Contents of 52/1
Holm, P.M., Heaman, L.M. & Pedersen, L.E.:
First direct age determinationfor the Kelseaa Dolerite Dyke, Bornholm, Denmark
Milàn, J. & Bromley, R.G.:
Dinosaur footprints from the Middle Jurassic Bagå Formation, Bornholm, Denmark.
Lindgren, J.:
Dental and vertebral morphology of the enigmatic mosasaurDollosaurus (Reptilia, Mosasauridae) from the lower Campanian (Upper Cretaceous) of southern Sweden
Schmidt, A.G., Riisager, P., Abrahamsen, N., Riisager, J., Pedersen A. & van der Voo, R.:
Palaeomagnetism of Eocene Talerua Member lavas on Hareøen, West Greenland
Knudsen, M.F., Abrahamsen, N. & Riisager, P. :
A rock- and palaeomagnetic study ofgeologically recent lavas and 1995 volcanic glass on Fogo (Cape Verde Islands).
Jørgensen, F., Sandersen, P.B.E., Auken, E., Lykke-Andersen, H. & Sørensen, K.:
Contributions to the geological mapping of Mors, Denmark – A study based on a large-scale TEM survey.
Contents of 52/2
Schmid, F. Håkansson, E. & Surlyk, F.
Walter Kegel Christensen 25 May 1942 – 18 October 2002
Heinberg, C.:
Morphotype biostratigraphy, diachronism, and bivalve recovery in the earliest Danian of Denmark.
Machalski, M. & Heinberg, C. :
Evidence for ammonite survival into the Danian (Paleogene) from the Cerithium Limestone at Stevns Klint, Denmark
Rasmussen, J.A., Heinberg, C. & Håkansson, E.:
Planktonic foraminifers, biostratigraphy and the diachronous nature of the lowermost Danian Cerithium Limestone at Stevns Klint, Denmark
Jagt, J.W.M. :
The youngest pelagic crinoids (latest Maastrichtian, the Netherlands).
Packer, S.R. & Hart, M.B.:
Coniacian–Santonian Radiolaria from the Upper Cretaceous of Bornholm, Denmark: A preliminary investigation
Košták, M. :
Goniocamax christenseni n. sp. (Belemnitellidae, Belemnitida) – a new species from the Upper Cretaceous of Russia.
Gale, A.S., Bengtson, P. & Kennedy, W.J. :
Ammonites at the Cenomanian–Turonian boundary in the Sergipe Basin, Brazil
Kollmann, H.A. :
Marine Palaeobiogeography of the Central European Late Cretaceous
Alsen, P. & Rawson, P. F. :
The Early Valanginian (Early Cretaceous) ammonite Delphinites (Pseudogarnieria) from North-East Greenland.
Harper, D.A.T., Alsen, P., Owen, E.F. & Sandy, M.R. :
Early Cretaceous brachiopods from North-East Greenland: Biofacies and biogeography.
Surlyk, F. & Noe-Nygaard, N. :
A forced regressive shelf-margin wedge formed by transition-slope progradation: lowermost Cretaceous Rauk Plateau Member, Jameson Land, East Greenland
Stouge, S.:
Barrandegnathus n. gen. (conodonta) from the Komstad Limestone (lower Mid Ordovician), Scandinavia, and its palaeogeographical significance
First direct age determinationfor the Kelseaa Dolerite Dyke, Bornholm, Denmark
Holm, Paul M., Heaman, Larry M. & Pedersen, Lise E. 2005–11–15: First direct age determination for the Kelseaa Dolerite Dyke, Bornholm, Denmark. Bulletin of the Geological Society of Denmark, Vol.52, pp. 1–6.
https://doi.org/10.37570/bgsd-2005-52-01
Abstract: The Danish island Bornholm on the southwestern margin of the Baltic Shield was subject to dyke injection during the Proterozoic. The dykes probably result from several magmatic events. We present U-Pb geochronological data for the largest of the dykes, the tholeiitic Kelseaa dyke. The resulting age, 1326 ±10 (2σ) Ma, places the dyke significantly earlier in the Proterozoic than previously assumed. No other dykes of this age have been reported from the western part of the Baltic Shield. The NE–SW strike of the Kelseaa dyke is evidence for extension oblique to the border of the Baltic Shield.The Kelseaa dyke is the first evidence for this event that was subsequent to the emplacement of theBornholm and Karlshamn (SE Sweden) granites and prior to the intrusion of the Central Scandinavian Dolerite Group, and possibly also the majority of mafic dykes on Bornholm.
Keywords: Baltic Shield, Proterozoic, mafic dyke, U-Pb baddeleyite.
Addresses:
Paul M. Holm [ paulmh [at] geol [dot] ku [dot] dk ] and L.E. Pedersen, Geological Institute, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen, Denmark,
L.M. Heaman, Department of Earth, Atmospheric Sciences, University of Alberta, Edmonton, T6G 2E3 Canada
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Dinosaur footprints from the Middle Jurassic Bagå Formation, Bornholm, Denmark
Milàn, J. & Bromley, R.G. 2005–11–15: Dinosaur footprints from the Middle Jurassic Bagå Formation, Bornholm, Denmark. Bulletin of the Geological Society of Denmark, Vol. 52, pp. 7–15.
https://doi.org/10.37570/bgsd-2005-52-02
Abstract: Dinosaur footprints have been found preserved on sandstone blocks discarded from the flooded clay pit Pyritsøen, south of Hasle, Bornholm. The sandstone belongs to the Middle Jurassic Bagå Formation, but the exact horizon is not known. Palynological studies confirm that the sandstone blocks originate from the Bagå Formation. Two specimens were collected, one showing two footprints from a sauropod dinosaur having a foot length of 68 cm, and a small pentadactyl footprint, 26cm long, interpreted as deriving from an armoured dinosaur. These are the first dinosaur footprints recorded from Denmark.
Keywords: Dinosaur footprints, sauropod, Middle Jurassic, Bornholm, Denmark.
Addresses:
Jesper Milàn [ milan [at] geol [dot] ku [dot] dk ], University of Copenhagen, Geological Institute, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark.
Richard G. Bromley [ rullard [at] geol [dot] ku [dot] dk ], University of Copenhagen, Geological Institute, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark.
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Dental and vertebral morphology of the enigmatic mosasaur Dollosaurus (Reptilia, Mosasauridae) from the lower Campanian (Upper Cretaceous) of southern Sweden
Lindgren, J. 2005–11–15: Dental and vertebral morphology of the enigmatic mosasaur Dollosaurus (Reptilia, Mosasauridae) from the lower Campanian (Upper Cretaceous) of southern Sweden. Bulletin of the Geological Society of Denmark, Vol. 52, pp. 17–25.
https://doi.org/10.37570/bgsd-2005-52-03
Abstract: Teeth, jawbone fragments and vertebrae of an unusual mosasaurine mosasaur, Dollosaurus, have been collected from marine strata of latest early Campanian age in the Kristianstad Basin, southern Sweden. This material enables a detailed analysis of dental and vertebral characters, which, in turn, are used to tentatively distinguish Dollosaurus from the closely related globidensine Prognathodon. However, the evidence is contradictory, and two evolutionary scenarios are possible: (1) the two genera represent separate offshoots of a single lineage; or (2) Dollosaurus represents the most basal ‘Prognathodon-like’ taxon known so far.
Keywords: Campanian, Cretaceous, Mosasauridae, Dollosaurus, Prognathodon, Sweden, teeth, vertebrae.
Addresses:
Johan Lindgren [ johan [dot] lindgren [at] geol [dot] lu [dot] se ], Geological Museum, University of Copenhagen, Øster Voldgade5–7, DK-1350 København K, Denmark, and Department of Geology, GeoBiosphere Science Centre, LundUniversity, Sölvegatan 12, SE-223 62 Lund, Sweden.
Palaeomagnetism of Eocene Talerua Member lavas on Hareøen, West Greenland
Schmidt, A.G., Riisager, P., Abrahamsen, N., Riisager, J., Pedersen A. & van der Voo, R. 2005–11–15: Palaeomagnetism of Eocene Talerua Member lavas on Hareøen, West Greenland. Bulletin of the Geological Society of Denmark, Vol. 52, pp. 27–38.
https://doi.org/10.37570/bgsd-2005-52-04
Abstract: The results of a palaeomagnetic sampling carried out along two vertical profiles (altogether 19 lavaflows, 126 samples) covering the entire stratigraphy of the Talerua Member lavas (~39 Myr old) that outcrop on the island Hareøen are presented and represent some of the youngest volcanism in the West Greenland flood volcanic province. Rock magnetic experiments and microprobe analysis demonstrate that the dominant magnetic mineral in all studied lavas is titanomagnetite that has experienced variable amounts of high temperature deuteric oxidation as well as low temperature hydro-thermal oxidation. Based on detailed demagnetization experiments, well-defined palaeomagnetic site-mean directions were isolated from all 19 lavas. The composite profile contains two magnetic polarity zones suggesting a maximum duration of Talerua Member volcanism of ~1.4 Ma. After grouping flows having the same remanent magnetic field direction, 13 individual readings of the palaeomagnetic fields were obtained. The palaeomagnetic pole with coordinates 76.3°N, 201.5°E (A95=7.4°, K=32.7, N=13) is in good accordance with palaeomagnetic poles from other continents rotated back to Greenland using plate kinematic rotation poles.
Keywords: Palaeomagnetism, magnetic polarity, West Greenland, Paleogene, volcanics, North Atlantic igneous province.
Addresses:
Anne G. Schmidt, Mærsk Olie og Gas AS, Esplanaden 50, DK-1263 Copenhagen K, Denmark;
Peter Riisager [ pri [at] snm [dot] ku [dot] dk ], Geological Museum, Øster Voldgade 5-7, DK-1350 Copenhagen K, Denmark and University of Lund, GeoBiosphere Science Centre, Sölvegatan 12, S-223 62 Lund,Sweden;
Niels Abrahamsen [ abraham [at] geo [dot] au [dot] dk ], Department of Earth Sciences, Aarhus University,Finlandsgade 8, DK-8200 Aarhus N, Denmark;
Janna Riisager [ janna_riisager [at] hotmail [dot] com ]
Asger KenPedersen [ akp [at] snm [dot] ku [dot] dk ], Geological Museum, Øster Voldgade 5-7, DK-1350 Copenhagen K, Denmark;
Rob van der Voo [ voo [at] umich [dot] edu ], Department of Geological Sciences, University of Michigan, Ann Arbor,MI 48109-1063, USA.
A rock- and palaeomagnetic study ofgeologically recent lavas and 1995 volcanic glass on Fogo (Cape Verde Islands)
Knudsen, M.F., Abrahamsen, N. & Riisager, P. 2005–11–15. A rock- and palaeomagnetic study of geologically recent lavas and 1995 volcanic glass on Fogo (Cape Verde Islands). Bulletin of the Geological Society of Denmark, Vol. 52, pp. 39–52.
https://doi.org/10.37570/bgsd-2005-52-05
Abstract: Fogo is the only island in the Cape Verde archipelago with accounts of historical volcanic activity. Here we present palaeomagnetic data from seven geologically recent lava flows on Fogo, including one glassy, volcanic flow from the eruption in 1995. Almost all samples behaved well during alternating-field (AF) and thermal demagnetisation, and the characteristic remanent magnetisations (ChRMs) were generally easily isolated. The dominant magnetic mineral in all flow units, including the glassy flow, is titanomagnetite with a varying titanium content. The non-glassy flow units alldisplay pseudo-single-domain (PSD) behaviour, whereas the hysteresis parameters for the glassy flow unit tend to plot in a region associated with mixtures of superparamagnetic (SP) and single-domain (SD) grains. Despite historical accounts of the eruptive activity on Fogo it was impossible toobtain unique correlations between the historical flow flelds and the non-glassy flow units presented in this study. One of six non-glassy flow units yields a direction consistent with existing approximative reference curves for the historical secular variation on Fogo. Consequently, we suspect that some of the non-glassy flow units have been subjected to post-cooling block rotation. The glassy flow from 1995 proved to be a reasonable recorder of the geomagnetic fleld, yielding a direction (dec = 353.8° and inc = 12.9°), quite similar to the International Geomagnetic Reference Field(1995) for this site location (dec = 346.8° and inc = 14.4°).
Keywords: Fogo, Cape Verde Islands, rock magnetism, hysteresis, palaeosecular variation, volcanicglass.
Addresses:
Mads Faurschou Knudsen [ madsk [at] earth [dot] ox [dot] ac [dot] uk ], Department of Earth Sciences, University of Aarhus,Finlandsgade 6–8, DK-8200 Aarhus N., Denmark, present address: Department of Earth Sciences, Univer-sity of Oxford, Parks Road, Oxford OX1 3PR, United Kingdom;
Niels Abrahamsen [ abraham [at] geo [dot] au [dot] dk ],Department of Earth Sciences, University of Aarhus, Finlandsgade 6–8, DK-8200 Aarhus N., Denmark,
Peter Riisager [ Peter [dot] Riisager [at] geol [dot] lu [dot] se ], Geological Museum, University of Copenhagen, Øster Voldgade5–7, DK-1350 Copenhagen K., Denmark, present address: GeoBiosphere Science Centre, Quaternary Sciences, University of Lund, Sölvegatan 12, S-223 62 Lund, Sweden.
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Contributions to the geological mapping of Mors, Denmark – A study based on a large-scale TEM survey
Jørgensen, F., Sandersen, P.B.E., Auken, E., Lykke-Andersen, H. & Sørensen, K. 2005–11–15. Contributions to the geological mapping of Mors, Denmark – A study based on a large-scale TEM survey. Bulletin of the Geological Society of Denmark, Vol. 52, pp. 53–75.
https://doi.org/10.37570/bgsd-2005-52-06
Abstract: Recent improvements of the transient electromagnetic (TEM) method provide unprecedented capabilities of imaging geological features in the uppermost few hundred metres of the subsurface. This is documented with an example from the island of Mors, Northern Jutland, Denmark, where 2655 TEM soundings have been acquired as a part of Viborg County’s hydrogeological investigation programme. Horizontal aspects of the interpreted TEM soundings are presented in thematic maps revealing variations of resistivities in specified depth intervals and depths to the resistivity basement, i.e. the deepest recorded low-resistive layer. Vertical aspects are displayed in cross-sections.The dense coverage of TEM soundings, combined with borehole logs, allows the precise delineation of major geological features. These comprise the Mors salt diapir, intricate systems of buried Quaternary valleys and several glaciotectonic complexes, all contributing to a complicated geological framework for the island. The layers above the salt diapir, which have been subject to severe erosion, are distinctly imaged in the thematic maps, even though they are frequently dissected by buried valleys. At least four generations of buried valleys can be identified on the basis of their preferred orientations; these were mainly formed during early glaciations. Large parts of the island were glaciotectonically deformed during the Late Weichselian subsequent to valley formation, and it is suggested that the presence of deep valleys may have affected the process of glaciotectonic deformation.
Keywords: Transient electromagnetic; TEM; hydrogeophysics; salt diapirs; buried valleys; glaciotectonic deformation; subglacial; Quaternary; Pleistocene; Mors; Denmark.
Addresses:
Flemming Jørgensen [ fj [at] vejleamt [dot] dk ], Vejle Amt, Damhaven 12, DK-7100 Vejle, Denmark.
Peter B.E. Sandersen [ psa [at] watertech [dot] dk ], Watertech a/s, Søndergade 53, DK-8000 Aarhus C, Denmark.
Esben Auken[ esben [dot] auken [at] geo [dot] au [dot] dk ], Hydrogeophysics Group, Department of Earth Sciences, University of Aarhus,DK-8200 Aarhus N, Denmark.
Holger Lykke-Andersen [ hla [at] geo [dot] au [dot] dk ], Department of Earth Sciences,University of Aarhus, DK-8200 Aarhus N, Denmark.
Kurt Sørensen [ kurt [dot] sorensen [at] geo [dot] au [dot] dk ], Hydrogeophysics Group, Department of Earth Sciences, University of Aarhus, DK-8200 Aarhus N, Denmark.
Morphotype biostratigraphy, diachronism, and bivalve recovery in the earliest Danian of Denmark
Heinberg, C. 2005-12-31. Morphotype biostratigraphy, diachronism, and bivalve recovery in the earliest Danian of Denmark. Bulletin of the Geological Society of Denmark, Vol. 52, pp. 81–95.
https://doi.org/10.37570/bgsd-2005-52-07
Abstract: Morphotype ratios among planktonic foraminifers are used as a stratigraphic tool within the Cerithium Limestone, part of the lowermost Danian type sequence at Stevns Klint, Denmark. Enhanced stratigraphic resolution provided by the method indicates that the base of the limestone is diachronous, becoming progressively younger northwards. The bivalve fauna of the Cerithium Limestone represents an early recovery fauna exhibiting a gradual recovery pattern from zero species at the stratigraphic base of the limestone to a rather constant level about 20 species through the upper half of the unit. A continuous cline, covering the entire stratigraphic interval, results when using evenness or dominance, rather than species number, as a community measure. This reflects a continued growth in equitability and decline in dominance, also after the levelling of the species number.
Keywords: Cerithium Limestone, diachroniety, planktonic foraminifer morphotype stratigraphy, Danian, Stevns Klint, K–T boundary, bivalve recovery.
Addresses:
Claus Heinberg [ heinberg [at] ruc [dot] dk ] Department of Environment,Technology and Social Studies, Roskilde University Center, P.O. Box 260, DK 4000, Roskilde, Denmark.
Evidence for ammonite survival into the Danian (Paleogene) from the Cerithium Limestone at Stevns Klint, Denmark
Machalski, M. & Heinberg, C. 2005-12-31. Evidence for ammonite survival into the Danian (Paleogene) from the Cerithium Limestone at Stevns Klint, Denmark. Bulletin of the Geological Society of Denmark, Vol. 52, pp. 97–111.
https://doi.org/10.37570/bgsd-2005-52-08
Abstract: Two ammonite species, Baculites vertebralis and Hoploscaphites constrictus, are recorded from the Cerithium Limestone (lower Danian, Paleogene) at Stevns Klint, Denmark. Most of the specimens represent internal and external moulds of shell fragments, the sole exception being a complete, well preserved internal mould of H. constrictus. The infilling of the body chamber and phragmocone of this specimen is indistinguishable from the surrounding limestone. The ð13C value for the phragmocone fill is 1.382, matching Danian values much better than the more positive Maastrichtian values for the fine-fraction ð13C curve of the Stevns Klint succession. Additionally, the phragmocone infill contains Operculodinella operculata, a calcareous dinocyst typical of the Danian at high latitudes. The specimen is thus interpreted to be an indigenous early Danian ammonite. In view of the mass occurrence of calcitic bryozoans, brachiopods, and bivalves in the topmost Maastrichtian chalk at Stevns Klint, the total absence of brachiopods and near-absence of bryozoans and calcitic bivalves in the Cerithium Limestone provide evidence against significant redeposition of Maastrichtian fossils into the latter unit. Consequently, all ammonites from the Cerithium Limestone studied are interpreted as early Danian survivors.
Keywords: Extinction, survival, ammonites, reworking, calcareous dinocysts, stable isotopes, K–Pg boundary, Danian, Maastrichtian, Denmark.
Addresses:
Marcin Machalski [mach [at] twarda [dot] pan [dot] pl ] Instytut Paleobiologii PAN, ul. Twarda 51/55, PL – 00-818 Warszawa, Poland.
Claus Heinberg [ heinberg [at] ruc [dot] dk ] Institut for Miljø, Teknologi og Samfund. Roskilde Universitetscenter, Box 260, DK 4000 Roskilde, Denmark.
Planktonic foraminifers, biostratigraphy and the diachronous nature of the lowermost Danian Cerithium Limestone at Stevns Klint, Denmark
Rasmussen, J.A., Heinberg, C. & Håkansson, E. 2005-12-31. Planktonic foraminifers, biostratigraphy and the diachronous nature of the lowermost Danian Cerithium Limestone at Stevns Klint, Denmark. Bulletin of the Geological Society of Denmark, Vol. 52, pp. 113–131. © 2005 by Geological Society of Denmark. ISSN 0011–6297.
https://doi.org/10.37570/bgsd-2005-52-09
Abstract: New material comprising more than four thousand specimens of planktonic foraminifers from the lowermost Danian Cerithium Limestone at Stevns Klint, Denmark, reveal significant lateral biostratigraphic differences along the 14 km long cliff. The Cerithium Limestone at Rødvig (Korsnæb) in the southern part of Stevns Klint is dominated by foraminiferal assemblages indicative of the Parvularugoglobigerina eugubina Zone (Pα). This pattern changes laterally towards the north, where the P. eugubina Zone becomes gradually thinner. At the northernmost locality investigated, Holtug quarry, the Cerithium Limestone unit is characterised solely by assemblages of the succeeding Parasubbotina pseudobulloides Subzone (P1a). This indicates that the Cerithium Limestone is diachronous and becomes gradually younger from the southern part of Stevns Klint towards the northern part. The data indicate that a hiatus including all of the P. eugubina Zone is present at the Fish Clay – Cerithium Limestone transition in the northern part of the cliff, whereas such a hiatus cannot be demonstrated in the southern part.
Keywords: Planktonic foraminifers, foraminiferal biostratigraphy, Early Danian, Cerithium Limestone, Stevns Klint
Addresses:
Jan A. Rassmussen [ janr [at] snm [dot] ku [dot] dk ], Geological Museum, University of Copenhagen, Øster Voldgade 5–7, DK-1350 Copenhagen K, Denmark (Previous address: Dept. of Stratigraphy, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K, Denmark),
Claus Heinberg, Dept. of Environment, Technology and Social Studies, Building 11.2, University Centre Roskilde, P.O. Box 260, DK-4000 Roskilde, Denmark
Eckart Håkansson, Geological Institute, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark.
The youngest pelagic crinoids (latest Maastrichtian, the Netherlands)
Jagt, J.W.M. 2005–12–31: The youngest pelagic crinoids (latest Maastrichtian, the Netherlands). Bulletin of the Geological Society of Denmark, Vol. 52, pp. 133–139. © 2005 by Geological Society of Denmark. ISSN 0011–6297.
https://doi.org/10.37570/bgsd-2005-52-10
Abstract: The roveacrinid Birgelenocrinus degraafi Jagt, 1999b, the youngest pelagic crinoid known to date, appears to be confined to the Maastricht Formation in the southeast Netherlands, ranging from the Kunrade Limestone facies (ecozone V, lower part) to within two metres below the K/T boundary (= Meerssen Member, top subunit IVf-6, ‘tuffaceous’ biocalcarenitic facies). Its disjunct distribution within this formation, i.e. occurring directly above omission surfaces or hardgrounds, suggests this is linked to local sea-level changes, which produced optimum feeding habitats. The morphology of theca and brachials show this species to have been truly pelagic; the collapse of the planktonic food chain at the end of the Cretaceous would explain the demise of this and other roveacrinids.
Keywords: Crinoids, Maastrichtian, the Netherlands, palaeobiology
Addresses:
John W.M. Jagt [john [dot] jagt [at] maastricht [dot] nl], Natuurhistorisch Museum Maastricht, de Bosquetplein 6-7, NL-6211 KJ Maastricht, the Netherlands.
Coniacian–Santonian Radiolaria from the Upper Cretaceous of Bornholm, Denmark: A preliminary investigation
Packer, S.R. & Hart, M.B. 2005–12–31: Coniacian–Santonian Radiolaria from the Upper Cretaceous of Bornholm, Denmark: A preliminary investigation. Bulletin of the Geological Society of Denmark, Vol. 52, pp. 141–158.
https://doi.org/10.37570/bgsd-2005-52-11
Abstract: A moderately diverse fauna of Late Cretaceous Radiolaria are described for the first time from the Arnager Limestone and Bavnodde Greensand formations exposed on the island of Bornholm (Denmark). Our preliminary investigation suggests that the fauna from the Arnager Limestone Formation is relatively abundant and is assigned to the Orbiculiforma vacaensis Subzone (Alievium praegallowayi Zone) of Coniacian age. Relatively poor recovery from the Bavnodde Greensand Formation precludes assignment to the zonation scheme of Pessagno, although, the radiolarian taxa present indicate that the formation can be no younger than Santonian. The ages given for both formations by the radiolarian faunas compare favourably with published macrofossil and microfossil data. The radiolarian faunas described are of moderate abundance and diversity when compared to contemporaneous faunas described elsewhere, particularly the Tethyan area. Maximum radiolarian abundance and diversity is reached in the middle of the Arnager Limestone Formation equating to a level of maximum water depth from the foraminiferal data. A decline in radiolarian recovery is recognised into the Bavnodde Greensand Formation and is associated with a reduction in relative water depth to inner and (?)middle shelf conditions, as indicated by foraminiferal data.
Keywords: Radiolaria, Upper Cretaceous, Coniacian, Santonian, Bornholm, Denmark
Addresses:
Stephen R. Packer [ s [dot] r [dot] packer [at] btinternet [dot] com ] Millennia Stratigraphic Consultants, 17 Brewhouse Lane, Rowsham, Buckinghamshire HP22 4QT, United Kingdom.
Malcolm B. Hart [ mhart [at] plymouth [dot] ac [dot] uk ] School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth, Devon, PL4 8AA, United Kingdom.
Goniocamax christenseni n. sp. (Belemnitellidae, Belemnitida) – a new species from the Upper Cretaceous of Russia
Košták, M. 2005–12-31: Goniocamax christenseni n. sp. (Belemnitellidae, Belemnitida) – a new species from the Upper Cretaceous of Russia. Bulletin of the Geological Society of Denmark, Vol. 52, pp. 159–166.
https://doi.org/10.37570/bgsd-2005-52-12
Abstract: A new species of Goniocamax Naidin: Goniocamax christenseni n. sp. is described from the Upper Turonian and the lowermost Coniacian strata of the Volga river region in Russia. The new species occur together with ‘primitive’ species of Goniocamax i.e. Goniocamax intermedius (Arkhangelsky) and G. surensis (Naidin), which suggests that two parallel evolutionary lineages in Goniocamax sensu Naidin, 1964 were present and both of unknown origin. The origin of G. lundgreni (Stolley) can be explained by gradual calcification of the anterior part of the guard in the intermedius/surensis group. G. christenseni n. sp. has a well calcified pseudoalveolus and an acute angle at the bottom of the ventral fissure of the wall of the pseudoalveolus. Thus, G. christenseni n. sp. resembles the first representatives of Belemnitella D’Orbigny and is considered the likely ancestor of the Belemnitella group. Phylogeny and palaeobiogeography of the Late Turonian belemnitellids (genera Praeactinocamax Naidin and Goniocamax Naidin) are discussed.
Keywords: Belemnites, Upper Cretaceous, Russia, taxonomy, palaeobiogeography.
Addresses:
Martin Košták [ kostak [at] natur [dot] cuni [dot] cz ], Institute of Geology and Palaeontology, Faculty of Science, Charles University Prague, Prague 2, Albertov 6, 128 43, Czech Republic.
Ammonites at the Cenomanian–Turonian boundary in the Sergipe Basin, Brazil
Gale, A.S., Bengtson, P. & Kennedy, W.J. 2005–12–31: Ammonites at the Cenomanian–Turonian boundary in the Sergipe Basin, Brazil. Bulletin of the Geological Society of Denmark, Vol. 52, pp. 167–191.
https://doi.org/10.37570/bgsd-2005-52-13
Abstract: Two distinctive ammonite faunas are described from the Cenomanian–Turonian boundary interval in the Sergipe Basin, Brazil. The Jardim 1 section assemblage comprises Euomphaloceras costatum Cobban, Hook & Kennedy, 1989, Burroceras transitorium Cobban, Hook & Kennedy, 1989, Pseudaspidoceras pseudonodosoides Choffat, 1898, and Vascoceras cf. gamai Choffat, 1898. This same association is found in New Mexico, where it occurs with the upper Cenomanian index fossil Neocardioceras juddii (Barrois & Guerne, 1898). On this basis the Sergipe assemblage is referred to the N. juddii Zone, and correlated with beds 79–84 of the Pueblo, Colorado section. These lie 1.14–0.63 m below the Global boundary Stratotype Section and Point (GSSP) for the base of the Turonian Stage, the base of bed 86, which corresponds to the first occurrence of the ammonite Watinoceras devonense Wright & Kennedy, 1981. The Japaratuba 16 locality in Sergipe yielded an assemblage of Pachydesmoceras kossmati Matsumoto, 1987, Watinoceras coloradoense (Henderson, 1908), Pseudaspidoceras flexuosum Powell, 1963, Pseudovascoceras nigeriense (Woods, 1911), Vascoceras globosum globosum (Reyment, 1954), V. simplex (Barber, 1957), and Pseudotissotia nigeriensis (Woods, 1911). The co-occurrence of W. coloradoense and P. flexuosum is also found in the Pueblo section, in bed 97, 1.65 m above the base of the Turonian.
These ammonite records thus allow the placement of the Cenomanian–Turonian boundary in the Sergipe-Alagoas Basin, and correlation with the Global Boundary Stratotype Section and Point at Pueblo.
Keywords: Ammonites, Cretaceous, Cenomanian, Turonian, Segipe, Brazil
Addresses:
Andrew Gale [ asg [at] nhm [dot] ac [dot] uk ], Department of Earth and Environmental Sciences, University of Greenwich, Medway Campus, Chatham, Kent ME4 4AW, UK.
Peter Bengtson [ bengtson [at] uni-hd [dot] de ], Geologisch- Paläontologisches Institut der Universität, Im Neuenheimer Feld 234, D-69120 Heidelberg, Germany.
William James Kennedy [jim [dot] kennedy [at] oum [dot] ox [dot] ac [dot] uk ], Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW, UK.
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Marine Palaeobiogeography of the Central European Late Cretaceous
Kollmann, H.A. 2005–12–31: Marine Palaeobiogeography of the Central European Late Cretaceous. Bulletin of the Geological Society of Denmark, Vol. 52, pp. 193–199.
https://doi.org/10.37570/bgsd-2005-52-14
Abstract: Late Cretaceous shallow marine mollusc assemblages show a distinct vertical differentiation into those of the inner and the outer shelf. The realms Theia (pro Tethys) and Kalais (pro Boreal, Temperate) can only be distinguished by means of inner shelf assemblages. Outer shelf assemblages are uniform across realm boundaries. The boundary between the inner and the outer shelf is biologically significant. It is interpreted to reflect the lower boundary of the tropical/subtropical surface mixed layer and extended as far north as southern Sweden in the Late Cretaceous.
Keywords: Palaeobiogeography, marine, Late Cretaceous, Europe
Addresses:
Heinz A. Kollmann [ heinz [dot] kollmann [at] nhm-wien [dot] ac [dot] at ] Naturhistorisches Museum, Vienna, Austria.
The Early Valanginian (Early Cretaceous) ammonite Delphinites (Pseudogarnieria) from North-East Greenland
Alsen, P. & Rawson, P. F. 2005–12–31: The Early Valanginian (Early Cretaceous) ammonite Delphinites (Pseudogarnieria) from North-East Greenland. Bulletin of the Geological Society of Denmark, vol. 52, pp. 201–212.
https://doi.org/10.37570/bgsd-2005-52-15
Abstract: Delphinites (Family Neocomitidae, Subfamily Platylenticeratinae) is described from Traill Ø and Wollaston Forland in North-East Greenland, where it is represented by two new species of the subgenus Pseudogarnieria: Delphinites (Pseudogarnieria) christenseni n. sp. and Delphinites (Pseudogarnieria) donovani n. sp. The material indicates the presence of equivalents of the Delphinites (Pseudogarnieria) undulatoplicatilis Zone of the Russian Platform, and of the Thurmanniceras pertransiens Zone of South-East France. These Greenland occurrences are therefore correlatable with the lowest biozones of the Valanginian Stage in both the Boreal and the Tethyan realms. The genus was previously known almost exclusively from the Russian Platform, and it has an essentially marginal Boreal distribution.
Keywords: North-East Greenland, ammonites, Neocomitidae, Platylenticeratinae, Delphinites, biostratigraphy, biogeography, Early Cretaceous, Valanginian
Addresses:
Peter Alsen [ petera [at] geol [dot] ku [dot] dk ], Geological Institute, University of Copenhagen, Øster Voldgade 10, DK- 1350 Copenhagen K, Denmark.
Peter F. Rawson [ p [dot] rawson [at] ucl [dot] ac [dot] uk ], Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK.
Early Cretaceous brachiopods from North-East Greenland: Biofacies and biogeography
Harper, D.A.T., Alsen, P., Owen, E.F. & Sandy, M.R. 2005-12-31: Early Cretaceous brachiopods from North-East Greenland: Biofacies and biogeography. Bulletin of the Geological Society of Denmark, Vol. 52, pp. 213–225.
https://doi.org/10.37570/bgsd-2005-52-16
Abstract: Augmentation and revision of the relatively diverse Valanginian brachiopod faunas from North- East Greenland confirm the existence of two mutually exclusive but broadly coeval assemblages, associated with two contrasting facies types. A Boreal, relatively shallow-water assemblage dominated by large terebratulids and ribbed rhynchonellids, including Cyrtothyris, Lamellaerhynchia and Praelongithyris characterizes the Falskebugt fauna. By contrast the Albrechts Bugt and Rødryggen fauna contains Tethyan elements, more typical of deeper water, including Lacunosella, Placothyris, Pygope and Rugitela. This early Cretaceous Out-of-Tethys migration confirms the early and persistent northward track of a proto Gulf Stream current. A new taxon, Placothyris kegeli, is described from the Albrechts Bugt and Rødryggen members of the Palnatokes Bjerg Formation.
Keywords: Brachiopods, Valanginian, palaeogeography, palaeoenvironments, North-East Greenland
Addresses:
Harper, D.A.T. [ dharper [at] snm [dot] ku [dot] dk ], Geological Museum, University of Copenhagen, Øster Voldgade 5-7, DK-1350 Copenhagen K, Denmark;
Alsen, P. [ petera [at] geol [dot] ku [dot] dk ], Geological Institute, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark;
Owen, E.F., Department of Palaeontology, The Natural History Museum, Cromwell Road, London SW7, UK,
Sandy, M.R. [ Michael [dot] Sandy [at] notes [dot] udayton [dot] edu ], Department of Geology, University of Dayton, 300 College Park, Dayton, OH 45469- 2364, USA.
A forced regressive shelf-margin wedge formed by transition-slope progradation: lowermost Cretaceous Rauk Plateau Member, Jameson Land, East Greenland
Surlyk, F. & Noe-Nygaard, N. 2005–12–31: A forced regressive shelf-margin wedge formed by transition-slope progradation: lowermost Cretaceous Rauk Plateau Member, Jameson Land, East Greenland. Bulletin of the Geological Society of Denmark, vol. 52, pp. 227–243.
https://doi.org/10.37570/bgsd-2005-52-17
Abstract: The Middle Jurassic – lowermost Cretaceous succession of Jameson Land, East Greenland records a marine, overall regressive–transgressive–regressive cycle with regressive maxima in the Late Bajocian and Late Volgian separated by a transgressive maximum in the Kimmeridgian. Smaller-scale regressive interludes took place in the Late Callovian and Mid Oxfordian. A shelf-slope-basin physiography started to develop in the Late Callovian due to increasing rifting and a relief of several hundred metres was attained during maximum end-Jurassic regression and deposition of the Volgian Raukelv Formation. The formation consists of a forestepping stack of laterally extensive shelf-edge wedges, each several tens of metres thick, composed of coarse-grained sandstone, showing highangle clinoform bedding and containing marine body and trace fossils. These clinoform beds are superimposed on the large-scale clinoforms of the shelf–slope–basin. The wedges onlap older shelf deposits in a landward direction and are overlain by thin transgressive sandstones or mudstones, or directly by the next coarse-grained wedge. The top wedge, comprising the Rauk Plateau Member, is of Late Volgian (i.e. earliest Cretaceous) age and is characterized by steep clinoforms truncated by internal erosional downlap surfaces. The clinoforms are simple avalanche beds, a few tens of centimetres thick, or they may be several metres thick and contain large-scale cross-bedded intrasets of probable tidal origin. The erosional events were associated with downshift of the succeeding clinoforms, recording minor sea-level fall and forced regression. The top surface of the Rauk Plateau wedge is incised by a system of minor channels leading to a large canyon-like valley. The wedge was deposited by transition-slope progradation below wave base during a period of sea-level stillstand punctuated by minor, stepwise falls. It provides an excellently exposed example of a laterally derived, coarse-grained shelf-margin wedge, showing high-angle clinoform bedding and representing an ancient counterpart to Holocene and Late Pleistocene prograding infralittoral wedges seen on seismic profiles across Mediterranean shelf edges.
Keywords: Late Volgian, Cretaceous, East Greenland, Raukelv Formation, Rauk Plateau Member, shelf-margin wedge, transition-slope, forced regression
Addresses:
F. Surlyk [ finns [at] geol [dot] ku [dot] dk ] & N. Noe-Nygaard [ nannan [at] geol [dot] ku [dot] dk ], Geological Institute, Geocenter Copenhagen, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark.
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Barrandegnathus n. gen. (conodonta) from the Komstad Limestone (lower Mid Ordovician), Scandinavia, and its palaeogeographical significance
Stouge, S. 2005–12–15: Barrandegnathus n. gen. (conodonta) from the Komstad Limestone (lower Mid Ordovician), Scandinavia, and its palaeogeographical significance. Bulletin of the Geological Society of Denmark, Vol. 52, pp. 245–255.
https://doi.org/10.37570/bgsd-2005-52-18
Abstract: A characteristic early Mid Ordovician conodont fauna first recorded from Bohemia is known from Morocco and southwestern Scandinavia. It is characterized by Barrandegnathus n. gen. (type species: Baltoniodus bohemicus Dzik, 1983). Barrandegnathus bohemicus is considered to be endemic to the Tornquist Sea, but it is often associated with Baltic Province conodonts. The fauna was first described from the Klabava Formation the sediments of which accumulated in the Prague Basin, Czech Republic and was subsequently recorded as reworked Ordovician conodont fauna preserved in Upper Silurian strata from Morocco and from the Komstad Limestone in southwest Scandinavia. The stratigraphical range of the species is confined to the late part of the early Mid Ordovician (Darriwilian; Volkhov Regional Stage). Barrandegnathus bohemicus probably migrated to Baltica with cold-water ocean currents moving from the high latitudinal Perunica terrane to the Gondwana supercontinent and to the southwestern margin of the Baltica continent. Baltic Province conodonts are recorded from cool-water carbonates at or just off the periphery of Gondwana. Rifting along the Gondwana margin followed by drifting of palaeocontinents and terranes towards mid-high latitudes promoted deposition of cool-water carbonates. Baltic Province conodonts are recorded from Gondwana and Gondwana derived continents. The distribution of cool-water carbonates and the associated conodont fauna shows that Baltic Province conodonts were not confined to the Baltica continent. Barrandegnathus n. gen. is introduced; the genus is represented by B. bohemicus (Dzik, 1983).
Keywords: Bornholm, Scania, conodonts, Middle Ordovician, biostratigraphy, palaeogeography, Barrandegnathus n. gen. bohemicus (Dzik, 1983).
Addresses:
Svend Stouge [ svends [at] savik [dot] geomus [dot] ku [dot] dk ], Geological Museum, Øster Voldgade 5-7, DK-1350 Copenhagen K, Denmark.
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Walter Kegel Christensen 25 May 1942 – 18 October 2002
Schmid, F. Håkansson, E. & Surlyk, F.: Walter Kegel Christensen 25 May 1942 – 18 October 2002
https://doi.org/10.37570/bgsd-2005-52-19