The Early-Middle Pleistocene Transition (EMPT, -1.4-0.4 Ma) marks a major shift in the Earth's climate system, with glacial-interglacial cycles evolving from -40,000-year obliquity-paced intervals to longer, asymmetric -100,000-year cycles. This transition occurred without major changes in orbital forcing, implying that internal climate mechanisms played a key role. However, these mechanisms remain poorly understood, especially in the understudied Eastern Mediterranean region. Here we reconstruct environmental and climate changes across the EMPT from the Ac & imath;go & uml;l Basin in southwestern T & uuml;rkiye (1.3-0.5 Ma). Vegetation dynamics, lake-level changes, and climate variability were investigated using a multi-proxy (pollen, NPPs) and multi-method approach combining the Modern Analogue Technique (MAT), Weighted Averaging Partial Least Squares regression (WA-PLS), Random Forest (RF), Boosted Regression Trees (BRT), and Climatic Amplitude Method (CAM). The pollen record reveals a persistent dominance of steppe vegetation, alternating between Amaranthaceae-Artemisia assemblages and grass-rich steppes with limited forest expansion during more humid phases. Relict taxa are rare and decline markedly during the EMPT, indicating that Southwestern Anatolia was less favourable for moisture-demanding species than other Mediterranean regions. Alternating abundances of Botryococcus and Chrysophyceae suggest fluctuations in lake level and trophic status under predominantly oligotrophic conditions. Pollen-based climate reconstructions indicate a general aridification trend, especially between 1.1 and 0.8 Ma, with more humid interglacials and drier glacials. These patterns align with other Eastern Mediterranean records and reflect both high-latitude ice-sheet dynamics and low-latitude forcing. Wavelet analysis reveals a dominant 41-ka obliquity cyclicity around 1.1 Ma.

The Li-rich claystone was formed within the Miocene volcano-sedimentary units in Emet borate deposits, in western Anatolia. This research identified hectorite and mixed-layer-illite/hectorite-abundant claystone that have technological and economic potential and have not been studied to date. The claystone was formed through the diagenetic alteration of rhyolitic and zeolitic tuffaceous units in a shallow lacustrine playa lake environment under arid climatic conditions. The parent rocks comprise altered and sericitized plagioclase and sanidine, opacited and chloritized biotite/muscovite, zeolite, quartz, and rock fragments cemented by argillizied, sericitized, and carbonatized matrix. Abundant hectoritic smectite and mixed-layer-illite/hectorite accompanied by accessory feldspar, quartz, locally calcite/dolomite, gypsum, and orpiment/realgar. The Li concentration reaches a max of 2200 ppm in the hectorite-abundant claystone and 218 ppm in the tuffaceous units. Smectite flakes are associated with illite fiber, feldspar, and amphibole. The degradation of sanidine, plagioclase, biotite/muscovite, and hornblende contributed to the positive correlation of SiO2 vs. Al2O3, K2O, TiO2, and total rare-earth elements (TREE) vs. SiO2, Al2O3, and K2O; MgO vs. Li values, and enhancement of MgO + CaO, Li, Sr + Rb, and TREE values, and LREE/HREE ratio; negative Eu anomaly and high concentration of S and As. These physicochemical compositions favored the formation of hectorite and mixed-layer-illite/hectorite. The SD and S18O values of hectorite and mixed-layer-illite/hectorite samples and the formation temperatures range from 98 to 119 degrees C reveal a burial diagenetic alteration process. The S18O and S13C values of the calcite samples suggest the mixing of thermal and fresh waters. The high 87Sr/86Sr ratios of calcite and gypsum reveal the consumption of Sr during the alteration processes. Additionally, the negative S34S values of realgar and orpiment suggest formation under acidic-neutral conditions via sulfate reduction or microbial cycling.

The Beypazari district is a large area of volcano-sedimentary rocks in the interior of central Anatolia, situated similar to 100 km northwest of Ankara. Trona, lignite, and bituminous shale occur in the lower part, and Na-sulfate and gypsum occur in the upper part of the sedimentary sequence of the Miocene Beypazari basin. The Neogene Beypazari Basin extends in an east-west direction from Beypazari to Nallihan and consists of a sedimentary sequence of up to 1200 m total thickness. The pre-Neogene basement rock assemblages of the Pontides limits the basin to the north. The Central Sakarya Region consisting of ultrabasic, granitic and metamorphic rocks bounds the basin to the south. The trona deposit, located 250-300 m below the surface, was discovered incidentally in the summer of 1982 by the General Directorate of Mineral Research and Exploration (MTA) while carrying out a drilling project on lignite deposits. An extensive exploratory drilling program was undertaken by MTA during the period 1983-1985 on behalf of Etibank. Proven trona reserves are 210 million metric tons, and total reserves are estimated to be 240 million metric tons. The Beypazari trona deposit is the world's second largest trona deposit after the Green River deposit, Wyoming, USA. In addition, there are similar to 400 million metric tons of lignite, 340 million metric tons of bituminous shale, and 1 million metric tons of Na-sulfate in the Beypazari Basin. The trona deposit located north of Zaviye village is associated with shale in the lower part of the Hirka Formation and alternates with bituminous shale and claystones. Based on borehole data, it is estimated that the areal extent of the trona deposit is similar to 8 km(2). The trona beds were deposited as two lens-like bodies within a 70-100 m thick zone in the lower part of the shale unit. A total of 33 trona beds are known: 16 in the lower trona lens and 17 in the upper lens. The total thickness of the lower trona horizon ranges from 40 to 60 m, and the total thickness of the upper trona horizon is similar to 40 m. The interval between the lower and the upper trona horizons varies from 30 m to 35 m. The central part of the trona deposit is generally thicker than the marginal parts, and the trona beds grade laterally into dolomitic mudstones and claystones toward the edges of the basin. The total thickness of the trona beds in both lenses varies between 21 and 34 m in the central parts, and 2.5 and 12 m in the marginal parts of the ore bodies. The common thickness of the individual trona beds in both trona horizons ranges from 0.4 m to 2 m. The isopach contours of both trona horizons are restricted by the Zaviye fault. The principal sodium-carbonate minerals are trona and minor nahcolite occurring in the marginal parts of the trona deposits, and trace amounts of pirssonite and thermonatrite occur locally. Trona and dolomite are associated throughout the trona zone. Calcite, zeolites, feldspars, and clays are the most common minerals within the rocks associated with the trona deposit. Trona crystals, generally white and occasionally grayish due to the presence of impurities, formed as massive crystals and as disseminated crystals in the claystone and shales. The products of zeolitization, dolomitization, and chloritization are rather widespread within the rock units associated with trona. The Beypazari Basin was affected by an extensional tectonic regime during the Middle-Late Miocene period. This extensional regime converted to a unidirectional compressional regime during the Late Miocene-Early Pliocene period. The sediments associated with the trona, lignite, and bituminous-shale deposits formed in fluvial, lacustrine, and playa-lake (perennial and ephemeral) environments. The Beypazari Basin is mainly filled by clastic materials and the penecontemporaneous products of adjacent volcanic activity, centered northeast of the basin. The most likely sources of Na for the formation of trona and other sodium-carbonate salts were thermal springs, tuffs interbedded with the sediments, and extensive Neogene volcanic rocks interfingering with sedimentary rocks in the northeastern part of the basin.

Ephesus was an important harbor city that flourished during the Roman period and ancient texts mention Almaden in Spain and the Cilbian fields of Ephesus as important cinnabar sources in antiquity. This work investigates whether imported cinnabar was used and whether this could be related to changes in painting activities over time. Microscopic analysis indicates a consistent preparation of cinnabar, hinting at a uniform source material quality or processing technique. However, the use of cinnabar varies among the architectural structures studied, indicating a plurality of painting techniques. A few of the analyzed cinnabar samples overlap with Turkish- and Balkan reference Pb isotope ratios; three samples from tabernas, however, deviate from this. The Hg isotope ratios reveal that cinnabar from carbonate-hosted deposits was likely used, and that processing of cinnabar included heating as suggested by ancient texts. Most notably, a correlation exists between the geochemical data and the painting technique - shifts in sourcing and cinnabar usage are potentially assignable to building chronology and/or usage. Through the lens of material provenance and processing, Ephesian cinnabar brings the organization of pigment trade into focus.

This study focuses on geological, microstructural, oxygen isotopic, and thermogravimetric investigations of Oltu stone, which is the most important turbostratic carbonaceous material in Turkey. The results of our investigations indicate that the carbonaceous Oltu stone material (specific gravity of 1.317) is not an organic material, such as jet, derived from fossilized wood. Rather, it is composed of a carbonaceous phase intermediate between amorphous carbon and crystallized graphite (termed turbostratic carbon), that is intercalated with flysch and formed by the reduction of seeping magmatic carbon dioxide during the diagenesis of Upper Jurassic-Lower Cretaceous marine sediments. Oxygen isotope analyses (SMOW) (using EA-IRMS) of both Oltu stone (δ18O = +37.2‰to +40.8‰) and the enclosing flysches (δ18O = +10.3‰ to +12.3‰) suggest that the nodules formed during diagenesis at a temperature of around 50 ℃. However, they are enclosed in flysches whose grains are derived from rocks that formed at significantly higher temperatures, perhaps above 100 ℃. The main industrial use of Oltu stone is as host material for diamond coating, as the sp3 bonds in the material can provide nucleation sites for diamond crystals and improve the nucleation rate at the early stage of diamond deposition on turbostratic carbon.

The Galatean Volcanic Province (GVP) lies within the Sakarya tectonic belt in the northwest of central Anatolia, Turkey, south of the North Anatolian Fault, cropping out over 12,000 km(2). It consists of Early Miocene intermediate to acid lavas, pyroclastic rocks, volcaniclastic deposits, and Late Miocene OIB-like basalts. Our study is based on new bulk geochemistry, SrNd isotopes, and Ar-40/Ar-39 dating of the volcanic rocks from the south-western part of GVP, but integrates all the available previous data to understand how magmas evolved in the post-collisional geodynamic condition in the GVP. The initial eruptions were rhyolitic, as domes or pyroclastic deposits (Group 1) and basaltic lavas (Group 2) during the Early Miocene. Group 2 is also represented by large volumes of basaltic-andesitic, trachyandesite-dacite/trachydacite lava flows, small intrusions, and pyroclastic deposits as generated between 21 and 14 Ma. Relatively low Sr-87/Sr-86 ratios (0.705-0.706) of the early rhyolites (Group 1), similar to all the rocks from Group (2), suggest the generation of hybrid melts with variable contributions of mantle-derived and crustal material. The volcanic activity ends with OIB-like basalts (11-7 Ma) showing the lowest Sr-87/Sr-86 (similar to 0.703) suggesting an asthenospheric origin. The geodynamic model, based on post-Cyprian slab rollback, results in long-term (22-13 Ma) post-collisional delamination/drip processes that support magmatism. This magmatism is generated in the lithospheric mantle, with the formation of basaltic melts and acid hybrid melts showing variable contributions of mantle-derived and crustal materials in a complex trans-crustal magma plumbing system. Complex mixing of various intra-crustal magmas and fractional crystallization processes generated a huge volume of volcanic rocks. The Late Miocene small-volume OIB basalts were asthenospheric melts that during the late stage recorded localized decompression melting processes.

The Li-bearing claystone and carbonate are sedimentary rocks deposited in the lacustrine environment hosting the Bigadic borate deposits in western Anatolia. The purpose of this paper is to explain the mineralogical, geochemical, stable isotope characterizations and formation of Li-rich claystone (hectorite, saponite), and have strategic, technological, and economic importance for the country's economy, which have not been sufficiently studied previously. In the rhyolitic and dacitic tuffs, sanidine and plagioclase crystals were altered, biotite and hornblende, Fe-oxidized, locally opaque, and chloritized in a sericitized, Fe-oxidized, argillized, calcified, and zeolitized glassy matrix. The claystone consists mainly of smectite and minor illite, volcanogenic quartz, feldspar, mica, hornblende, and occasionally calcite, aragonite, dolomite, and gypsum/anhydrite. Hectorite and saponite were determined based on the expansion of their basal peaks following heating at 500 degrees C and solvation with ethylen-glycol; additionally, hectorite expanded, and saponite was not affected after glycerine-saturated Cssmectite and heating at 100 degrees C for 20 h. Smectite shows webby to crenulated forms, and coexist with feldspar, volcanic glass, rhomboidal calcite, blocky gypsum/anhydrite, and Fe-oxide phases. The Li values increase up to 2650 ppm in the smectite-rich claystone and marl, and up to 449 ppm in the volcanic rocks. The positive correlation of REE with each of SiO2, Al2O3, and K2O; positive correlation of MgO vs. Li, and increase of MgO + CaO, Sr, Li, LREE relative to MREE and HREE; negative Eu anomaly and high values of As and S suggest that the feldspar, mica, and hornblende alteration originating from the Miocene volcanic and pyroclastic materials and presence of gypsum/anhydrite during the hydrothermal alteration activities were the sources for the smectite formation. The high negative & delta;18O values of calcite, the & delta;D and & delta;18O values of smectite and & delta;34S & PTSTHOUSND; and & delta;18O & PTSTHOUSND; values of gypsum, and the 87Sr/86Sr isotope ratios range of calcite and gypsum suggest the contribution of mixing meteoric and hydrothermal environmental conditions during the depositional and diagenetic process(es) in the playa lake environment.

The Kaymaz gold deposit comprises Damdamca, Karakaya, Küçük Mermerlik, and Kızılağıl ore zones within an area underlain by serpentinite and far-traveled Paleozoic-Mesozoic high-pressure metamorphic rocks. The Kızılağıl ore zone is hosted in silicified quartz schist, whereas the others are hosted in silica altered serpentinite. Pyrite-I, arsenopyrite, marcasite, magnetite, pentlandite, millerite, nickeline, bravoite, and fine-grained native gold and silver comprise the first stage, whereas pyrite-II and chalcopyrite represent the second ore stage. The Kaymaz gold deposit has been defined as a silica-listwaenite hosted gold deposit according to host rock relations and mineralogical properties.Gold, Ag, and As were found to be highly correlative in whole-rock silica-listwaenite analyses. Higher As content of the pyrite-I, coexisting native gold and silver together with the whole-rock analyses indicate that these metals were derived from the same source, possibly the Kaymaz granite. On the other hand, clathrate formations observed in some of the first stage fluid inclusions confirm that high Ni in the pyrite-I may have been derived from the serpentinites. However, a distinct lack of the separated carbonic phase and clathrate formations in the second stage fluid inclusions as well as their lower Th and salinities, reveal that higher Co in the pyrite-II possibly dissolved from the metabasites by meteoric solutions.

Cereals are a central resource for the human diet and are traditionally assumed to have evolved from wild grasses at the onset of the Neolithic under the pressure of agriculture. Here we demonstrate that cereals may have a significantly longer and more diverse lineage, based on the study of a 0–2.3 Ma, 601 m long sedimentary core from Lake Acıgöl (South-West Anatolia). Pollen characteristic of cereals is abundant throughout the sedimentary sequence. The presence of large lakes within this arid bioclimatic zone led to the concentration of large herbivore herds, as indicated by the continuous occurrence of coprophilous fungi spores in the record. Our hypothesis is that the effects of overgrazing on soils and herbaceous stratum, during this long period, led to genetic modifications of the Poaceae taxa and to the appearance of proto-cereals. The simultaneous presence of hominins is attested as early as about 1.4 Ma in the lake vicinity, and 1.8 Ma in Georgia and Levant. These ancient hominins probably benefited from the availability of these proto-cereals, rich in nutrients, as well as various other edible plants, opening the way, in this region of the Middle East, to a process of domestication, which reached its full development during the Neolithic.

The Askale sub basin hosts Early Miocene evaporites intercalated with clastic sediments and carbonates. Gypsum and anhydrite rich evaporite samples are characterized by high CaO and SO4 contents, and low Na2O, K2O, MgO, and B contents. The Sr contents are 228 = 13100 ppm in evaporite samples, 169 = 992 ppm in claystone, 181 = 60090 ppm in marl, and 15150 ppm in limestone. All the samples are also characterized by enrichment in light rare earth elements (REE) with La-N/Lu-N = 0.667 4.243 and have variable Ce-N / Ce* (0.823 - 1.353) ratios. Measured Eu-N/Eu* values of the samples display strong and variable negative and positive Eu anomalies. 834SCDT and 818O values of gypsum and anhydrite samples have wide ranges from 21.30 parts per thousand to 25.62 %o, and 11.5 parts per thousand to 19.1 parts per thousand, respectively. Most of these values are heavier than expected Miocene marine gypsum composition and may be resulted from reduction and oxidation reactions of sulfide species in brines. Sr-87/Sr-86 ratios range from 0.707475 (Delta(SW) = -169.8) to 0.708175 (Delta(SW) = -99.8), close to and / or slightly lower than an Early Miocene marine isotopic composition. Petrochemical and isotopic data indicate that the Askale basin evaporites developed in subtropical conditions via multiple marine transgressions onto a shallow platform or lagoonal environment.

The formation of large, economic borate deposits requires a boron-rich source, the means of transporting and concentrating the boron in a restricted environment, and mechanisms for the preservation of the deposit. There are several Miocene basins in western Turkey containing world-class borate reserves, with mineralization present as stratabound deposits in volcano-sedimentary successions. Although it is well-documented that the conditions required to form and preserve large borate deposits are most common in post-collisional tectonic settings (of which western Anatolia is a prime example), recent advances in the understanding of extensional tectonics and volcanism in this region, make it possible to gain fresh insights into their formation. Here, we suggest that formation of one of the largest borate deposits in the world was intimately related to the recently recognized Kirka-Phrigian caldera that lies in the northernmost part of the Miocene Eskisehir-Afyon volcanic field. Following caldera collapse, the basin filled with lacustrine sediments and volcaniclastic deposits with the boron mineralization concentrated in two main sub-basins: Sarikaya and Gocenoluk. The close spatial and temporal relationship between borate deposition and the vast Early Miocene ignimbrite deposits that surround the caldera (and contain high levels of elements associated with mineralization) strongly suggest that the ignimbrites were the major source of boron. The boron was transported by geothermal fluids and post-volcanic gases that vented into warm water at the base of the caldera-paleolake system and was then concentrated during cycles of sedimentation and evaporation, with most of the mineralization concentrated along a N-S striking fault system.

Trona deposits have limited distribution in the Earth's crust, but extraordinary concentrations can be found in some places, commonly in combination with borate and other salt deposits. Four main continental trona provinces are recognized at a global scale. They are located in Anatolia (Turkey), Wyoming (USA), Whuceng (China) and Botswana (Southern Africa). The origin of trona deposits is related to alkaline volcanism, thermal spring activity, closed basins and arid climate. Quaternary sodium carbonate minerals (trona minerals) are present in salars (Andes), playa lakes (Lake Van, Turkey and Botswana) and salt pans (USA and Tibet). Some conditions are essential for the formation of economically viable trona deposits: formation of shallow lake environments; source derived explosive andesitic to rhyolitic volcano-sedimentary sequences; concentration of sodium and bicarbonate in the lake, related to direct ash fall into the basin, or hydrothermal solutions along faults; thermal springs near areas of volcanic activity; arid to semi-arid climatic conditions; alkaline lake water. Many minerals contain Na carbonate, but the three that are most important from a worldwide commercial standpoint are trona, nahcolite, and pirssonite, which are produced in a limited number of countries, along with subordinate bradleyite, shortite and thenardite. Pirssonite occurs in organic-rich muds (oil shales). Trona and nahcolite are precipitated subaqueously (in lake waters) and as an interstitial phase in playa muds. Evaporite minerals are closely related to pyrite in oil shales and are also associated with diagenetic silicates (Mg-rich smectites, zeolites, K-feldspar, searlesite, and idiomorphic quartz) and dolomite formed by reaction of alkaline brines with pyroclastic deposits. Natural sodium carbonate minerals (soda minerals) are exploited commercially either from buried fossil trona deposits formed in Tertiary playa-lake sediments or by extraction from the brines of recent alkaline lakes and playas. Most of the world's commercial trona deposits are mined by underground and solution mining methods. Many modern industries use industrial trona minerals.

A 601 m long sedimentary sequence was drilled in Lake Acigol, located in the lakes region of SW Anatolia, near the Denizli travertine from which the oldest hominin of Turkey was unearthed. Among all dating methods applied to the sedimentary sequence, paleomagnetism, through the recognition of geomagnetic chrons, was the most successful and led to a quasi linear age model, with the 601 m long sedimentary record covering the last 2.3 Ma. An attempt to use the atmospherically deposited Be-10 as a dating method was not very successful but provides interesting clues on this new method. Long-term lake level changes are depicted through lithological variations, in particular the carbonates and evaporites abundance. This change could be influenced by both long term cooling during the last 2 Ma and tectonic activity, which may in particular be responsible for a maximum water depth at around 1.8 Ma. Despite active tectonic influence, the sedimentary facies description and the magnetic susceptibility record (cleaned from tephra intervals) show that climate fluctuations (i.e., glacial-interglacial alternations) are likely recorded in the sedimentary succession, with warm periods marked by enhanced carbonate precipitation and cold and dry periods characterized by more detrital input linked to reduced vegetation cover and consequently more erosion in the catchment area. Preliminary pollen data, used to interpret magnetic susceptibility fluctuations, show that an average dry and open landscape prevailed around Acigol lake during the whole record.

We integrate stratigraphic, petrographic and geochemical analysis of subsurface data (wells) together with field surveys to study the sedimentation of a marginal Miocene sub-basin of the Southeastern Anatolian Foreland Basin (SEAFB; SE Turkey). This sub-basin, located in the Batman-Siirt region, is characterized by the existence of evaporites (carbonates, sulphates and chlorides) and alluvial detritus which were divided in the following five lithostratigraphic members, from older to younger: Lower and Upper Yapılar; and Lower, Middle and Upper Sulha. These members deposited in an epicontinental mudflat during the Early Miocene. Both the bromine content and the sulphur and oxygen isotope composition (δ34SV-CDT and δ18OV-SMOW) of halite and sulphates samples, respectively, also suggest a marine origin of the precipitation brines. However, influence of geothermal fluids and dissolution-and-re-precipitation of evaporites from uplifted areas in these brines, such as the Early Miocene members and/or Triassic units, is interpreted. Comparing and integrating our results with data documented in previous works, it is here recognized that the depositional model of the studied sub-basin differs from that which explain the coeval sedimentation of units situated in the western part of the SEAFB. Moreover, our model shows some depositional and paleoenvironmental similarities with Miocene evaporites located in the Mesopotamian Foreland Basin. This work provides valuable insights on the Middle Miocene Salinity Crisis which is related to the evolution of the Neotethys closure.

The Çaldağ Ni–Co deposit is characterized by a reddish brown oxide lateritic regolith, containing residual Ni deposit formed by the intense tropical weathering of peridotites. Nickel–Co ore is associated with transported ferricrete during the late Paleocene – middle Eocene, represented by colloform Fe oxides and residual lateritization during the Oligocene. The lateritic regoliths are developed over dunitic ultramafic rocks and consist mainly of smectite, berthierine, kaolinite, gypsum, pyrite, takovite, and pecoraite. These units were examined using polarized-light microscopy, X-ray diffraction, scanning and transmission electron microscopy, and geochemical methods. Mineralogical zonation from the base of the profile upwards has the following zones: ultramafic bedrocks, serpentinized ultramafic rocks (saprock), saprolite, carbonate- and sulfide-bearing zone, ferruginous saprolite zone, and silcrete. In addition, Fe oxides, smectite and opal-CT, and quartz increase towards the surface, whereas olivine, pyroxene, and serpentine decrease upwards in response to chemical weathering. Nickel–Co mineralization associated with Fe oxides and smectitic clays formed under wet and dry conditions, respectively, as a result of an increased Fe 2 O 3 + Al 2 O 3 + Ni + Co/MgO ratio. Field observations and mineralogical and geochemical analyses reveal that the smectite formed under basic conditions was controlled by multistage chemical weathering of ultramafic and volcanic rocks and by the concentrations of Si, Al, Fe, and Mg. Locally, concentrations of S in conjunction with Fe and Ca resulted in precipitation of goethite–hematite, gypsum, and pyrite in dissolution voids in association with smectite under acidic conditions that developed in a well-drained system.