by GÉZA CSÁSZÁR
INTRODUCTION
The results achieved in the field of stratigraphy in the first century of the Hungarian Geological Survey, formerly called Royal Geological Sur
vey, have been summarized in a publication issued on the occassion of the 100th anniversary of its foundation. It can be gathered from read
ing this book that in a major part of the century- long past the scientific achievements were in proportion to the scale of the work, mostly to that of the geological mapping. Technical methods and means gained greater importance during the past two decades ago. It cannot be denied that the scale of mapping has invariably played an important role. The development in techniques, methodology and at least so much in view has become primary during the past one-fourth of a century. When the financial con
ditions were much more favourable to the Sur
vey, also subcontractors were employed with the involvement of key researchers of the uni
versity departments and of the industrial re
search centres belonging to the sphere of ven
turers, in order to get questions answered if the Survey was in no position to deal properly with certain problems. The results achieved due to this co-operation or to OTKA (i.e. National Scientific Research Fund) have also been in
cluded in the present account.
The achievments will be treated here accord
ing to four topic as it follows: the influence of international stratigraphic organizations; the state of affairs in the field of different branches and methods of stratigraphy; the state of the chronostratigraphic units; Hungarian stratig- raphers' activity abroad.
THE INFLUENCE OF INTERNATIONAL STRATIGRAPHIC ORGANIZATIONS The dissipation of the isolation formerly so typical of the East European societies began in the field of geology with the Mesozoic Confer
ence organized in Budapest in 1959. The thaw
ing was even accelerated after the Centenary Celebrations of the Geological Survey (1969).
More and more Hungarian experts were al
lowed to take part in the work of scientific or
ganizations. It was probably due to the meet
ings arranged in Hungary that J. Fülöp was honoured with the presidency of the Committee of the Mediterranean Mesozoic of the Inter
national Geological Congress, between 1960 and 1968. Since 1964, G. Hámor has been a member of the (Regional) Committee of the Mediter
ranean Neogene Stratigraphy (CMNS, later RCMNS), being also charmain of the RCMNS Congress held in Budapest in 1985. From 1975, J. Halmai has served as the secretary of the Sub
committee of the Neogene Stratigraphy. From the point of view of the Neogene studies in Hungary; the Congress of the organization held at Bratislava in 1975 is regarded as being of decisive importance because the regional para- stratigraphic scale accepted there is effective up to this day. At the Budapest Congress the Hungarian party submitted a proposal for deal
ing with Miocene stages. In the field of Meso
zoic studies, J. Haas was elected corresponding member of the Triassic Subcommittee and G.
Császár ordinary member of the Cretaceous Subcommittee. At the same time, the latter was also requested to organize a Tethys Working Group.
In stratigraphy, divergent views manifested themselves in different approaches and in the use of different terminologies, or in the fact that the same terminology was used with different contents. To co-ordinate the ways of approach and to develop a common stratigraphical lan
guage an International Subcommittee of Strati
graphic Classification (ISSC) was created and joined by M. Kretzoi at first privately then as an organizational member, starting from the estab
lishment of the Hungarian Stratigraphic Com
mittee in 1973. A work of more than two de
cades resulted in the publication of the Inter
national Stratigraphic Guide (1976). Prior to this, with the use of the rough draft of the Guide, a work entitled "Stratigraphic classifica
tion and nomenclature and Guidelines for their use" was issued by the Hungarian Geological Survey in 1975. The majority of the members of this Committee were chosen from the Survey (J.
Konda, K. Szepesházy, M. Kassai, K. Balogh, G.
Scholz, J. Haas, E. Dudich, L. Gidai, L. Korpás, G. Hámor, Á. Jámbor, I. Horváth, A. Rónai and E. Krolopp). After due discussions, the guide
lines were edited and published by the Survey.
The tasks of the Hungarian Stratigraphic Com
mittee were formulated in the Introduction as follows:
(1) Promotion of an up-to-date study of the stratigraphic units of Hungary and the har
monization of the results attained in the country and abroad,
(2) Edition and publication of a Stratigraphic Encyclopaedia in Hungarian,
(3) Consultations to be held and positions to be taken up in timely theoretical and practical questions of stratigraphy.
It was for the first time in this publication that distinction was made between the strati
graphic areas on the basis of their particular lithological and paleontological features, to
gether with their time of formation. Lithostrati- graphy, biostratigraphy and chronostratigraphy were distinguished as independent branches.
The authors claimed that the differences be
tween chronostratigraphy and geochronology should be emphasized.
The work conducted in the scope of ISSC was later extended to other stratigraphic branches too.
It may not be underrated the influence generated by the creation of the International Geological Correlation Program (IGCP) whose post of Secretary was occupied during three cy
cles by a former Deputy Director of the Survey, E. Dudich. Among the large number of IGCP
projects quite a few ones are stratigraphic or at least somewhat related to stratigraphy. From the Hungarian angle the following projects were most important: Nos. 5 and 276 (Early Palaeo
zoic and Precambrian), Nos. 4 and 106 (Permian and Triassic), Nos. 58, 245, 262 and 362 (Cretaceous), No. 174 (Eocene and Oligocene), No. 25 (Neogene) and No. 148 (Quantitative Stratigraphy). Particularly outstanding is No 25 (Stratigraphic Correlation Tethys-Paratethys Neogene), in which Hungary was represented first by T. Báldi, and later by G. Hámor. In the series dealing with the description of strato- types the Pannonian volume was edited by the Hungarian Academy of Sciences. As far as the Neogene stratotypes are concerned that of the Egerian stage is found in Hungary. Project No.
262 (Tethyan Cretaceous Correlation) was the first one with a coleader from the Survey (G.
Császár). It supported the work of the Tethys Working Group of IUGS, also financially, in dealing with the correlation of pelagic, shelf (carbonate platform and clastic)-type and ter
restrial deposits. Hungarian scientists, mainly of the Survey, were very active in the projects related to the Palaeozoic and to the problem of the Permian/Triassic boundary.
SITUATION OF THE BRANCHES OF STRATIGRAPHY IN HUNGARY
Lithostratigraphy
According to the principles of stratigraphy;
lithostratigraphy is expected to define natural units of the Earth's crust in terms of lithology.
The basic unit is the formation: the rock sequences have to be divided entirely into for
mations. The Survey has undertaken this work officially to be done upon uniform principles.
Some traditional names such as "Kiscell Clay"
and "Schichten von Zirc" have also been adopted as official and normative denomina
tions. At the same time, numerous new names have been introduced as originating from the re
spective type localities of the formations. The intensive work has resulted in the preparation of a chart showing Hungary's lithostratigraphic formations, published by the Survey (Csá- szár&Haas, eds. 1983). It demonstrates the facial and palaeoenvironmental characteristics of the formations distinguished and denominated till the day, according to a grouping of systems, from the Triassic up to the Quaternary,
il-lustrated by raster and colours. Due to uncer
tainties related to the classification of the Palaeozoic and Precambrian terraines, the units are represented by their names only and accord
ing to their approximate age. The chart contains in total 286 units of formation rank, 1 unit without a standard name, moreover 5 bare rock names and 57 units without rank put in the Palaeozoic-Precambrian block. The overall num
ber of official and unofficial names is 292.
The Editorial Board consisted of T. Báldi, A.
Barabás, G. Császár, E. Dudich, J. Fülöp, J. Haas, G. Hámor, Á. Jámbor, B. Jantsky, A. Rónai and T.
Szederkényi.
By 1991 the subcommittees have produced concise descriptions of the formations and also have revised the charts. The extended and specified key enabled the editors to depict the grade and the prevailing lithological features of the metamorphic units, making thereby the Palaeozoic rocks to be of equal rank in the rep
resentation. The material intended to be printed in the form of brochure contained 61 lithostrati- graphic units (50 formations, 1 formation group and 10 complexes) with English and Hungarian denominations. The pertinent short descriptions of the formations have also been given in two languages. The community of Hungarian geolo
gists regrets that the long-expected work has re
mained in manuscript because of lack of funds.
Data of the 1983 chart and of that prepared for publication are compared below
T ab le 1
Formation
With no rank and na
me
Formati
groupon Complex
1983 1993 1983 1993 1993
Quaternary 41 35
Pannonian 38 47 9
Miocene 39 52 1
Oligocene 10 11 2 1
Eocene 15 18 1
Cretaceous 28 44 1
Jurassic 31 44 2
Triassic 42 77 2
Permian 21 15
Earlier Palaeozoic 33 50 4 1 10
Total 286 393 7 17 10
In all, 357 key-and-reference geological sec
tions have been registered in the territory of
Hungary. Their study was shared by many col
leagues working at universities, museums or in the industrial sector. The maintenance of expo
sures belonging to the key sections, however, has almost entirely been undertaken by the Geo
logical Survey. Till 1991, the number of expo
sures being under some kind of protection (local, regional or national) came to 368 as shown in Table 2
T b M f 2 Geological
system A B C D E F
Quaternary 35 1 14 13 7 21
Pannonian 47 34 13 2 36
Miocene 52 30 20 30
Oligocene 11 3 18 9 18
Eocene 18 16 11 16
Cretaceous 44 50 24 2 52
Jurassic 44 68 35 68
Triassic 77 2 79 42 79
Permian 15 10 3 10
Earlier Palae
ozoic 50 43 23 1 43
Total 393 7 357 188 12 368
A: AH formations, B: Chronostratigraphic key-section, C: Lithostratig- raphic key-and-reference section, D: Formation represented by key-sec
tion, & Exposure protected for other reason, F: AU exposures to be protected
The detailed stratigraphic study of the geo
logical key section was done parallelly with the editorial work described above. The results are contained in 266 reports stored in the National Geological Data Base. Three-page excursion guides have been printed for 169 sections.
However, only the first steps have been taken for an applied geological evaluation of the for
mations described. Only the hydrogeological description of the Triassic formations in the Ba
laton Highland has been completed.
Since many formations have no surface key section or even they have no outcrops at all, it was necessary to introduce a system of subsur
face i.e. borehole key sections. Thanks to the former intensive mineral exploration activity, lots of well logs were available with precious core samples stored in sample depositories. At present core samples of 261 boreholes qualified as key sections are guarded. The short descrip
tion of 236 drilled sections have been pub
lished.
Biostratigraphy
The use of the widely applied term "biostrati
graphy" involves many inconsistencies given by the mixing of the terms "biozone" and "chrono- zone" of unclear contents. A fundamental characteristic of biostratigraphy gets recognized very slowly by the geologists. This is the prin
ciple that the existence of a biozone is strictly dependent on the presence (or absence) of the relevant fossil. Thus the boundaries of a bio
zone are not necessarily (and generally) formed by time horizons but they are defined by the un
even surfaces of a rock body. Any fossil group or its elements can be used to create a biozone.
For marking out chronozones or standard zones the fossils of planktonic or nectonic organisms are the most suitable tools, however, many times the possibility is taken for a fact, and the biozone is represented as chronozone without checking in time and space the real conditions.
Not accidentally, this deeply rooted "branch"
triggers most of the debates inside the ISSC.
At least in the Mesozoic, the fossil group of Ammonites has been used for a long time for correlation. The significance of ammonites, nevertheless, has somewhat decreased because of the increasing role of nannofossils and micro
organisms, which are more common and easier to examine, moreover sometimes they offer more favourable time range than ammonites can do. Nonetheless, the global scale is invaria
bly based on Cephalopoda, and we, Hungarians fee! quite lucky, for professor B. Geczy has founded a school in this respect. Despite the fact that these palaeontologists have not been staff members of the Survey, a living contact ex
isted between us up to several years ago.
Cephalopods older than Triassic are rare in present-day Hungary. Some specimens, mainly orthocone nautiloids were found in North Hun
gary. Because of their rarity they cannot be used for designating zones. The largest number of taxa have been collected from the Permian Nagyvisnyó Limestone (14) and from the Silurian olistolite of the Strázsahegy Formation (6). Some specimens have also been found in the Carboniferous Mályinka Formation (Schréter 1974),
The importance of ammonites in the strati
graphy of the Balaton Highland has been well known for a long time. The pertinent studies made in the past century and about the begin
ning of this century were continued by I. Szabó, followed by A. Vörös. Vörös joined the system
atic key section studies relating to the geologi
cal mapping of the Balaton Highland. In the Aszófő type locality section of the Pelsonian substage A. Vörös has divided the Balatonites ba
latonicus zone into three subzones, in accor
dance with Assereto's zoning, and recognized also the lower subzone of the Paraceratites trinodosus zone. He proposed this section as the stratotype of the Pelsonian substage. Equally important is the study and evaluation of the ammonites collected from eight sections re
covering the Anisian/Ladinian boundary beds, these sections comprise the interval between the trinodosus and the curionii zones, with the inclu
sion of the reifzi zone representing the base of the Ladinian, and being divided into five hori
zons.
Numerous papers and a few monographs are dealing with the study, description and a many- sided stratigraphic evaluation of the ammonites collected systematically from the Jurassic sec
tions of the Transdanubian Central Range mainly during the 60's.
From the results the significance of the mon
ograph written on the Tata Mesozoic block by J.
Fülöp can be stressed (Fülöp 1975). This is the only one to offer a comprehensive description of all the fossils, including the ammonites con
tained in a thin (43 m) Jurassic sequence of a quasi-continuous deposition. Upon the am
monite zones defined by specialists it has been established that despite the apparently con
formable succession of beds the top of the Rhaetian stage and the lower half of the Het- tangian are missing, and the Dogger zones are also incomplete. The Kimmeridgian/Berriasian interval (Pálihálás and Szentistvánhegy Lime
stones) excels with an incredibly rich ammonite fauna. The study of the Sinemurian/Toarcian interval, as based mainly upon the Bakony sec
tions, was done by B. Géczy (Geczy 1972, 1974 and 1993) at the level of zone and subzone. The presence of the following zones has been recog
nized in the Middle Jurassic sections: all the 5 Sinemurian, 6 Pliensbachian and 4 Bajocian zones ranging from the humphriesianum zone to the parkinsonii zone, moreover 4 out of the 5 am
monite zones ranging from the zigzag zone up to the raricostatum zone (Galácz 1984). Vigh, G.
(1984) has marked out genuine ammonite bio
zones in three Malm sections of the Trans
danubian Central Range, some of which differ from the standard zones even by their names, too. On the basis of 145 taxa found in the Mo
gyorós-domb section at Sümeg, Vigh has
estab-lished altogether 3 Middle Tithonian and 2 Upper Tithonian zones. On the basis of 112 taxa encountered in the Lokut-domb section, he has divided the Lower and Middle Tithonian into 2 subzones. Upon examining 50 taxa, he de
scribed the very condensed sequence of the Papréti-árok section to have been uncertainly divisible (Lower Tithonian: 2 zones, Middle and Upper Tithonian: one zone each). He considered 29 taxa to be sufficient to demonstrate the pre
sence of all the three chronozone-type zones of the Berriasian stage. G. Vigh concluded that the Felsővadács breccia lying over the bossieri zone may belong to the to the Valanginian stage. At the same place Galácz, A. (1984) recorded the existence of two Oxfordian zones and of three Tithonian zones separated by hiatuses.
In some Malm sections of the Bakony Mts Főzy, 1. (1987) recognized evidences of quasi- continous sedimentation (Pálihálás) and strongly broken deposition (Eperkéshegy at Olaszfalu) on the basis of detecting zones. He recognized several hiatuses of different impor
tance in the Malm sections of the Gerecse Mountains, at Szél-hegy and Asszony-hegy near Tardos (Főzy 1992, unpublished report).
Upon the study of ammonites collected from the Közöskúti-árok section of Hárskút in the Bakony Mts, A. Horvath (in Knauer&Horváth 1986) has divided the Berriasian portion of the section into 3 zones and 7 subzones. The Albian age of the Bersek Marl (Gerecse) dated on the basis of nannoplanktonic floral elements was denied unambiguously by Főzy (1993, unpub
lished report), because the ammonites collected from the uppermost part of the Bersek Marl For
mation and from the lowermost part of the Lábatlan Sandstone testify to the presence of the Lowermost Hauterivian. In contrast with the Barremian age of the youngest detrital strata of the sequence (Köszörűkőbánya Conglomerate Member of the Lábatlan Sandstone Formation), faunal evidence (ammonites) indicates an Ap
tian age for its underlying beds drilled by bore
hole Neszmély 4.
The zoning based upon a rich ammonite as
semblage of the Pénzeskút Marl in the Trans- danubian Central Range (Scholz 1979) has been made more accurate by Horváth (In Császár et al. 1987a), outlining three ammonite zones and two subzones situated between the Vraconian substage and the Middle Cenomanian. A speci
men of Placenticeras polyopsis as determined by Summesberger, found in Upper Cretaceous rocks almost devoid of ammonites dates the age
of the lower part of the Jákó Marl as late San- tonian (in Partényi 1986).
The Hidasivölgy Marl in the Mecsek Mts that had been classified into the Hauterivian, was re
assigned to the upper two zones of the Lower Valanginian and to the lower zone of the Upper Valanginian (Bujtor 1993). In the Bisse Marl and Boly Sandstone belonging to the Villány belt the Upper Albian inflatum zone (with all its four subzones) and dispar zone, moreover the pre
sence of the Cenomanian mantelli zone were rec
ognized by the same author (1990, M.Sc. thesis).
Conodonta studies date back to the 1960's, but really important stratigraphic results first appeared from the end of the 1970's linked with the names of S. Kovács and H. Kozur. Due to the almost entire lack of graptolites and trilo- bites the biostratigraphic and chronostrati- graphic subdivision of the Hungarian Palaeo
zoic has become feasible by means of conodonts as the most important fossil group thereto, however, they rival with ammonites for a dis
tinctive role also in Triassic stratigraphy.
Up to now conodonts have been collected from the Uppony, Szendrő, Bükk and Mecsek mountains, playing an important part in the fundamental change of the stratigraphy of these regions. The first successful work in this respect was done by Kozur and Mock (1977). Kovács
Up to now conodonts have been collected from the Uppony, Szendrő, Bükk and Mecsek mountains, playing an important part in the fundamental change of the stratigraphy of these regions. The first successful work in this respect was done by Kozur and Mock (1977). Kovács