Many wells on the Scotian Shelf, offshore from Nova Scotia, have drilled into overpressured zones. In particular, the wells comprising the venture gas field have all encountered overpressures at depths below 4.5 km. The characteristics of the overpressure zones in the Venture field vary in some important details from overpressured zones on the U.S. Gulf Coast. In the Venture field the shales in the overpressured zones are observed to be normally compared and interbedded with layers of overprussed sandstones. This is in contrast to the Gulf Coast, where the shales in the overprussured zone are undercompacted. Resistivity logs, sonic logs, and bulk density logs all provide some indications of overpressures in the Venture field but are not as unequivocal indicators of overpressure as they are on the Gulf Coast. Theoretical investigations of the causes of overpressures in an environment such as the Venture field show that overpressures are unlikely to be caused by loading of sediments. The most probable cause of overpressures is recent and continuing fluid generation, which is related to the transformation of kerogen to hydrocarbons. Limits are placed on the average permeabilities and fluid generation rates which are required if overpressures are to be produced by fluid generation. ¿ American Geophysical Union 1988