For example coals occur where it is wet, bauxite occurs where it is warm and wet, evaporites and calcretes occur where it is warm and dry, and tillites occur where it is wet and cool. The ancient distribution of these, and other, rock types can tell us how the global climate has changed through time and how the continents have travelled across climatic belts. Geologic and Tectonic History. In order to reconstruct the past positions of the continents it is necessary to understand the development of the plate tectonic boundaries that separate continents and bring them back together again. Only by understanding the regional geological and tectonic evolution of an area can you determine the location and timing of rifting, subduction, continental collision and other major plate tectonic events.
Some paleogeographic features change very slowly and are easy to map.
Other paleogeographic features change very rapidly and, therefore, any map, at best, is an approximation. Continental lithosphere, because it is less dense, is more bouyant and is not easily subducted, or recycled back into the Earth's interior. As a result, continents are made-up of very old rocks, some dating back 3.8 billion years. What has changed, is the shape and the distribution of continents across the globe. The ocean basins, on the other hand, are all less than 150 million years old.