Ithnayn, Harrat

The 4000 km2 Harrat Ithnayn volcanic field contains scattered shield volcanoes and scoria cones. It merges with the much larger Harrat Khaybar volcanic field to the south. The field overlies Cambrian sandstones and Precambrian basement rocks. Vents form a general N-S pattern, but are more scattered than those of Harrat Khaybar. Harrat Ithnayn rocks are of basaltic and basanitic composition and lack the silicic components present in neighboring Harrat Khaybar. The youngest lava flows from Harrat Ithnayn are less than 4500 years old. An uncertain report of an historical eruption in 1800 CE is considered unlikely by Camp et al. (1991), who mapped no eruptive products younger than about 1500 years.