Geochemical proxies of paleoenvironmental conditions are presented from studies of modern lacustrine deposits from White Rock Lake, Dallas Texas, Upper Pennsylvanian through Lower Permian paleosols from Mora County New Mexico, and Upper Paleozoic lacustrine strata from the Congo Basin, D.R. Congo.
The composition of sedimentary organic matter of White Rock Lake is utilized to establish a temporal relationship between urbanization of the local watershed and lake system. Geochemical proxies of watershed conditions allow for the evaluation of changes in lake morphometry, which are correlated with historical records of urbanization. The δ13C and C/N values of sedimentary organic matter indicate a shift from contributions from predominantly allochtonous C4 photosynthesizers to primarily C3 photosynthesizing organisms. These trends suggest increased primary productivity and an influx of detrital material into White Rock Lake is resultant from urbanization of the watershed landscape.
Lithostratigraphic, mineralogic, and stable isotope proxies of equatorial paleoclimate from Upper Pennsylvanian-Lower Permian strata of the Taos Trough, north-central New Mexico is utilized to reconstruct paleopedogenic conditions. The stratigraphic distribution of paleosol morphologies and clay mineral assemblages suggests a stepped change from a subhumid, seasonal climate in Missourian time to a nonseasonal arid climate in end-Wolfcampian time.
Lithostratigraphy, mineralogy, and isotopic values of lacustrine sediments from Upper Carboniferous-Lower Permian strata in the Lukuga Formation, central DR Congo are presented. This regional reconstruction of Permo-Carboniferous terrestrial paleoclimate supports the notion that Gondwanaland was characterized by repeated shifts from glacial to inter- and/or non-glacial conditions.
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Milleson, Mary, "Geochemical Analysis of Soil and Lake Deposits as Indicators of Paleoenvironmental Conditions; Examples from Texas, New Mexico, and D.R. Congo" (2019). Earth Sciences Theses and Dissertations. 12.