Minerals were analysed that had been found in penguin guano and in underlying silicate weathering crust phosphatized by guano leachates. Struvite and hydroxylapatite were found in guano, leucophosphite, minyulite, amorphous aluminum phosphate and taranakite in phosphatized layer, and in some distance from the zone of ornithogenic soils — vivianite. Minerals were identified by the X—ray analysis and results of this identification were confirmed by the microscope studies and the analysis of chemical composition. Results of the thermogravimetric analysis of the selected minerals occurring in monomineral agglomerations (struvite, minyulite, amorphous aluminum phosphate, taranakite) are also presented. Relation between distribution of those minerals in ornithogenic soils and changes in chemical composition of mineral-forming guano leachates during their infiltration through soil, were described.