000232849 001__ 232849
000232849 005__ 20181203024908.0
000232849 0247_ $$2doi$$a10.1038/s41467-017-01225-9
000232849 022__ $$a2041-1723
000232849 02470 $$2ISI$$a000413830500003
000232849 037__ $$aARTICLE
000232849 245__ $$aBurial-induced oxygen-isotope re-equilibration of fossil foraminifera explains ocean paleotemperature paradoxes
000232849 260__ $$aLondon$$bNature Publishing Group$$c2017
000232849 269__ $$a2017
000232849 300__ $$a10
000232849 336__ $$aJournal Articles
000232849 520__ $$aOxygen-isotope compositions of fossilised planktonic and benthic foraminifera tests are used as proxies for surface-and deep-ocean paleotemperatures, providing a continuous benthic record for the past 115 Ma. However, visually imperceptible processes can alter these proxies during sediment burial. Here, we investigate the diffusion-controlled re-equilibration process with experiments exposing foraminifera tests to elevated pressures and temperatures in isotopically heavy artificial seawater (H-2 O-18), followed by scanning electron microscopy and quantitative NanoSIMS imaging: oxygen-isotope compositions changed heterogeneously at submicrometer length scales without any observable modifications of the test ultrastructures. In parallel, numerical modelling of diffusion during burial shows that oxygen-isotope reequilibration of fossil foraminifera tests can cause significant overestimations of ocean paleotemperatures on a time scale of 10(7) years under natural conditions. Our results suggest that the late Cretaceous and Paleogene deep-ocean and high-latitude surface-ocean temperatures were significantly lower than is generally accepted, thereby explaining the paradox of the low equator-to-pole surface-ocean thermal gradient inferred for these periods.
000232849 700__ $$aBernard, S.$$uSorbonne Univ, IMPMC, CNRS UMR 7590, MNHN,UPMC,IRD UMR 206, 61 Rue Buffon, F-75005 Paris, France
000232849 700__ $$aDaval, D.$$uUniv Strasbourg EOST, LHyGeS, CNRS UMR 7517, 1 Rue Blessig, F-67084 Strasbourg, France
000232849 700__ $$aAckerer, P.$$uUniv Strasbourg EOST, LHyGeS, CNRS UMR 7517, 1 Rue Blessig, F-67084 Strasbourg, France
000232849 700__ $$aPont, S.$$uSorbonne Univ, IMPMC, CNRS UMR 7590, MNHN,UPMC,IRD UMR 206, 61 Rue Buffon, F-75005 Paris, France
000232849 700__ $$0246343$$aMeibom, A.$$g220185$$uEcole Polytech Fed Lausanne, Lab Biol Geochem, Sch Architecture Civil & Environm Engn, CH-1015 Lausanne, Switzerland
000232849 773__ $$j8$$q1134$$tNature Communications
000232849 909C0 $$0252426$$pLGB$$xU12552
000232849 909CO $$ooai:infoscience.tind.io:232849$$particle$$pENAC
000232849 917Z8 $$x220185
000232849 937__ $$aEPFL-ARTICLE-232849
000232849 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED
000232849 980__ $$aARTICLE