Minero-petrographic, geochemical, and multiisotopic characterization of the ancientbanded travertine quarries of the Lycus Valley (Denizli, Türkiye)

The Lycus Valley in Western Anatolia has been the site of numerous civilizations since ancient times due to historical, geopolitical, and climatological characteristics. Banded travertine is a ubiquitous architectural stone observed in ancient settlements in the Lycus Valley. Banded travertines referred to as “Alabastro Fiorito,” “Alabastro Listato,” and “Alabastro Rossa” in archaeological bibliographies have been extracted from the ancient quarries of Çukurbağ, Hierapolis, Develi-Akköy, Gölemezli, and Tripolis in the Lycus Valley and are characterized by white, yellow, brown, red, and red-burgundy colored bands with thicknesses ranging from a few millimeters to centimeters. The banded travertines have similar mineral compositions and consist of carbonate minerals (calcite, aragonite, and ±dolomite). However, the colored bands have a goethite and hematite composition, with X-ray diffraction and confocal Raman spectrometry studies supporting these results. They have a distinctive colloform texture (partially balloon-like structure), a radial dendritic texture, and a micritic laminated texture. The Lycus Valley travertines have characteristically high Sr contents and are geochemically similar to travertines of thermogenic origin. Compared to the North American Shale Composite (NASC) and Average Phanerozoic Limestones (APL), they show significant depletion in the concentrations of Al, Ca, Fe, Ti, Cr, Ni, Ba, Rb, Sr, Zn, Pb, Ce, La, and Nd. The δ13CV-PDB and δ18OV-PDB values of the Lycus Valley travertines range from 5.41‰ to 6.68‰ and from –16.05‰ to –12.09‰ in Çukurbağ, from 5.09‰ to 5.63‰ and from –14.85‰ to –9.18‰ in Hierapolis, from 4.69‰ to 5.16‰ and from –14.98‰ to –11.62‰ in Develi-Akköy, from 4.21‰ to 4.51‰ and from –15.29‰ to –13.76‰ in Gölemezli, and from 2.99‰ to 3.99‰ and from –15.93‰ to –13.01‰ in Tripolis. The geological ages of the banded travertines from the Çukurbağ, Hierapolis, Develi-Akköy, Gölemezli, and Tripolis quarries were determined to be 24.11 ± 0.13 to 91.1 ± 1.4 ka, 55.10 ± 0.22 to 158.3 ± 4.8 ka, 55.59 ± 0.23 to 74.92 ± 0.32 ka, 303.0 ± 20 to 408.0 ± 15 ka, and 2.09 ± 59 to 351.01 ± 8.12 ka, respectively.