Authigenic barite in paleothermo cirque deposits of the Yamal Peninsula

Authigenic mineral formation in permafrost environments represents a scientifically significant yet little understood field of cryolithology. This study provides the first comprehensive documentation and analysis of authigenic barite discovered in frozen sediments of thermocirques on the Yamal Peninsula, with a particular focus on its potential as a novel indicator of cryogenic processes. The research methodology combines advanced analytical techniques including high-resolution scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and comprehensive geochemical characterization of ice-ground systems. A key methodological innovation is the development and application of specialized polymer replica techniques that enable precise preservation of primary cryogenic textures and microstructures in frozen samples, overcoming the limitations of conventional sample preparation methods. The results obtained demonstrate that authigenic barite forms distinctive rosette-shaped micro-aggregates within ice-ground micro-pores, with the crystal morphology indicating in situ growth under cryogenic conditions. Detailed geochemical analysis reveals that barite formation is fundamentally controlled by freeze-induced solute redistribution processes, where specific ionic ratios (particularly elevated SO₄²⁻/Ca²⁺) and neutral pH conditions preferentially promote barium sulfate precipitation over calcium sulfates. These findings show authigenic barite as a sensitive paleoindicator of cryogenic processes including thermodenudation, segregation ice formation, and freeze-thaw solute concentration. The study provides crucial new insights into low-temperature geochemical processes operating in permafrost environments, with important implications for understanding cryosphere evolution under contemporary climate change scenarios.