Carbonatization of Serpentinites of the Mid-Atlantic Ridge: 2. Evolution of chemical and isotopic (δ¹⁸O, δ¹³С, Rb, Sr, Sm, Nd) compositions during exhumation of abyssal peridotites

The alteration of oceanic lithosphere by fluids is the primary driver of water-rock reactions with ultramafic and mafic rocks that transform CO2 into carbonates. Carbonation of peridotites involve the generation of carbonate veins and large-scale carbonatization of serpentinized peridotites exposed on the ocean floor at slow-spreading and ultraslow-spreading ridges and in ophiolites on continents. We report geochemical and isotope data (δ¹⁸O, δ¹³C, Rb, Sr, Sm, Nd) on ultramafic rocks that provide insights into the isotopic trends and fluid evolution of peridotite carbonation and help to understand heterogeneities in alteration and carbonization within peridotite-dominated serpentinization system. The main goal of this work is to reconstruct the hydration history and to understand conditions, isotope and chemical changes during carbonatization and serpentinization of mantle peridotites. Our studies show a comparative analysis of petrological, geochemical, isotope data (strontium, neodymium, oxygen and carbon) and degree of fluid–rock interaction during uplift and emplacement of carbonated serpentinites and present a reconstruction of the long-term fluid interaction of abyssal peridotites from the Mid-Atlantic Ocean Ridge.