Finn forfatter "Hammer, Øyvind"

Viser treff 1-17 av 17

  • A new age model for the Ordovician (Sandbian) K-bentonites in Oslo, Norway 
    Ballo, Eirik Magnus Gottschalk; Augland, Lars Eivind; Hammer, Øyvind; Svensen, Henrik (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    During the Late Ordovician, large explosive volcanic eruptions deposited worldwide K-bentonites, including the Millbrig and Deicke K-bentonites in North America and the Kinnekulle K-bentonite in Scandinavia. We have studied ...
  • A new high-resolution stratigraphic and palaeoenvironmental record spanning the End-Permian Mass Extinction and its aftermath in central Spitsbergen, Svalbard 
    Zuchuat, Valentin; Sleveland, Arve; Twitchett, Richard; Svensen, Henrik; Turner, Holly E; Augland, Lars Eivind; Jones, Morgan Thomas; Hammer, Øyvind; Hauksson, Bjarki; Haflidason, Haflidi; Midtkandal, Ivar; Planke, Sverre (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    Research on the Permian-Triassic boundary (PTB) along the northern margins of Pangaea (exposed today in the Arctic region) has been heavily reliant on field observations, where data resolution was consequently determined ...
  • Are Early Triassic extinction events associated with mercury anomalies? A reassessment of the Smithian/Spathian boundary extinction 
    Hammer, Øyvind; Jones, Morgan Thomas; Schneebeli-Hermann, Elke; Hansen, Bitten Bolvig; Bucher, Hugo (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)
    High concentrations of mercury, possibly connected with widespread volcanism of the Siberian Traps, have previously been associated with the Smithian/Spathian (Early Triassic) boundary (SSB) in the Sverdrup Basin, Tethyan ...
  • Beak and skull shapes of human commensal and non-commensal house sparrows Passer domesticus 
    Riyahi, Sepand; Hammer, Øyvind; Arbabi, Tayebeh; Sánchez, Antonio; Roselaar, Cees S; Aliabadian, Mansour; Sætre, Glenn-Peter (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2013)
    Background The granivorous house sparrow Passer domesticus is thought to have developed its commensal relationship with humans with the rise of agriculture in the Middle East some 10,000 years ago, and to ...
  • Bivalve beds reveal rapid changes in ocean oxygenation in the Boreal Middle Triassic – a case study from Svalbard, Norway 
    Engelschiøn, Victoria Sjøholt; Bernhardsen, Sofie; Wesenlund, Fredrik; Hammer, Øyvind; Hurum, Jørn Harald; Mørk, Atle (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    A fossil-rich interval in the organic rich marine black mudstone of the Middle Triassic Botneheia Formation on eastern Svalbard was logged in high-resolution on an extremely well exposed section with emphasis on bivalve ...
  • A climatic trigger for the giant Troll pockmark field in the northern North Sea 
    Mazzini, Adriano; Svensen, Henrik; Forsberg, Carl Fredrik; Linge, Henriette; Lauritzen, Stein-Erik; Haflidason, Haflidi; Hammer, Øyvind; Planke, Sverre; Tjelta, Tor-Inge (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)
    Pockmarks are seafloor craters usually formed during methane release on continental margins. However, the mechanisms behind their formation and dynamics remain elusive. Here we report detailed investigations on one of the ...
  • Decrypting Magnetic Fabrics (AMS, AARM, AIRM) Through the Analysis of Mineral Shape Fabrics and Distribution Anisotropy 
    Mattsson, Tobias; Petri, Benoît; Almqvist, Bjarne S.G.; McCarthy, William; Burchardt, Steffi; Palma, Octavio; Hammer, Øyvind; Galland, Olivier (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Anisotropy of magnetic susceptibility (AMS) and anisotropy of magnetic remanence (AARM and AIRM) are efficient and versatile techniques to indirectly determine rock fabrics. Yet, deciphering the source of a magnetic fabric ...
  • Integrating subsurface and outcrop data of the Middle Jurassic to Lower Cretaceous Agardhfjellet Formation in central Spitsbergen 
    Koevoets, Maayke Jacqueline; Hammer, Øyvind; Olaussen, Snorre; Senger, Kim; Smelror, Morten (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The Longyearbyen CO2 storage project drilling and coring campaign in central Spitsbergen provided new insights on the shale-dominated Middle Jurassic to Lower Cretaceous Agardhfjellet Formation, which is the onshore ...
  • Is the hyoid a constraint on innovation? A study in convergence driving feeding in fish-shaped marine tetrapods 
    Delsett, Lene Liebe; Pyenson, Nicholas; Miedema, Feiko; Hammer, Øyvind (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Abstract The hyoid apparatus is essential for underwater feeding in marine tetrapods, but it is unclear whether this complex has evolved as convergently as other traits, such as dentition or locomotion. Here we compare the ...
  • Linking geology and microbiology: Inactive pockmarks affect sediment microbial community structure 
    Haverkamp, Thomas Hendricus Augustus; Hammer, Øyvind; Jakobsen, Kjetill Sigurd (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    Pockmarks are geological features that are found on the bottom of lakes and oceans all over the globe. Some are active, seeping oil or methane, while others are inactive. Active pockmarks are well studied since they harbor ...
  • Mesozoic marine reptiles from Spitsbergen and their ecosystems 
    Delsett, Lene Liebe; Druckenmiller, Patrick Scott; Hammer, Øyvind; Hryniewicz, Krzysztof; Knutsen, Espen Madsen; Koevoets, Maayke Jacqueline; Nakrem, Hans Arne; Roberts, Aubrey Jane; Hurum, Jørn Harald (Journal article / Tidsskriftartikkel / SubmittedVersion, 2019)
    In the Mesozoic seas, the apex predators were reptiles. From the Arctic archipelago of Svalbard, the Spitsbergen Mesozoic Research Group has excavated numerous well preserved marine reptile skeletons in order to understand ...
  • New late jurassic teleost remains from the agardhfjellet formation, Spitsbergen, Svalbard 
    Koevoets, Maayke Jacqueline; Hurum, Jørn Harald; Hammer, Øyvind (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The Agardhfjellet Formation (Middle Jurassic to lowermost Cretaceous) of Svalbard (Norwegian Arctic) is well known for its abundant and unique marine reptile fauna, of ichthyosaurs and plesiosaurs. In an attempt to reconstruct ...
  • Stratigraphy and age of the Grippia niveau bonebed, Lower Triassic Vikinghøgda Formation, Spitsbergen 
    Hansen, Bitten Bolvig; Hammer, Øyvind; Nakrem, Hans Arne (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    We report on a newly excavated Spathian (Lower Triassic) bonebed on Marmierfjellet, Central Spitsbergen. The bonebed contains a varied material of bones and teeth from marine vertebrates along with conodont elements. The ...
  • Structure and function of respiratory turbinates in phocid seals 
    Mason, Matthew J.; Wenger, Lea M.D.; Hammer, Øyvind; Blix, Arnoldus S (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    In terrestrial mammals, the respiratory turbinate bones within the nasal cavity are employed to conserve heat and water. In order to investigate whether environmental temperature affects respiratory turbinate structure in ...
  • The history of exploration and stratigraphy of the Early to Middle Triassic vertebrate-bearing strata of Svalbard (Sassendalen Group, Spitsbergen) 
    Hurum, Jørn Harald; Engelschiøn, Victoria Sjøholt; Økland, Inghild Halvorsen; Bratvold, Janne; Ekeheien, Christina; Roberts, Aubrey Jane; Delsett, Lene Liebe; Hansen, Bitten Bolvig; Mørk, Atle; Nakrem, Hans Arne; Druckenmiller, Patrick Scott; Hammer, Øyvind (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The palaeontology of the Lower to Middle Triassic succession in Spitsbergen has been studied for more than a century and a half. Our ability to properly interpret the evolutionary and ecological implications of the faunas ...
  • The origin of telemarkites from the mesoproterozoic of telemark, Norway 
    Gyøry, Emil; Hammer, Øyvind; Jorde, Knut; Nakrem, Hans Arne; Swajda, Michael; Domeier, Mathew (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The possible macrofossil Telemarkites enigmaticus from the Mesoproterozoic Gjuve Formation, Telemark supracrustals, southern Norway, was described by Dons in 1959. We here present finds of similar, but larger structures ...
  • The Slottsmøya marine reptile Lagerstätte: depositional environments, taphonomy and diagenesis 
    Delsett, Lene Liebe; Novis, Linn Kristin; Roberts, Aubrey Jane; Koevoets, Maayke Jacqueline; Hammer, Øyvind; Druckenmiller, Patrick Scott; Hurum, Jørn Harald (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2016)
    The Late Jurassic Slottsmøya Member Lagerstätte on Spitsbergen offers a unique opportunity to study the relationships between vertebrate fossil preservation, invertebrate occurrences and depositional environment. In this ...