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1

Palaeoenvironmental changes in the Transylvanian Basin during the Early Miocene revealed by the foraminifera assemblages

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Székely S. F. , Beldean C. , Bindiu R. , Filipescu S. , Săsăran E.

Geological Quarterly

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2016

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tom Vol. 60, No. 1

167--180

EN

The evolution of the Transylvanian Basin during the Early Miocene has been restored from the succession of palaeoenvironments inferred from the sedimentological trend and succession of specific foraminifera assemblages from Lower Miocene Tihău section in northwestern Transylvanian Basin. Planktonic foraminifera suggest a Burdigalian age and recorded sea-level changes, climatic and productivity events. Benthic foraminifera offered valuable data on the palaeoenvironmental evolution, with a large-scale progradational (coarsening up) sedimentary succession influenced by regional tectonics. The succession of depositional events include: i) transgressive coarse grained deposits with typical mediterranean assemblages of bivalves in beach environments; ii) the glauconitic facies which can be associated to the maximum flooding surface of the transgression; iii) the sedimentation continued on a narrow shelf influenced by deltas during the highstand; iv) influence of regional tectonics and subsequent filling with turbidites associated to fan deltas.

2

Sedimentology and Diagenesis of the Miocene Nutaysh Member of the Burqan Formation in the Midyan Area, Northwestern Saudi Arabia

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Al-Ramadan K. , Dogan A. , Senalp M.

Geological Quarterly

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2013

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tom Vol. 57, No. 1

165–-174

EN

Turbidite sandstones deposited in rift settings are currently among the main targets of hydrocarbon exploration. However, the impact of style of sedimentation, cyclicity and diagenesis on reservoir quality of such sandstones is relatively poorly explored in the literature. The sedimentology, stratigraphic architecture, and diagenetic alterations of deep marine sandstones of the Mocene Nutaysh member of the Burqan Formation in the Midyan area (Saudi Arabia) are described based on number of measured sedimentologic sections, lithofacies identification in the field and laboratory studies. Three lithofacies types are here identified in the measured sections. These are from bottom to top: (1) “Lithofacies A” consisting of massive to thickly-bedded, coarse-to-very coarse-grained sandstone and conglomerates; (2) “Lithofacies B” consisting of well-bedded, coarse-to-medium-grained, well-sorted sandstone, and (3) “Lithofacies C” consisting of thin-bedded, fine to very fine-grained, current-rippled sandstone, bioturbated shaley siltstone and marl. The main diagenetic processes in the sandstones include the formation of grain-coating smectite and rhombic dolomite. Small amounts of cements include the formation of authigenic kaolinite and calcite. The reservoir quality is anticipated to have been preserved under the transformation of smectite to deep burial illite, which is believed to prevent formation of quartz cements.

3

The Aquitanian marine deposits in the basement of Polish Western Carpathgians and its palaeogeogrraphical and palaeotectonic implications

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Oszczypko N. , Oszczypko-Clowes M.

Acta Geologica Polonica

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2003

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tom Vol. 53, nr 2

101-122

EN

Early Miocene mudstones and conglomerates were discovered in the Andrychów 6 borehole, beneath the Polish Western Carpathians. These dark grey mudstones contain calcareous nannoplankton belonging to the Aquitanian NN1 zone, which can be correlated with the Egerian Stage of the Central Paratethys. The marine mudstones are underlain by conglomerates and sandy-silty deposits of Oligocene age, which overlapped the Early Palaeozoic-Precambrian platform basement. The conglomerates display features of fan delta deposits, and were supplied with material derived from erosion of the uplifted part of platform basement (Cieszyn-Slavkov Ridge). The Egerian mudstones from the Andrychów 6 borehole, and the Eggenburgian Zebrzydowice Formation known from the Karvina and Cieszyn area, reflect a progressive flooding of the European Platform during the Egerian/Eggenburgian transgression. The Egerian-Oligocene mudstones and conglomerates, as well as the Zebrzydowice Formation are equivalents of the youngest flysch deposits in the Outer Carpathians. The Egerian deposits from the Andrychów area and the Eggenburgian Zebrzydowice Formation from the Cieszyn and Ostrava areas are relicts of a broad marine embayment which flooded southern Poland and linked terminal flysch basinand the adjacent European shelf. The sub-thrust Aquitanian (Egerian) to Langhian (Early Badenian) deposits in the Andrychów-Zawoja-Cieszyn area recorded a sedimentary-tectonic evolution of the southern edge of the European Platform. This time span covers the Egerian-Eggenburgian/Ottnangian marine deposition, the Late Ottnangian overthrust of the Outer Carpathians, the Karpatian alluvial fan deposition, uplift of the Cieszyn-Slavkov Ridge, the Late Karpatian-Early Badenian marine transgression and the subsequent Late Badenian to Sarmatian telescopic thrusting of the Outer Carpathians.

4

Coastal sandy spit deposits (Lower Burdigalian/Eggenburgian) in the Alpine-Carpathian Foredeep of Lower Austria

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Nehyba S. , Roetzel R.

Geological Quarterly

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2021

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tom Vol. 65, No. 4

art. no. 50

EN

In the type-area of the Eggenburgian regional stage (Lower Burdigalian) sands with large-scale clinoforms were studied north-west of Eggenburg (Lower Austria). Stratigraphic and facies architecture, palaeocurrent pattern and inferred palaeogeographic setting show that these sands are deposits of W-E trending and SW to SSE prograding coastal spit systems, attached to crystalline shoals or islets in the shallow marine Eggenburg Bay. The spits were dominantly formed by shoal parallel accretion above fair-weather wave base due to longshore transport. The 4-5 m thick clinoforms with bottomset, foreset and topset structures contain up to 3.6 m thick, steeply inclined foresets, dominated by sediment gravity-flow deposition. Relatively stable depositional conditions, characterized by strong unidirectional currents, high sand supply and sufficient accommodation space are assumed for their formation. However, internal reactivation surfaces indicate variations in current activity, orientation and velocity. The deposits of spit systems are interpreted as part of a transgressive systems tract. The provenance analysis reveals the local Moravian and Moldanubian crystalline rocks as principal source. The spit sands of the Burgschleinitz Formation show the highest mineralogical maturity within the studied Lower Miocene succession. Intense reworking and redeposition of material from older deposits is evident. Due to the ongoing transgression deposits of the following Gauderndorf Formation and Zogelsdorf Formation exhibit a larger catchment area with input of high amounts of fresh weathered material.

5

Newly discovered Early Miocene deposits in the Nowy Sącz area (Magura Nappe, Polish Outer Carpathians)

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Oszczypko N. , Oszczypko-Clowes M. A.

Geological Quarterly

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2002

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tom Vol. 46, No 2

117-134

EN

In the Nowy Sącz area Early Miocene marine deposits have been discovered in the southern part of the Rača Subunit, and at the front of the Bystrica Subunit of the Magura Nappe. These deposits belong to the Zawada Formation, which is represented by medium- to thick-bedded glauconitic sandstones with intercalations of thick-bedded marls and marly claystones. The formation is at least 550 m thick. Calcareous nannofossils show the age of the formation to be Early Burdigalian (NN1-2-3 biozones). Due to a lack of exposures the relationship between the deposits of the Malcov and the Zawada formations is not yet clear. However, comparing the youngest age of the Malcov Formation in the Nowy Sącz I borehole (NP 25) with the age of the Zawada Formation suggests sedimentary continuity transition between these formations.

6

Radiometric dating of the Tertiary volcanics in Lower Silesia, Poland. V. K-Ar and palaeomagnetic data from Late Oligocene to Early Miocene basaltic volcanics of the North-Sudetic Depression

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Birkenmajer K. , Pécskay Z. , Grabowski J. , Lorenc M. W. , Zagożdżon P. P.

Annales Societatis Geologorum Poloniae

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2007

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tom Vol. 77, No 1

1-16

EN

This is the fifth contribution to geochronological, petrologic-geochemical and palaeomagnetic studies of the Tertiary basaltoids of Lower Silesia, Poland. It covers the area of the North-Sudetic Depression close to its contact with the Fore-Sudetic Block (6 new sites). The oldest K-Ar date was obtained from basanite plug at Sichów (BP-34: 27.80ą1.27 Ma) located exactly on the Sudetic Marginal Fault. It determines the age of the fault as Late Oligocene. Five other sites (BP-35-39) yielded radiometric ages between 20.07ą0.90 Ma and 18.72ą0.81 Ma (Early Miocene). The volcanics investigated are typical within-plate basaltoids represented by ankaratrite and basanite. The Late Oligocene Sichów intrusion (BP-34) is normally magnetized, the Early Miocene basaltic rocks (ankaratrite BP-39 and basanites: BP-35-38) reveal reversed magnetization.

PL

Piąta część datowań K-Ar i badań paleomagnetycznych trzeciorzędowych wulkanitów Dolnego Śląska obejmuje odsłonięcia tych skał w obszarze niecki północnosudeckiej, w sąsiedztwie sudeckiego uskoku brzeżnego. Otrzymano sześć dat w granicach 27,80š1,27 Ma (późny oligocen: Sichów, BP-34) – 18,72š0,81 Ma (niższy miocen = burdygał: Wilków, BP-37). Późnooligoceńska data dla ankaratrytowego czopu Sichowa (BP-34), który znajduje się na sudeckim uskoku brzeżnym, określa taki wiek tego uskoku. Zbadane skały bazaltowe – bazanity i ankaratryty (melabazanity) są typowymi przedstawicielami wulkanizmu sródpłytowego. Skład chemiczny ogniska magmowego podlegał ewolucji, co przejawiło się w badanych skałach wzrostem zawartości potasu i kobaltu w okresie czasu między wyższym oligocenem a niższym miocenem. Czopy ankaratrytu i bazanitu zostały zbadane pod względem paleomagnetycznym: najstarszy z nich, 27,80 Ma (BP-34: ankaratryt) wykazuje namagnesowanie normalne, pozostałe pięć, 20,07–18,72 Ma (BP-39: ankaratryt; BP-35–38 – bazanity) wykazuje namagnesowanie odwrócone.

7

Radiometric dating of the Tertiary volcanics in Lower Silesia, Poland

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Birkenmajer K. , Pécskay Z. , Grabowski J. , Lorenc M. W. , Zagożdżon P. P.

Annales Societatis Geologorum Poloniae

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2004

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tom Vol. 74, No 1

1-19

EN

The Tertiary volcanic rocks of the Fore-Sudetic Block (FSB), Lower Silesia (Poland), exposed between Strzelin in the east and Legnica in the west, typically represent within-plate basalts. Petrologically, they consist mainly of alkali basalts, basanites, tephrites and ankaratrites. 16 new K-Ar dates are recorded, spanning the Oligocene (31 Ma) through Early Miocene (Burdigalian c. 18 Ma) time. The majority of these K-Ar dates plot around two significantly different ages: 27š1.5 Ma, and 20š1.5 Ma. They indicate the presence in the FSB of two distinct separate phases of Tertiary vulcanicity: (i) the first phase, mainly Late Oligocene (Chattian), with a peak at c. 27; (ii) the second phase, Early Miocene (Aquitanian-Burdigalian), with a peak at about 20 Ma. These phases seem to be separated by a gap in vulcanicity about 3 Ma long at the Oligocene/Miocene boundary. Correlation of K-Ar-dated volcanic activity in the FSB with specific radiometrically-dated polarity intervals, poses some problems, and cannot be regarded definite at this stage of investigations. Considering the whole set of K-Ar and palaeomagnetic data from 40 sites, between the Opole area in the east and the Legnica area in the west, we suggest that volcanism of the first phase (Oligocene), although significantly spread out in time across multiple reversals, took place mostly during two well-defined, previously recognized events: (i) an older, reversed Odra event (within the C9r chron: 28.1š1.2 Ma); and (ii) a younger, normal Gracze event (within the C8n chron: 26.5š1.1 Ma). The second phase (Early Miocene) volcanism includes mainly a continuous set of reversely magnetized sites (mostly a single reversed C6r chron: 20.5š0.87 Ma).

8

The Early Miocene residual flysch basin at the front of the Central Western Carpathians and its palaeogeographic implications (Magura Nappe, Poland)

86%

Oszczypko-Clowes M. , Oszczypko N. , Piecuch A. , Soták J. , Boratyn J.

Geological Quarterly

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2018

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tom Vol. 62, No. 3

597--619

EN

In the Polish sector of the Magura Nappe, along the front of the Pieniny Klippen Belt, strongly tectonized calcareous flysch up to 1000 m thick is exposed. Previously these deposits, composed of thin- to thick-bedded flysch, with a packet of Łącko-type marls, have been included into several Paleocene/Eocene formations, e.g., the Szczawnica Formation. This formation contains a poor assemblage of agglutinated foraminifera and a relatively rich assemblage of calcareous nannoplankton, with abundant reworked species. The youngest species give evidence of the NN2 Zone (Lower Miocene). Additionally, in three profiles (Szlachtowa, Knurów and Waksmund) of the Kremna Fm., Early Miocene foraminifera have been recognized. This research documented that during the Burdigalian, at the front of Central Western Carpathians, there still existed a residual marine basin probably up to 100 km wide. These deposits also contain thick packages of exotic carbonate conglomerates derived from the SE, previously regarded as the Jarmuta Formation.

9

Mélanges and broken formations at the boundary zone of the Magura and Silesian nappes (Gorlice area, Polish Outer Carpathians) : a result of sedimentary and tectonic processes

86%

Starzec K. , Malata E. , Wronka A. , Malina L.

Geological Quarterly

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2015

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tom Vol. 59, No. 1

169--178

EN

Based on geological ﬁeld mapping, analyses of cores from explanatory wells, and foraminiferal age control data, we have differentiated a few types of mélanges and broken formations at the bordering zone between the Magura and Silesian nappes (Gorlice area in the Polish Outer Carpathians). These mélanges and broken formations differ in composition and structure due to different settings and processes of their formation. Several levels of broken formation within the uppermost part of the Krosno Beds were formed as mass-transport deposits at the southern slope of the Silesian Basin. They may record tectonic pulses related to advancing accretionary wedge within Magura area and directly predate the stage of the larger-scale sedimentary mélange formation at the front of the wedge. This mélange is composed mainly of the material representing the Magura succession (Siary Subunit) and the Krosno type sediments of the Silesian succession. It was emplaced within the Silesian basin in the Early Miocene time. The so-called “Harklowa peninsula”, whose geological structure has been the subject of discussions and various interpretations in the past years, is built of this type of mélange. The other recognized type of broken formation and mélange represents the chaotic bodies formed at the base of the Magura Nappe.The results of our studies contribute to better understanding of the structural evolution of this part of the Outer Carpathians

10

cf. Trimeresurus Lacepede [Reptilia: Squamata: Viperidae: Crotalinae] from the late Early Miocene of Japan

86%

Holman J. A. , Tanimoto M.

Acta Zoologica Cracoviensia

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2004

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tom 47

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nr 1-2

EN

A single middle trunk vertebra from the Sakurado Facies of the Yamanouchi Member of the Akeyo Formation (late Early Miocene), Mizunami City, central Japan, is identified as cf.Trimeresurus (a living crotaline genus) based on the very close morphological similarity of the fossil to the modern and Pleistocene species Trimeresurus flavoviridis (HALLOWELL, 1861) and on zoogeographic grounds. This is the oldest record of the Crotalinae from Asia. Additional fossil material of this crotaline is needed in order to make a more specific identification.

11

An aquatic water scavenger beetle in Early Miocene amber from the Dominican Republic (Coleoptera: Hydrophilidae)

72%

Fikacek M. , Engel M. S.

Annales Zoologici

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2011

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tom 61

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nr 4

EN

We describe a fossil hydrophilid beetle Anacaena paleodominica sp. nov. from the Early Miocene amber of the Dominican Republic, which is the only definitive amber inclusion of the family Hydrophilidae documented. The species belongs to the Recent Anacaena suturalis species group known from the Nearctic, Neotropical, and Australian regions. The fossil demonstrates that representatives of the species group may already have been widespread and common by the Early Miocene, and indicates a possible Miocene/post-Miocene extinction of the aquatic insect fauna on the island of Hispaniola.

12

A framework of ichthyofaunal ecostratigraphy of the Oligocene-Early Miocene strata of the Polish Outer Carpathian basin

58%

Kotlarczyk J. , Jerzmańska A. , Świdnicka E. , Wiszniowska T.

Annales Societatis Geologorum Poloniae

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2006

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tom Vol. 76, No 1

1-111

EN

The paper presents the results of an analysis of ichthyofaunal variability throughout the section of the Menilite-Krosno Series (MKS) in the Outer Carpathians of Poland. The studied tanathocoenoses were formed at the bottom of a more than 2,000 m deep northern basin of the Tethys, being largely represented by the continental rise and bottoms of its narrow furrows, and - to a lesser degree - the continental slope and slopes of a submarine high. Lateral variability of statististically representative assemblages of tanathocoenoses hosted in thin, isochro- nous horizons is interpreted as a result of both local changes of ichthyocoenoses and the influence of post-mortem relocation of fishes that mainly dwelled the shelf and upper continental slope. Vertical variability, in turn, is considered as a resulting from changeable conditions of the ecological environment, the input and outflow of taxa whose evolution proceeded in the Indo-Pacific area, and the species extinction. Changeability of ichthyofauna within a ca. 16-m.y.-long interval made it possible to document and formally describe 9 zones and 4 subzones of ichthyofauna of ecostratigraphic character. These zones comprise index, representative and accompanying taxa that belong to different ecological groups. Conceptual models of the origin of ichthyofaunal assemblages of individual zones are presented. It is suggested that the origin of assemblage differentiation resulted from the appearance and disappearance of the oxygen minimum zone in the water column, global and local sea level changes, topography of the basin bottom, as well as final basin infilling by sediments of submarine fans. The described and preserved collection of fossil Carpathian fishes, housed at the Department of Palaeozoology of the University of Wrocław, requires further specialized palaeontological studies in order to reconstruct a more complete composition of the Oligocene-Early Miocene ichthyofauna.

13

Deep water chondrichthyans from the Early Miocene of the Vienna Basin (Central Paratethys, Slovakia)

58%

Underwood C. J. , Schlogl J.

Acta Palaeontologica Polonica

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2013

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tom 58

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nr 3

EN

Sampling of latest Burdigalian (Miocene) silty clays from the Malé Karpaty Mountains in the Slovakia revealed a deep−water, low diversity shark fauna. The fauna is dominated by teeth of very small squaliform sharks, including two new species, Eosqualiolus skrovinai sp. nov. and Paraetmopterus horvathi sp. nov. The generic composition of the squaliform fauna is more similar to that known from the Eocene than that of today, suggesting a post–early Miocene faunal turnover within this clade, at least locally. Nectobenthic, non squaliform sharks are rare, but include the new sawshark species Pristiophorus striatus sp. nov., while minute teeth of an enigmatic taxon described here as Nanocetorhinus tuberculatus gen. et sp. nov. probably indicate the presence of a previously unrecorded planktivore. The unusual composition of the fauna, with the complete absence of taxa known to be of medium to large size, suggests an unusual, and probably very stressed, palaeoenvironment.

14

Suidae and Sanitheriidae from Wadi Moghra, Early Miocene, Egypt

58%

Pickford M. , Miller E. R. , El-Barkooky A. N.

Acta Palaeontologica Polonica

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2010

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tom 55

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nr 1

EN

New suid and sanithere material from Wadi Moghra, early Miocene, Egypt, is described and discussed. The new material greatly improves the sample size and diversity of suoids known from North Africa, and includes one species of Sanitheriidae and three species of Kubanochoerinae. The Moghra suoid assemblage most closely resembles that from Gebel Zelten, Libya, suggesting that at least part of the Moghra deposits may overlap in time with part of Zelten, i.e., is equivalent in age to MN 4–5 of the European mammal zonation, or PIII of the East African one. Information from suids and sanitheres is consistent with previous interpretations, that the Moghra deposits were formed under swampy and littoral paleoenvironmental conditions.

15

Olistolity w serii śląskiej i ich związek z fazami rozwoju basenu śląskiego

58%

Cieszkowski M. , Golonka J. , Krobicki M. , Ślączka A. , Waśkowska A. , Wendorff M.

Geologia / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie

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2009

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tom T. 35, z. 2/1

13-21

EN

Olistoliths of various ages, provenance and dimensions are known in all of the higher-rank tectonic units of the Outer Carpathians. Their occurrences at various stratigraphic levels (Late Jurassic - Early Miocene) are related to different stages of development of the flysch basins, from the stage of rifting to post-rifting, through the orogenic phases, and further to the post-orogenic period.

16

Early Miocene evolution of the rodent Megacricetodon in Europe and its palaeobiogeographical implications

58%

Oliver A. , Pelaez-Campomanes P.

Acta Palaeontologica Polonica

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2016

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tom 61

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nr 1

EN

The Megacricetodon material from Aliveri (Isle of Evia, Greece) was previously assigned to Megacricetodon primitivus, implying palaeobiogeographical relationship between south-eastern and south-western Europe. The material from Aliveri is here assigned to the new species Megacricetodon hellenicus sp. nov. This form has significant morphological differences compared to other Early Miocene species from Europe. This new evolutionary hypothesis of this genus has implications on the Early Miocene paleobiogeography of Europe. This work presents a new interpretation on the earliest European representative of the genus Megacricetodon from Aliveri localities. Analyses of the Megacricetodon material from MN 4 and MN 5 localities enable to propose a new palaeobiogeographical framework in which there are three main migration events of the genus Megacricetodon into Europe, each corresponding to different lineages that evolved independently. The new Greek taxon is considered the first migration wave from Anatolia, representing an endemic lineage different from any other European Megacricetodon.

17

A primitive cephalomyid hystricognath rodent from the Early Miocene of Northern Patagonia, Argentina

58%

Kramarz A. G.

Acta Palaeontologica Polonica

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2005

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tom 50

|

nr 2

EN

A new genus and species, Banderomys leanzai, from the Cerro Bandera Formation (early Miocene?) of Neuquén province, Argentina, is described. It is known through a mandibular fragment with two molars and several isolated cheek teeth. With wear the upper molars develop a bilobate pattern, whereas the lowers molars attain a trilophodont one. Banderomysis referred to the Cephalomyidae because it has an “asymmetric” dental pattern as other members of the family, but it is less hypsodont, and therefore it is more primitive than any other contemporary or older cephalomyids so far known. A phylogenetic analysis suggests that the relationships between the Cephalomyidae and the Cavioidea are closer than what was traditionally assumed. The cephalomyids would have radiated in pre−Deseadan times, from an ancestor with a dentition very close to that of Banderomys, and reached their main diversity during the Deseadan–Colhuehuapian lapse, when they constituted the dominant hypsodont rodent group in South America.

18

The oldest known Miocene snake fauna from central Europe: Merkur-North locality, Czech Republic

58%

Ivanov M.

Acta Palaeontologica Polonica

|

2002

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tom 47

|

nr 3

EN

The Early Miocene Merkur−North locality (MN 3a) represents the oldest known Miocene ophidian locality in Europe east of Germany. The snake assemblage is characterised by high species diversity and includes the following families: Boidae (Bavarioboa sp.), Colubridae (Coluber dolnicensis, Coluber suevicus, Coluber caspioides, cf. Elaphe sp., Natrix merkurensis sp. nov., Natrix sansaniensis), Elapidae (Elapidae gen. et sp. indet.), and Viperidae (Vipera sp.—“Vipera aspis” complex). Fossils of the extinct species, Coluber dolnicensis, Coluber suevicus, and Natrix sansaniensis, represent their earliest known occurrences. The cranial elements of C. suevicus and N. sansaniensis are described for the first time. Discoveries of cf. Elaphe sp. may represent the earliest fossil member of the genus Elaphe. Elapidae gen. et sp. indet. probably represents the oldest known member of the cobras.

19

Remarks on palaeoenvironmental changes based on reviewed Tertiary insect associations from the Krusne hory piedmont basin and the Ceske stredohori Mts in Northwestern Bohemia [Czech Republic]

58%

Prokop J.

Acta Zoologica Cracoviensia

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2003

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tom 46

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nr Suppl.

EN

Cenozoic insect fauna of northwestern Bohemia is preserved in fluviolacustrine deposits of the Krušné hory piedmont basins and the České středohoří Mts. The fossil insect assemblages are correlated with palaeobotanical results. The local palaeoenvironmental conditions such as the distance from the shoreline or water depth are interpreted. A reflection of changes in distribution of fossil entomofaunas is compared with relevant world localities of different palaeoenvironments. The sparse fossil insect taphocoenoses fill a gap in record of significant diverse non-marine invertebrate communities and serve for reconstruction of terrestrial palaeoecosystems. The selected fossil sites demonstrate insect taphocoenoses formed under conditions of the palaeoenvironment of a diatomaceous lake with subtropical forests (Kučlín), lowlands of riparian and mesophytic forests (Kundratice - Seifhennersdorf), warm-temperate swamp to riparian forests (Bílina mine) and lake sedimentation near mixed mesophytic forests (Mokřina). The aim is to compare fossil entomofaunas from several periods within Tertiary in northwestern Bohemia and search for analogous palaeoenvironmental conditions in other areas. The results are correlated with the previously proposed palaeobotanical models.

20

Cambrian microfossils from glacial erratics of King George Island, Antarctica

58%

Wrona R.

Acta Palaeontologica Polonica

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2004

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tom 49

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nr 1

EN

Limestone erratics in the Early Miocene glacio−marine Cape Melville Formation of King George Island, West Antarctica, have yielded Early and Middle Cambrian small skeletal fossils (SSF) accompanied by calcified cyanobacteria, archaeocyath and spiculate sponges, trilobites and echinoderms. The SSF assemblage comprises disarticulated sclerites of chancelloriids, halkieriids, tommotiids, lapworthellids, palaeoscolecids, hyolithelminths, lingulate brachiopods, helcionelloid molluscs, hyoliths, and bradoriids. All 24 described species are common to Antarctica and Australia. Most are recorded here from Antarctica for the first time, including Shetlandia multiplicata gen. et sp. nov. and two new species Byronia? bifida and Hadimopanella staurata. The lithological and fossil contents of the boulders are almost identical with autochthonous assemblages from the Shackleton Limestone in the Argentina Range and Transantarctic Mountains. Cambrian outcrops around the Weddell Sea are a plausible source of the erratics. The fauna is closely similar to that from the uppermost Botomian Wilkawillina Limestone in the Flinders Ranges and Parara Limestone on Yorke Peninsula, and Toyonian Wirrealpa and Aroona Creek Limestones in the Flinders Ranges, as well as the Ramsay Limestone on Yorke Peninsula, all in the Arrowie and Stansbury Basins of South Australia. These very similar faunal and facies successions for Antarctica and Australia strongly support their common biotic and sedimentary evolution on the same margin of a greater Gondwana supercontinent throughout the Early Cambrian.