TRANSFORMATION OF HYDROXYAPATITE OF BONE PHOSPHATE FROM THE OCEAN BOTTOM DURING FOSSILIZATION

Abstract

Samples of Recent–Miocene fish and marine mammal bones from the bottom of the Atlantic and Pacific oceans and Miocene Maikop deposits (Transcaspian region) are studied by the X-ray diffraction (XRD) technique combined with the chemical and energy-dispersive (EDX) analyses. Changes of lattice parameters and chemical composition of bioapatite during the fossilization and diagenesis suggest that the development of skeletal apatite proceeds from the dahllite- type hydroxyapatite to the francolite-type carbonate-fluorapatite. It is assumed that a jump-type transition from dahllite to francolite during the initial fossilization reflects the replacement of biogeochemical reactions in living organisms, which are subject to nonlinear laws of nonequilibrium thermodynamics, by physicochemical processes according to the linear equilibrium thermodynamics.