k_tazpaleo.html


Late Cretaceous to Early Tertiary Paleogeography of Arizona (65-55 Ma).

For the first time in the Phanerozoic, the entire region is uplifted well above sea level. The Laramide Orogeny caused both regional uplift and extensive deformation. The older to partly coeval Sevier Orogeny caused thrusting to the south and west and the Laramide and Sevier combined caused regional crustal thickening. Streams flowed northward from southern and central Arizona into southern Utah. Few deposits of this age are present in Arizona, presumably because this was a time of degradation.