Chemical component depositions in the microbial mats and travertine in the Khoito-Gol thermal spring (Eastern Sayan)

The results of studies of the chemical composition of water, travertine, and microbial mats in the Khoito-Gol mineral spring (Eastern Sayan) are presented. It was shown that the formation of mineral deposits, travertine, and microbial mat is connected with the active functioning of microorganisms and geological and geodynamic conditions. It has been revealed that the diversity of cyanobacterial and sulfur microbial mats increases as the distance from the springs of the thermal water grows. Microbial mats are hardened with carbonates being converted into solid travertine crusts that are built upon the top of older structures to form multi-meter domes. The concentration function of the microbial mats and thermal water showed higher coefficients of accumulation of nickel and beryllium.

ЗНАЧЕНИЕ ГИДРОГЕОЛОГИЧЕСКИХ ПРИРОДНЫХ ПАМЯТНИКОВ В РАЗВИТИИ ЭКОЛОГИЧЕСКОГО ТУРИЗМА

Since the very beginning of tourism, nature has been the main driving force behind travel. Obviously, natural monuments are one of the attractive places for tourists. Today ecotourism based on natural monuments and attractions has become one of the leading sectors of the economy in many countries of the world. Travels associated with natural monuments are now the most promising and intensively developing areas of recreational activities. Keywords: ecotourism, natural monuments, hydro-geological monuments, mineral spring, kyahriz

Temporal evolution of 3He/4He isotopic ratio at Dos Aguas cold mineral spring, La Palma, Canary Islands

<p>Recent volcanic activity of La Palma island, the fifth in extension (706 km<sup>2</sup>) and the second in elevation (2,423 m a.s.l.) of the Canarian archipelago, has taken place exclusively in the last 123 ka at the southern part of the island, where Cumbre Vieja volcano, the most active basaltic volcano in the Canaries, has been constructed. A total of seven volcanic eruptions have been reported along the main north-south rift zone of Cumbre Vieja in the last 500 years. On October 7<sup>th</sup> and 13rd, 2017, two remarkable seismic swarms interrupted a seismic silence of 46 years in Cumbre Vieja volcano with earthquakes located beneath Cumbre Vieja volcano at depths ranging between 14 and 28 km with a maximum magnitude of 2.7. Five more seismic swarms were registered in 2020.</p><p><sup>3</sup>He/<sup>4</sup>He ratio has been monitored at Dos Aguas cold mineral spring in La Palma Island since 1991 to date as an important volcano monitoring tool able to provide early warning signal of future volcanic unrest episodes. Magmatic helium emission studies have demonstrated to be sensitive and excellent precursors of magmatic processes occurring at depth. The highest <sup>3</sup>He/<sup>4</sup>He ratio reported to date from the Canarian archipelago has been measured at Dos Aguas: 10.24 R<sub>A</sub> (being R<sub>A </sub>the ratio in atmospheric helium) (Padrón et al., 2015). This value is higher than any value found either in the lavas or terrestrial fluid in the Canary Islands, and indicates an important mantle contribution.<sup>  </sup>According to the temporal evolution of the magmatic component of helium at Dos Aguas, we suggest the occurrence of aseismic magma rising episodes beneath La Palma within the upper mantle towards an ephemeral magma reservoir in the period 2007-2017. However, in the period 2017-2020, magma rising have produced seismic swarms that were accompanied also by the highest <sup>3</sup>He/<sup>4</sup>He ratio measured at Dos Aguas (10.42 R<sub>A</sub>); both geochemical and geophysical signals confirm an upward magma migration towards a subcrustal magma reservoir beneath La Palma island.</p><p> </p><p>Padrón et al., (2015). Bull Volcanol 77:28. DOI 10.1007/s00445-015-0914-2</p>

Hydrochemical Formation Mechanism of Mineral Springs in Changbai Mountain, China

Changbai Mountain area in China is an important mineral water storage and development area. The hydrochemical composition of mineral water is the decisive factor for mineral-water quality. Therefore, it is necessary to study the hydrochemical characteristics and genesis of mineral water in Changbai Mountain area. Considering the integrity of basin and groundwater system, the study area was classified into three areas where mineral springs are densely distributed. For these areas, according to the mineral water parameter contents, the springs are further classified into single-type (metasilicic acid) mineral spring and compound mineral spring. By examining 74 mineral water samples collected from 2018 to 2020, the characteristics and formation mechanism of the hydrochemical components of the spring water were analyzed by mathematical statistics, model construction, cluster analysis, and principal component analysis. The results show that the formation of single-type mineral spring is controlled by rock weathering; compound mineral springs are the product of CO2-rich, weakly acidic, confined hot groundwater with high salinity and its mixing with shallow groundwater as it rises along the fracture. Volcanic geological process greatly influence the formation of the hydrochemical components of mineral springs on the North slope of Changbai Mountain. The mineral springs on the Longgang Mountain are greatly affected by human activities. The results of cluster analysis only considering hydrochemical components are consistent with the classification of the areas with concentrated distributions of mineral springs as determined by hydrogeological and geomorphological studies. The results of this study are useful for understanding the distribution, hydrochemical characteristics, and formation mechanism of mineral springs in Changbai Mountain area of China and provide the theoretical basis for the protection and development of mineral spring water.

Different Waters for Different Performances: Can We Imagine Sport-Related Natural Mineral Spring Waters?

Preserving the hydration status means to balance daily fluids and salt losses with gains, where the losses depend on several physiological and environmental factors. Especially for athletes, these losses could be relevant and negatively influence the performance: therefore, their hydro-saline status must be preserved with personalized pre- and rehydration plans all along the performance period. Scientific literature in this field is mainly dedicated to artificial sport drinks. Different territories in most world areas are rich in drinking natural mineral spring waters with saline compositions that reflect their geological origin and that are used for human health (often under medical prescription). However, scarce scientific attention has been dedicated to the use of these waters for athletes. We therefore reviewed the existing literature from the innovative viewpoint of matching spring water mineral compositions with different athletic performances and their hydro-saline requirements.