Geochemistry and U-Pb detrital zircon ages of metasedimentary rocks of the Lower Unit, Western Tatra Mountains (Slovakia)
KOHUT M1, POLLER U.2, GURK C.2,3, TODT W.2
1Dionyz Stur State Institute of Geology, Mlynska dolina 1, SK-817 04 Bratislava, Slovakia.
milan.kohut@geology.sk
2Max-Planck-Institut fur Chemie, Abt. Geochemie, Postfach 3060, D-55020 Mainz, Germany.
3Johannes Gutenberg Universitat Mainz, Geowissenschaftliches Institut, D-55020 Mainz, Germany.
ABSTRACT: A combined geochemical, isotopic and detrital zircon dating study has been carried out on metasedimentary rocks
of the Lower Unit from the Western Tatra Mountains (Slovakia) forming an eastern border of European
Variscides. Geochemical data suggest derivation of the protolith - magmatogenic greywackes and claystones from
the recycled continental island arc source. 87Sr/86Sr(350) isotopic ratios between 0.713 and 0.723 together with
low εNd(350) values of -9.5 to -11.1 and/or Pb isotope composition indicate a crustal origin of the investigated
rocks. Detrital zircons from the metasediments often display homogeneous magmatic zoning with 207Pb/206Pb ages
from 660 to 515 Ma and/or inherited components, with old cores displaying ages from ca. 1980 to 1800 Ma. These
late Paleoproterozoic detrital source ages are similar to the Nd model ages of the studied metasedimentary rocks
with t(DM2st) ca 1960 ~ 1830 Ma. The Late Cambrian (ca 500 Ma) age represents the last magmatic activity of
the precursor rocks and/or it defines the maximum age for sedimentation of the present day metasediments. A
possible source for the clastic material of the Lower Unit from the Western Tatra Mountains was the peri-Gond-
wanan continental margin alike the eastern border of the Bohemian Massif - Moravo-Silesian zone or Sudetic
block.
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Wenlock (Silurian) graptolitic shales from the Kocaeli Peninsula (Derince-Izmit), NW Turkey
SACHANSKI V.1, GONCUOGLU M.C.2, GEDIK I.3
1Bulgarian Academy of Sciences, Geological Institute, Acad. G. Bonchev St. Bl. 24, 1113 Sofia, Bulgaria.
v_sachanski@geology.bas.bg
2Middle East Technical University, Department of Geological Engineering, 06531 Ankara, Turkey.
mcgoncu@metu.edu.tr
3General Directorate of Mineral Research and Exploration, Department of Geological Research, 06520 Ankara, Turkey.
igedik19@gmail.com
ABSTRACT: Alternating dark grey to black thin-bedded limestones and yellowish-grey calcareous shales in a recently discovered section in Izmit (Derince), eastern Kocaeli Peninsula, yielded graptolites of the middle part of the Wenlock - Cyrtograptus lundgreni Zone and possibly Upper Cy. rigidus-Cy. perneri Zone. This is the first record of graptolitic
shale facies rocks in the Kocaeli Peninsula. The succession described is more akin to the Silurian of the Zongul-
dak Terrane than the shallow-marine carbonate facies of the Istanbul Terrane. It is therefore suggested that the con-
tact between the Istanbul and Zonguldak terranes should be located to the west of Izmit (Derince)
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The Upper Oxfordian (Jurassic) thecideide brachiopods from the Kujawy area, Poland
KRAWCZYNSKI C.
Warsaw University, Institute of Geology, Al. Zwirki i Wigury 93, 02-089 Warszawa, Poland.
c.krawczynski@uw.edu.pl
ABSTRACT: Thecideide brachiopods from the slope facies of a sponge-cyanobacterial bioherm exposed in the Wapienno and
Bielawy quarries (Kujawy, Poland) are described. Numerous specimens were found in the upper part of the section, in the Hauffianum-Planula Subzones of the Oxfordian, and constitute the first record of these brachiopods from the Jurassic deposits in the area. Two species: Rioultina wapiennensis sp.nov. and Neothecidella ulmensis QUENSTEDT, 1858, are described, the first being the only representative of the genus Rioultina found in Poland. Excellent preservation of some specimens enabled recognition of details of their internal morphology usually inaccessible in fossil material, including features associated with reproduction and the development of the brachidium. Study of relatively large numbers of thecideides still cemented to the substrate, together with analysis of the associated fauna, allowed the reconstruction of aspects of their ecology.
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Barremian and Early Aptian ammonites from the Godula Facies of the Silesian Unit in the Outer Western Carpathians, Czech Republic
VASICEK Z.
Institute of Geonics of Academy of Sciences of the Czech Republic, Studentská 1768, 708 00 Ostrava - Poruba, Czech Republic
Zdenek.Vasicek@vsb.cz
ABSTRACT: The Early Cretaceous ammonites from the Hradiste Formation (Wernsdorfer Schichten in original concept) in
the Czech part of the Silesian Unit of the Outer (Flysch) Western Carpathians are described. This rich material,
collected over more than 40 years, includes many usually fragmentarily preserved ammonites. The majority of
specimens are preserved as "half-ammonoids" a small portion of them have pyritized inner whorls with preserved
suture lines. 15 species-level taxa are described, partly in open nomenclature. One species, ?Valdedorsella hoheneggeri, is described as new; albeit its generic classification remains uncertain. The ammonites described span the late Early Barremian (Niclesia pulchella ammonite Zone) to basal Aptian (Deshayesites oglanlensis ammonite Zone).
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The ecological significance of solitary coral and bivalve epibionts on Lower Cretaceous (Valangianian-Aptian) ammonoids from the Italian Dolomites
LUKENEDER A.
1Natural History Museum Vienna, Department of Geology and Palaeontology, Burgring 7, A-1010, Vienna, Austria.
alexander.lukeneder@nhm-wien.ac.at
ABSTRACT: Lower Cretaceous deposits of the Puez section in the Dolomites (northern Italy) yielded a rich ammonoid fauna
(28 genera, n = 424) showing unique epifaunal encrustations by the ahermatypic solitary scleractinian ?Cycloseris LAMARCK, 1801. The coral encrusted only the outer shell surfaces of the ammonoids; the inner surface remained unaffected. Such a Cretaceous community and the relationship between the two fossil groups are described for the first time. The shells of dead ammonoids sank to the sea bottom and became colonized by the coral larvae, as documented by the location of the epibionts on only one side of the shells. The coral was fixed to the ammonoid shell for its entire life. Only the 'sediment free' upper side of the ammonoid shells could be inhabited by epibionts such as corals and serpulids. The encrustation of ammonoid shells by the bivalve Placunopsis represents a different situation in that both sides of the ammonoid shells were affected, pointing to encrustation of floating ammonoids. This long-term infestation in the water column contrasts with coral settlement on the sea-floor. Ammonoid specimens encrusted by Placunopsis never exhibit encrustation by corals. The am-monoid-coral relationship from the Dolomites is documented from the Valanginian to Aptian interval. Examples
of coral epibionts on ammonoids and other fossil groups throughout the geological column are briefly reviewed.
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Ammonites and associated macrofauna from the early Late Albian of the Zippelsforde 1/64 core, NE-Germany
LEHMANN J.1, TROGER K-A.2, OWEN H.G.3
1Geosciences Collection, Faculty of Geosciences, University of Bremen, Klagenfurter Strasse, 28357 Bremen,
Germany.
jens.lehmann@uni-bremen.de
2Faculty of Geosciences, Geotechnique and Mining, Bergakademie Freiberg, Meißner-building, Zeunerstr. 12,
09599 Freiberg, Germany.
troeger@geo.tu-freiberg.de
3Department of Palaeontology, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom.
hugh243@btinternet.com
ABSTRACT: The macrofaunal content of an exceptionally fossiliferous Late Albian core section is described from Zippels-
forde in the Brandenburg district in eastern Germany. The main faunal horizon includes among others Euhoplites vulgaris, Mortoniceras (Deiradoceras) albense, Neohibolites minimus, Inoceramus cf. anglicus and Actinoceramus sulcatus. This assemblage indicates a Hysteroceras varicosum Zone, Hysteroceras orbignyi Subzone age. That interval is known from the Anglo-Paris as well as from the Lower Saxony Basin in western Germany, but not was previously recorded from the North East German Basin. Therefore, the record fills a palaeogeographical gap between the Albian in the Carpathians and that of Central Europe. The superjacent interval contains Aucellina gryphaeoides, dating it as latest Albian (Mortoniceras (M.) inflatum Zone, late C. auritus Subzone or younger), and thus indicating a significant condensation within the Late Albian.
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Cenozoic tectonic evolution of the Poznan-Olesnica Fault Zone, central-western Poland
WIDERA M.1, CWIKLINSKI W.2, KARMAN R.2
1Institute of Geology, A. Mickiewicz University, Makow Polnych 16,PL- 61-606 Poznan, Poland.
widera@amu.edu.pl
2Hebo Poznan Sp. z o.o., Podolska 27a,PL-60-615 Poznan, Poland.
rkarman@wp.pl
rumburak113@wp.pl
ABSTRACT: The Poznan-Olesnica Fault Zone (P-OFZ) of central-west Poland is an over 150 km long, up to 10 km wide, and up
to 200 m deep graben that developed during Early Oligocene to Pliocene times on the flank of the NE-dipping Fore -
Sudetic Homocline. Fault systems of this extensional structure appear to reach pre-Zechstein basement in the area of
the Fore-Sudetic Homocline that forms an integral part of the Bohemian Massif. The P-OFZ was affected by several
stages of subsidence, separated by periods of inversion and/or tectonic quiescence between the Triassic and Cenozoic.
Structurally, this dislocation zone can be linked with the Variscan faults, reactivated at that time. During the second
half of the last century, the northern parts of the P-OFZ graben were intensively explored by cored boreholes because
of their lignite content. Conventional back-stripping methods could not be applied to the tectonic analysis of the POFZ due to the limited thickness of the graben fill, its poor dating and the presence of relatively thick lignite seams.
Therefore, phases of accelerated subsidence were determined by comparing the thickness of individual lithostratigraphic
units within the graben and on its flanks. The total subsidence of the different graben segments was quantified by determining the aggradation coefficient (AC) and by taking the consolidation coefficient (CC) of lignite seams into consideration. Subsidence analyses indicate that the initial Early Oligocene extensional phase of the P-OFZ was followed by an Early-Middle Miocene extensional subsidence phase and a probably latest Miocene-Pliocene final extensional
phase.
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Novocrania turbinata (Brachiopoda) from the Early Pliocene of the Azores (Portugal)
KROH A.1, BITNER M.A.2, AVILA S.P.3
1Natural History Museum Vienna, Department of Geology & Palaeontology, Burgring 7, 1010 Vienna, Austria.
andreas.kroh@nhm-wien.ac.at
2Instytut Paleobiologii PAN, ul. Twarda 51/55, PL-00-818 Warszawa, Poland
bitner@twarda.pan.pl
3Departamento de Biologia, Universidade dos Acores, Rua da Mãe de Deus, Apartado 1422,
9501 - 801 Ponta Delgada, Acores, Portugal.
avila@notes.uac.pt
ABSTRACT: Novocrania turbinata (POLI, 1795) is documented from the Early Pliocene strata of Santa Maria Island (Azores, Portugal), extending the range of this species to the central Northern Atlantic Ocean. This record increases the
meagre brachiopod fauna known from the Pliocene of the Azores, which so far consisted only of Terebratulina retusa (LINNAEUS, 1758). It may also represent an example of a thermophilic species that disappeared locally due to Late Pliocene-Pleistocene climate deterioration.
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