Arctic Paleo-Oceanography in Late Cenozoic Time

Abstract

Sediment cores from the Arctic Ocean yield significant faunal and lithologic evidence of alternating cold and milder periods for the last 6 million years. Although high-latitude continental glaciation commenced prior to 6 million years ago, the Arctic Ocean remained free of permanent pack ice up to approximately 0.7 million years ago, after which successive ice-covered and ice-free conditions existed.

Calcareous microfossil-based orbital cyclostratigraphy in the Arctic Ocean

“…More than 200 radiocarbon dates, most using accelerated mass spectrometry (AMS) on mollusks, benthic and planktic foraminifers are available from box, multi-and piston cores from Arctic Ocean ridges (Poirier et al, 2012). These dates demonstrate convincingly what has been known since the earliest studies of Arctic Ocean sediment (Herman, 1970), that calcareousrich intervals of sedimentation characterize the Holocene interglacial and the warm Marine Isotope Stage 3 interstadial period. In contrast, calcareous microfossils and other age controls are absent or very rare in glacial and stadial sediments.…”

“…Although the effects of GICs on the sedimentary record are complex, GICs are evident in manganese concentrations (Jakobsson et al, 2000;L€ owemark et al, 2014;Stein et al, 2015), color, grain size and bulk density , mineral and trace element content (Fagel et al, 2014), neodymium (Haley et al, 2008), organic geochemistry (Yamamoto and Polyak, 2009;Schubert and Stein, 1996;Stein et al, 2001), foraminiferal d 18 O Spielhagen et al, 2004;Knies et al, 2007;Adler et al, 2009) and calcareous microfossils (Herman, 1970;Poore et al, 1994;Polyak et al, 2009;Hanslik et al, 2013).…”

Marine Geology and Oceanography of the Arctic Seas

“…and was accompanied by freezing of the Arctic Ocean (Herman, 1970). The increase in glacier ice volume as compared with the present volume, during the maximum of Pleistocene glaciation as esti- Flint, 1971, Fig.…”

“…Dansgaard et al, . 1971 and from Arctic Ocean bottom sediments it appears that the Arctic Ocean has probably been frozen for the past 70.000 to 100.000 years (Herman, 1970). The continuous presence of at least part of the Greenland ice sheet over the past 120,000 years also suggests that during this period the Arctic Ocean did not warm up much above its present temperature.…”

“…old were found (Curry 1966). Herman (1970), studying sediment cores from the Arctic Ocean, found ice-rafted detritus in sediments deposited >3 m.y.b.p. From the fauna and lithology of these cores, it appears that increased iceberg and shelfice production and melting occurred between 2.4 and 0.7 m.y.b.p.…”