Difficulties in the isotopic indication of the genesis Yamal's massive ice. Part 2. Kharasavey

Abstract

Massive ice, located at different depths in the permafrost of the Kharasavey gas condensate field, many massive ice formations occurred in different forms such as layers, lenses and laccoliths. Massive ice near the Kharasavey village was repeatedly studied and tested in detail, and ice formations were found both within the first sea terrace and within the third sea terrace. The isotopic and chemical composition of massive ice can be explained by different ways. We believe that it indicates intrasedimental formation of massive ice. This study is based on data on the values of δ18О, δ2H and dexc in massive ice, as well as the chemical composition of the ice to establish possible conditions for the massive ice formation. Geochemical studies of sediments within the coastal areas of the Kharasavey showed that variability in the distribution of salts in sediments reaches a maximum here, especially in the transition zone from sea to land. The isotopic and chemical characteristics of the ice indicate that ice had been formed in an open system (i.e., with free flow of water from the reservoir). At the same time, the water in the reservoir was changed; at the first stages, it was most likely a mixture of sea and fresh water, which was subsequently desalinated more and more.