Arabian Journal Of Geosciences, vol.14, no.16, pp.1-19, 2021 (SCI-Expanded)
This research reports the first Sr isotope chemostratigraphy, geochemistry, and provenance of the volcanic and volcanoclastic sequence (tuff/tuffite) in the Adana Basin (southern Turkey) whilst correlating it with the other volcano-sedimentary units in the central and SE Turkey. The examined tuffites are observed as thin but widespread volcano-sedimentary layers which include crystal-rich and terrigenous material that are seen throughout the southern margins of the Adana Basin, S Anatolia. The tuffs in the sequence mostly contain feldspar, hornblende, rare quartz, mica, carbonate rock clasts, shell fragments, clay, calcite, zeolite, and glass shards. The geochemical multi-element patterns of the tuff level rich in volcanic material present a volcanic arc-related geodynamical environment that was located close to an active continental margin. Geochemically, the tuffs present marked negative P, Ti, and Nb anomalies depending on MORB-normalized multi-element diagrams that suggest a supra-subduction geodynamic setting. The tuff levels of the Salbaş member are geochemically described by high SiO2 (68.40–72.33 wt%), Al2O3 (12.01–14.14 wt%), and relatively low MgO (0.84–2.05 wt%) and CaO (1.35–2.17 wt%) ratios together with the depletion in Ti, Nb, and P. Electron microprobe analyses show the chemical composition of both feldspar, hornblende minerals, and glass shards in tuffs. The 87Sr/86Sr ratios provided from four samples of volcano-sedimentary rocks ranged between 0.708054 and 0.708409 and between 0.708397 and 0.708427, respectively. The results of strontium dating on the tuffites yielded isotopic ages between 20 and 27 Ma (Burdigalian–Chattian), corresponding to the Upper Oligocene–Lower Miocene time interval. The tuffites which contain high amounts of terrigenous material, fossils, and sedimentary structures and textures are thought to have been transported from a source area in the north and were originally deposited during the Middle–Upper Miocene period. The geochemical, isotopic, sedimentological, and petrographic features of the volcano-sedimentary rocks in this region indicate that they are related to the subduction of the Inner Tauride Ocean and are consistent with the characteristics of volcano-sedimentary units in Central Turkey.