The measured calcium carbonate content of soils to a depth of 100 mm at a large urban development site has increased over 18 months at a rate that corresponds to the sequestration of 85 t of CO2/ha (8.5 kg of CO2 m(-2)) annually. This is a consequence of rapid weathering of calcium silicate and hydroxide minerals derived from the demolition of concrete structures, which releases Ca that combine...

Inorganic carbonate in soil occurs predominantly as the sparingly soluble alkaline-earth carbonates, calcite (CaCOs) and dolomite (CaMg(CO,),). Calcite is usually the dominant form in active pedogenic environments (Doner & Lynn, 1977; Nelson, 1982). There are only a few reported occurrences of aragonite (CaCOs) and vaterite (CaCOs) in soils. Sodium carbonate and magnesium carbonate and hydroxyc...

carbon and sulfur isotopic data are helpful in understanding environmental conditions under which soils are formed. soils from 18 sampling sites along a climotoposequence from higher laleh zar mountains (4,351 m above sea level with xeric-mesic soil moisture-temperature regimes) to shahdad depression (250 m above sea level with arid-hyperthermic soil moisture-temperature regimes) in kerman prov...

Carbonates of the Ojo Huelos Member of the San Pedro Arroyo Formation include ostracodal limestones, brecciated micritic limestones, vuggy, mottled limestones, peloidal graistones/packstones, pisolitic rudstones and nodular limestones. These lithofacies record deposition in lacustrine, palustrine and alluvial environments. Lacustrine (ostracodal) limestones are isotopically heaviest, with nodul...

Isotopic signatures of soil components are commonly used to infer past ecologic and climatic shifts in the soil record. The theory behind the fractionation of isotopes that occurs during ecosystem processes is well understood; however, few isotopic studies have explored ecosystem relationships in modern soils. We discuss relationships of stable carbon isotopic signatures in plant tissue, soil o...

Pedogenic carbonate is widespread at mid latitudes where warm and dry conditions favor soil growth from spring to fall. The mechanisms timing of pedogenic formation are more ambiguous in the tropical domain, long periods water saturation high respiration enhance calcite dissolution. This paper provides stable carbon, oxygen clumped isotope values Quaternary Miocene carbonates domain Myanmar, ar...

Following the discovery of the "Taung Child" (Australopithecus africanus) in 1924 in the Buxton-Norlim Limeworks near Taung, the fossil-bearing deposits associated with the Dart and Hrdlička pinnacles have been interpreted as the mined remnants of cave sediments that formed within the Plio-Pleistocene Thabaseek Tufa: either as a younger cave-fill or as contemporaneous carapace caves. When combi...