a p h y llu m p r im a e v u m (LEMOINE) red alga is frequently observed as an accompanying form. T h e lo w e r p a r t o f th e G a ja v ö lg y M e m b e r ( B e d s ) This rock overlies with unconformity the karstified surface of the Mesterhajag Member of the Zirc Limestone. Its lower, 20-cm-thick part contains limestone rich in glauconite, and glauconitic marl with slightly rounded pebbles of the older members of the Zirc Limestone, as well as chert nodules. This lower horizon consists of clayfilm- intersected, 20-to 60-cm-thick beds which are grey, greenish-grey, silty, fine-sandy and glauconitic, with a sand content decreasing upwards, and with carbonized plant fragments, and a large amount of Serpula and Echinoidea detritus. Intensive bioturbation and a great number of trace fossils are also observable therein.

10 ÍZ J ] JE ":3 3Ü F. *í^ ]» E S S 7 y 8 ( 9 u 0 I I 4 J 2<^ 3^ M o Ifi#* Fig. 7. The results of microfaunal study of profile Jasd 2, middle interval (Mesterhajag Member) of the Zirc Limestone Formation Geological log: I. alien calcareous sand, 2. glaukonite, 3. glaukonitic cavity infilling, 4. fossiliferous limestone elastics in glaukonitic limestone, 5. clay intercalations, 6. fractured and clay-filmed internal structure, 7. wormtracks, 8. calcareous worm-tubes, 9. Orbitolina, 0. corals,. gastropods, 2. bivalves, 3. carbonized plant remains, 4. sea urchins, 5. pyrite and limonite nodules, 20: number of strata; frequency:. sparse, 2. few, 3. mean, 4. frequent, 5. abundant 7, ábra. A Zirci Mészkő Formáció középső szakaszának (Mesterhajagi Tagozat) mikrofauna vizsgálati eredményei a Jásd 2 szelvényben Rétegoszlop:. idegen mészhomok, 2. glaukonit, 3. glaukonitos üregkitöltés, 4. faunatartalmú mészkőtörmelék glaukonitos mészkőben, 5. agyagközbetelepülés, 6. repedezett agyagfilmes szerkezet, 7. féregjárat, 8. meszes féregcső, 9. Orbitolina, 0. korall,. csiga, 2. kagyló, 3. szeneseden növénymaradvány, 4. tengeri sün, 5. pirit- és limonitgumók, 20: rétegszám; gyakoriság:. szórványos, 2. kevés, 3. közepes, 4. gyakori, 5. sok

11 B e n th o n ic f o r a m in i f e r s The benthonic foraminiferal assemblage is shown in Fig. 7. No remarkable difference from that of the Mesterhajag Member is experienced. S a b a u d ia m i- n u ta (H o f k e r ) has a somewhat greater number of specimens. Orbitolina can only be observed in fragments. P la n k to n ic f o r a m in i f e r s They are represented mainly by Hedbergella species (planispira, infracretacea, delrioensis). Their number of specimens shows a tendency of increasing upwards in the profile. F a v u s e lla w a s h ite n s is, P r a e g lo b o tr u n c a n a sp. and R o - ta lip o r a sp. (beds 4-5) are only encountered sporadically. C a lc a r e o u s a lg a e P a r a p ly llu m p r im a e v u m LEMOINE I n c e r ta e s e d is C a lc is p h a e r u la in n o m in a ta BONET with its amount showing a rapid increase in sample to sample in the upper part of the sequence. In samples from the uppermost part it is frequent or abundant. M e ta z o a n Ostrea, Serpula, Gastropoda, Ostracoda, Holothuroidea. The first three taxa are frequent. T h e a g e o f th e lo w e r p a r t o f th e G a ja v o lg y M e m b e r According to the occurrences of P r a e g lo b o tr u n c a n a sp. and R o ta lip o r a sp., the age of the concerned horizon can be dated as Late Albian, and more closely, as Early Vraconian. P r o f ile B a k o n y n d n a ( T h e b o u n d a r y s tr a to ty p e b e tw e e n th e G a ja v o lg y M e m b e r o f th e Z ir c L im e s to n e a n d th e P d n z e s k tit M a r l) The site of the profile is shown in Fig. 8. The section dealt with here constitutes the boundary stratotype between the Gajavolgy Member of the Zirc Limestone and the P6nzeskut Marl (Fig. 9). An abandoned small quarry found in the valley of the brook Gaja-patak, in a cut of forest logging road is a protected exposure now. This profile represents tabular limestone beneath the Penzeskut Marl, its thickness being appr. 5m down to the lower fossiliferous horizon. Each limestone bed has a thickness of 5 to 40 cm. They are light brown, light grey. Their texture is small- or medium-grained, with a glauconite content increasing upwards. Carbonized plant remains, sporadically chert nodules or some chert pebbles are also observed. In the upper part inclined bedding, intensive bioturbation, and a great number of trace fossils are observed together with a large amount of calcareous

12 sand grains transported from the eroded older part of the Zirc Limestone (Ravasz-Baranyi, L. in Császár et al. 983). The Pénzeskút Marl grades out of it more or less continuously, with the limestone becoming nodular and with a rapid increase of glauconite content. The stratigraphy based on planktonic fo- Fig. 8. The position of the Gajavölgy Member of the Zirc Limestone Formation in profile Bakonynána 8. ábra. A Zirci Mészkő Formáció felső, Gajavölgyi Tagozatának helye a Bakonynána szelvényben raminifers of the Pénzeskút Marl has recently been discussed in a monograph by the author (Bodrogi, I. 989). F o r a m in if e r s An assemblage dominated by calcareous benthons and plankton (Plates VI and VII). C a lc a r e o u s a lg a e A r c h a e o lith o th a m n iu m r u d e LEMOINE K y m a lith o n b e lg ic u m (FOSLIE) P a r a p h y llu m p r im a e v u m LEMOINE I n c e r ta e s e d is C a lc is p h a e r u la in n o m in a ta BONÉT is dominant. It occurs even in mass in the Pénzeskút marl. P ith o n e lla o v á lis (Kaufmann) is sporadically encountered. C a d o s in a c a llo s a K nauer (Plate VII, Fig. 0) and another C a d o s in a sp. nov. (det. Knauer, J.) appears in the lower part of the Pénzeskút Marl. S tr a tig r a p h y The appearance of planktons as listed below is of great importance for stratigraphy: P la n o m a lia b u x to r fi (Gandolfi)

13 s? 2 ' c a f ; "*»' 53 o i i 3» s. = -S ns-2 u. CO. i ^ I f J «: x P la n k to n * * Í.2 : x S' J i F O R A M I N I F E R A. ; n 5 j s 3 l l " : c : - C a lc a re o u s b e n th o s i J > 2 I f B cs e i g t S. s i Z a 2 2 c O u in a u e lo c u lm a a tt. d a n u b ia n a I 6 e Ő).3 o A g g 2 a b lu t i e n ' 5 c a i! s? 2 3 S > i a t e d h g s 3 * o 'E O - l l c E E % o o o 5 5»- </> < a lg e E * > ' In c. s e d. Í i '5! ; i «0.tt > Cl. o o m tf) < l II i i i i l i i i u 'c cc CL a. <0 «o a. o QC j, R o ta lip o ra t ic in e n s is P la n o m a ltn a b u x t o r f i c 0 > o c CO < a ro «2EH! 0 4d l» HU r a 7^* Fig. 9. The results of microfaunal study of profile Bakonynána, boundary stratotype of the Zirc Limestone Formation and the Pénzeskút Marl Formation Geological log: I. soil, 2. talus, 3. limestone with clay film, 4. nodular limestone, 5. clay, claymarl and marl, 6. calcareous marl and marl (nodular), 7. intraclasts; 26: number of strata; frequency:. sparse, 2. a few, 3. mean, 4. frequent, 5. abudant 9. ábra. A Zirci Mészkő Formáció és a Pénzeskúti Márga Formáció Bakonynána határsztratotípus szelvényének mikrofauna vizsgálati eredményei Rétegsor:. talaj, 2. lejtőtörmelék, 3. agyagfilmes mészkő, 4. gumós mészkő, 5. agyag, agyagmárga, 6. mészmárga, gumós márga, 7. intraklasztok; 26: rétegszám; gyakoriság:. szórványos, 2. kevés, 3. közepes, 4. gyakori, 5. tömeges R o ta l ip o r a tic in e n s is (G a NDOLFI) R o ta l ip o r a a p p e n in ic a (R e n z) P r a e g lo b o tr u n c a n a s te p h a n i (G a n d o l f i) A new taxon enlisted in the group of calcareous benthos is represented by N e z z a z a t a gr. c o n ic a (S m o u t h ) (Plate I, Fig. 4). A new species in the group

14 of arenaceous benthonic forms is C o s k in o lin e lla sp. nov., identified from the exposure for the first time (Plate VI, Figs. through 3). T h e a g e o f th e G a ja v ö lg y M e m b e r in p r o f ile B a k o n y n á n a Ammonites species identified by N oszky, J. (966), later by Scholtz, G. (973, 974, 979) and Horváth, A. (985) in the immediate cover of the member, the upper fossiliferous horizon found at the base of the Pénzeskút Marl Formation are as follows: S to l ic z k a ia d is p a r D ORBIGNY S to l ic z k a ia d is p a r b la n c h e tti (PICT, et CAMP.) A n is o c e r a s (A.) a r m a tu m (Sow.) On the basis of the above-listed species the age of the sequence has been dated to be as old as Early Vraconian and assigned to Stoliczkaia dispar blanchetti subzone of Stoliczkaia dispar zone. The age of the sequence assigned to the R o ta l ip o r a tic in e n s is P la n o - m a lia b u x to r fi subzone, the lower subzone of the R o ta l ip o r a a p p e n in ic a interval zone corresponding to the S to lic z k a ia d is p a r zone is dated to be as old as Late Albian, more precisely, Early Vraconian. R o ta l ip o r a a p p e n in ic a (Renz) can be identified first in bed 23 of the sequence (Plate VII, Fig. ). In the Bakonynána profile the overlying bed of the Gajavölgy Member, the lower part of the Pénzeskút marl is also assigned to the Stoliczkaia dispar blanchetti subzone, or to the R. tic in e n s is P I. b u x to r f i subzones of the corresponding R o ta lip o r a a p p e n in ic a zone and is also considered to be Early Vraconian in age. Faunal relationship There is a faunal relationship with the Urgonian of the Villány Mts (Nagyharsány Limestone Formation) and the Apátvarasd Limestone in the Mecsek Mts. This relationship is mainly indicated by the common Orbitolina species or Orbitolina-related species. T h e V illá n y M ts a n d th e ir S E F o r e la n d From the youngest middle and older Late Albian interval of borehole Lippó 2, which is in inverse position as proved by microfaunal data O r b ito lin a (M.) te x a n a (Roemer) and 0. (M.) s u b c o n c a v a (Leymerie) species have been identified by the author Bodrogi, I. (987). The sequences of the Beremend quarry and the Urgonian Tenkes-hegy Limestone also contain O. (M.) texana. The red neptunian dykes found in the latter contains fragments of C o s k in o lin e lla n. sp. bearing Bakonynána crinoidal limestone, the Rotalipora appeninica- and F a v u - s e lla w a s h ite n s is bearing intraclasts of the Bisse Marl and the detritus of the O. (M.) ta x a n a bearing Urgonian limestone. In the two areas both the Urgonian limestone and the overlying marl are of similar age and facies and have similar microfaunal assemblage.

15 M e c s e k M ts In the Vékény valley-head, at the southern contact of the Turanian Vékény Marl, in the diabase- detrital crinoidal Apátvarasd Limestone pressed tectonically into the marl, sections of the new Coskinolinella species as well as of the C o s k in o lin e lla n a v a r r o e n s is Ramirez Del Pozo species described from the Late Albian Urgonian Limestone in the Spanish-French Pyrenean can be recognized. The Hedbergella bearing, F a v u s e lla w a s h ite n s is containing pelagic Bisse marl accompanied by diabase detritus can also be recognized here as pressed into the Turanian marl. A w id e r e n v ir o n m e n t B. Peybernes and M. A. Conrad (977, 979) were the first to reveal the similarities of the Urgonian limestone sequences in Hungary with the similar rocks in the Pyrenean. My studies of foraminifers and calcareous algae in the 80 s exhibited a close relationship with the Outer Dinarides (Velic 988) and the Gargano platform (Luperto-Sinni 986). Similar relationships with the platform in Bulgaria and Greece can also be recognized (pers. comm, by S. Monopolis, 992). Besides faunal and floristic similarities, however, there is a significant difference: S a lp in g o p o r e lla d in a r ic a RADOICIC does not occur in the Urgonian Limestones, neither of the Bakony, nor of the Villány and Mecsek Hills. However, the Schrattenkalk of Vorarlberg, in contrast with the opinion of G. Stäche (88 82), only shows similarities in facial features. In regard to its age (Barremian Early Aptian) it considerably differs from the facies of Bakony. A paper on a comparative foraminiferal calcareous algal examination of the Nagyharsány Limestone and the Rhomberg profiles of the Vorarlberg Schrattenkalk has gone to press (Bodrogi Bóna Lobitzer in press). Acknowledgement My thanks are due to Prof. A. Arnaud-Vanneau (Grenoble) and Prof. R. Schroeder (Frankfurt) for supervising the determination of the Orbitolina species and their advices, moreover to M. A. Conrad (Geneve) for the great help provided at consultations, to G. Császár for allowing me to study in the field profiles and for allowing me to use his lithostratigraphic classification and a part of his collection of thin sections. I am also indebted to Mr. H. Lobitzer (Wien) for being an inspiration to me in doing the revision and preparing this paper. Z. Balla J. Knauer, and I. Nagy my colleagues, were a great help to me by their professional assistance.

16 REFERENCES IRODALOM BODROGI, I. 986: A Pénzeskúti Márga plankton foraminiferái. Doktori disszertáció 45. ELTE AD, Budapest, Manuscript. BODROGI, I. 989: A Pénzeskúti Márga Formáció plankton Foraminifera sztratigráfiája. Planktonic Foraminifera Stratigraphy of the Pénzeskút Marl Formation. Földt. Int. Évk. LVIII. 5., 27, Budapest. CSÁSZÁR, G. 986: A Dunántúli-Középhegységi közép só-kréta formációk rétegtana és kapcsolata a bauxitképzódéssel. Geol. Hung. Ser. Geol Budapest. HAUER, F. 862a: Petrefacten aus dem Bakonyerwald. Jb. K. K. Geol. Reichsanst. B , Wien. HAUER, F. 862b: Ober die Petrefacten der Kreidefonnation des Bakonyer Waldes. Sitzungsber. K. Akad. Wiss Wien. HORVÁTH, A. 985: Ammoniten-Stratigraphie der Pénzeskút Maergel-Formation. Ergäbnisse der Mitteleuropäischen Gruppe in Project 73/./58., Mid. Cretaceous Events. Österr. Akad.. Wiss. Schriften. Erdwiss. Komiss Bd Taf. 4. Springer-Verlag, Wien, New York. KNAUER, J. KOPEK, G. 982: Magyarázó a Bakony-hegység es földtani térképsorozatához. Dudar. Földt. Int. 59., Budapest. KNAUER, J. 880: BOHN, P. KAISER, M KOPEK, G. VÉGH, S. közreműködésével: Magyarázó a Bakony-hegység es földtani térképsorozatához. Lókút. Földt. Int. 0. Budapest. MÉHES, K. 964: The foraminiferal genus Orbitolina from Hungary. Acta Geol. 8. ( 4) Budapest. NOSZKY, J. 964: A Bakony-hegység északi részének földtani vizsgálata. Földt. Int. Évi Jel. 96-ról, Budapest. MONOSTORI, M. BODROGI, I. CSÁSZÁR, G. 989: Olaszfalu, Eperkés Hill. XXIst European Micropaleontological Colloquium, 4 3. IX Hungary Guidebook, Budapest. MONOSTORI, M. BODROGI, I. CSÁSZÁR, G. 989: Bakonynána, Zsidó Hill. XXIst European micropaleontological Colloquium, 4 3. IX Hungary. Guidebook, Budapest. NEUMANN, M. SCHROEDER, R. et al. 98: Tableau de répartition stratigraphique des Grand Foraminiféres caractéristiques du Crétacé moyen de la region méditerranéenne. Cretaceous Rés London. PEYBERNES, B. 977: Découverte des Algues Floridées du Facies de Vimport dans l Albien des Monts Bakony (Hongrie) et données biostratigraphiques nouvelles. sur le Mesocrétacé hongrois. PEYBERNES, B. 979: L'Urgonien de Hongrie. The Urgonian limestones of Hungary. Geobios, Memoire Special No fig. 4. plat. 2. Lyon. SCHOLTZ, G. 979: Die Ammoniten des Vracon (Oberalb- Dispar-Zone) des Bakony-Gebirges (West. Ungarn) und eine Revision der Wichtigstem Vracon-Arten der Westmediterranen Faunen provinz. Paleontographica A. 65. ( 2), 80, Stuttgart. SCHROEDER, R. NEUMANN, M. 985: Les Grandes Foraminiferes du Cretacé Moyen de la Région Mediterranéenne. Geobios, Menőire Special No , Ed. de Univ. Clode Bemard, Lyon. SIDÓ M. 980b: A Zirci Mészkő Formáció Foraminiferái. Földt. Int. Adattár, Budapest.

17 A ZIRCI MÉSZKŐ FORMÁCIÓ FELSZÍNI SZTRATOTÍPUS SZELVÉNYEINEK FELÜLVIZSGÁLATA, RÉTEGTANI TAGOLÁSA FORAMINIFERÁK, MÉSZALGÁK ALAPJÁN (ÉSZAK-BAKONY, FELSŐ-ALBAI) BODROGI ILONA Magyar Állami Földtani Intézet Budapest, Stefánia út 4, H-l 43 ETO: ( ) 563.2( ) T á r g y s z a v a k : Formáció Foraminifera, mészalga, Észak-Bakony, felső-albai, Zirci Mészkő A Magyarhoni Földtani Társulat felkérésére végeztem el a Zirci Mészkő Formáció felszíni sztratotípus szelvényei (Olaszfalu Eperkéshegy, Jásd 2, Bakonynána ) foraminifera és mészalga társulásainak revízióját és mutattam be a 989-ben hazánkban megrendezett XXI. Európai Mikropaleontológiai Kollokviumon. A rendezvény során végzett további gyűjtéssel kiegészített vizsgálati eredményeket és konklúziókat az alábbiakban foglalom össze:. A Zirci Mészkő Fm. tagozatrangú felszíni sztratotípus szelvényei folyamatos szelvényben nem tanulmányozhatók. A Zirci Mészkő legidősebb tagozata (Eperkéshegyi T.) és a fekü Tési Agyagmárga felszíni határsztratotípusa nincs kijelölve és nincs megvizsgálva. 2. A legidősebb Eperkéshegyi Tagozat zátonyképzdőményt, a középső Mesterhajagi Tagozat háttéri lagúnát és platform-homokot, a legfiatalabb Gajavölgyi Tagozat viszonylag gyorsan süllyedő külső platform peremet képvisel. Fedője a Pénzeskúti Márga, pedig már medenceperemi képződmény (lásd J. WlLSON 975). 3. Feküje a Tési Agyagmárga Fm. középső-albai korú (JUHÁSZ M. 979), fedője a Pénzeskúti Márga Fm. Ammonitesek (SCHOLTZ G. 974, 979., HOR VÁTH A. 985) és plankton Foraminiferák alapján (B o d r o g i, I. 986, 989) felső-albai korú, azon belül is alsó-vrakóni. A Zirci Mészkő felszíni határsztratotípus szelvényei rétegtani helyzetük és Foraminifera faunájuk alapján a felső-albaiba tartoznak, legfelső tagozataik (Gajavölgyi és Mesterhajagi) annak alsó-vrakóni alkorszakában képződtek a Bakonynánai szelvényből azonosított R o ta lip o r a a p p e n ic a alapján. (B o d r o g i, I. 986, 989), illetve az O r b ito lin a (C.) c o n ic a megjelenése alapján a Jásd 2 szelvényben.

18 4. A B. Peybernes (977) által határozott O r b ito lin a c o n c a v a (Leymerie) faj, melynek pontos mintavételi helye ismeretlen, anyagunkban nem fordult elő. 5. Azonosított Orbitolina fajok: O. (M ) s u b c o n c a v a, O. (M ) a p e r t a, 0. (C.) c o n ic a. Az első faj felső-apti albai taxon, a két utóbbi a vracon alsó részén lép be. 6. Figyelmet érdemelnek a felső-albai kisbentosz Nezzazatidae fajok: N e z - z a z a ta s im p le x, N. gr. c o n v e x a, N e z z a z a tin e lla p i c a r d i, valamint D o b r o g e lin a? a n g u la ta, I n v o lu tin a h u n g a r ic a, G u b a u d ia c a p ita ta. 7. Átsoroltam az O r b ito lin a te x a n a la ta MÉHES, 964 alfajt az O r b ito lin a (M.) a p e r t a (Erman), 884 fajhoz. 8. Új Coskinolinella fajt azonosítottunk a Gajavölgyi Tagozatból. Leírása folyamatban van. 9. Mészalgák: Dasycladaceae csak a formáció alsó tagozatának legidősebb mintáiban fordult elő, a S a lp in g o p o r e lla h a s i faj képviseli. Fölötte csak Vimport-algákat (Corallinaceae) találtunk: A r c h a e o lith o th a m n iu m r u d e, K y m a lith o n b e lg ic u m, P a r a p h y llu m p r im a e v u m és A c ic u la r ia div.sp. 0. Kifejezett faunahasonlóság és mészalgaflóra rokonság mutatkozik a Spanyol Francia Pireneusok, a Vercorsi platform és a Dinaridák felé, de faunaés mészalgaflóra affinitás van a bulgáriai görögországi középső-kréta platform felé is (szóbeli közlés, S. Monopolis 992).. Lényeges különbség viszont, hogy sem a bakonyi, sem a mecseki, sem a villányi urgon mészkőben nem fordult elő a S a lp in g o p o r e lla d in a r ic a Radoicic faj.

19 PLATES TÁBLÁK

20 Plate I I. tábla V f. S a lp in g o p o r e lla h a s i Conrad, Radoicic et Rey, inclined equatorial section and detritus, bed 2 Olaszfalu, Eperkés-hegy 40 x 2. D ic y c lin a s c h lu m b e r g e r i MUNIER CHAEMAS and S a lp in g o p o r e lla h a s i d e t r itu s, bed 3, Olaszfalu, Eperkés-hegy 20 x 3 : C h a r e n tia c u v illie r i Neumann, bed 22/b, Olaszfalu, Eperkés-hegy 36 x 4. N e z z a z a ta gr. c o n ic a (SMOUTH), axial section, bed 2, Bakonynána profile 80 x

21

22 Plate II II. tábla. Strongly corroded rudisted shell, Eperkés-hegy, sample 6 53 x 2. S a lp in g o p o r e lla h a s i Conrad, Radoicic et Rey, subequatorial section, Eperkés-hegy, bed 5 53 x 3. M a r in e lla lu g e o n i PFENDER, Eperkés-hegy bed x

23

24 Plate III III. tábla 2. D o b r o g e lin a? a n g u la ta Calvez, Eperkés-hegy. No x 2. No. 24/b 36 x 3 5. N e z z a z a tin e lla cf. s im p le x Omara, Eperkés-hegy 3 ^ t. No. 9/c 36 x 5. No x 6. Miliolina, Eperkés-hegy No x 7 9. N e z z a z a tin e lla p ic a r d i (HENSON), No. /b 36 x 0. I n v o lu tin a h u n g a r ic a (SlDÓ), Eperkés-hegy 0. No. 9/a 53 x. No. /a 53 x

25 A revision of stralotype sections of'the Zirc... 24

26 Plate IV IV. tábla. C o n ic o r b ito lin a c o n ic a (d Archiac), Jásd 2. No x 2. O r b iío lin a (M :) a p e r t d (ERMAN), Jásd 2. No x 3. O r b ito lin a (M.) a p e r ta (Erman), Hárskút, from the collection of K. M éhes K x

27 A revision of stratotype sections of the Zirc

28 Plate V V. tábla. P a r a p h y llu m p r im a e v u m (Lemoine), Jásd 2. No x 2. C u n e o lin a p a v o n ia (d Orbigny), Eperkés-hegy No x 3. S p ir o p le c ta m m in a sp., Eperkés-hegy No x 4. V e r n e u ilin id a e, Eperkés-hegy No x 5. A r e n o b u lim in a sp., Eperkés-hegy No x 6. M ilio lin a, Eperkés-hegy No. 9/b 36 x 7. P r a e g lo b o tr u n c a n a sp., Eperkés-hegy No x 8. D o b r o g e lin a sp., Eperkés-hegy No. 9/b 36 x 9. C a d o s in a sp., Bakonynána No x 0. O r b ito lin a (M.) cf. s u b c o n c a v a (Leymerie), Eperkés-hegy No. 22/a 36 x. S a b a u d in a m in u ta (Hofner), Eperkés-hegy No x

29 A revision of stratotype sections of the Zirc

30 Plate VI VI. tábla 3. C o s k in o lin e lla n. sp., Bakonynána. No x 4. M a r s s o n e lla o x y c o n a (Reuss), Bakonynána. No x 5.? M a r s s o n e lla sp., Bakonynána. No x 6. D o r o th ia g r a d a ta (Berthelin), Bakonynána. No x 7. T r ita x ia sp., Bakonynána. No x 8. P ith o n e lla o v á lis (Kaufmann), Bakonynána. No x

31

32 Plate VII VII. tábla. R o ta l ip o r a a p p e n in ic a (Renz), Bakonynána. No x 2. R o ta l ip o r a sp., Bakonynána. No x 3. C e r c id in a s u p r a c r e ta c e a V ogler, Bakonynána. No x 4. N o d o s a r ia sp. micritized Bakonynána. No x 5. K y m a lith o n b e lg ic u m (Foslie), Bakonynána. No x / 6 7. F a v u s e lla w a s h ite n s is (Carsey), Bakonynána. 6. No x 7. No x 8. H e d b e r g e lla p la n is p ir a (Tappan), Bakonynána. bed 9 36 x 9. Q in q u e lo c u lin a aff. d a n u b ia n a Neagu, Bakonynánana. No x 0. C a d o s in a c a llo s a Knauer, Bakonynána. No x. G a v e llin e lla in te r m e d ia (Berthelin), Bakonynána. No x 2. E r la n d ia sp., Bakonynána. No x 3. P a r a p h y llu m p r im a e v u m (Lemoine), Bakonynána. No x (The numbers mark the No. of the thin section)

33

34