Remanent magnetization patterns of the oceanic lithosphere determined on the basis of the thermal evolution of the lithosphere, while taking into account both thermal and viscous magnetizations, give rise to magnetic anomalies to those observed by Magsat over the Cretaceous quiet zones of the Atlantic Ocean and by marine magnetic surveys over anomaly 33. Viscous magnetization acquired during a given core field polarity period is not removed completely by that acquired in the next period of opposite polarity because of cooling of the lithosphere and the strong temperature dependence of viscous magnetization. The magnetization pattern of layer 2A resembles that of the standard seafloor spreading magnetic model, consisting of normally and reversely magnetized zones separated by vertical boundaries, and produces symmetric magnetic anomalies. The magnetization pattern of the middle crust is similar to that of layer 2A for high magnetic blocking temperature models, but it is slightly skewed with respect to layer 2A for low magnetic blocking temperature models. The magnetization pattern of the lower crust is strongly skewed relative to that of layer 2A and has diffuse boundaries with pronounced slopes between normally and reversely magnetized zones. It produces magnetic anomalies with appreciable skewness, suggesting that observed skewness of marine magnetic anomaly 33 arises from the magnetization of this layer. The magnetization pattern of the upper mantle is appreciably skewed and almost devoid of small-scale variations. It produces strongly skewed magnetic anomalies at satellite altitudes which may explain the observed skewness of Magsat anomalies over the Cretaceous quiet zones of the Atlantic Ocean. ¿ American Geophysical Union 1989