ON POSSIBLE GAS-HYDRATE NATURE OF LOESS-G ROUND SAGGING

The possibility for finding traces of paleohydrates is considered. Und er discussion are natural mechanisms of loess sagging on wetting. It i s shown that the famous cryo-evaporation and cryo-sublimation hypothes es cannot explain the observed maximum sagging magnitudes, to 0.15 and more. Analysis is given to physical properties of natural gas hydrate s, especially, to a much greater increase in volume of water involved in a gas-hydrate phase as compared with an ice phase. New data support the hypothesis that the formation of gas hydrates in subsurface depos its during the glacial period and their destruction with gas released to the atmosphere during the interglaciation period is one of the poss ible mechanisms of the Formation of macroporosity and sagging of loess grounds. The presence of loess rocks, macroporous and sagging on wett ing, suggests possible development of gas hydrates there during cold e pochs.