Landforms of Continental Glaciation

Examine the diagrams of a region during glaciation and the same region after glaciation while reading the material below.  

Figure 19. 12 Aerial photo of a portion of the Northern Unit of Kettle Moraine, WI. The rugged terrain and kettle lakes of the moraine is visible in much of the photograph.

A moraine is a glacially formed accumulation of unconsolidated debris. Moraines often take the form of a belt of low hills composed of till. Where the leading edge of the glacier was located a terminal or end moraine can be found. The terminal moraine marks the furthest advance of the ice sheet. Behind the terminal moraine is found a recessional moraine deposited when the ice sheet receded and stopped for a period of time. Often, uplands will cause an ice sheet to separate into lobes.

Figure 19.13 Wisconsin-age moraine in northern Illinois (Click image to enlarge)

  Interlobate moraines form between lobes of the ice sheet. Ground moraine is till that was lodged beneath the glacier and generally found behind the terminal moraine. Ground moraine. Wetland areas are often created in ground moraine which is a convenient way of identifying them from a topographic map.

Figure 19.14 Outwash plain, Copper River region, Alaska (Courtesy USGS DDS21 Click image to enlarge)

An outwash plain forms ahead of the terminal moraine as melt water from the snout of a glacier deposits stratified drift. The outwash plain is a relatively flat surface that may be pock marked with depressions called kettles. If numerous kettles are present the surface is called a pitted outwash plain.

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