Organic Compounds of Medium Volatility in the Thermal Fields of Urup Island, Kuriles, and the Kamchatka Peninsula: A Comparative Analysis
Vladimir Kompanichenko, V. A. Poturay
Abstract
Abstract— The paper presents the first data on the composition of organic compounds of medium volatility in hot springs at Urup Island, Kurile Archipelago. The samples were taken from the Klyuchevoy and Otlivnaya thermal fields, with temperatures from 60 to 85°C and pH from 2.3 to 6.6. Organic compounds were analyzed on a Shimadzu GCMS-QP2010S gas chromatography-mass spectrometer. The thermal waters contain 21 organic compounds, which belong to five homologous series. The most widespread compounds are alkanes (48–52% of the total peak area) and aromatic hydrocarbons (37–38%). The homologous series of isoalkanes, alkenes, and amides were identified in small amounts. Comparison of the data with those provided by earlier similar studies in Kamchatka reveals close similarity in the composition of the dominant organic components in these geothermal regions: the predominance of aliphatic and aromatic hydrocarbons (more than 60%). However, the compounds in the hot waters of Kamchatka springs and wells are much more diverse. For example, the waters also contain carboxylic acids and their esters, terpenes, aldehydes, ketones, and alcohols. In addition to organic components, whose genesis is assessed as biogenic, some geochemical features of the identified compounds (in particular, the molecular mass distribution of the alkanes) indicate that the organic matter (OM) was partly generated by thermogenic processes. The analyzed samples of thermal waters from Urup Island generally yielded the first generalized data on the composition of medium volatility organics in the hydrothermal systems of the Kuril–Kamchatka volcanic arc.