TURKISH JOURNAL OF EARTH SCIENCES

Cover and Contents

2026-03-17

Geochemical characteristics and REE potential of red soils in the Seydişehir–Akseki region (Türkiye)

2026-01-25

MUAZZEZ ÇELİK KARAKAYA et al.

The karst-type bauxite deposits located in southwestern Türkiye represent the most significant bauxite resources in the country. Surrounding these bauxite deposits are widespread red soil deposits of varying sizes, developed over lithologically diverse rocks. This study aims to investigate the origin of these red soils, which were examined in two distinct groups based on their spatial relationship to the underlying geology. The first group of red soils is found on or within the fractures of karstic limestones, while the second group is primarily located in proximity to ophiolitic rocks. The investigation focused on the physical properties, as well as the mineralogical and chemical compositions, of these soils. Although both groups display partially similar mineralogical compositions and major element contents, notable differences were observed in their trace element, and especially rare earth element (REE), concentrations. The total REE contents range from 206 to 433 ppm in the first group and 853 to 4487 ppm in the second group. No significant correlations were identified between REE concentrations and either trace or major element oxides. The Ce anomalies is slightly positive (mean 1.0, std=0.18) in the most first group samples, with one second group sample at 1.07, while remaining samples exhibited a strong negative anomaly (mean 0.40, std=0.40). A positive Eu anomaly was observed in the first group (1.11), while no anomaly was found in the second group (0.99). These variations, including the wide range in REE contents and the absence of correlation with other geochemical parameters, suggest that the red soils may have different origins. The PASS-normalized REE and immobile element trends of the first group are partially aligned with the trends observed in schists, whereas the second group displays a markedly different pattern—largely parallel to that of ophiolitic rocks, and showing greater enrichment than all rock types examined in the study area.

Conulariids from the late Serpukhovian (Late Mississippian) carbonate deposits of NE Europe

2025-11-27

ANDREY VLADIMIROVICH ZHURAVLEV et al.

The Late Mississippian (late Serpukhovian) conulariids are described from the deep carbonate platform facies of the northern Cis-Urals. The fossil assemblage also includes brachiopods, foraminifers, ostracods, conodonts, Sphenothallus (?), crinoids, and rare bryozoan and fish remains. Conulariid remains are represented by isolated rods and articulated thecae of Paraconularia aff. subulata (Hall). A carbon isotope study suggests that the conulariids were low-level consumers, likely feeding on seston.

A comprehensive analysis of Türkiye’s beaches: spatial distribution, morphometry, and human impacts

2025-11-27

MUHAMMED ZEYNEL ÖZTÜRK et al.

The classification and morphometric characteristics of beaches is crucial for understanding coastal dynamics, evaluating natural and anthropogenic pressures, and supporting effective coastal management and conservation strategies. This is particularly important for countries like Türkiye, where extensive and diverse coastlines play a key role in tourism, the economy, and ecological sustainability. This study presents the first comprehensive, nationwide inventory and characterisation of Türkiye’s beaches, encompassing its 8483 km coastline. Using satellite imagery, 6110 beaches were identified and classified according to environmental conditions, with analyses conducted on their morphological characteristics, sea boundaries, and provincial distributions. The results show that rocky coast and river-mouth beaches constitute 81% of the total beaches but only 46% of the total beach length. Conversely, deltaic and low-lying beaches represent just 2.6% of the total number but comprise 37% of the total length, highlighting their significance despite their scarcity. Along the Mediterranean and Black Sea coasts, where mountain ranges extend parallel to the shoreline, beaches are fewer in number yet tend to be longer and broader. In contrast, the tectonically active and highly indented Aegean Sea coastline, with numerous bays, gulfs, and peninsulas, has the highest beach density, though these beaches are generally shorter. These findings underscore the role of coastal morphology and geological processes in shaping beach characteristics. In addition to natural factors, anthropogenic activities strongly influence Türkiye’s coasts: while coastal engineering structures have reshaped many Black Sea beaches, construction and tourism pressures are most evident along the Aegean coast, with Mediterranean beaches showing the highest proportion of human impact relative to their total number. This comprehensive analysis provides essential data to guide sustainable coastal management and conservation strategies in Türkiye.

Deformation conditions and quantifying strain in the Chai-Kour shear zone in the Zagros orogenic belt of Iran

2025-11-27

SAEEDE KESHAVARZ et al.

Strain analyses and kinematic studies in orogenic belts are essential for understanding their deformation mechanisms. The Chai-Kour brittle-ductile shear zone is located in the central Sanandaj-Sirjan metamorphic belt, southeast of the Zagros orogen. The present study analyzes deformed mylonitic rocks to clarify the deformation kinematics, temperature, and strain geometry of the Chai-Kour shear zone. Previously developed kinematic shear indicators such as S-C shear bands, deformed porphyroclasts, asymmetric boudins, and folds provide an overall top-to-the-southeast sense of shear in the Chai-Kour shear zone. Quartz micro-thermometry confirms that the Chai-Kour rocks were initially affected by a high-temperature (550–650 °C) deformation that was followed by a postsuperimposed low-temperature (380–420 °C) deformation. Rf/ϕ strain measurements reveal a plane-strain deformation geometry. The estimated Wm by the Rigid Grain Net technique ranges from 0.54 to 0.73, suggesting simultaneous contributions of simple (38–54%) and pure (46–62%) shear components. Spatial variation of deformation indicates that the simple shear component increases towards the northeast and southwest boundaries of the shear zone. The present study suggests that this shear zone experienced a 55–75% shortening perpendicular to its boundaries. These deformation characteristics in the Chai-Kour shear zone have been influenced primarily by a transpressive tectonic regime with lateral extrusion, resulting from the continuing oblique convergence of the Afro-Arabian plate with the continental crust of central Iran. This tectonic evolution resembles that experienced in other collisional zones, such as the Alpine and Himalayan orogens.