Geological and organic geochemical data show that the organic-rich Lower Jurassic ＇＇Nordegg Member＇＇ could not have been a major source for the 269.4x10(9) m3 oil in place in the Lower Cretaceous tar sands/heavy oil deposits in eastern Alberta. Stratigraphic reconstructions indicate that upward expulsion of ＇＇Nordegg＇＇ oil was prevented by the overlying Poker Chip Shale, except for a small region near the eastern subcrop edge of the ＇＇Nordegg＇＇, where the Poker Chip has been removed by erosion. It is only in this restricted area that the ＇＇Nordegg＇＇ is overlain by permeable sands belonging to the Lower Cretaceous Mannville Group (Bluesky/Gething interval). Some ＇＇Nordegg＇＇ oil has been expelled downward into subcropping Triassic and Permian reservoirs. The middle, silty marlstone unit of the ＇＇Nordegg＇＇ has been suggested as the conduit for the migration of mature ＇＇Nordegg＇＇ oil to the eastern subcrop edge beneath the Mannville. This theory is not supported by oil-source rock biomarker analysis of extracts from this middle unit and adjacent source rock and, thus, up-dip migration of oil through the middle unit of the ＇＇Nordegg＇＇, from mature sources in the west to low maturity regions near the eastern subcrop edge, is not indicated. The amount of oil expelled by mature ＇＇Nordegg＇＇ source rock subcropping permeable Mannville strata is estimated to range from 5.9 to 17.6x10(9) m3 oil. This volume of oil is sufficient to have filled the Bluesky/Gething interval in the Peace River tar sands (Eastern Alberta), but is insufficient to account for the additional huge volumes of oil in the underlying Paleozoic carbonates and other tar sands heavy oil deposits (i.e., Buffalo Head Hills, Wabasca-Grand Rapids, Athabasca, Cold Lake).