The geologic province and thermo-tectonic age maps were compiled in 1997 to ensure a consistent method of providing values for these two parameters. The maps depict only features approximately 150 km across and greater due to the fact that the resolution of the maps should be consistent with the resolution of the seismic refraction data.

Era Age Time Span
Cenozoic and Mesozoic 0-245 Ma 245 m.y.
Paleozoic 245-570 Ma 325 m.y.
Late Proterozoic 500-900 Ma 400 m.y.
Middle Proterozoic 900-1600 Ma 700 m.y.
Early Proterozoic 1600-2500 Ma 900 m.y.
Archean > 2500 Ma    -- 

References and Acknowledgments