Analysis of geochemical properties of eruption products of mud volcanoes in the Lower Kura depression

Due to its location, the Lower Kura depression is included in the north-west part of the South Caspian basin. It stretches from northwest to southeast and enters the South Caspian basin. It is a deep-seated (buried) depression. Its crystalline base is located at a depth of 20-22 km. Two main anticlinal linear zones are separated on the border of the depression: Kalamaddin-Bandovan and Padar-Neftchala. In addition, the Kursangi and Southern Kursangi uplifts, freely located between them, were discovered. One of the main features of this oil and gas region is the extensive development of mud volcanoes in its territory. Within it 33 mud volcanoes were discovered characterized by intensive oil-gas eruptions. In this article, based on the detailed analysis of the existing geological-geophysical material, the distribution area of the mud volcanoes developed in the depression, and the geo- chemical characteristics of their eruption products were reviewed. The goal is to determine the gases contained in the products thrown by volcanoes to the earth’s surface and to study their distribution over the area. For this purpose, the content of methane gas, heavy hydrocarbons, nitrogen and carbon dioxide in eruption materials was studied. According to the results obtained from the analysis, the composition of the gases in the mud volcanoes present in the depression consists mostly of methane. The amount of methane in the eruptive products of Agzibir volcano varies from 86.3% to 98.88% (Kalamaddin mud volcano). The average mark of methane gas ranges from 86.6% (Akhtarmaardi) to 91.3% (Harami). At the same time, maps were drawn up to determine the distribution of gases in the eruptive materials in the study area. At the same time, a map of the location of the Galmaz mud volcano, a geological profile passing through the mud volcano was created. The amount of gases released into the atmosphere was determined based on the analysis of mud volcano eruption products in the south-west and north-east parts of the Galmaz area. As a result of geological and geophysical studies it was determined that the chemical composition of the eruption products of the Galmaz mud volcano is different. The analysis show that most of the gases released from the volcano into the atmosphere consist of methane gas. It is 9 gas - 97.42%. The amount of other gases is relatively small: heavy hydrocarbons – 0.04%, nitrogen- 0.48%, CO2- 2.06%. The deposits related to mud volcano are mainly massive, structural and tectonically screened types. However, hydrocarbons accumulated within traps are formed oil-gas and gas individual deposits.