Transformation Pathway of Carbonate Pedofeatures Based on Their Micromorhology and Carbon Isotope Data in the Northern Caucasus Region,Russia

Carbonate pedofeatures (CPs) in a chronosequence of paleosols buried under kurgans in the Northern Caucasus region of Russia in a period from the end of the 4th to the middle of the 5th centuries AD (It seams that there is no time left) were studied by using a set of morphological and isotopic methods. The CPs in chernozem-type soils of Russia are usually represented by crystallomorphic calcite whereas the non-segregated carbonates occurred at the same horizons-by collomorphic one. Those two morphotypes of calcite have the differences in elemental composition and isotopic composition of carbon and, hence, should have different origins-from true and colloidal solutions, respectively. The same differences including radiocarbon age have been revealed for pseudomycelium of the ABca horizon of the youngest paleosols as compared with the same CPs of other paleosols in the chronosequence studied. Our assumption is that it was succeeded in finding that the pseudomycelium right away after its precipitation from a colloidal solution migrated from the lower soil horizons to the surface horizons during the periods of climatic aridization. After a short time interval (not more than 25-50 years) collomorphic calcite in the pseudomicelium of the yongest paleosols mentioned above will likely become by "usual" acicular calcite.

Micromorphological features of soils formed on calcium carbonate–rich slope deposits in the Polish Carpathians

Seven soil profiles developed on calcium carbonate–rich slope deposits in the Polish Carpathians were studied in order to:i)determine the micromorphological features of heterogeneous soils formed in a carbonate depositional environment,and ii)track primary and secondary calcium carbonate forms and their distribution in such stratified soils.Three cases of soils with different arrangements of calcium carbonate were distinguished,controlled mostly by slope processes.For instance,the increasing content and random distribution of angular and subangular rock fragments found in the overall soil matrix and the irregular coarse:fine size limit suggested different intensities of accumulation and mixing of soil material transported along the slope.Slope processes,together with the calcium carbonate content,mineralogical characteristics and texture influenced the type and arrangement of the bfabric pattern.The calcium carbonate distribution within the soils,besides the obvious inheritance from parent material,was governed by the translocation and mixing of deposits on slopes.The climatic conditions prevailing in the area favour the development of secondary forms of calcium carbonate.However,only three of the seven studied profiles contained pedogenic forms of calcium carbonate,yet they were distributed randomly.The occurrence,distribution and preservation of secondary carbonates depended on the content of primary calcium carbonate and soil features such as texture.The transported material down the slope may indicate a very low content of primary calcium or lack thereof,hence its pedogenic forms could not be created.

Anthropogenic Pedofeature in Andosols in Santome Shinden, One of the Representative Sites of the Satoyama Environment in Japan

Santome Shinden, a representative site of the Satoyama landscape in Japan, has its origins in 1696 when the common land of wild grass on the Musashino plateau was developed into a strip-shaped land division, which consists of residential area, upland field, and secondary forest. We investigated soils with different land use over 300 years;they are under the secondary forest, and in the upland field where fallen leaves compost derived from secondary forest has been applied continuously for about 300 years since the development. The measured exchangeable cation values suggested that the nutrients in the secondary forest were taken out to the field as fallen leaves. On the surface layer of the upland field soil, characteristic granules of dark brown coated peds (DBC peds) were developed strongly. However, on the surface layer of the secondary forest soil, the DBC peds were not found. Electron probe micro analyzer analysis showed that the outside (dark brown part) of the DBC peds, which was observed only in the upland fields was rich in carbon. The dark brown coated pedofeature was suggested to have an anthropogenic effect due to the long-term application of fallen leaves compost. The anthropogenic activities, which were fallen leaves compost application and cultivation for about 300 years, were thought to affect the soil micromorphology. Therefore, the peds newly found in the Santome shinden field were considered to be a soil microstructure that symbolizes anthropogenic activities.