Effect of acid mine drainage on the mineralogy of a dystric cambisol

Two natural soil profiles non-acidified and acidified with acid mine drainage (AMD) were selected for study. Interactions between acid mine drainage and the soil were evaluated by the changes in the mineral composition applying XRD, transmission electron microscopy (TEM), analytical electron microscopy (AEM), and selective area electron diffraction (SAED). The main differences between the acidified and the non-acidified soil were in the presence of jarosite and in the authigenesis of two types of amorphous and/or poorly crystalline matter (Fe-rich; Al, Si-rich). The most frequent Fe-rich matter was identified as ferrihydrite. It appears to be in two morphological varieties: “massive” (composed of spheroidal particles) and “mohair” (composed of layered particles).