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Showing 1 to 10 of 10 for “"Pedogenic Carbonates"”.
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Pedogenic carbonates in loess formation rates, formation conditions and source apportionment assessed by isotopes and molecular proxies
Interest in secondary (pedogenic) carbonates as an archive for paleoclimatic reconstructions in arid and semiarid regions has increased during recent decades. Their carbon (C) isotope composition represents the conditions prevailing during their formation because they are formed by precipitation of …
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Stable isotope paleohydrology of pedogenic carbonates in the Wayan Formation (Albian) from the wedge-top depozone in the North American Cretaceous Western Interior Basin
… to the late Albian C15 C-isotope segment. Pedogenic carbonates from the WF principally consist of micritic calcite, with carbon-oxygen isotope values that array along meteoric calcite lines (MCLs) with δ18O values that range between -9.47 up to -8.39‰ VPDB. At approximately 42°N …
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Climate and habitat reconstruction of hominid sites in northern China with paleosol stable isotopes
… carbon isotopes of soil organic matter and pedogenic carbonates, and oxygen isotopes of pedogenic carbonates, can provide evidences for tree:grass ratios, air surface temperature and soil moisture conditions. These data can also help resolve disagreements about paleoenvironments at hominid …
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Multi-proxy palaeoclimate reconstruction of the permian-triassic mass extinction event
… alluvial fans. Most of the paleosols include pedogenic carbonates at different stages of development, both above and below the P/Tr boundary. By the Triassic there is evidence of depressed water tables and increased seasonality. Analyses of the S13Qarba nd S18Ocarbsi gnatures of these …
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Early hominid habitat preferences in East Africa: Stable isotopic evidence from paleosols
… of paleosol (buried soil) organic matter and pedogenic carbonate is used in this thesis to estimate the original proportion of tropical grasses (C$\sb4$ plants) to woody vegetation (C$\sb3$ plants) across the ancient land surfaces. Interpretation of physiognomic types of tropical plant …
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Geochemical Investigations of Mineral Weathering: Quantifying Weathering Intensity, Silicate versus Carbonate Contributions, and Soil-Plant Interactions
… in soil profile and in the 87Sr/86Sr ratios of pedogenic carbonates, appear to be driven by changes in tectonic, rather than climatic, regime. All three papers are good examples of how 87Sr/86Sr isotopic tracer studies can shed light on pedogenic formation rates and internal processes. The …
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Miocene paleoenvironments and paleosol pH proxies.
… subhumid climate. Stable carbon isotopes from pedogenic carbonates are consistent with a surprisingly large amount of C4 biomass, which was used in conjunction with the presence of microcharcoal grains and rodent community paleoecology to interpret an open-canopy habitat for the site. Finally, …
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Fluvial sequence stratigraphy and paleoclimate of the Upper Triassic (Norian-Rhaetian) Chinle Strata, northern New Mexico.
… are applied to the isotopic composition of pedogenic carbonates in order to construct two age-equivalent, relatively continuous pCO2 and temperature records that span the eight million years preceding the Triassic-Jurassic (T-J) boundary. The [delta]13C data reveal relatively low Late Norian …
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Regolith and associated mineral systems of the Eucla Basin, South Australia.
… the purpose of discriminating between marine and pedogenic carbonates. This methodology has provided significant breakthroughs in the discrimination of carbonate materials, particularly for landscapes with a complex marine or marginal marine history.
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The role of wind and water in shaping earth's plateaus
… and oxygen and carbon isotopes obtained from pedogenic carbonates; these records are compared to other environmental proxies, including hydrated volcanic glass shards from volcanic ashes intercalated in the sedimentary strata. There are few quantitative estimates of eolian bedrock-removal …