Exemplified by the carbonate-apatites from the phosphate-bearing crust of weathering of the Magan and Yraas Massifs in the Maimecha-Kotui Province of ultrabasic-alkaline rocks and carbonatites, the EPR spectra of CO2−⁠, CO3−⁠, and CO33− radicals observed in them have been shown to be typomorphic and, thus, appropriate for separating endogenic and supergene varieties.

Analysis of experimental data shows that the spectra in endogenic and supergene apatites are complicated superpositions of several individual centers. Computer simulation using the ESRI program permitted us to recognize them, to identify and calculate proportions (contributions) of components in complex spectra. It has also been documented that the form of absorption lines in endogenic specimens is isotropic, and in supergene ones, anisotropic, i.e., isotropic and anisotropic EPR spectra of carbonate radicals with corresponding parameters are recorded.

These features reflect dynamic characteristics of radicals (rotating or fixed in the structure) and is due to molecular bound water, which is always present in supergene apatites and absent from endogenic high-temperature varieties, as inferred from data of chemical analysis, IR spectroscopy, and nuclear magnetic resonance.

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