Geoheritage Values of a Mature Monogenetic Volcanic Field in Intra-continental Settings: Harrat Khaybar, Kingdom of Saudi Arabia

Abstract

Harrat Khaybar is one of the most extensive of about 15 volcanic fields located in the western margin of the Arabian Peninsula. Most of these fields are located in the Kingdom of Saudi Arabia about 100–150 km inland from the Red Sea. The volcanic area is located near the culturally and religiously important city of Al Madinah. The field hosts monogenetic volcanoes such as scoria cones, tuff rings, spatter cones and extensive lava flow fields. It also contains several silicic lava domes and associated block-and-ash fans whose deposits fill inter-cone regions. Some of the field’s volcanoes are inferred to have been erupted as recently as about 1000 AD, based on historic documents and geomorphologic evidence. There are no data available to directly support or better constrain the timing of the latest eruptions of the field. The area is also one of the highest regions of Saudi Arabia with a plateau at about 1500 m above sea level, topped by Jabal Abyad (2093 m) and Jabal Quidr (2022 m) volcanoes. Due to the elevation, Harrat Khaybar has a cold arid climate with a unique ecosystem and landscape. The region’s high aesthetic value is derived from the bright white colour of several of its volcanoes which are dominantly rhyolitic ash. These edifices are strikingly different from the dark-coloured lava fields (harrats) of Arabia. Based on appearance, Harrat Khaybar has geoheritage value and could be a major geoconservation and geoeducation region of Arabia. Geological research in the region started only recently and is restricted to geological mapping and geochemical studies. Interest has recently increased because of the recognition of the field’s potential volcanic hazards. There is a push to establish a geoheritage inventory of Harrat Khaybar with the aim of assessing the geoheritage framework of the region and developing more geotourism, geoeducational programmes and a geopark. Key volcanic geotopes and their geosites provide unique opportunities for a stand-alone geopark offering geoeducation and geotourism programmes in the region. The concept has been proposed to the geoheritage resource management of Harrat Rahat just south of Harrat Khaybar and Al Madinah City and could serve as a link between the two historically active volcanic fields located near Al Madinah.