Harrat Rahat: The Geoheritage Value of the Youngest Long-Lived Volcanic Field in the Kingdom of Saudi Arabia

Mantle origin and crustal differentiation of basalts and hawaiites of northern Harrat Rahat, Kingdom of Saudi Arabia

“…Results from other project components are summarized as chapters in this volume and in related publications in the scientific literature. This report builds on prior petrologic studies of Harrat Rahat by Moufti (1985), Camp and others (1987), Roobol (1989, 1992), Moufti and others (2012), and Murcia and others (2016), although interpretations and conclusions presented herein differ in some respects from those prior works.…”

Explosive trachyte eruptions from the Al Efairia volcanic center in northern Harrat Rahat, Kingdom of Saudi Arabia

“…3). Trachytes are almost exclusively restricted to the northern part of Harrat Rahat in the Matan volcanic center, Al Efairia volcanic center, and a single trachyte eruption at Al Wabarah (Moufti, 1985;Stelten and others, 2018;Downs and others, 2019). Here, we focus on the geochronology and field relations of the most explosively emplaced trachyte eruptive products from the Al Efairia volcanic center.…”

“…Most eruptions associated with the late Cenozoic Arabian intraplate volcanic fields produced mafic lava flows and scoria cones (basalt and hawaiite) with minor intermediate magmas (mugearite and benmoreite) and even fewer evolved magmas with >60 weight percent SiO 2 (trachyte and comendite). These more evolved late Cenozoic magmas are mostly confined to the Harrat Rahat volcanic field and composite Harrat Khaybar, Ithnayn, and Kurá volcanic fields in Saudi Arabia (Moufti, 1985;Roobol, 1989, 1991;Camp and others, 1991;Roobol and Camp, 1991;Moufti and others, 2013;Stelten and others, 2018). Quantification of eruption ages, extents and volumes, and understanding eruptive behavior is fundamental to interpreting the evolution of a predominantly mafic volcanic field such as Harrat Rahat.…”

“…1,2). These trachytes erupted from a cluster of highstanding vents within a part of Harrat Rahat that is termed the Al Efairia volcanic center (names of volcanic features largely follow Moufti [1985]). Field relations, geochemistry, petrography, paleomagnetism, and 40 Ar/ 39 Ar radiometric ages have allowed us to assemble a high-resolution map of trachytes that erupted explosively within the Al Efairia volcanic center (fig.…”

Overview of the Cenozoic geology of the northern Harrat Rahat volcanic field, Kingdom of Saudi Arabia

“…These more silicic eruptions developed lava domes and spines that periodically collapsed and generated smallvolume, juvenile-pumice-and lithic-rich pyroclastic deposits (for example, units trg, tg4, and tma). Sub-Plinian eruptions resulted in craters and moderately pumiceous pyroclastic deposits that are preserved as much as 9 km from their sources (for example, Moufti, 1985;Camp and Roobol, 1989;Stelten and others, 2018;Downs andothers, 2019, 2023b). Cryptodomes, which are geomorphic features that have a lava dome-like morphology, can be more than 1 km in diameter and are uplifted more than 100 m high; they formed as evolved magma intruded into the near surface, where it spread beneath, and eventually uplifted, the older volcanic rocks.…”