The thin, fragile and living Earth's surface may be seen as the filling in a giant sandwich. The bottom layer of bread in the sandwich is the core of the earth from its molten center to its floating continental masses. The top layer is the atmosphere from the layer nearest the ground that supports life to upper reaches of the stratosphere. The gooey layer of jam in which we live forms the interface of these two masses.

Geological processes are important to the designer. Geology creates the land forms we build upon; it controls the drainage and percolation on a site; it forms the rock and mineral base of the soils and it controls the short and long-term processes that continually rework the landscape. Regional geology provides the first clues to our understanding of design components.

We can appreciate a landscape intuitively. We can enjoy its hills, its rivers and valleys, its wetlands and flood plains, its rock outcroppings, its lake and sea shores and its swamps and marshes. A greater understanding of how the landscape was formed and the processes that are still shaping it is necessary for its use in design. The big picture, the continental level, might be a good place to start. For those in North America, Ron Redfern's, The Making of a Continent (New York: Times Books, 1983) is an excellent resource. With text, illustrations and photographs he traces the evolutionary story of the continent placing our local landscapes in their greater context.

Getting closer to home we find that physical geographers have mapped the locations of various physiographic units of land at a variety of scales. These are wonderful resources for understanding our place in our region. The example of the eastern United States, which shows the 'coastal plain' and Appalachian 'piedmont' physiographic provinces is typical of these maps. The characteristics of the coastal plain, the piedmont and the fall line zone in between are quite different and would influence how we design upon them.


from: Lobeck, Armin K. 1958. Things Maps Don't Tell Us: An Adventure in Map Interpretation. New York: McMillian

An even more detailed level of description is provided by texts on specific land forms such as John Shelton's, Geology Illustrated (San Francisco: Freeman, 1966) and maps of geology done by geological surveys at the state, region, county and quadrangle levels. Specific formation and rock types, chemical composition and characteristics for various types of uses may be provided. Building on our intuitive feel for the land with these readily available resources will make us more informed permaculture designers.