Abstract Understanding the fluid-rock interactions occurring in terrestrial mud volcanoes is a premise for elucidating the (bio)geochemical processes involved in the release of aqueous fluids, mud and gases to the Earth's surface and atmosphere. For the first time, fluid and mud ejecta from the mud volcanoes at Bahar and Zenbil, located in eastern Azerbaijan and in the shallow coastal water of the South Caspian, were collected and analyzed for their mineralogical, textural and chemical composition. The expelled aqueous fluids have a Na-Cl-(HCO3) composition and are generated by the mixing of evaporitic Caspian seawater and ancient, low- to high-salinity, sedimentary pore water at temperatures of 32 ± 3 °C and 42 ± 5 °C for the mud volcanoes at Bahar and Zenbil, consistent with mud chambers to be situated in the Pliocene sediments at 2–3 km depth. These aqueous fluids are strongly enriched in major solutes, like Na, Cl, HCO3, B, Br, NH4 and DOC, as well as in some trace elements (As, Ba, Cu, Fe, Li, Sr and Zn), with concentrations up to 220 times that of the current Caspian seawater. This chemical concentration is caused mainly by a combination of (i) strong surface evaporation, ion exchange and adsorption-desorption involving smectite clays, redox-driven reactions and carbonate mineral precipitation at relatively shallow depths (not deeper than 4 km) as well as (ii) thermal breakdown of organic matter and methane production in deeply buried (4 to 7 km depth) organic-rich strata. Biogenic processes are only of minor importance. The mud is sourced from all horizons the mud volcanoes are cross-cutting, partly altered by diagenetic processes. Alteration is comprised of illitization of smectite during burial diagenesis (120 to 150 °C), replacements of feldspar by kaolinite and smectite, weathering of sulfide minerals, Fe-(oxy)hydroxide formation, as well as oxidation of methane and organic matter in the near sub-surface environments at low temperature (

中文翻译：

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泥火山流体-岩石相互作用机制的新见解：对巴哈尔和赞比尔（阿塞拜疆）的流体起源和泥浆来源的影响

摘要 了解发生在陆地泥火山中的流体-岩石相互作用是阐明含水流体、泥浆和气体向地球表面和大气释放所涉及的（生物）地球化学过程的前提。首次收集了位于阿塞拜疆东部和南里海浅海沿岸的巴哈尔和赞比尔泥火山喷出的流体和泥浆，并分析了它们的矿物学、结构和化学成分。排出的水性流体具有 Na-Cl-(HCO3) 成分，由蒸发的里海海水和古老的、低到高盐度的沉积孔隙水在 32 ± 3 °C 和 42 ± 5 °C 的温度下混合产生C 代表 Bahar 和 Zenbil 的泥火山，与位于上新世沉积物中 2-3 公里深度的泥浆室一致。这些水性流体富含主要溶质，如 Na、Cl、HCO3、B、Br、NH4 和 DOC，以及一些微量元素（As、Ba、Cu、Fe、Li、Sr 和 Zn），浓度是目前里海海水的 220 倍。这种化学浓度主要是由 (i) 强烈的表面蒸发、离子交换和吸附 - 解吸引起的，包括蒙脱石粘土、氧化还原驱动的反应和相对较浅深度（不超过 4 公里）的碳酸盐矿物沉淀以及（ ii) 深埋（4 至 7 公里深）富含有机物地层中有机物的热分解和甲烷产生。生物过程只是次要的。泥浆来自泥火山横切的所有地平线，部分被成岩过程改变。蚀变包括在埋藏成岩作用期间（120 至 150 °C）蒙脱石的伊利石化、高岭石和蒙脱石替代长石、硫化物矿物的风化、Fe-（羟基）氢氧化物的形成以及甲烷和有机物在低温下的近地表环境（