Gypsiferous carbonates at Honaz Dağı (Denizli): First documentation of Triassic gypsum in western Turkey and its tectonic significance

This paper is the first to document the presence of Triassic evaporites from the Anatolide-Toride carbonate platform by providing stratigraphic, structural, mineralogic, petrographic and isotopic analyses. We have performed isotopic analyses on selected gypsum samples with δ34S values vary between +15.1% and +18.1‰ and 87Sr/86Sr ranges between 0.707761 and 0.707772. The new isotopic data is very similar to Late Triassic gypsum of the Mediterranean belt, and therefore, the age of the gypsum-bearing formation is assigned as Late Triassic. We have carried out a detailed study in the area of Honaz Dağı, 20 km east of Denizli, SW Turkey and its close vicinity. Here, gypsum-bearing rocks are well exposed, allowing us to establish the stratigraphic and tectonic position of the sequence.The gypsiferous carbonate sequence occurs as a tectonic slice with no observed stratigraphic contacts. It is structurally overlain by a Mesozoic-Early Tertiary turbiditic-olistostromal unit, Late Triassic–Liassic dolomitic limestone and Cretaceous ophiolite. The gypsiferous sequence is characterized by intercalation of white–grey massive gypsum and black dolomitic limestone. The gypsum at the outcrops seems to be secondary formed by the hydration of precursor anhydrite, and shows typical porphyroblastic and alabastrine textures with corroded anhydrite relics.The deformation affecting the Late Triassic gypsum-bearing sequence has been grouped under two major phases. First, thrusting with intense folding and imbrication showing compressional deformation with top-to-the-NE sense of shear. This deformation is widespread in the Kaleboğazı formation and the structurally overlying dolomitic Gereme formation. Second, the formation of E-W trending high-angle normal faults and N-trending strike-slip faults, which control the present day structural frame of the region.