The evolution of the Atlantic ocean circulation is not only of interest from the climatic perspective of defining possible states of the climate system, but also because of the economic importance of the links between the siting of fossil fuel resources and oceanic productivity. Thus, much exploration effort is currently being devoted to quantifying the extent to which palaeo-upwelling is associated with palaeoproductivity.

A reduced-gravity 1.5 layer model is used to reconstruct the upper ocean circulation. This model is validated against satellite-derived primary productivity data, and a quantitative relationship between model-predicted upwelling and oceanic primary productivity is proposed. Sedimentary data are compiled to quantitatively estimate palaeoproductivity using an empirical formula and to qualitatively predict the distribution of palaeo-upwelling. We combine these two independent approaches to examine palaeogeographic reconstructions and to define the upper layer circulation during the late Jurassic, mid-Cretaceous, late Cretaceous, and Eocene. This enables us to explore the development of the equatorial gateway, primary productivity, and western boundary currents through the evolution of the Atlantic basin.

In a warm, and weakly stratified ocean with oxygen-depleted bottom water, the effectiveness of
palaeoproductivity due to upwelling is shown to support a positive feedback system linking productivity and anoxia in the geologic past. This sheds light on the productivity versus anoxia debate.

The onset of the proto-Gulf Stream with vigorous seasonal variability is found in the late Jurassic, a much earlier time than what was believed in 1950 (Carson, 1950). The poleward volume transports of the proto-western boundary currents increased towards the present-day. However, our estimate of the associated poleward heat fluxes is much less than that required to maintain warm climate during the mid-Cretaceous and Eocene. Hence it is inferred that the thermohaline circulation would have been drastically enhanced if oceanic heat flux were integral for the 'greenhouse' earth.