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Oxygen isotope analyses of diagenetic cements can provide detailed evidence of sedimentary burial processes and conditions, as the delta O-18 values of precipitating minerals reflect contemporaneous local delta O-18(water) and temperature conditions. Uncertainties in the timing and rates of pore water delta O-18 evolution in sedimentary basins can complicate interpretation of these records. Fracture-bridging (0.5-1 mm) quartz cements observed in sandstones of the Cretaceous Travis Peak Formation in the East Texas basin show clear growth-zoning by cathodoluminescence and contain detailed fluid inclusion records of temperature that make them excellent candidates for interrogating prolonged histories of basin temperature and the evolution of delta O-18 in basin pore water. New secondary ion mass spectrometer (SIMS) delta O-18 quartz isotopic data from fluid inclusion-rich quartz bridges in Travis Peak sandstones record a steady increase of pore water delta O-18 values from similar to 5 to 7 parts per thousand (VSMOW; Vienna Standard Mean Ocean Water) as the sandstone warms from similar to 130 to 150 degrees C. To help evaluate whether this trend could be generated solely from local water-rock interactions in response to burial compaction, a one-dimensional closed system isotopic burial model was created to simulate how delta O-18(water) values change in a quartz-dominated sandstone during diagenesis. Using both directly measured and inferred rates of Travis Peak compaction, the magnitude of change in delta(18)O(water )that we calculate from quartz bridge geochemistry cannot be reasonably modeled solely by local quartz mechanical compaction, pressure solution, and cementation processes, necessitating significant fluxes of silica and high delta O-18 water from outside of the sandstones prior to maximum burial. This indicates that even units which appear surrounded by significant barriers to fluid flow (i.e., mudrock-bounded channel sandstones) may have been infiltrated and diagenetically modified by large fluxes of fluid on geologic time scales.