The overall size of the continental glacier system is determined by the balance between zones of accumulation and ablation. The depositional features of continental glaciers are more varied than those of alpine glaciers. The greater variably is related to differences in the size of the systems and the topography they encounter. They tend to be extensive in length and to have a slightly concentric shape reflective of the lobate nature of the ice front. Terminal and recessional moraines deposited by continental glaciers provide the same type of information about glacier dynamics as in the alpine glacial system.
Lateral moraines are absent.
Intraglacial landscape Figure 14-2. The ground moraine commonly fills river valleys and destroys the preglacial drainage system. For this reason, areas of extensive ground moraine are usually poorly drained and can be recognized as swampy areas on topographic maps. The shape of drumlins provide an excellent indicator of the direction of ice flow. The tear-drop shape of contour lines that outline a drumlin can be used to describe the direction of ice flow.