Blar i forfatter "Kirsimäe, K."

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    • Oxygenated conditions in the aftermath of the Lomagundi-Jatuli Event: The carbon isotope and rare earth element signatures of the Paleoproterozoic Zaonega Formation, Russia 

      Kreitsmann, T.; Lepland, Aivo; Bau, M.; Prave, A.R.; Paiste, Kärt; Mänd, K.; Sepp, H.; Martma, T.; Romashkin, A.E; Kirsimäe, K. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-09)
      The c. 2.0 Ga Zaonega Formation of the Onega Basin (NW Russia) has been central in efforts to understand what led to the initial rise (Great Oxidation Event, GOE) and postulated fall in free atmospheric oxygen and associated high-amplitude carbon cycle excursions, the Lomagundi-Jatuli Event (LJE) and subsequent Shunga Event during Paleoproterozoic time. The Formation accumulated shortly after the ...

    • The pyrite multiple sulfur isotope record of the 1.98 Ga Zaonega Formation: Evidence for biogeochemical sulfur cycling in a semi-restricted basin 

      Paiste, Kärt; Pellerin, André; Zerkle, A.L.; Kirsimäe, K.; Prave, A.R.; Romashkin, A.E; Lepland, Aivo (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-21)
      The pyrite sulfur isotope record of the 1.98 Ga Zaonega Formation in the Onega Basin, NW Russia, has played a central role in understanding ocean-atmosphere composition and inferring worldwide fluctuations of the seawater sulfate reservoir during the pivotal times of the Paleoproterozoic Era. That, in turn, has led to a concept that Earth's atmospheric oxygen levels underwent global-scale changes. ...

    • Two-billion-year-old evaporites capture Earth’s great oxidation 

      Blättler, C.L.; Claire, M.W.; Prave, A.R.; Kirsimäe, K.; Higgins, J.A.; Medvedev, P.V.; Romashkin, A.E; Rychanchik, D.V.; Zerkle, A.L.; Paiste, Kärt; Kreitsmann, T.; Millar, I.L.; Hayles, J.A.; Bao, H.; Turchyn, A.V.; Warke, M.R.; Lepland, Aivo (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-20)
      Major changes in atmospheric and ocean chemistry occurred in the Paleoproterozoic era (2.5 to 1.6 billion years ago). Increasing oxidation dramatically changed Earth’s surface, but few quantitative constraints exist on this important transition. This study describes the sedimentology, mineralogy, and geochemistry of a 2-billion-year-old, ~800-meter-thick evaporite succession from the Onega Basin in ...