New data on eruptions of mud volcanoes in Azerbaijan

Abstract

Relevance. The article is devoted to new eruptions of the most active mud volcanoes Shikhzarli and Gushchu in the Shamakhi-Gobustan region of East Azerbaijan. These volcanoes are characterized by frequent manifestations. Thus, since 1844, 26 eruptions of the Shikhzarli mud volcano have been recorded. The most intense eruption occurred in February 1902 after the catastrophic Shamakhi earthquake. Aim. The geological position of mud volcanoes, seismological data that determined the depth of the source and the energy of the eruption are considered. A brief historical review of the eruptions is given. Methods. The geological structure of the areas where mud volcanoes are located is presented on the basis of new data obtained in recent years on the tectonics of mud volcanic regions of Azerbaijan. In particular for this reason was used Gobustan, with the identification of fault structures and microblocks located between them, as well as tectonic units – allochthon, parautochthon and autochthon. In one of these microblocks (Bayanata), there is the Shikhzarli mud volcano, which belongs to the parautochthon. Almost all the eruptions of the Shikhzarli and Gushchu mud volcanoes, as well as their last manifestations, are induced by earthquakes that have occurred in the regions close to them and are registered by 5-7 seismic stations. The previous eruption of the Gushchu mud volcano in the Shamakhi region in January 2020 was the result of tremors in the neighboring Ismayilli region. In the historical review of the considered mud volcanoes, characteristic and distinctive features of their manifestations are noted. The last (16th) eruption of the Gushchu mud volcano occurred from a new eruptive center, at a distance of 700 m to the north of the main crater of the volcano that has been active for more than a hundred years. Results. The results of geochemical analysis of volcanic breccias, especially oil-bearing rocks – sandstones and oil shales of EoceneMiocene deposits are presented to assess the prospects for oil and gas content of the areas where the considered mud volcanoes are located. Within the Bayanata microblock, oil and gas accumulations can be discovered under a mud volcanic chamber.