The time-temperature burial relationships that influence organic maturation processes in the Upper Triassic-Lower Jurassic rift basin sediments and the Middle Jurassic shelf-edge carbonates and sand-shale facies of the North Atlantic Georges Bank basin are believed to be regionally influenced by sediment loading and residual subsidence associated with the contractions and cooling of a thinned lithosphere and crust. Localized zones of high heat flow may have occurred during the rifting process. Relict heat flow from such sources may have influenced the principal zone of oil formation (PZOF) in the Georges Bank basin. Plots of specific temperature-sensitive, intercompound ratios of isomeric groups for light hydrocarbons that separate chromatographically in the cyclohexane t rough methylcyclohexane range and plots of the molecular ratio of n-hexane to methylcyclohexane were found to be consistent with the temperature-sensitive, saturated hydrocarbon to organic carbon ratios. These ratios suggest that the threshold of intense oil generation in the depocenter of the basin begins at a depth of about 3.2 km with the PZOF occurring between 3.9 and 4.9 km. Correlation of these temperature-sensitive maturation parameters with the time-temperature burial history models indicates that Middle to Lower Jurassic and probable Liassic to Upper Triassic units may be the most favorable exploration targets within the main Georges Bank basin.

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