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1

Taxonomic problems of some zonal species of the genus Palmatolepis and the correlation of the Frasnian of the East European Platform with conodont zonations

Ovnatanova Nonna S., Kononova Lyudmila I.

Acta Geologica Polonica

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2020

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Vol. 70, no. 1

107--124

EN

Most of the Frasnian regional stages of the Ukhta region, South Timan, Russia, are composed of basinal deposits, however, the hassi and jamieae zones of the Standard Conodont Zonation cannot be easily recognised in this region. A revision of the previously elaborated succession of the Timan-Pechora associations revealed that the correlation problems are connected with the taxonomic interpretation of the zonal species Palmatolepis hassi and Palmatolepis jamieae. Analysis of the conodont collection of Professor W. Ziegler from the Rhenish Slate Mountains, Germany, especially from the interval encompassing the Lower hassi to Upper rhenana zones, has provided evidence of the lack of validity of the jamieae Zone as a separate stratigraphic unit. This statement is based on the composition of the jamieae and Lower rhenana conodont associations and the absence of P. jamieae near the lower boundary of the zone in the stratotype and other sections of the Rhenish Slate Mountains, becoming more common upsection. The correlation between the Timan-Pechora conodont associations III–XI, the Standard Conodont Zonation (Ziegler and Sandberg 1990) and the Frasnian Zonation (Klapper 1989; Klapper and Kirchgasser 2016) is suggested herein. The Domanikian Regional Stage corresponds to the punctata–Late hassi zones of the Standard Conodont Zonation and to Frasnian Zones 5–10. The boundaries of Frasnian Zones 8–9 need to be further specified in South Timan. The correlation between the Standard Conodont Zonation and the Frasnian Zonation of Klapper is elaborated.

2

Sporadoceratid ammonoids from the Shotori Range (east-central Iran) - a case of putative gigantism caused by hydraulic sorting?

Korn Dieter, Ghaderi Abbas, Devaere Léa, Hairapetian Vachik, Khanehbad Mohammad, Belka Zdzisław

Acta Geologica Polonica

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2019

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Vol. 69, no. 1

27--49

EN

The Shotori Range of east-central Iran (east of Tabas) has yielded Famennian ammonoid assemblages dominated by the family Sporadoceratidae. Four genera Maeneceras Hyatt, 1884, Iranoceras Walliser, 1966, Sporadoceras Hyatt, 1884 and Erfoudites Korn, 1999 are represented. The conodont assemblage of one sample containing Iranoceras revealed an Upper marginifera Zone age. The ammonoid assemblages are characterised by comparatively large specimens; they reach conch diameters of 300 mm (including the body chamber) and the mean size is larger than 100 mm. The preservation of the material from the Shotori Range and size comparison with sporadoceratid assemblages from the Anti-Atlas of Morocco and the Rhenish Mountains of Germany suggest that hydraulic sorting has resulted in a bias towards large conchs, explaining the size distribution, rather than latitudinal differences. The new species Maeneceras tabasense is described; the genus Iranoceras is revised with a new description of the two species Iranoceras pachydiscus (Walliser, 1966) and Iranoceras pingue (Walliser, 1966).

3

Conodonts and ostracodes from the late Tournaisian bathyal sequence of the Polar Urals

Zhuravlev A. V., Sobolev D. B.

Contemporary Trends in Geoscience

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2018

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Vol. 7, iss. 1

48--58

EN

Early Carboniferous (late Tournaisian) conodonts, recovered from siliceous shales and silicites of the Nyan-Vorga Formation within the Lemva tectonic belt of the Polar Urals (Russia), include the biostratigraphically important taxa Siphonodella lanei, Gnathodus typicus, Dollymae hassi, and Scaliognathus anchoralis, marking the following conodont zones of the upper Tournaisian: crenulata, typicus, and anchoralis. Associated species include representatives of genera Siphonodella, Polygnathus, Pseudopolygnathus, Dollymae, Gnathodus, Kladognathus, and Idioprioniodus. These conodont faunas provide the first biostratigraphically constrained correlations between bathyal deposits of the Lemva Allochthone in the Polar Urals and the “standard” conodont zonation. Ostracodes found in the silicite of the typicus Zone are represented by Sagittibythere ? sp. and Tricornina (Bohemia) sp. The ostracodes are reported from the bathyal deposits of Urals for a first time. The traces of the global Mid-Aikuanian Event are recognized in the upper part of the Tournaisian bathyal succession. This event led to turnover in conodont associations and is followed by increasing in conodont diversity.

4

Biostratygrafia utworów dewonu i karbonu z centralnej części masywu małopolskiego na podstawie konodontów

Malec J.

Biuletyn Państwowego Instytutu Geologicznego

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2015

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nr 462

41--81

PL

W profilach otworów wiertniczych Pągów IG 1 i Węgrzynów IG 1 (centralna część masywu małopolskiego) wykonano badania konodontów z utworów węglanowych dewonu i najniższego karbonu. W profilu Węgrzynowa na podstawie konodontów udokumentowano utwory żywetu, franu i famenu datowane na poziomy dolny falsiovalis–górny postera, oraz turneju i wizenu z poziomów delicatus–texanus. W profilu Pągowa na podstawie konodontów udokumentowano fran i famen w zakresie poziomów jamieae–górny rhenana oraz dolny expansa. Niepełna sukcesja poziomów konodontowych w profilach Pągowa i Węgrzynowa wskazuje na obecność luk stratygraficznych. W Pągowie luki stwierdzono w utworach dewonu górnego oraz między utworami dewonu i karbonu, natomiast w Węgrzynowie w utworach z pogranicza dewonu i karbonu. W rejonie Węgrzynowa osady dewonu górnego były deponowane w zbiorniku o znacznie większej subsydencji niż w rejonie Pągowa. Utwory dewonu górnego masywu małopolskiego i obszarów ościennych odpowiadające zbliżonym przedziałom biostratygraficznym są podobne pod względem litologicznym i biofacjalnym.

EN

The conodont study was performed on Devonian and lowermost Carboniferous carbonate rocks from the Pągów IG 1 and Węgrzynów IG 1 boreholes located in the central part of the Małopolska Massif. Based on the conodont biostratigraphy, sediments assigned to the Givetian, Frasnian and Famennian (lower falsiovalis–upper postera zones) and to the Tournaisian and Visean (delicatus–texanus zones) were examined in the Węgrzynów section. The Pągów section is represented by Frasnian and Famennian sediments ascribed to the jamieae–upper rhenana and lower expansa zones. The incomplete conodont zone succession in the Pągów and Węgrzynów sections indicates the presence of stratigraphic gaps. In Pągów, these hiatuses were pinpointed in the Upper Devonian and between the Devonian and the Carboniferous, whereas in Węgrzynów at the Devonian–Carboniferous boundary. In the Węgrzynów area, deposition of the Upper Devonian sediments occurred in a basin, showing much greater subsidence than that in the Pągów area. In the Late Devonian sediments of the Małopolska Massif and neighbouring areas of much the same biostratigraphic intervals are similar in terms of lithologic and biofacies characteristics.

5

The Permian and Triassic in the Albanian Alps

Gaetani M., Meço S., Rettori R., Henderson C. M., Tulone A.

Acta Geologica Polonica

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2015

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Vol. 65, no. 3

271--295

EN

The sedimentary succession of the Permian to Middle Triassic of the Albanian Alps is described, as part of the eastern Adria passive margin towards the Tethys. A carbonate ramp deepening towards NE in present day coordinates developed during the Middle Permian and was affected by block faulting with the deposition of carbonate breccia. The Early Triassic was characterized by intense terrigenous deposition with several cobble conglomerate units up to 80 m-thick, and by oolitic carbonate shoals. The fine clastic deposition ended gradually during the earliest Anisian and a wide calcarenitic ramp occupied the area, with small local carbonate mounds. Basinward, the red nodular limestone of the Han Bulog Formation was interbedded with calcarenitic material exported from the ramp. Drowning to more open conditions occurred towards the end of the Pelsonian. Subsequently, cherty limestone and tuffitic layers spread over the entire area. Towards the end of the Ladinian, with the end of the volcanic activity, red pelagic limestone was deposited locally for a short period. By the latest Ladinian most of the area returned to shallow-water conditions, with a peritidal carbonate platform. In the Theth area, in contrast, a basin with black organic-rich dolostone and limestone developed which seems to be unique in that part of the Adria passive margin. The occurrence of cobble conglomerate units in the Lower Triassic testifies to very active block faulting and high accommodation, not yet described for the area.

6

Olenekian (Early Triassic) fossil assemblage from eastern Julian Alps (Slovenia)

Kolar-Jurkovšek T., Vuks V. J., Aljinović D., Hautmann M., Kaim A., Jurkovšek B.

Annales Societatis Geologorum Poloniae

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2013

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Vol. 83, No. 3

213--227

EN

New palaeontological and sedimentological data from the Lower Triassic strata of the eastern Julian Alps in Slovenia are presented., They are unusual for the Early Triassic of the Alps in representing a relatively deeper, unrestricted marine (mid-ramp) setting. There are two basic microfacies types in the section investigated (types A and B), which are organized as couplets with coarse-grained tempestitic deposits (microfacies A), overlain by laminated or bioturbated lime mudstones and/or marls (microfacies B), frequently containing ammonoids. This pattern is interpreted as storm deposition with occasional winnowing of bottom sediments and the formation of coarse-grained skeletal deposits (lags), followed by the slow settling of suspended particles, when the storm waned, in addition to background deposition. Dominantly lime mud deposition and the presence of ammonoids indicate deposition on a more distal, deeper ramp with an unrestricted connection to the open sea. Intense reworking of bottom skeletal-rich sediment and accumulation of storm lags suggest deposition above the storm wave base, possibly in a wide low-energy mid-ramp environment. Faunas from such settings have been reported relatively rarely from the Early Triassic of the Alps. The macrofauna contains ammonoids, bivalves and gastropods, whereas the microfauna is represented by foraminifer tests and conodont elements; rare fish remains also occur. In the foraminifer assemblages, species of Ammodiscus, Hoyenella, Glomospirella dominated, corresponding to the widespread “Glomospira-Glomospirella” foraminifer community, with some miliolids and nodosariids. The conodont fauna is characterized by Triassospathodus hungaricus (Kozur et Mostler), indicating an early Spathian (Olenekian) age. The fossil assemblage highlights the wide distribution of Early Triassic taxa in the Tethys and facilitates its worldwide correlation. Its relatively low diversity by comparison with shallow marine settings is interpreted as an evolutionary proximal-distal trend in the wake of the end-Permian mass extinction. Re-diversification first occurred in nearshore settings and expanded into deeper/distal marine environments through geological time.

7

Middle Devonian conodonts and structural implications for Świętomarz : Śniadka section (Holy Cross Mountains)

Woroncowa-Marcinowska T.

Annales Societatis Geologorum Poloniae

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2012

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Vol. 82, No. 4

349–-360

EN

The paper presents a new interpretation of the geological structure and stratigraphy of the Devonian in the Świętomarz–Śniadka section. The uppermost Śniadka Formation (equivalent to the Nieczulice Formation), was described previously from the northern part of the section between exposures of the sandstones and shales of the Świętomarz Formation. The present study revealed the presence in the mentioned area of Sitka Coral-Crinoid Limestone Member and the Sierżawy Member, referable to the Skały Formation. Black, thin-bedded limestones, occurring here, were assigned to the upper part of the Sierżawy Member. Conodont assemblages indicate that the Sitka Coral-Crinoid Limestone Member corresponds to the hemiansatus Zone, whereas most of the Sierżawy Member represents the timorensis – rhenanus/varcus zones. The presence of the North American species Icriodus janaea is documented for the first time in Poland. Clay shales and marls with Maenioceras terebratum are considered to be the uppermost part of the Sierżawy Member. These stratigraphic data are the basis for a new interpretation of the geological structure of the Bodzentyn Syncline.

8

Biostratygrafia konodontowa dewonu środkowego obszaru radomsko-lubelskiego

Narkiewicz K.

Prace Państwowego Instytutu Geologicznego

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2011

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T.196

147--192

PL

Praca jest syntezą wcześniejszych, publikowanych wyników badań konodontowych dewonu środkowego obszaru radomsko-lubelskiego uzupełnionych o nowe dane z czterech wierceń. Ogółem przeanalizowano 10 profili wiertniczych i 169 próbek, w tym 92 pozytywne, z których uzyskano łącznie około 1600 okazów konodontów. W badanej kolekcji wyróżniono 10 rodzajów i 41 taksonów w randze gatunków i podgatunków, z których 10 znaleziono w Polsce po raz pierwszy. Szereg oznaczeń taksonomicznych i wiekowych zweryfikowano lub ustalono na podstawie nowych obserwacji. Analizowane konodonty należą głównie do biofacji płytkomorskich, zdominowanych przez rodzaje Polygnathus i Icriodus. Dlatego, w analizie biostratygraficznej nie zastosowano zonacji „standardowej” opartej na formach głębokowodnych i (lub) otwartomorskich, ale posłużono się podziałami alternatywnymi. Umożliwiło to wydzielenie 10 poziomów i podpoziomów konodontowych, aczkolwiek w szeregu przypadków możliwe było jedynie szerokie określenie wieku osadów. Zintegrowane dane makro- i mikrofaunistyczne oraz sporowe pozwoliły na identyfikację pięter eifel i żywet oraz podpięter żywetu. Dokładniejsze ustalenie granic chronostratygraficznych było możliwe w przypadku granicy emsu z eiflem, żywetu z franem oraz granic podpięter żywetu: dolnego/środkowego i środkowego/górnego. We wszystkich badanych profilach uzyskane dane pozwoliły na sprecyzowanie chronostratygrafii, która dotychczas była oparta głównie na makrofaunie o szerokich zasięgach wiekowych.

EN

The paper is a synthesis of previously published results of conodont studies of the Middle Devonian in the Radom–Lublin area, supplemented with new data from four boreholes. Altogether, the study was based on 10 borehole sections and 169 samples, including 92 positive from which ca. 1600 specimens have been obtained. The collected material was assigned to 10 genera and 41 taxa of species and subspecies rank, including 10 found for the first time in Poland. Several previous taxonomic and age determinations were verified or established again based on new observations. The analysed forms belong mainly to shallow-marine biofacies dominated by genera Polygnathusa and Icriodus. Therefore, it was hardly possible to apply the “standard” zonation based on deeper-water/open marine taxa and alternative zonations were used instead. This allowed to distinguish 10 zones and subzones, although in several cases only broad age determinations were possible. Integration of the present conodont results with other micro- and macrofaunal as well as palynostratigraphic data allowed to identify the Eifelian and Givetian stages, the latter subdivided into substages. A more precise dating of lithostratigraphic boundaries was possible in the case of the Emsian/Eifelian and Givetian/Frasnian boundaries as well as the Lower/Middle and Middle/Upper Givetian boundaries. In all the investigated sections the obtained results allowed to constrain chronostratigraphy which was previously based mainly on macrofauna with wide stratigraphic ranges.

9

Biostratygrafia konodontowa dewonu górnego lubelszczyzny

Narkiewicz K., Bultynck P.

Prace Państwowego Instytutu Geologicznego

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2011

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T.196

193--254

PL

Zbadano 203 próbki konodontowe, w tym 114 pozytywnych, z 15 profili wiertniczych, w większości z utworów franu formacji modryńskiej, a ponadto z fameńskiej formacji bychawskiej i firlejskiej. Ze 100 próbek z profili franu uzyskano 2139 okazów zaliczonych do 9 rodzajów, w obrębie których oznaczono 81 taksonów niższego rzędu. Czternaście gatunków znaleziono i udokumentowano w Polsce po raz pierwszy. Wobec braku form indeksowych wiek zespołów określano głównie na podstawie zestawienia zasięgów stratygraficznych wszystkich elementów znalezionych w próbce. Najwyższą część formacji telatyńskiej w centralnej części basenu lubelskiego, tuż poniżej podstawy formacji modryńskiej, zaliczono do franu dolnego (profile otworów Giełczew PIG 5, Mełgiew 2). Datowania utworów frańskich pozwalają też na zawężenie wieku poszczególnych ogniw tworzących formację modryńską. Udokumentowano diachronizm górnej granicy formacji modryńskiej, która wypada w famenie dolnym w profilu Opole Lubelskie IG 1, a w najwyższym franie w profilu Giełczew PIG 5. Granica franu z famenem biegnie w pobliżu granicy formacji modryńskiej i firlejskiej (Korczmin IG 1). Granica między formacją bychawską a firlejską w segmentach lubelskim i stężyckim przebiega w obrębie wyższego famenu dolnego albo niższego środkowego. W segmencie komarowskim datowanie stropowych partii formacji firlejskiej sugeruje natomiast, że dolna granica formacji hulczańskiej wypada w pobliżu granicy famenu dolnego i środkowego.

EN

Investigations were based on 203 conodont samples, including 114 positive, from 15 borehole sections mainly representative of the Modryń Formation (Frasnian), and also comprising the Famennian Bychawa and Firlej formations. The Frasnian conodont collection was obtained from 100 samples which contained 2139 specimens attributed to 9 genera and 81 lower rank taxa, including 14 species found and documented in Poland for the first time. Age of the assemblages was determined mainly basing on a comparison of stratigraphic ranges of all elements found in a sample. Uppermost part of the Telatyń Formation, just below the base of the Modryń Formation was ascribed to the Lower Frasnian in the Lublin (Central) Segment of the Lublin Basin (Giełczew PIG 5, Mełgiew 2). The conodont biostratigraphy of the Frasnian sections allows to constrain also the age of particular members constituting the Modryń Formation. Upper formation boundary appears diachronous, running in the Lower Famennian in the Opole Lubelskie IG 1 and in the uppermost Frasnianin the Giełczew PIG 5. The boundary between the Bychawa and Firlej formations in the Central and Stężyca (NW) segments is traced in the upper Lower Famennian or lower Middle Famennian. On the other hand, in the Komarów Segment (SE) the data from the uppermost part of the Firlej Formation suggest that the base of the overlying Hulcza Formation runs near the Lower/Middle Famennian boundary.

10

Biostratigraphy of the Emsian to Eifelian in the Holy Cross Mountains (Poland)

Fijałkowska-Mader A., Malec J.

Geological Quarterly

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2011

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Vol. 55, No. 2

109-138

EN

The paper give a biostratigraphic interpretation of the Emsian to Eifelian in the Łysogóry and Kielce regions of the Holy Cross Mountains, based on the different groups of microfossils: miospores, conodonts, ostracods and foraminifers. Four miospore zones were identified in the uppermost Pragian, Emsian and lowermost Eifelian: Verrucosisporites polygonalis-Dibolisporites wetteldorfensis (PW), Emphanisporites annulatus-Brochotriletes bellatulus (AB), Emphanisporites foveolatus-Verruciretusispora dubia (FD) and Acinosporites apiculatus-Grandispora protea (AP). In the Łysogóry region, the Emsian and lowermost Eifelian comprises four cono-dont zones: serotinus,patulus,partitus and costatus, three ostracod assemblages and several foraminifer assemblages. In the Kielce region, deposits from the Emsian/Eifelian boundary interval yield conodonts from the patulus and partitus zones, two ostracod assemblages and assemblages of agglutinated foraminifers. The joint biostratigraphic analysis allows a tentative correlation of the lithostratigraphic units from both areas. It also provides independent control/calibration on the different biostratigraphical systems. The Pragian/Emsian boundary is located in the lower part of the Barcza Formation and in the lower part of the Haliszka Formation, whereas the Emsian/Eifelian boundary lies in the upper part of the Grzegorzowice Formation and in the upper part of the Winna Formation.

11

New data on the stratigraphy of the Ordovician at Pobroszyn, Holy Cross Mts., Central Poland

Bednarczyk W., Stempień-Sałek M.

Acta Geologica Polonica

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2011

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Vol. 61, no. 1

47-58

EN

New biostratigraphic and lithostratigraphic data are presented for the tectonically reduced Ordovician succession at Pobroszyn in the Łysogóry region of the Holy Cross Mountains, central Poland. Only some of the chronostratigraphic units known from the Łysogóry region can be recognized in this section. However, based on lingulate brachiopods, conodonts, acritarchs and chitinozoa, the units present may be referred to the Late Tremadoc, Late Arenig, Early Lanvirn, Late Lanvirn, Early Caradoc and to the Middle Caradoc and Ashgill. New lithostratigraphic units are established in the lower part of the Ordovician of the Pobroszyn section: the Opatówka Mudstone/Sandstone Formation (?Late Tremadoc) and the Pobroszyn Sandstone Formation (Late Arenig). Three species of lingulate brachiopods are described, of which two are new: Myotreta anitae and Eoconulus lilianae. The conodonts and acritarchs are illustrated and briefly discussed.

12

New conodont and palynological data from the Lower Palaeozoic in Northern Camdag, NW Anatolia, Turkey

Boncheva I., Goncuoglu M., Leslie S., Saydam G., Gedik I., Sachanski V., Konigshof P., Lakova I.

Acta Geologica Polonica

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2009

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Vol. 59, no. 2

157-171

EN

Two main thrust slices in the Camdag area (NW Anatolia), were informally named the Southern and Northern Camdag units. New micropaleontological and palynological data about the Ordovician, Silurian and Devonian in the Northern Camdag have allowed a better understanding of the Early Palaeozoic evolution of this critical area between the Istanbul Terrane in the west and the Zonguldak Terrane in the east. The Middle Ordovician age obtained from the conodont-bearing limestone band within the Aydos Formation in this study is in agreement with the data from the Zonguldag Terrane. Acritarch evidence suggests a Late Ordovician age of the upper part of Aydos Formation. This paper concerns the Northern unit. Three members are distinguished in the Findikli Formation and dated biostratigraphically. The lower member (Black Shale Member) of the Findikli Formation is absent from the Kabalak Dere section, but was assigned elsewhere to the Llandovery on the basis of graptolites. The middle member (Shale-Siltstone Member) is dated as Wenlock and Ludlow on the basis of acritarchs. The upper member (Shale-Limestones Member) spans a continuous upper Silurian - Lower Devonian succession. The overlaying Ferizli Formation is assigned to the Middle Devonian on the basis of conodonts. The new stratigraphic data indicate that the Southern Camdag unit corresponds to the Istanbul Terrane and the Northern Camdag unit to the Zonguldak Terrane. The tectonic contact between the Northern and the Southern units is a steep south-verging thrust-fault.

13

Givetian and early Frasnian cono donts from the Compte section (Middle-Upper Devonian, Spanish Central Pyrenees)

Liao J.-C., Valenzuela-Ríos J. I.

Geological Quarterly

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2008

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Vol. 52, No 1

1-1

EN

The Givetian and Frasnian conodont suc cession investigated in the Compte section (Spanish Pyrenees) is subdivided into nine Givetian standard conodont zones and two Frasnian zones (MN zones). This succession allows precise identifcation of the lower/middle Givetian, middle/upper Givetian and of the Givetian-Frasnian boundaries by means of index conodonts. The joint entry of Mesotaxis falsiovalis and Skeletognathus norrisi in the same bed shows local isochroneity of the beginning of the falsiovalis and norrisi zones in the latest Givetian. In the earliest Frasnian the sequence of Ancyrodella pristina, A. soluta and A. rotundiloba is observed whilst A. binodosa is lacking. The conodont assemblages consist of key species of the following nine genera: Polygnathus, Icriodus, Tortodus, "Ozarkodina", Schmidtognathus, Klapperina, Mesotaxis, Skeletognathus and Ancyrodella. This is the first conodont report from the Pyrenees showing such a detailed succession of enormous correlation potential.

14

The Devonian of Western Karakorum (Pakistan)

Gaetani M., Mawson R., Sciunnach D., Talent J.

Acta Geologica Polonica

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2008

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Vol. 58, no. 3

261-285

EN

Devonian rocks crop out in several thrust sheets in the sedimentary belt of North-Western Karakorum, both to the south and to the north of the Reshun Fault. Gently metamorphosed Devonian dolostones and volcanics are also present in the Tash Kupruk Zone north of the thrust sheet system. The most complete succession is found in the Karambar Thrust sheet where dolostones and recrystallized limestones (Vandanil Formation) lie above the black shales and siltstones of the Baroghil Group. The age of the Vandanil Formation is poorly defined, approximating latest Silurian or earliest Devonian at its base and proven to be Pragian in the 4th of its 5 lithozones. The overlying Chilmarabad Formation is divided into two members. The lower member is a mixed siliciclastic-carbonate package, present in most southern and western thrust sheets. The upper member is ubiquitous; it consists of dolostones, often stromatolitic. The calcareous part of the Tash Kupruk Zone consists of similar facies. The carbonate flats of the Chilmarabad Formation display a trend towards emersion towards the top, and are overlain, with regional unconformity, by the basal unit of the Shogram Formation. The base of the latter consists of arenite and fine conglomerate (deposited in an alluvial setting) overlain by alternating marine bioclastic limestones and litharenites with one or two coral bafflestones in the middle to upper part. The age of the lowermost part of the Shogram Formation is Givetian, extending through the Frasnian and seemingly into the Famennian, but the last is poorly documented (contrasting with the classic Shogram and Kuragh sections of Chitral); it reflects a return to fine terrigenous input. The inferred palaeogeography accords with the Northern Karakorum having been part of the Gondwana margin during the Devonian. Awide, mostly calcareous platform, characterised extensive areas of the Karakorum, Central Pamir, Badakhshan and, in a minor way, Central Afghanistan (Helmand Block). The sandstone petrography suggests that clastics polluting the carbonates originated from erosion of a pre-existing sedimentary cover. During the Givetian a first rifting episode, possibly echoing the opening of an ocean to the east, affected the whole area,with volcanic outpourings in the rifts, while eroding shoulders fed the basins, though never extending as deep as the crystalline basement. A minor volcanic input is also recorded. The tectonic pulse almost ceased during the Frasnian, gradually resuming towards the end of the Devonian.

15

Upper Silurian to Middle Devonian conodont faunas from the Rabat-Tiflet area (northwestern Moroccan Meseta)

Benfrika El.M., Bultynck P., El Hassani A.

Geological Quarterly

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2007

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Vol. 51, No 4

393-406

EN

Conodont faunas are generally sparse in Pridolito middle Givetian deposits from the Rabat-Tiflet area in the north western Moroccan Meseta. The Pridoli and Lochkovian rocks consist of dark platy limestones alternating with dark shales containing graptolites in some levels. In the over lying part of the succession carbonate rocks predominate with the development of reefoid limestones in the lower Givetian. The eosteinhornensis, sulcatus, dehiscens vel kitabicus, laticostatus/inversus, partitus, ensensis, hemiansatus, timorensis and rhenanus/varcus zones have been recognized by occurrence of the conodont in dexspecies.The first appearance of Belodella devonica, occurring together with the graptolite Monograptus uniformis is used as a regional index species for the base of the Devonian. The age of some levels in the succession were previously dated by graptolites, dacryoconarids and rare goniatites.

16

Growth in early species of the conodont Ancyrodella and implications for correlation of the Middle-Upper Devonian boundary

Miller C.G.

Geological Quarterly

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2007

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Vol. 51, No 4

443-452

EN

The first occurrence of the conodont Ancyrodella rotundiloba has been used extensively for correlating the Middle-Up per Devonian (Givetian-Frasnian) boundary in sections worldwide despite many arguments as to its precise taxonomic definition. These arguments are summarised herein and three ontogenetic series illustrated from three samples across the Givetian-Frasnian boundary within the Vorota Formation of the Kozhym River section, Sub-Polar Urals, Russia. General trends within the three ontogenetic series suggest that the ratio of basal pit width to platform width in Ancyrodella pristina, and Ancyrodella recta in creases through ontogeny but the morphology of lateral secondary keel extensions to the basal pit remains constant and is a useful taxonomic feature. Folds and collars on the basal surface occur only in the later stages of development. The out line of the platform within species is variable and controlled by the formation of incipient nodes in juveniles; gerontic specimens can also have very variable platform out lines. Measure ments of platform width to basal pit width ratios and platform shape out lines may not therefore be a good way to compare between species. The three ontogenetic series provide typical late Givetian and early Frasnian examples and increase the potential for correlation of the Middle-Upper Devonian boundary particularly using juvenile Ancyrodella specimens.

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Facies transition and biostratigraphic correlation of the Upper Silurian and Lower Devonian in West Bulgaria

Boncheva I., Sachanski V., Lakova I., Yaneva M.

Geological Quarterly

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2007

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Vol. 51, No 4

407-418

EN

Upper Silurian and Lower Devonian shelf deposits in West Bulgaria are exposed in three main Alpine tectonic units: the West Balkan Unit, the Lyubash Monocline and the Morava Unit. The West Balkan and Lyubash units consist of siliciclastic deposits: black graptolitic shales, banded pale shales and black siltstones. The Ludlow, Pridoli, Lochkovian, Pragian and Emsian were recognized on the basis of graptolite and tentaculite faunas. In the Morava Unit, the Ludlow black shales are progressively replaced by clayey limestones and nodular and micritic limestones in the Pridoli and Early Devonian. Newly obtained conodonts show the presence of the siluricus, eosteinhornensis, woschmidti, postwoschmidti, delta-pesavis, sulcatus, dehiscens and gronbergi zones. Petrographic study of the Morava Unit shows an increasing carbonate content and shallowing conditions upwards. The biostratigraphical correlation and facies interpretation reveal the coeval existence of two different depositional environments within the same shelf basin as well as a gradual shift in proximal direction.

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Conodont-based graphic correlation of upper Givetian-Frasnian sections of the Eastern Anti-Atlas (Morocco)

Gouwy S., Haydukiewicz J., Bultynck P.

Geological Quarterly

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2007

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Vol. 51, No 4

375-392

EN

A high-resolution correlation of ten upper Givetian-Frasnian sections spread over the differ ent facies environments of the Eastern Anti-Atlas (Morocco) is established using graphic correlation. The mea sured strati graphic ranges of eighty-five cono dont taxa have been as sem bled into a chronostratigraphic framework. The developed regional composite subdivides the Frasnian into 501 composite standard units (CSU) based on the original thickness of the reference section (Bou Tchrafine). This is a higher resolution than obtained by the classic biozone correlation. Based on the conodont data available for this correlation project, the jamieae and Lower rhenana zones could not be recognised in the sections.

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Conodont biostratigraphy of the Frasnian-Famennian boundary in the Esfahan and Tabas areas, Central Iran

Gholamalian H.

Geological Quarterly

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2007

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Vol. 51, No 4

453-476

EN

The Frasnian-Famennian (F-F) boundary in Central Iran has been investigated on the basis of conodont faunas (34 species and subspecies) from four sections: Chahriseh near Esfahan, and Kal-e-Sardar, Howz-e-Dorah and Ghale-Kalaghu near Tabas. The F-F boundary in the Chahriseh section is located in a one-metre interval between beds EX1 and F-F9 whereas in the Kal-e-Sardar section it is at the base of bed Cly1. The F-F boundary can not be recognized in the Howz-e-Dorah and Ghale-Kalaghu sections be cause of uncon form able relation ships and erosion of the upper most late Frasnian beds indicated incidentally by reworked boulders (indicating con temporaneous tectonic activity) and by the abrupt appearance of contrasting environments, including tempestites at the base of the lower Famennian. The best conodont and palaeoenvironmental data were obtained from the Kal-e-Sardar section where a deeper marine environment prevailed during the late Frasnian, be coming shallower in the early Famennian; the Chahriseh section displays small fluctuations in sea level during the early Famennian. The conodont faunas display the inception of the Polygnathus communis group in the late Frasnian (rhenana-linguiformis zones) and the appearance of Icriodus alternatus mawsonae in the Late rhenana Zone. A new age-range is suggested for Polygnathus aequalis Klapper and Lane, from the transitans to the linguiformis zones. Three conodont biozones are represented in the late Frasnian to early Famennian of the Chahriseh section, two late Frasnian and one early Famennian in the Kal-e-Sardar section and two biozones in the late Frasnian and early Famennian of both the Howz-e-Dorah and Ghale-Kalaghu sections. Two new species are described: Polygnathus tabasianus (Early to Late crepida zones) and Polygnathus vachiki (Late rhenana-linguiformis zones).

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Conodont biostratigraphy of shallow marine Givetian deposits from the Radom-Lublin area, SE Poland

Narkiewicz K., Bultynck P.

Geological Quarterly

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2007

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Vol. 51, No 4

419-442

EN

Detailed conodont data were obtained from 66 samples in 9 deep wells representative of three palaeogeographic regions of the Mid Devonian epicontinental basin of southeastern Poland: (1) the elevated part of the East European Platform representing the basin margin, (2) the Lublin Graben with a larger proportion of open marine systems, (3) the Radom Area characterized by more off shore, purely marine deposition and larger subsidence rates in the Radom Area. The 1344 specimens collected were as signed to 8 genera: Icriodus, Polygnathus, Ancyrodella, Belodella, Mehlina, Neopanderodus, Pandorinellina and Skeletognathus, and 38 taxa of species or subspecies rank. The vertical distribution of the conodont as semblages studied in particu ar sections is highly irregular and discontinuous with many barren intervals con rolled by less suitable palaeocological conditions, mostly representing restricted and/or very shallow-water facies. We found only a single index species characteristic of deeper marine facies, as applied in the standard conodont zonation. There -fore the biostratigraphic interpretation also takes into account the total range of all taxa found in particular samples, established after acritical analysis of adequately published total ranges of these taxa. The stratigraphicranges of the following taxa were modified: Icriodus arkonensis arkonensis, I. a. walliserianus, I. eslaensis, I. platyobliquimarginatus, I. subterminus, I. aff. I. subterminus, Polygnathus ansatus, P. latifossatus, P. linguiformis linguiformis, P. timorensis and P. varcus. As a result of the stratigraphic analysis of the conodon't assemblages we distin guished five zones in the Givetian of the studied area, i.e. the rhenanus/varcus, ansatus, hermanni, norrisi (=lower part of Lower falsiovalis Zone) zones, and also two in formal units, the subterminus and insita fau nas. We documented the co-occurrence of I. subterminus and P. latifossatus which supports the earlier supposition of Rogers (1998) that the Lower subterminus Fauna may partly corre pond to the Lower hermanni Zone.