1. 1 Cordillera Provinces Geology of National Parks

2. 2 Rocky Mountain System

3. 3 Isostasy At Work Isostasy states that differences in elevation are compensated for by low-density roots Imagine a sponge floating in water  Part of the sponge floats above the level of the water-it has positive elevation  Compensating that elevation is a low-density root-the portion of the sponge below the water (sponge is less dense than water)

4. 4 Isostasy Wood block is denser than foam, so more of the wood is submerged

5. 5 Loading and Unloading Crustal loading, as by ice, water, sediments, or volcanic flows, leads to isostatic depression or downwarping; removal of load, to isostatic uplift or upwarping