Geochemical proxies and formation mechanism of Hatay (Başlamış) travertine and relation with Dead Sea Fault Zone (S-Turkey)

Abstract

This study is the first investigation of the Başlamış (Hatay) travertines formed in the northern part of the left-lateral strike-slip Dead Sea Fault Zone. In this study, Başlamış travertines are examined in terms of structural, mineralogical and formation mechanism by conducting geochemical, hydrogeochemical and facies analysis. The Başlamış travertine occurrences are characterized by successions of terraces and pools developed in slope depositional system, mound depositional system and depression depositional system. The travertines have been classified into five lithotypes, namely: laminated, coated bubble, reed, intraclasts and micritic travertine. According to the thin section, XRD, SEM and EDX analysis, the Başlamış travertines are divided into two groups, the first group contains aragonite and secondary minerals such as silica and clay minerals, while the second group consists only of calcite minerals, therefore, the travertines are morphologically classified as aragonite-bearing travertines and massive calcite bearing travertines. The negative correlation between Ca and Sr abundances in travertine samples indicates that some Ca was replaced by Sr in the calcite lattice. Relatively rich trace element content in the Başlamış travertines is attributed to leaching of the underlying gabbro and limestone. Higher concentrations of some of the elements were probably the result of diagenetic processes and syngenetic mineralization. The Başlamış travertines are defined as meteogene travertine deposits and are fed with meteoric-origin waters along Dead Sea Fault Zone in terms of hydrogeochemical results. The conceptual model of the Başlamış travertine shows that the travertines are formed by precipitation of dissolving the limestone. The heat source of the geothermal fluid forming the travertines is of tectonic origin.