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Showing 1 to 10 of 10 for “"pedogenic carbonate"”.
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Morphology and development of the Red Rock Canyon alluvial fan, Clark County, Nevada
Changes in morphology and pedogenic carbonate accumulation establish relative ages of a chronosequence of calcic soils and pedogenic calcretes that underlie four surfaces identified on the Red Rock Canyon alluvial fan. All surfaces identified are formed of limestone alluvium, occur at elevations of …
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Soil geomorphology of the eastern Sevilleta Long Term Ecological Research Site
… Formation paleosols, massive cementation by pedogenic carbonate, and chaotic pedogenic carbonate pendants are notably absent in soils formed on the 1 – 3.5 Ma surface. It is hypothesized that abandonment of geomorphic surfaces, largely due to down-cutting by the ancestral Rio Grande, and slow …
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Influence of climate and the expansion of C4 grasses on sequence-scale cyclicity and landscape development during the late Miocene to Pleistocene of West Texas.
… geochemistry of bulk paleosol samples and pedogenic carbonate suggest C₄ expansion at 7.25 Ma and provide a pCO₂ reconstruction of the late Miocene to Pleistocene. C₄ onset coincides with a decreasing sedimentation rate, less frequent channel avulsion events, and an increase in paleosol …
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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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The sedimentary petrology of carbonate nodules in the Elliot Formation, Karoo Supergroup, main Karoo Basin (South Africa)
… associated with genetically poorly-constrained carbonate nodules. The origin of carbonate nodules i.e., pedogenic versus diagenetic, is important as pedogenic carbonate nodules can be used as palaeoclimate indicators, while diagenetic nodules carry limited palaeoclimatic information on the …
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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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Analysis of deposition, erosion, and landscape stability during the late Quaternary using multi-proxy evidence from Owl Creek, Central Texas, USA.
… isotope analyses of soil organic matter and pedogenic carbonate. These buried soils provide a record of changes in paleoecological and paleo-alluvial conditions spanning ~14 ky. Morphological and geochemical differences between buried soils reflect changes in landscape attributable to …
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A Stratigraphic and Geochronologic Analysis of the Morrison Formation/Cedar Mountain Formation Boundary, Utah
… central Utah reveals a diagnostic suite of pedogenic and sedimentologic characters across the previously enigmatic boundary. The uppermost Morrison Formation is characterized by redoximorphic paleosol features, including iron concentrations, manganese-coated grains, and intense …
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PALEOPEDOLOGY AND PALEOGEOMORPHOLOGY OF THE EARLY OLIGOCENE ORELLA AND WHITNEY MEMBERS, BRULE FORMATION, WHITE RIVER GROUP, TOADSTOOL GEOLOGIC PARK, NEBRASKA
… more recognizable. Paleosols follow different pedogenic pathways in direct response to depositional setting. Whereas all paleosols formed through top-down pedogenesis in alluvial settings, paleosols in aeolian-dominated settings formed though pedogenic upbuilding during aggradational phases and …
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The geochemistry of fossil termite nests in Calitzdorp, Western Cape, South Africa
… movement frequently leads to post-construction carbonate precipitation within termitaria. Fossil termitaria near Calitzdorp, Western Cape, South Africa, were described nearly two decades ago, but no detailed work has been performed on them until now. Here, these calcretised Quaternary features, …