Ground Magnetic Surveying and Susceptibility Mapping Across Weathered Basalt Dikes Reveal Soil Creep and Pedoturbation

Ground magnetic survey profiles across a soil-covered and weathered mafic dike in sedimentary host rock not only permit to delineate the strike, width burial depth of intrusive basalt sheet, but also reflect subsurface deformation its clayey weathering products. We illustrate this finding practical geomorphological applicability by an example from mid-German Heldburg Dike Swarm, where blue- olive-gray basalt-derived clays inherited just space previously occupied basalt, large parts iron minerals their strong induced remanent magnetization. Such ductile basaltic “marker soils” deform move with surrounding low-magnetic soils, remain distinguishable contrasting colors high susceptibility. surveys can therefore soil creep distance at meter- decimeter-precision. Magnetic mapping dike’s cross-section exploration trench in-situ susceptometry permits analyze past great detail. Weathering solifluction transforms simple “vertical sheet” anomalies dikes into complex, still interpretable composite patterns, providing new promising exploratory approach for field studies concerned pedoturbation.