Issautier B.,Bureau de Recherches Géologiques et Minières |
Le Nindre Y.-M.,University Paris - Sud |
Memesh A.,Saudi Geological Survey SGS |
Dini S.,Phanerozoic rocks Mapping Unit |
Viseur S.,Aix - Marseille University
GeoArabia | Year: 2012
The Late Triassic (Norian-Rhaetian) Minjur Sandstone provides a remarkable case study for understanding and modelling the spatial distribution of sand bodies in a fluvial-deltaic system. As such it has been studied in connection with the geological storage of CO2 in complex heterogeneous formations. Detailed sedimentological mapping of the formation's vertical and lateral variations in and around the type section at Khashm al Khalta (Khashm al Minjur), which is the area of interpreted maximum inlet/outlet activity, has provided a relatively detailed picture of the sequence stratigraphy. As originally described, shallow-marine flooding with the development of tidal mud flats and carbonate facies occurred near the middle of the formation, splitting it into a lower member dominated by subtidal, brackish and scattered fluvial environments, and an upper member marked by the appearance of meandering point bars capped upward by very proximal deposits forming thick (20 m) coarse-grained sandstone bars that can be followed over several kilometers. The general trend at formation scale is thus upward thickening and coarsening sedimentation related to an increasing clastic influx and the development of fluvial systems, with the fluvial upper member being dominated by amalgamated sand bars. The sequence stratigraphy indicates nine depositional sequences involving four depositional environments: sabkha, tidal, estuarine and fluvial-continental. The lower Minjur is a transgressive tract of four sequences of which Sequence 4 reflects maximum flooding and correlates with maximum flooding surface (MFS) Middle Norian Tr80. Sequence 5 corresponds to a meander system at the base of the upper Minjur, and is followed by sequences 6 to 9 reflecting an increasing clastic influx generating amalgamated coarse-grained bars. The upper Minjur thus represents a highstand systems tract.
Abdelwahed M.F.,King Abdulaziz University |
Abdelwahed M.F.,National Research Institute of Astronomy and Geophysics |
El-Masry N.,King Abdulaziz University |
El-Masry N.,Suez Canal University |
And 5 more authors.
Journal of Asian Earth Sciences | Year: 2016
High-resolution tomographic images of the crust and upper mantle beneath Harrat Al-Madinah, Saudi Arabia, are obtained by inverting high-quality arrival-time data of local earthquakes and teleseismic events recorded by newly installed borehole seismic stations to investigate the AD 1256 volcanic eruption and the 1999 seismic swarm in the study region. Our tomographic images show the existence of strong heterogeneities marked with low-velocity zones extending beneath the AD 1256 volcanic center and the 1999 seismic swarm area. The low-velocity zone coinciding with the hypocenters of the 1999 seismic swarm suggests the presence of a shallow magma reservoir that is apparently originated from a deeper source (60-100. km depths) and is possibly connected with another reservoir located further north underneath the NNW-aligned scoria cones of the AD 1256 eruption. We suggest that the 1999 seismic swarm may represent an aborted volcanic eruption and that the magmatism along the western margin of Arabia is largely attributed to the uplifting and thinning of its lithosphere by the Red Sea rifting. © 2016 Elsevier Ltd.
Bamousa A.O.,Taibah University |
Memesh A.M.,Saudi Geological Survey SGS |
Dini S.M.,Saudi Geological Survey SGS
Carbonates and Evaporites | Year: 2014
The Ath-Thumamah depression exists 20 km north of Riyadh, Saudi Arabia within the Arabian Platform's interior Homocline, and covers an area of about 50 × 20 km2. This study examines whether the Ath-Thumamah depression has evolved tectonically by extensional faulting event or it is a subsidence-induced depression. The study depends on field-based work, with complementary analysis and interpretations of landsat images and digital elevation maps. The upper Jurassic calcarenite Arab Formation is a regional oil reservoir in Saudi Arabia, and is overlain and sealed by the Hit Anhydrite Formation. The Arab Formation is part of Shaqra Group, and is exposed in the study area and affected by interstratal karstification at the Ath-Thumamah depression. The Arab Formation is overlain by Cretaceous Thamamah Group, which subsequently subsided and collapsed due to dissolution of the Hit Formation. Dissolution and collapse features include basin-and-dome landforms, dissolution breccias, sinkholes and deep canyons. The interstratal features and landforms dominate the Shaqra and Thamamah groups and are limited to the Ath-Thumamah depression. Ath-Thumamah depression is interpreted as a keystone graben, superimposed on a regional open fold, known in this study as Banban anticline. The development of the keystone graben accommodated the deposition of Neogene Sha'al Formation and Quaternary Eolian sand dunes. Karstification features and landforms are developed during the pluvial phases of the Mid Pleistocene time and modified the graben into interstratal karsts depression. Therefore, the Ath-Thumamah depression had developed tectonically and modified by geomorphic processes. © 2013 Springer-Verlag Berlin Heidelberg.
Hussein M.T.,King Saud University |
Lashin A.,King Saud University |
Lashin A.,Benha University |
Al Bassam A.,King Saud University |
And 2 more authors.
Renewable and Sustainable Energy Reviews | Year: 2013
Saudi Arabia is enriched by many geothermal resources that are located along the western coastal part of the Red Sea, in the form of a number of hot springs and many volcanic eruptions. Wadi Al-Lith is considered one of the most promising geothermal targets that encounter many hot springs with a good surface temperature upto 95 C. This paper aims mainly to evaluate the geothermal potential of the main hot spring at Wadi Al-Lith area (Ain Al Harrah). The available remote sensing images are analyzed and a number of 2D electric resistivity profiles are interpreted to delineate the surface geological lineaments and the subsurface structural elements that control the movement of the thermal water. It is found that the main surface lineaments are structurally oriented along NNE-SSW and NE-SW directions with a frequency percentage of 52% and an average lineament length of 835 m. Furthermore the subsurface structural elements, as inferred from the interpretation of the geophysical 2D electric profiles, have assumed the same directions beside the NW-SE direction. The characteristics of thermal water of the hot spring are indicated through analyzing the major and minor elements of some collected water samples. Geo-thermometers are applied to estimate, subsurface temperature, heat flow and discharge enthalpy. These parameters are found to be 136 C, 183 mW/M2 and 219 kJ/kg, respectively. An estimate of the geothermal reserve using the volumetric method, gave total stored heat energy of 1.713×1017 J (rock and fluid) and a geothermal reserve potential of 26.99 MWt. It appears from our research that the estimated energy is quite enough for operating a medium scale power plant that utilizes low boiling point fluid (Kalina Cycle) for limited electricity production, beside other low-temperature applications (district heating, green houses and medical therapy). © 2013 Elsevier Ltd.