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Calcite veins are commonly found at shallow depth (a few metres below the surface) in damage zones of active normal fault systems in southwest Turkey. Although earlier studies demonstrated the link between the vein formation and seismicity, the association of near-surface carbonate precipitation with climate-driven hydrological conditions (water table, amount of precipitation and evaporation, and water discharge) is poorly understood. In this study, using the U/Th dating method we investigate the timing of vein formation and the interrelationship between tectonic and climatic-related hydrological processes. Carbonate precipitation is interpreted to occur as a result of sudden pressure drops and CO 2 release after earthquake-induced fracturing. Vein formation mostly occurred during glacial periods, which coincide with slow growth rates and higher oxygen isotope values of speleothems from the Eastern Mediterranean region. We relate these episodes to reduced winter rainfall due to the decrease in westerly flow in SW Turkey. These somewhat drier conditions influenced the chemical composition of circulating water, creating conditions conducive to carbonate precipitation and sealing of damage zones. These conditions also facilitated CO 2 accumulation and overpressure build-up in the rupture zones. Failure of the faults resulted in the release of large volumes of CO 2 -rich fluids and the generation of shallow carbonate veins. It is proposed that during phases of increased winter rainfall CO 2 is advected to the surface and discharged as passive degassing when meteoric water circulation is enhanced. While regional tectonics is the ultimate driver of fault activity and fracture formation, climate-driven near-surface hydrological changes may have played an important role in modulating CO 2 -rich fluid circulation and surface discharge. • Late Quaternary carbonate vein/breccia occurs in earthquake-induced fracture zones. • Timing of vein formation mostly coincide with glacial periods. • CO 2 overpressure build-up in the rupture zones was facilitated by drier climate. • Faulting may lead to release of CO 2 -rich fluids from depth to the near surface. [ABSTRACT FROM AUTHOR]

The marine isotope stage (MIS) 5a to 4 transition (∼74 ka) was associated with rapid ice sheet expansion, declining moisture availability globally, and significant upheaval of terrestrial ecosystems across the northern hemisphere. Here, we present precisely dated speleothem trace element records spanning ∼90 to 70 ka from Dim Cave (Southern Türkiye) which provide crucial information regarding the climate response to this transition from the Eastern Mediterranean region. Trace element variability recorded in stalagmite DIM-E3 captures shifts in detrital influx, bedrock dissolution, and soil activity that collectively record two climatic signals: (1) high regional moisture availability between MIS 5c and 5b, and (2) increasingly arid conditions across the MIS 5a to MIS 4 transition. Both are contemporaneous with evidence for severe drying recorded across the Eastern Mediterranean and Middle East, as well as Asia, Europe, South America, and the North Atlantic. These results shed new light on the environmental consequences of rapid change in a climatologically sensitive region, and underscore the significance of atmospheric teleconnections in propagation of abrupt climate variability during the last glacial period. • The MIS 5-to-4 transition (∼74 ka) requires closer study in the Eastern Mediterranean. • We present precisely dated speleothem trace element records spanning ∼90 to 70 ka from Dim Cave (S. Türkiye). • Speleothem DIM-E3 records distinct changes in detrital influx, bedrock dissolution, and soil activity. • An abrupt shift to aridity is observed across the MIS 5a to MIS 4 transition. • Results underscore the consequences of rapid climate change in this hydroclimatically-sensitive region. [ABSTRACT FROM AUTHOR]

Central Anatolia represents one of the most outstanding examples of intraplate deformation related to both continental collision and back-arc extension generating non-uniformly distributed stress fields. In this study, we provide direct field evidence of various stress directions and investigate carbonate-filled fracture systems in the Central Anatolian Volcanic Province using U/Th geochronology and isotope geochemistry for evaluating the episodes of latest volcanic activity under regional stress. Field data reveal two independent fracture systems in the region. Successive fracture development has been controlled by two different volcanic eruption centers (Hasandağ Composite Volcano and Acıgöl Caldera). Trace element, and stable (C and O) and radiogenic (Sr) isotope compositions of carbonate veins indicate different fluid migration pathways for two different fracture systems. The U/Th age data for carbonate veins of two independent fracture systems indicate that the crustal deformation intensified during 7 episodic periods in the last 150 ka. The NNE-trending first fracture system was formed as a result of strain cycles in a period from 149 ± 2.5, through 91 ± 1.5 to 83 ± 2.5 ka BP. Subsequent deformation events represented by the ENE-trending second fracture zone have been triggered during the period of 53 ± 3.5, 44 ± 0.6 and 34 ± 1 ka BP before the first fracture zone resumed the activity at about 4.7 ± 0.15 ka BP. Although further studies are needed to evaluate statistical significance of age correlations, the periods of carbonate precipitation inferred from U-Th age distributions in this study are comparable with the previous dating results of surrounding volcanic eruption events. [ABSTRACT FROM AUTHOR]