Volatile Contents during the Formation of Olivinite and Olivine-Monticellite Rocks of the Krestovskaya Alkaline–Ultrabasic Carbonatic Intrusion, Polar Siberia: Pyrolysis-Free Gas Chromatography-Mass Spectrometry Data

The parental larnite-normative alkaline ultramafic melt consistently forming olivinite and olivine-monticellite rocks of the Krestovskaya alkaline-ultrabasic carbonatic intrusion is enriched with hydrocarbons (HC) and their derivatives, nitrogenated, chlorinated, fluorinated, sulfonated compounds, as well as HO and CO according to pyrolysis-free gas chromatography-mass spectrometry data (GC-MS). The aliphatic, cyclic, oxygenated compounds, and very few heterocyclic compounds are determined among the hydrocarbons. During the crystallization of olivine in olivinites, fluids are enriched in hydrocarbons (59.30 rel. %), excluding nitrogenated, chlorinated, and sulfonated derivatives and including predominant amount of oxygenated compounds (52.17 rel. %) and subordinate amount of aliphatic and cyclic compounds (6.70 rel. %). During the crystallization of perovskite in olivine-monticellite rocks, the amount of oxygenated hydrocarbons slightly decreases (34.77 rel. %) and aliphatic and cyclic compounds increases up to 10.55 rel. %. The crystallization of monticellite is accompanied by the predominance of aliphatic and cyclic hydrocarbons (59.67 rel.%) and subordinate amounts of oxygenated hydrocarbons (29.35 rel. %). The fact that the calculated H/(O + H) ratio is 0.78 and 0.77 for fluids in olivine and perovskite, respectively indicates the reducing conditions of crystallization of these minerals.