The mode and nature of ice‐flow mechanism leading to ice‐lobe formation during deglaciation is described. These mechanisms are deduced primarily from their geomorphological and stratigraphical effects: the arc‐like formations fringing the ice lobes, certain patterns of landform elements, and in some cases the stratigraphical signs indicating ice‐marginal readvance or lack of it. Several ice‐lobe creation mechanisms are presented along with the associated landform patterns they produce. The theory encompassing the fan‐like ice flows, the ice‐lobe formation, and the arc formations fringing them is applied to the deglaciation in Soviet Karelia and adjacent Finland. Deglaciation proceeded here from the southeast to the northwest, and complex arc formations derived from the major ice lobes. The Finnish Lake District lobe, the North Karelian lobe, the Kuusamo lobe, and the other lobes in northeastern Finland were in general metachro