ISOTOPIC LOGS OF THE SEA OF CORTEZ: OXYGEN AND CARBON STABLE ISOTOPES IN OTOLITHS OF MARINE FISH RECORD THE IMPACT OF DIVERTING THE COLORADO RIVER FROM THE SEA. By Kirsten Rowell ______________________ Copyright ! Kirsten Rowell 2006 A Dissertation Submitted to the Faculty of the DEPARTMENT OF GEOSCIENCES In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 2006