Hay, William W. (2002) A new view of Cretaceous paleoceanography. In: Tethyan/Boreal Cretaceous Correlation. , ed. by Michalik, J.. VEDA Publishing House of the Slovak Academy of Sciences, Bratislava, Slovak Rep., pp. 11-37.

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Abstract

The modern ocean is comprised of four units: an equatorial belt shared by the two
hemispheres, tropical-subtropical anticyclonic gyres, mid-latitude belts of water with steep meridional
temperature gradients, and polar oceans characterized by cyclonic gyres. These units are separated
by lines of convergence, or fronts: subequatorial, subtropical, and polar. Convergence and
divergence of the ocean waters are forced beneath zonal (latitude-parallel) winds. The Early Cretaceous
ocean closely resembled the modem ocean. The developing Atlantic was a larger analog of the
modem Mediterranean and served as an Intermediate Water source for the Pacific. Because sea-ice
formed seasonally in the Early Cretaceous polar seas, deep water formation probably took place
largely in the polar region. In the Late Cretaceous, the high latitudes were warm and deep water
moved from the equatorial region toward the poles, enhancing the ocean's capacity to transport heat
poleward. The contrast between surface gyre waters and intermediate waters was aJmost surely less,
making them easier to upwell, but because their residence time in the oxygen minimum was less and
they contained less nutrients. By analogy to the modem ocean, "Tethyan" refers to the oceans between
the subtropical convergences and "Boreal" refers to the ocean poleward of the subtropical
convergences.

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