Intensity of Chemical Weathering Over Three Meta-igneous Rocks: Importance for Trace Metals Enrichment in Soil Profiles

The study discusses the relationship between the intensity of weathering and trace metals concentrations in soil horizons. Weathering intensity was calculated with indices such as Ruxton ration (RR), chemical index of alteration (CIA), chemical index of weathering (CIW), plagioclase index of alteration (PIA), volgt weathering indices (V) and weathering index of parker (WIP) on three igneous and meta-igneous rocks: porphyritic biotite granite, porphyroblastic gneiss and migmatite gneiss. Soil samples were analysed for major oxides and trace elements. The results of the weathering intensity were compared to trace metals in soil profiles. Results show that soil profile with the highest trace elements exhibit the least intensity of weathering while soil profile with the least metal enrichment shows the highest weathering intensity. This study demonstrates the correlation between the rate of the chemical weathering and the release/leaching of metals from rock or soil. The leached metals are deposited into the environment.