Geochemical and biostratigraphic data from offshore wells along the Atlantic margin of North America define a depositional history dominated by coastal-plain and shallow-shelf facies containing degraded and residual continent-derived kerogen. Exceptions to this generalization are 4 depositional facies containing hydrogen-rich amorphous kerogen assemblages.

The rocks containing hydrogen-rich amorphous kerogen assemblages are: (1) Upper Jurassic inner-shelf facies probably deposited in algal-rich lagoonlike environments, (2) Lower Cretaceous nonmarine coaly facies, probably deposited in algal-rich swamplike environments, (3) middle Cretaceous abyssal-plain facies probably deposited by turbidity currents that originated on an algal-rich slope, and (4) Miocene outer-shelf to upper-slope facies probably deposited under algal-rich upwelling systems.

Correlation of these facies to seismic packages allows for extrapolation of probable organic facies distribution throughout the continental margin. Such modeling of organic facies distributions in conjunction with plate-tectonic and ocean-circulation models permits refinement of strategies for hydrocarbon exploration.

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