Arctic paleo-oceanography in late cenozoic time.
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.
Herman
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