Ruddiman W F
Science. 1969 Jun 6;164(3884):1164-7. doi: 10.1126/science.164.3884.1164.
Foraminferal dominance values above 50 percent and associated diversity minimums in surface sediments of the North Atlantic coincide with past extremes of temperature, productivity, or salinity in overlying surface waters. These parameters delimit a cold PolarSubpolar water mass and an impoverished, saline Southern Sargasso Central water mass for the late Recent. Anticipated pole-to-equator diversity and dominance gradients in the open ocean are virtually eliminated by the stronger trends of the vigorous subtropical North Atlantic gyre.
北大西洋表层沉积物中，有孔虫优势值高于50%以及相关的多样性最小值，与过去上覆表层水体温度、生产力或盐度的极端情况相吻合。这些参数界定了晚更新世寒冷的极地-亚极地水团和贫瘠的、含盐的南马尾藻海中央水团。开阔海洋中预期的从极地到赤道的多样性和优势度梯度，实际上被活跃的亚热带北大西洋环流的更强趋势所消除。
