Environmental impact and sedimentary structures of mud volcanoes in southeast of the Caspian Sea basin, Golestan Province, Iran

Abstract

Mud volcanoes are defined as main elements of geological structures and ways through and within which buried argillaceous loose sediments and lithified rocks. The Gharniaregh Tappeh and Naftelijeh mud volcanoes are the most attractive geomorphological phenomena in continental which appear along the eastern coast of the Caspian Sea. The Naftelijeh mud volcano is more active than Gharniaregh–Tappeh, while the latter is saltier than the former, indicating its proximity to salt domes. The ejected materials from these mud volcanoes are often comprised slurry of fine solids silt and clay suspended in liquids, which may include water (frequently acidic or salty) and hydrocarbon fluids. The most part of the gases released are methane. Carbon dioxide and nitrogen are also emitted but in much lesser quantities. The complicated morphology of the volcanoes can be rough terrain, cone-shaped and buildings mentioned columnar shape. The morphology of the effects can be uneven terrain such as hills and buildings used in the column. Emissions caused significant environmental impact, including the loss of plants and vegetation destruction is quite evident in the region. Like all other natural phenomena, mud volcanism phenomenon can affect the environment both positively and negatively, which is discussed here. Catastrophic reduction of Paleo - Caspian size combined with the increasing scale of mud volcanic activity caused the oversaturation and intoxication of water by methane leading to the mass extinction of mollusks, fishes and other groups of sea inhabitants.