The depth to carbonate nodular (Bk) horizon in soils (D in cm) is correlated with mean annual precipitation (P in mm), so that Bk horizons are deep in subhumid regions, but shallow in semiarid regions. Previous quantifications of this relationship are unchanged by this new compilation of 807 soils: P 5 137.24 1 6.45D 1 0.013D2, where R2 5 0.52, and standard error (S.E.) 5 6147 mm. In most North...

A survey of the interactions between phosphorus (P) species and the components of calcareous soils shows that both surface reactions and precipitation take place, especially in the presence of calcite and limestone. The principal products of these reactions are dicalcium phosphate and octacalcium phosphate, which may interconvert after formation. The role of calcium carbonate in P retention by ...

The Quaternary environmental history of the northern Great Basin is characterized by a combination of lower temperature and higher moisture than present. Using water-balance analysis of soils sampled along a climatic gradient, we demonstrate that long-term average effective moisture was about 2-4 cm yr-1 greater than present. Although this long-term average represents most of Quarternary time, ...

Paleosol carbonates from trenches excavated as part of a landscape-scale project in Bed I of Olduvai Gorge, Tanzania, were analyzed for stable carbon and oxygen isotopic composition. The approximately 60,000-year interval ( approximately 1.845-1.785 Ma) above Tuff IB records evidence for lake and fluvial sequences, volcanic eruptions, eolian and pedogenic processes, and the development of a flu...

ABSTRACT- Paddy soils make up the largest anthropogenic wetlands on earth. Present study was performed to investigate and compare soil formation of paddy soils with long-term rice cultivation history with non-paddy soils and study the effect of waterlogging on soil pedogenesis. Soil samples were taken from paddy and non-paddy soils derived from the same calcareous parent materials. Some pedogen...

In arid and semi-arid climates, soil development is strongly influenced by seasonal patterns biogenic activity, often results in pervasive pedogenic horizons consisting of highly concentrated carbonate. Brazil, such enriched calcium carbonate are common relatively well-studied paleosols the Upper Cretaceous Marília Formation. However, detailed analyses on sequence mineral precipitation phases r...