Magnetic and chemical parameters of andic soils and their relation to selected pedogenesis factors

摘要: In the case of andic soils − developed on volcanic rocks permanently humid conditions are essential for andosolisation processes. Although usually rich in highly magnetic iron oxides, knowledge about these minerals with respect to soil development is missing. The aim this contribution investigate relationship between and basic chemical properties basement parameters related pedogenesis factors. studied sites located basaltic lava flows eastern part French Massif Central. Investigated pedons alu-andic, sil-andic, vitric were pedologically described analysed by a set soil-chemical methods. Magnetic include low-field volume-specific mass-specific susceptibility, frequency-dependent remanent (including S-ratio) coercivities. Chemical included pHH2O, organic matter, total cation exchange capacity, base saturation, content Fe Al extracted dithionite-citrate, acid-ammonium oxalate, pyrophosphate solutions. Micro-morphology Andosols parent material was observed scanning electron microscopy, completed energy dispersive spectrometry. factors represented parent-rock age, annual precipitation, thickness. Our findings suggest that (1) precipitation most important factor strong relative grain-size, concentration ferrimagnetic minerals, aluminium dissolved matter; (2) parent-material age shows well-pronounced grain-size susceptibility ratio saturation induced magnetisation (Mrs/Ms), selective dissolution parameters, pHH2O; (3) thickness profile link Mrs/Ms, matter.