The Geology of Azerbaijan forms a constituent geological part of the Alpine fold belt. Sedimentary deposits embracing the southwestern parts of the Major and Minor Caucasus, including the intermountain Kur River trough, as well as the Mid- and South Caspian basins consist of diversity fold systems. The Earth's crust thickness in Azerbaijan varies in the range from 38 to 55 km. Its maximum thickness is observed in the Minor Caucasus area, while its minimum thickness is typical for the Talysh foothills. The geological setting of the area consists of sedimentary, volcanic-sedimentary, volcanic and terrestrial deposits embracing almost the entire stratigraphic range beginning from Pre-Cambrian through Holocene time.