There is already a known correlation between observed temperatures and 18O temperatures from previous research in Chione (C.) fluctifraga and Chione (C.) cortezi (Goodwin et al, 2002). Thus, C. cortezi and C. fluctifraga can be used to decipher and reconstruct past climate conditions. However, in contrast, little is known on the growth tolerance to temperature of the bivalve Corbicula fluminea. Oxygen and carbon isotope profiles were collected from two deceased Corbicula fluminea species in the Colorado River delta. Growth increment profiles were obtained by collecting powder samples varying with equal distances from the umbo. The drilled powders represent a minute fraction in weight of the shell (Aucour et al, 2003). From these collected samples, the same procedure was followed by Goodwin, et al, 2002; samples were heated for 30 minutes in vacuo at 70 oC to remove voile material, followed by carbonate isotopic analyses (using Micro mass Optima IRMS with an Isocarb common acid—bath autocarbonate device), and then reacted at 90oC with 105% ortho—phosphoric acid. Using the modified SMOW scale Grossman and Ku's paleotemperature equation, 18O is a function of temperature and 18O of water. Similar correlations are found to be a rich source of information as to proceed further in the that C. fluminea grows between 14.61 and 30.58 oC. Although date of death is not known from the two samples, there is an oblivious similar trend between distance from umbo with 13C and 18O that confimrs Corbicula fluminea's use as a proxy indicator in the Colorado River Delta.