4. Inspect the industry input materials key for extraction industries (Figure 2-2). The key shows
there are either FEW and SMALL BUILDINGS or in some cases there are NONE OBVIOUS. In
the latter case, these materials originate from materials or cultivated environment and unless
activity is present, they would appear as total features of terrain. However, when identifying crops
or planted forests where a definite pattern can be noted, input materials are obvious.
Figure 2-2. Industry Input Materials Key.