Preliminary geologic map of the Thaniyat Turayf Quadrangle, sheet 29C, Kingdom of Saudi Arabia

Abstract

The Thaniyat Turayf quadrangle, sheet 29C, lies in the northwestern part of Saudi Arabia near the border with Jordan. The quadrangle is located between lot 29° O0'-30° 00' N. and long 37°30'-39° 00' E. It includes the southwestern rim of the Sirhan-Turayf Basin and is underlain by Silurian to Miocene-Pliocene sedimentary rocks that are partly covered by surficial duricrust, sand, and gravel. Most of the sedimentary rocks of the map area are of marine origin, varying from outer shelf to near-shore and coastal-lagoon environments. Episodes of fluvial-deltaic deposition reflecting marine regression occurred in the Devonian, and continental and lacustrine sedimentation are characteristic of the Miocene. Tensional structures, such as linear-joint fractures, grabens, and block faulting, probably resulted from rifting associated with the opening of the Red Sea. The map area contains the southern part of the Southwestern Area, an important phosphate-rock province that includes the Thaniyat Phosphorite member. Total estimated resources of phosphorite in three select areas of the Thaniyat Phosphorite member are 978,000,000 t with an average grade of 24 percent A new structural concept introduced in this report extends the Wadi as Sirhan graben complex southeastward into the An Nafud. This concept increases the size of the potentially oil-and-gas-bearing Wadi as Sirhan region to include the An Nafud.

Saqqar: A 34 km diameter impact structure in Saudi Arabia

“…The Devonian strata along the southern margin were mapped in the field by Meissner et al. () and Wallace et al. () as the Ja'alat as Samra fault and fold system (Fig.…”

“…The surface geology of the Saqqar area was mapped by Meissner et al. () and Wallace et al. () for phosphate exploration.…”

Upper Eocene planktonic foraminifera from northern Saudi Arabia: implications for stratigraphic ranges

“…It is part of the Syrian Arc System (Guiraud et al, 2001) where subsidence in the early Paleogene Tethyan seafloor resulted in deposition of carbonate and mixed sediments (Al-Rawi, 2014). The Rashrashiyah Formation crops out in the eastern flank of the Sirhan Basin (31.46 • N, 37.36 • E) and consists of upper Eocene chalks, claystone and limestone (Meissner et al, 1990;Halawani, 2001;Aljahdali et al, 2020) (Figs. 2 and 3).…”