Bulletin of the Geological Society of Denmark最新文献

{"title":"Stratigraphy and geochemical composition of the Cambrian Alum Shale Formation in the Porsgrunn core, Skien–Langesund district, southern Norway.","authors":"N. Schovsbo, A. T. Nielsen, A. O. Harstad, D. Bruton","doi":"10.37570/bgsd-2018-66-01","DOIUrl":"https://doi.org/10.37570/bgsd-2018-66-01","url":null,"abstract":"The fully cored BHD-03-99 borehole (hereafter referred to as the Porsgrunn borehole and core) penetrated Ordovician and Cambrian strata in the Skien–Langesund district, southern part of the Oslo region in Norway. Hand-held X-ray fluorescence (HH-XRF) measurements combined with spectral gamma ray and density core scanning of the Middle Cambrian – Furongian Alum Shale Formation have been made and compared with similar measurements obtained on Alum Shale cores from Scania (southernmost Sweden) and Bornholm (Denmark). The Porsgrunn drill site is located in an area that was only mildly overprinted by Caledonian tectonics and represents one of the few sites in the Oslo area where a nearly untectonised sedimentary succession can be studied in terms of thickness and geochemistry. The Alum Shale Formation is 28.8 m thick in the Porsgrunn core, excluding the thickness of five 0.9–5.5 m thick dolerite sills of assumed Permian age. In the Alum Shale Formation the bulk densities are around 2.7 g/cm3 with a slightly decreasing trend up through the formation. The shale has total organic carbon (TOC) values up to 14 wt%, which is comparable to the TOC levels for the Alum Shale elsewhere in the Oslo area and for dry gas matured Alum Shale in Scania and Bornholm. The basal Furongian is characterised by a gamma ray low and an increase in Mo interpreted to reflect the Steptoean Positive Carbon Isotope Excursion (SPICE) event. The Porsgrunn core data suggest that the Mo concentration remained high also after the SPICE event. Characteristic, readily identified features in the gamma log motif are named the Andrarum gamma low (AGL), base Furongian gamma low (BFGL), Olenus triple gamma spike (OTGS) and the Peltura gamma spike (PGS). No Lower Ordovician Alum Shale is present. The 14.8 m thick Furongian part of the Alum Shale represents the Olenus, Parabolina, Leptoplastus, Protopeltura and Peltura trilobite superzones judging from log-stratigraphic correlations to Scania and Bornholm. The Middle Cambrian interval is 14.0 m thick and includes the Exsulans Limestone Bed and 1.4 m of quartz sandstone. A 0.3 m thick primary limestone bed may be an equivalent to the Andrarum Limestone Bed. The succession represents the Paradoxides paradoxissimus and P. forchhammeri superzones. The Alum Shale Formation rests atop the 13.0 m thick Lower Cambrian Stokkevannet sandstone (new informal name) that in turn directly overlies the basement. Overall, the stratigraphic development of the comparatively thin Alum Shale Formation resembles the condensed sequence seen on Bornholm.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2018-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49566924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new myriacanthid holocephalian from the Early Jurassic of Denmark.","authors":"C. Duffin, J. Milán","doi":"10.37570/bgsd-2017-65-10","DOIUrl":"https://doi.org/10.37570/bgsd-2017-65-10","url":null,"abstract":"A new myriacanthid holocephalian is described from the Hasle Formation (probably the Uptonia jamesoni subzone to the Acanthopleuroceras valdani subzone, Early Pliensbachian, Early Jurassic) of Bornholm, Denmark, on the basis of isolated upper posterior (palatine) and lower posterior (mandibular) tooth plates. Oblidens bornholmensis gen. et sp. nov. differs from all other myriacanthids for which the same dental elements are known, in the distribution of the hypermineralised tissue covering the occlusal surfaces of the tooth plates, and the arrangement of the ridges transecting the tooth plate surface and so varying their surface relief. Oblidens is the first myriacanthid holocephalian to be recorded both from the Pliensbachian and from Denmark. The presence of a further, undetermined myriacanthid tooth plate is noted from the same locality.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2017-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45661736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Graptolite biostratigraphy of the lower Silurian of the Sommerodde-1 core, Bornholm, Denmark","authors":"D. K. Loydell, N. Walasek, N. Schovsbo, A. T. Nielsen","doi":"10.37570/bgsd-2017-65-09","DOIUrl":"https://doi.org/10.37570/bgsd-2017-65-09","url":null,"abstract":"The Sommerodde-1 core provides a continuous record through the subsurface of southern Bornholm from the Wenlock Series (Silurian) through to the Lower Cambrian. The Silurian graptolite biostratigraphy of the core is described. For the Rhuddanian and Aeronian (lower and middle Llandovery), the succession and thickness of biozones are very similar to those in the Øleå rivulet nearby. For the upper Llandovery, the lower Telychian Spirograptus guerichi and Sp. turriculatus biozones are significantly thicker in the core than in Øleå, whilst the uppermost Telychian (represented by more than 30 m of strata in nearby sections) is largely absent in the core. This is likely to be a reflection of synsedimentary faulting influencing deposition. It has previously been suggested that much of the Sheinwoodian is missing on Bornholm; this is not the case. The Sheinwoodian is represented by an apparently continuous sequence, at least 31 m thick, in the Sommerodde-1 core.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2017-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42941328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stratigraphy of the marine Lower Triassic succession at Kap Stosch, Hold with Hope, North-East Greenland","authors":"F. Surlyk, M. Bjerager, S. Piasecki, L. Stemmerik","doi":"10.37570/bgsd-2017-65-07","DOIUrl":"https://doi.org/10.37570/bgsd-2017-65-07","url":null,"abstract":"","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2017-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48794779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review of the danian vertebrate fauna of southern Scandinavia","authors":"J. Adolfssen, J. Milán, M. Friedman","doi":"10.37570/BGSD-2017-65-01","DOIUrl":"https://doi.org/10.37570/BGSD-2017-65-01","url":null,"abstract":"The vertebrate fauna in the Danian deposits of Denmark and southern Sweden is reviewed. Remains of sharks and bony fishes are widely distributed but not common in the Danian limestones, with the exception of the K/Pg-boundary clay, the Fiskeler Member, at the UNESCO World Heritage Site Stevns Klint, which can include substantial quantities of shark teeth and fragments of bony fishes. Articulated remains of bony fishes are known from the Fiskeler Member at Stevns Klint and the København Limestone Formation in the Limhamn quarry. Sharks are only found as isolated teeth and rare isolated vertebrae. The gavialoid crocodylian Thoracosaurus is represented by a complete skull and associated postcranial material and an additional jaw fragment from the Limhamn quarry. Remains of a crocodylian skull, a cervical vertebra, a limb bone and isolated teeth have been found in the Faxe quarry, and a single possibly alligatorid tooth is known from the basal conglomerate of the Lellinge Greensand Formation from now closed exposures below Copenhagen. Fragmentary turtle material has been found in the Faxe and Limhamn quarries and in the København Limestone in Copenhagen, and bird remains are exclusively known from the Limhamn quarry. Despite the fragmentary nature of many of the finds, the total picture of the vertebrate fauna of southern Scandinavia is quite diverse comprising four classes, 23 orders, 41 families and 54 identifiable genera of which most can be identified to species level.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2017-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45345898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The ongoing search for the oldest rock on the Danish island of Bornholm: new U-Pb zircon ages for a quartz-rich xenolith and country rock from the Svaneke Granite","authors":"T. Waight, S. Serre, Sebastian H. Næsby, T. Thomsen","doi":"10.37570/bgsd-2017-65-06","DOIUrl":"https://doi.org/10.37570/bgsd-2017-65-06","url":null,"abstract":"The ongoing search for the oldest rock on the Danish island of Bornholm: new U-Pb zircon ages for a quartz-rich xenolith and country rock from the Svaneke Granite. by pp. Previous geochronological studies on the Danish island of Bornholm have not identified any rocks older than c. 1.46 Ga. New LA-ICP-MS U-Pb zircon ages are presented for a xenolith within, and the country rock gneiss adjacent to, the Svaneke Granite on Bornholm. The xenolith is fine-grained and quartz-rich and was likely derived from either a quartz-rich sedimentary protolith or a hydrother-mally altered felsic volcanic rock. The relatively fine-grained felsic nature of the country rock gneiss and the presence of large zoned feldspars that may represent phenocrysts suggest its protolith may have been a felsic volcanic or shallow intrusive rock. A skarn-like inclusion from a nearby locality likely represents an originally carbonate sediment and is consistent with supracrustal rocks being present at least locally. Zircon data from the xenolith define an upper intercept age of 1483 ± 12 Ma (2 σ , MSWD = 2.5) with a poorly defined lower intercept age of 474 ± 250 Ma, and a weighted average 207 Pb/ 206 Pb age of 1477.9 ± 4.6 Ma; both these ages are older than the host Svaneke Granite (weighted average 207 Pb/ 206 Pb age of 1465.0 ± 4.8 Ma). Zircons from the gneiss define an upper intercept age of 1477.7 ± 6.8 Ma when anchored at 0 Ma, and a weighted average 207 Pb/ 206 Pb age of 1475.4 ± 6.6 Ma which overlaps statistically with the Svaneke Granite age. These ages are currently the oldest ages determined for in situ rocks on Bornholm. Evidence for substantially older basement lithologies (e.g. 1.8 Ga as observed in southern Sweden) remains absent. The zircons display clear oscillatory zoning, have Th/U typical of magmatic zircons and in some cases preserve inherited cores, all of which suggest that the ages are robust and do not represent resetting due to incorporation within or intrusion by the Svaneke Granite. Inherited zircons are not common; they have ages ( c . 1.6–1.8 Ga) that are similar to those observed in other felsic basement lithologies on Bornholm. These new results suggest that prior to intrusion of the Svaneke Granite, the upper crust on Bornholm was dominated, at least locally, by lithologies similar in composition to the currently exposed felsic basement. The protoliths to the two samples investigated here must have been buried to mid-crustal depths over a relatively short time period ( c . 10 Ma) prior to intrusion of the Svaneke Granite. This suggests a dynamic tectonic environment and is consistent with evidence for broadly simultaneous magmatism and deformation in basement rocks at 1.46 Ga in southern Scandinavia and burial and metamorphism of sediments in southern Skåne.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69889969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glacial erratic boulders from Jutland, Denmark, feature an uppermost lower Cambrian fauna of the Lingulid Sandstone Member of Västergötland, Sweden","authors":"Thomas Weidner, G. Geyer, J. R. Ebbestad, Volker Seckendorff von","doi":"10.37570/bgsd-2015-63-06","DOIUrl":"https://doi.org/10.37570/bgsd-2015-63-06","url":null,"abstract":"Reinvestigation of glacial erratic boulders from Jutland, Denmark, and from northern Germany,has revealed a moderately diverse fauna with the trilobites Holmiella? sp., Epichalnipsus anartanus,Epic ...","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69890411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Depositional environments of Lower Cretaceous (Ryazanian– Barremian) sediments from Wollaston Forland and Kuhn Ø, North-East Greenland","authors":"Sebastian Pauly, J. Mutterlose, P. Alsen","doi":"10.37570/BGSD-2013-61-02","DOIUrl":"https://doi.org/10.37570/BGSD-2013-61-02","url":null,"abstract":"","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2013-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69889851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coastal evolution of a cuspate foreland (Flakket, Anholt, Denmark) between 2006 and 2010.","authors":"L. Clemmensen, M. Bendixen, L. Nielsen, S. Jensen, Louise Schrøder","doi":"10.37570/BGSD-2011-59-04","DOIUrl":"https://doi.org/10.37570/BGSD-2011-59-04","url":null,"abstract":"Flakket is a cuspate marine foreland on the north coast of Anholt in the Kattegat sea. it is composed of a number of gravel-rich beach ridges typically covered by aeolian sand and intervening swales and wetlands including a relatively large lagoon. the most recent evolution of the coastline of this marine foreland between may 2006 and september 2010 is documented in this paper. Flakket is under erosion on its northwestern side, which has retreated up to 40 m during the observation period. the shoreline of the northeastern side of the beach-ridge plain moved up to 70 m in a seaward direction during the same period.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2011-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69889724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Walter Kegel Christensen\u000025 May 1942 – 18 October 2002","authors":"F. Schmid, E. Håkansson, F. Surlyk","doi":"10.37570/bgsd-2005-52-19","DOIUrl":"https://doi.org/10.37570/bgsd-2005-52-19","url":null,"abstract":"Our friend and colleague Walter Kegel Christensen died prematurely at the age of 60 years, at the peak of his career. This commemorative volume gathers the tributes from a wide range of his scientific friends and colleagues.","PeriodicalId":55310,"journal":{"name":"Bulletin of the Geological Society of Denmark","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2005-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69889902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}