ESR diagnostics of sedimental preservation of carbonate in belemnite rostra

The comparison of ESR characteristics of Mn2+ ions and electron-hole centers in carbonate of belemnite rostra from Late Jurassic sediments of the Volga and Sysola Basins, Russia, is presented. It was established that forming of impurities of newly formed calcite in the rostrum is marked by the change of shape of ESR Mn2+ spectrum. A specific feature of biogenic carbonate of rostra is the presence of a trivalent form of isomorphic impurities of manganese ions, probably localized in aragonite-like contact zones of calcite fibers with organic matter.