Using an inversion technique, we show that pollen translucency with depth can be used as a quantitative tool to estimate the thermal history of sedimentary sequences. The overall trend of translucency is a decrease with increasing depth.In this study, three wells in southern Louisiana were examined, each havingCarya (a pollen genus including present‐day Pecans and Hickories) translucency measurements with depth, and one of the wells containing measurements of vitrinite reflectance with depth. High sedimentation rates (>250 ft/MM yrs of shale) require the use of a fluid flow/compaction burial history program linked with theCaryainversion algorithm. Thermal history is estimated by the interaction of a heat flux taken to be linear in time, and a time‐temperature integral for the inversion ofCaryatranslucency. The former involves β, a linear heat‐flux coefficient to be determined, while the latter involves two previously unknown constants: TC, a critical temperature, below which the translucency is stable (no carbonization), and TD,a scaling constant, roughly analogous to a doubling temperature. TDand Tcare chemical constants, and should be consistent in the three wells, while β should be consistent when determined independently by vitrinite reflectance andCaryatranslucency inversions. Grid searches for an acceptable solution in TCvs.TDvs. βspace were carried out for each of the three wells to determine the best TDTCand β for each well. A goodness‐of‐fit criterion, contoured in TDvs.TCvs. βspace, defines a volume of solutions within fixed error limits. Estimates of TD= 75 ± 30°K and TC= 290 + 20°K, for the genusCarya,are consistent for all of the wells. Acceptable β ranges, determined by theCaryainversion, overlap for the neighbouring wells. and the ranges are also consistent with β determined by the independent inversion of vitrinite reflectance in one of the wells.We conclude thatCaryatranslucency can be used as a quantitative thermal indicator. Application of the inverse method to translucency measurements on other palynomorphs having longer. or different, age ranges than the Eocene‐Recent lifetime f