Characterisation of pedogenic carbonates in Calcocambisol at a location within the Dinaric part of Croatia

Abstract

[EN]Pedogenic carbonates are secondary carbonate deposits and are a constitutional part of many soils. We analysed a 95 cm deep Calcocambisol soil profile at a location in the Dinaric part of Croatia. Here, pedogenic carbonates are more abundant in the deeper part of the profile (>23 cm), and their amount and size increase with depth corresponding to soil properties along the profile. These pedogenic carbonates are spherical to irregular in shape and can be classified as nodules. Microscopical analysis of these nodules shows that dissolution and re-precipitation of carbonate take place in situ, without considerable movement through the soil profile. The growth of the nodules starts from multiple centres of nucleation, and their internal structure is a result of spatial and temporal environmental conditions in the soil matrix during carbonate precipitation. The inclusion of noncarbonate particles and preservation of the original soil structure confirm the replacive nature of nodule growth. Furthermore, the internal structure of nodules reveals multiple stages of calcite precipitation, indicating seasonal or event-based precipitation of carbonate.