Elemental geochemistry to complement stable isotope data of fossil travertine: Importance of digestion method and statistics

Abstract

Elemental data from travertines are a treasure of depositional and diagenetic information. However, correct interpretation requires proper data acquisition and treatment. This study shows how results from elemental analyses complement sedimentological and other geochemical, i.e. isotopic, data and thereby contribute to our understanding of fossil travertines. Multivariate statistical element analyses, after multiple travertine digestion methods, demonstrate the link between elements, their mineralogical phases, and ultimately their origin. This study reveals that carbonate-phase related elements in travertines (Sr, S, Ba, Mg and Na) originate dominantly from the fluid source rocks. In combination with the ?18O and ?13C signatures, they are thus key geochemical variables for comparison of different travertine geobodies. Geochemical data analysis (elemental concentrations and isotope signatures), as illustrated here for the Turkish Ballık travertines, supports interpretation with regard to fluid source rock, distance from the vent and relative intensity of processes like evaporation and degassing. For fossil travertines, geochemical data can thus provide crucial insights for understanding the hydrologic system. In particular when information is restricted to borehole data, like in subsurface reservoirs, their application could be decisive. © 2019 Elsevier B.V.