Blar i Bergen Open Research Archive på forfatter "Johannessen, Karen Cecilie"
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A late Paleoproterozoic (1.74 Ga) deep-sea, low-temperature, iron-oxidizing microbial hydrothermal vent community from Arizona, USA
Little, Crispin T.S.; Johannessen, Karen Cecilie; Bengtson, Stefan; Chan, Clara S.; Ivarsson, M.; Slack, John F.; Broman, Curt; Thorseth, Ingunn Hindenes; Grenne, Tor; Rouxel, Olivier J.; Bekker, Andrey (Journal article; Peer reviewed, 2021)Modern marine hydrothermal vents occur in a wide variety of tectonic settings and are characterized by seafloor emission of fluids rich in dissolved chemicals and rapid mineral precipitation. Some hydrothermal systems vent ... -
Low-temperature thermochronological and structural study of the inner Hardangerfjord area, southern Norway
Johannessen, Karen Cecilie (Master thesis, 2012-10-29)The origin of the mountainous topography in southern Norway is at present unresolved. Post-Devonian sediments are absent onshore, making quantification of crustal uplift and fault displacements difficult. Low-temperature ... -
On the biogenicity of Fe-oxyhydroxide filaments in silicified low-temperature hydrothermal deposits: Implications for the identification of Fe-oxidizing bacteria in the rock record
Johannessen, Karen Cecilie; McLoughlin, Nicola; Vullum, Per Erik; Thorseth, Ingunn Hindenes (Peer reviewed; Journal article, 2020)Microaerophilic Fe(II)‐oxidizing bacteria produce biomineralized twisted and branched stalks, which are promising biosignatures of microbial Fe oxidation in ancient jaspers and iron formations. Extracellular Fe stalks ...