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Paleosols are well preserved beneath Upper Cretaceous continental sediments from the eastern Gulf Coastal Plain to the northern Mississippi Embayment. These buried soils are remnants of land surfaces that weathered during Cretaceous time and formed on several rock types, including Precambrian(?) metamorphic rocks and Paleozoic limestone and sandstone. Most soil profiles have distinctive morphologic features and exhibit pedogenic horizon zonation with ferruginous and clay-rich B horizons grading downward to saprolite and parent material within 7 m. Organic matter is not preserved, but pedotubules, which we interpret as fossil roots or burrows, are present in many paleosols. Illuvial and residual concentrations of Al2O3 and Fe2O3 occur in upper soil horizons where kaolinite and halloysite are the principal clay minerals. A variety of precursor minerals, including 2:1 lattice clays, muscovite, feldspar, and biotite, are present in the lower part of the soil profiles. Variations in pedogenesis were caused by differences in parent material and by local geomorphic factors such as paleoslope and drainage. The rates of paleosol development and the residence times of the various land surfaces are uncertain, but the times of burial and preservation range from Cenomanian to early Maestrichtian. Chemical and mineralogic characteristics of these paleosols are similar to those of modern soils of tropical to subtropical climates; however, the fossil soils may be polycyclic, and their pedogenic characteristics could have been modified by postburial diagenesis. Climatic reconstructions based on paleobotanical, lithostratigraphic, and paleotemperature data from Cretaceous sediments support our interpretation that these paleosols formed in a warm, humid environment on well-vegetated piedmont surfaces.

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