Enregistrement sédimentaire des variations climatiques quaternaires sur la bordure NW du Rift de la Mer Rouge (Egypte) [ Sedimentary record of quaternary climatic changes on the NW border of the Red Sea rift (Egypt). ]

Quaternaire ◽  
1994 ◽  
Vol 5 (3) ◽  
pp. 181-188
Author(s):  
Odette Conchon ◽  
Frédéric Baltzer ◽  
Bruce Purser
Keyword(s):  
Red Sea ◽  
Climatic Changes ◽  
Sedimentary Record ◽  
Red Sea Rift

Thermal Imaging of the Lithosphere beneath Arabian Shield and Implications for "Harrats" Volcanic Field

2021 ◽  
Author(s):  
Mohamed Sobh ◽  
Khaled Zahran ◽  
Nils Holzrichter ◽  
Christian Gerhards
Keyword(s):  
Red Sea ◽  
Seismic Velocity ◽  
Volcanic Field ◽  
Arabian Plate ◽  
Thickness Variation ◽  
Arabian Shield ◽  
Lithospheric Thickness ◽  
Lithospheric Thinning ◽  
Red Sea Rift ◽  
Seismic Swarms

<p><span>Widespread Cenozoic volcanisms in the Arabian shield including “Harrats” have been referring to lithospheric thinning and/or mantle plume activity as a result of Red Sea rift-related extension.</span></p><p><span>A fundamental key in understanding the deriving mechanism of these volcanic activities and its relationship to 2007-2009 seismic swarms required a reliable model of the present-day lithospheric thermo-chemical structure.</span></p><p><span>In this work, we modeled crustal and lithospheric thickness variation as well as the variations in thermal, composition, seismic velocity, and density of the lithosphere beneath the Arabian shield within a thermodynamically self - consistent framework.</span></p><p><span>The resulting thermal and density structures show large variations, revealing strong asymmetry between the Arabian shield and Arabian platform within the Arabian Plate.</span></p><p><span>We model negative density anomalies associated with the hot mantle beneath Harrats, which coincides with the modelled lithosphere thinned (~ 65 km) as a result of the second stage of lithospheric thinning following the initial Red Sea extension.</span></p>

Impact of basin architecture on diagenesis and dolomitization in a fault-bounded carbonate platform: outcrop analogue of a pre-salt carbonate reservoir, Red Sea rift, NW Saudi Arabia

2019 ◽  
Vol 26 (3) ◽  
pp. 448-461 ◽  
Author(s):  
Khalid Al-Ramadan ◽  
Ardiansyah Koeshidayatullah ◽  
Dave Cantrell ◽  
Peter K. Swart
Keyword(s):  
Red Sea ◽  
Elevated Temperatures ◽  
Carbonate Platform ◽  
Isotope Analysis ◽  
Carbonate Reservoir ◽  
Carbonate Platforms ◽  
Hydrocarbon Reservoir ◽  
Red Sea Rift ◽  
Platform Margin ◽  
Clumped Isotope

The early Miocene Wadi Waqb carbonate in the Midyan Peninsula, NE Red Sea is of great interest not only because of its importance as an archive of one of the few pre-salt synrift carbonate platforms in the world, but also as a major hydrocarbon reservoir. Despite this importance, little is known about the diagenesis and heterogeneity of this succession. This study uses petrographical, elemental chemistry, stable isotope (δ13C and δ18O) and clumped isotope (Δ47) analyses to decipher the controlling processes behind the formation of various diagenetic products, especially dolomite, from two locations (Wadi Waqb and Ad-Dubaybah) that have experienced different diagenetic histories. Petrographically, the dolomites in both locations are similar, and characterized by euhedral to subhedral crystals (50–200 µm) and fabric-preserving dolomite textures. Clumped isotope analysis suggests that slightly elevated temperatures were recorded in the Ad-Dubaybah location (up to 49°C), whereas the Wadi Waqb location shows a sea-surface temperature of c. 30°C. These temperature differences, coupled with distinct δ18OVPDB values, can be used to infer the chemistry of the fluids involved in the dolomitization processes, with fluids at the Wadi Waqb location displaying much higher δ18OSMOW values (up to +4‰) compared to those at the Ad Dubaybah location (up to −3‰). Two different dolomitization models are proposed for the two sites: a seepage reflux, evaporative seawater mechanism at the Wadi Waqb location; and a fault-controlled, modified seawater mechanism at the Ad-Dubaybah location. At Ad-Dubaybah, seawater was modified through interaction with the immature basal sandstone aquifer, the Al-Wajh Formation. The spatial distribution of the dolostone bodies formed at these two locations also supports the models proposed here: with the Wadi Waqb location exhibiting massive dolostone bodies, while the dolostone bodies in the Ad-Dubaybah location are mostly clustered along the slope and platform margin. Porosity is highest in the slope sediments due to the interplay between higher precursor porosity, the grain size of the original limestone and dolomitization. Ultimately, this study provides insights into the prediction of carbonate diagenesis in an active tectonic basin and the resultant porosity distribution of a pre-salt carbonate reservoir system.

scholarly journals Use of a high-precision gravity survey to understand the formation of oceanic crust and the role of melt at the southern Red Sea rift in Afar, Ethiopia

2015 ◽  
Vol 420 (1) ◽  
pp. 165-180 ◽  
Author(s):  
E. Lewi ◽  
D. Keir ◽  
Y. Birhanu ◽  
J. Blundy ◽  
G. Stuart ◽  
...  
Keyword(s):  
Oceanic Crust ◽  
High Precision ◽  
Red Sea ◽  
Gravity Survey ◽  
Red Sea Rift

Hydrothermal activity at the ultraslow- to slow-spreading Red Sea Rift traced by chlorine in basalt

2015 ◽  
Vol 405 ◽  
pp. 63-81 ◽  
Author(s):  
Froukje M. van der Zwan ◽  
Colin W. Devey ◽  
Nico Augustin ◽  
Renat R. Almeev ◽  
Rashad A. Bantan ◽  
...  
Keyword(s):  
Red Sea ◽  
Hydrothermal Activity ◽  
Red Sea Rift ◽  
Slow Spreading

scholarly journals Receiver function constraints on crustal seismic velocities and partial melting beneath the Red Sea rift and adjacent regions, Afar Depression

2014 ◽  
Vol 119 (3) ◽  
pp. 2138-2152 ◽  
Author(s):  
Cory A. Reed ◽  
Sattam Almadani ◽  
Stephen S. Gao ◽  
Ahmed A. Elsheikh ◽  
Solomon Cherie ◽  
...  
Keyword(s):  
Partial Melting ◽  
Red Sea ◽  
Receiver Function ◽  
Seismic Velocities ◽  
Afar Depression ◽  
Red Sea Rift

Simple shear detachment fault system and marginal grabens in the southernmost Red Sea rift

2013 ◽  
Vol 608 ◽  
pp. 1268-1279 ◽  
Author(s):  
Samson Tesfaye ◽  
Woldai Ghebreab
Keyword(s):  
Red Sea ◽  
Simple Shear ◽  
Detachment Fault ◽  
Fault System ◽  
Red Sea Rift

scholarly journals Early magmatism in the greater Red Sea rift: timing and significance

2016 ◽  
Vol 53 (11) ◽  
pp. 1158-1176 ◽  
Author(s):  
William Bosworth ◽  
Daniel F. Stockli
Keyword(s):  
Red Sea ◽  
Plate Boundary ◽  
Rift System ◽  
Northern Ethiopia ◽  
Gulf Of Suez ◽  
East African ◽  
Red Sea Rift ◽  
Lithospheric Extension ◽  
Extensional Faulting ◽  
Northern Red Sea

Throughout the greater Red Sea rift system the initial late Cenozoic syn-rift strata and extensional faulting are closely associated with alkali basaltic volcanism. Older stratigraphic units are either pre-rift or deposited during pre-rupture mechanical weakening of the lithosphere. The East African superplume appeared in northeast Africa ∼46 Ma but was not accompanied by any significant extensional faulting. Continental rifting began in the eastern and central Gulf of Aden at ∼31–30 Ma coeval with the onset of continental flood volcanism in northern Ethiopia, Eritrea, and western Yemen. Volcanism appeared soon after at Derudeb in southern Sudan and at Harrats Hadan and As Sirat in Saudi Arabia. From ∼26.5 to 25 Ma a new phase of volcanism began with the intrusion of a dike field reaching southeast of Afar into the Ogaden. At 24–23 Ma dikes were emplaced nearly simultaneously north of Afar and reached over 2000 km into northern Egypt. The dike event linked Afar to the smaller Cairo mini-plume and corresponds to initiation of lithospheric extension and rupture in the central and northern Red Sea and Gulf of Suez. By ∼21 Ma the dike intrusions along the entire length of the Red Sea were completed. Each episodic enlargement of the greater Red Sea rift system was triggered and facilitated by breakthrough of mantle-derived plumes. However, the absence of any volumetrically significant rift-related volcanism during the main phase of Miocene central and northern Red Sea – Gulf of Suez rifting supports the interpretation that plate–boundary forces likely drove overall separation of Arabia from Africa.

scholarly journals Late Oligocene–Early Miocene Nukhul Sequence, Gulf of Suez and Red Sea

GeoArabia ◽  
2012 ◽  
Vol 17 (1) ◽  
pp. 17-44 ◽  
Author(s):  
Moujahed I. Al-Husseini
Keyword(s):  
Red Sea ◽  
Isotope Analysis ◽  
Sedimentary Facies ◽  
Early Miocene ◽  
Rift System ◽  
Gulf Of Suez ◽  
Late Oligocene ◽  
Depositional Sequence ◽  
Red Sea Rift ◽  
Northern Red Sea

ABSTRACT Egypt’s Late Oligocene–Early Miocene Nukhul Formation was deposited during the earliest geological evolution of the Gulf of Suez and Red Sea Rift System. In this paper the formation is cast as a depositional sequence based on published sections, and correlated across the Gulf of Suez and northern Red Sea. The resulting correlations indicate that deposition was initiated in local grabens by the oldest continental clastics of the lower member of the Nukhul Formation, the Shoab Ali Member. The member overlies the Suez Rift Unconformity, a term proposed for the entire Red Sea. Although this member can attain a thickness of ca. 1,000 ft (305 m) locally in grabens, it is generally absent over horsts. Sedimentary facies of the member are interpreted as indicating an initial alluvial-fluvial setting that evolved to an estuarine and coastal setting. The upper part of the Nukhul Formation records a regional shallow-marine transgression, which can be subdivided into three correlative Upper Nukhul members. These sediments are absent over the highest paleo-horsts, but reach up to 900 ft (275 m) in thickness in grabens. In the southern Gulf of Suez the Ghara Member represents the Upper Nukhul members. In places it consists of four cycles, each of which starts with an anhydrite bed and is overlain by deposits of mixed lithology (sandstone, marl, and limestone). The four cycles are interpreted as transgressive-regressive subsequences that can be correlated across ca. 60 km in the Gulf of Suez. The Ghara Member correlates to Saudi Arabia’s Yanbu Formation, which consists of massive salt in wells drilled on the Red Sea coastal plains. The Yanbu Salt is dated by strontium-isotope analysis at ca. 23.1–21.6 Ma (earliest Aquitanian). The Nukhul Formation is capped by the Sub-Rudeis Unconformity or correlative Rudeis Sequence Boundary, and overlain by the Rudeis Formation. The Nukhul Formation is here proposed as the Nukhul Sequence and defined in the Wadi Dib-1 Well, wherein it consists of Nukhul subsequences 1 to 10 (in descending order, ranging in thickness between 33–84 m). The lower six Nukhul subsequences 10 to 5 are characterized by shale-to-sandstone cycles of the Shoab Ali Member, and the upper four are represented by the cycles of the Ghara Member. The 10 subsequences are interpreted as tracking the 405,000 year eccentricity signal of the Earth’s orbit and to span ca. 4.0 million years between ca. 25.0 and 21.0 Ma.

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