Свойства флюидного состояния и фазовый переход, вероятно, впервые привлечены для объяснения механизмов вулканического и гидротермального процессов. Индикатором земного флюида оказался цезий. Состав глубинного ювенильного флюида по гидротермам и газово-жидким включениям — совпал. Свойства флюида в значительной мере определяют тип вулканизма, гидротермальный процесс и рудообразование.

Nowadays, scientists are debating about two possible origins of waters on the Earth: (i) water comes from space with meteorite and comet material, and (ii) water is a consequence of the differentiation of depth substance of the Earth. Most researchers lean towards second version. There is also a point of view that accumulation of surface waters of the Earth is due to juvenile (intra-planetary) waters, which bring approx. 37 cubic kilometers into the global volume each year. It makes the relevant an issue of the surface discharge of ‘juvenile’ waters (i.e. waters that have not been in a superficial circuit), as well as the establishment of physical and chemical type of such waters and the proof of their juvenile character. In my article, I probably first propose to use properties of fluid state and phase transition for explaining the mechanisms of volcanic and hydrothermal processes. I formulate my hypothesis, based on two known fact.The first is that there is a certain type of hydrothermal fluids, which is characterized by high levels of cesium and its huge outwash (they are chloro-sodic, high temperature hydrothermal fluids, for example, water of geysers in Valley of Geysers in Kamchatka or in Yellowstone National Park). The second fact is that in this case, geochemistry of cesium does not permit its accumulation in the solution due to leaching. These two facts combined with several other indicators have led me to the conclusion that substance of these type hydrothermal fluids (i) is monogenic, (ii) it climbs up the isolated channel through the crust, and (iii) it is in an initial fluid state. Localization of hydrothermal fluids discharges that, according to many observations, is confined to the calderas of longlived volcanic centers, i.e. to the ring geological structures with magma conduit, through which magma rises during eruptions for hundreds of thousands or millions years. It also indicates the location of the fluid substance. Finally, comparison between the physical and chemical characteristics and geological position of these type hydrothermal fluids of different volcanic regions of the world shows their high similarity, which also indirectly indicates their monogenesis and depth. It allows to consider such fluids, in terms of composition of elements and their ratio (but not in terms of condition and structure of such hydrothermal fluids), almost corresponds to the deep juvenile fluid (DJF), which climbs up the isolated magma conduit of long-lived volcanic center from the depths below crystalline crust. Core fault in rising channel of these type hydrothermal fluids leads to a longtime (kiloannum) DJF discharge in the enclosing rocks with a high yield. In this case, DJF will differentiate and change complexly. As a result, the new thermal mineral waters and a variety of novel solid mineral substances will arise. In my analysis, I identified DJF participate in volcanic eruptions: traces of cesium systematically present in acidic volcanic rocks; they are also found in the products of basic volcanism and in the composition of high-temperature bottom crateral fumaroles of active volcanoes. The ability to dissolve gases and aluminum silicates is a characteristic of water in the fluid state, but this peculiarity is lost during phase change, and this explains the features of volcanic eruptions mechanism. I conclude that, in general, the nature of eruption is defined by ratio ‘fluid-aluminum silicates’ in magma conduit: (i) with the predominance of the fluid, strong explosions occur over the magma; (ii) when magma prevail over fluid, lava outflow occurs; (iii) in the presence of the fluid mixed with aluminosilicates, both fragmentation of magmas and eruption of ashes and pumices are happen. In general, studying deep juvenile fluide, its composition and location is the right way to understanding unified law of ore formation.