Soil development on basic and ultrabasic rocks in cold environments of Russia traced by mineralogical composition and pore space characteristics

Recent soils from basic (amphibolite and meta-gabbro amphibolite) and ultrabasic (serpentinous dunite) rocks formed in cold and humid climates of Northern Eurasia (Russia) were studied to detail the characterization of soils and rocks with special attention to the interdependence of porosity system and rock mineralogy. The study plots were located in taiga and tundra zones of East Fennoscandia and the Polar UralMountainsyesBelgorod State National Research Universit

Soil development on basic and ultrabasic rocks in cold environments of Russia traced by mineralogical composition and pore space characteristics

yesRecent soils from basic (amphibolite and meta-gabbro amphibolite) and ultrabasic (serpentinous dunite) rocks formed in cold and humid climates of Northern Eurasia (Russia) were studied to detail the characterization of soils and rocks with special attention to the interdependence of porosity system and rock mineralogy. The study plots were located in taiga and tundra zones of East Fennoscandia and the Polar UralMountainsBelgorod State National Research Universit

Temperature Dependence of Surface Polar State of SrTiO3 Ceramics Obtained by Piezoresponse Force Microscopy

The existence of polar state on the surface of strontium titanate ceramics was obtained by piezoresponse force microscopy (PFM) in temperature range from 8 to 295K. This polar state is nonswitchable and relaxes fast at room temperature. This fact is attributed to charge injection from tip, which provoked the formation of oxygen vacancies in subsurface layer. Low temperature dynamics of surface piezoresponse reveals an increasing of PFM contrast at 110-130K, associated with surface structural phase transition. Temperature dependence of the average level of piezoresponse signal exhibits two peaks due to bulk structural phase transition and coherent quantum state

Microclimate affects soil chemical and mineralogical properties of cold alpine soils of the Altai Mountains (Russia)

Purpose: The present work focuses on cold alpine soils of the Altai Mountains (Siberia, Russia). Permafrost is widespread and often occurs at a depth of about 100 cm. The area is characterised by extremely cold winters and cool summers: the aim was consequently to find out whether weathering could be more intense on thermally less unfavoured conditions or whether the abundance of water could be a more important factor. Materials and methods: We investigated 10 soils in a very small area close to a local glacier tongue. Five of the investigated soils were south-facing and the other five north-facing. The soils have the same parent material (mica-rich till), altitude, topography and soil age. The vegetation is alpine grassland that is partially intersected with some juniper and mosses. Soil chemical properties such as organic C, N, soil organic matter quality (using DRIFT), pH value, (oxy)hydroxides, total elemental contents (XRF) and soil micromorphology and mineralogy (using diagnostic treatments and XRD) were determined. The age constraint of the site was given by geomorphic studies together with 14C dating of a nearby peat bog and the stable organic matter fraction of the soils. Results and discussion: The soils have a Holocene age. The results showed astonishingly clearly—similarly to the European Alps—that the north-facing soils have a higher weathering state. This is expressed by lower pH values, higher oxalate and dithionite extractable Fe, Al, Mn and Si contents, higher C and N concentrations and stocks when compared to the south-facing sites. No statistically significant differences with respect to weathering indexes could be detected. The geochemical evolution of the soils seems to be enhanced at north-facing sites, even though very severe climatic conditions prevail. Furthermore, biodegradation seems to be less pronounced on north-facing compared to south-facing sites as poorly degraded organic matter is accumulated. This gives rise to more organic ligands that promote metal binding and their subsequent eluviation along the soil profile. Conclusions: We consequently must assume that weathering is not limited by low temperatures in the active layer but is rather controlled by soil moisture that seems to be higher during the warmer period in the north-facing soils