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Draa River

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Journal Article
Published: 01 December 2008
Journal of the Geological Society (2008) 165 (6): 1059–1073.
... Be terrestrial cosmogenic nuclide (TCN) methods. Alluvial fan and terrace incision was controlled partially by a drop in base level during the Pliocene or early Pleistocene as the outlet channel, the Draa river, progressively cut through the Anti-Atlas to the south of the Ouarzazate foreland basin, the drainage...
FIGURES
First thumbnail for: Timing and nature of Quaternary fluvial incision i...
Second thumbnail for: Timing and nature of Quaternary fluvial incision i...
Third thumbnail for: Timing and nature of Quaternary fluvial incision i...
Image
 The Draa canyon in the Anti-Atlas (location shown in Fig. 2a). South of the Ouarzazate basin margin, in the Anti-Atlas Precambrian rocks, the Draa river incision is more than 300 m deep. The view also shows light-coloured, flat-lying conglomerate deposits of Anti-Atlas origin resting on the crystalline basement (arrow). The aggradation of these Mio-Pliocene alluvial deposits near the ridge of the Anti-Atlas suggests that overfilling of the Ouarzazate basin is a possible cause for the change from internal to external drainage.
Published: 01 December 2008
Fig. 3.  The Draa canyon in the Anti-Atlas (location shown in Fig. 2a ). South of the Ouarzazate basin margin, in the Anti-Atlas Precambrian rocks, the Draa river incision is more than 300 m deep. The view also shows light-coloured, flat-lying conglomerate deposits of Anti-Atlas origin resting
Journal Article
Journal: GSA Bulletin
Published: 07 April 2020
GSA Bulletin (2020) 132 (11-12): 2475–2488.
... ( Havholm and Kocurek, 1994 ; Rodríguez-López et al., 2014 ; Rubin and Hunter, 1982 ). For example, the unique aeolian facies association of draa bedform in erg environment could be recognized through thorough sedimentary facies analysis ( Mountney, 2006 ). In addition, the architecture created by trains...
FIGURES
First thumbnail for: Sedimentological characteristics and aeolian archi...
Second thumbnail for: Sedimentological characteristics and aeolian archi...
Third thumbnail for: Sedimentological characteristics and aeolian archi...
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Schematic diagram of passive drowning of the Twyfelfontein erg system in the Huab Basin by Lower Cretaceous basalts (mainly Tafelkop type basalts in Huab Outliers south of Huab River and a mix of Tafelkop and Tafelberg-type basalts along the main river sections). A) The transverse-draa-dominated major erg is first drowned, which restricts sediment mobility. B) Remaining unburied sediment is reworked to form minor erg and bypass surfaces where sand infiltrates basalt cooling cracks but does not form dunes. The minor erg is then drowned by lava. C) Further lava drowning isolates more sediment from the active eolian system creating a sediment-poor eolian system of isolated barchanoid dunes, which are themselves drowned by lava. D) Successive drowning locks up more sediment until no more dunes are formed on lava surfaces. This is followed by differential diagenesis to form red and white sandstone. Drowning sequence is modified from Jerram et al. (1999a, 2000a, 2000b).
Published: 19 December 2017
Fig. 4.— Schematic diagram of passive drowning of the Twyfelfontein erg system in the Huab Basin by Lower Cretaceous basalts (mainly Tafelkop type basalts in Huab Outliers south of Huab River and a mix of Tafelkop and Tafelberg-type basalts along the main river sections). A) The transverse-draa
Journal Article
Published: 09 June 2021
Bulletin de la Société Géologique de France (2021) 192 (1): 31.
... isotopiques varient grandement, de 17,738 (Bou Skour) à 18,905 (Draa Sfar) pour le rapport 206 Pb/ 204 Pb, et de 15,521 à 15,706 pour le rapport 207 Pb/ 204 Pb. La source du plomb des gisements étudiés se situe dans la croûte continentale supérieure, excepté pour ceux de l’Anti-Atlas (Bou Skour, Imiter…) et...
FIGURES
First thumbnail for: Plombotectonique des gisements du Maroc
Second thumbnail for: Plombotectonique des gisements du Maroc
Third thumbnail for: Plombotectonique des gisements du Maroc
Journal Article
Journal: Geology
Published: 14 June 2021
Geology (2021) 49 (10): 1171–1176.
...-southwest–striking dikes were sampled ( Fig. 2C ). Results of the ID-TIMS baddeleyite geochronology on one dike (G18M01) showed that its age should be 1.4–1.36 Ga (see the Supplemental Material). Dikes with predominantly northeast-southwest strikes have also been observed in the Bas Drâa inlier, ∼180 km...
FIGURES
First thumbnail for: Reorienting the West African craton in Paleoproter...
Second thumbnail for: Reorienting the West African craton in Paleoproter...
Third thumbnail for: Reorienting the West African craton in Paleoproter...
Journal Article
Published: 20 December 2021
Journal of Sedimentary Research (2021) 91 (12): 1275–1304.
... strata to fully integrate changes in diverse facies within and between contiguous deposits. Brookfield's (1977) classification applies ordinal numbers to surfaces to cover the larger (1st order), intermediate (2nd order), and smaller (3rd order) surfaces, based on a theoretical model of draa...
FIGURES
First thumbnail for: Defining bounding surfaces within and between eoli...
Second thumbnail for: Defining bounding surfaces within and between eoli...
Third thumbnail for: Defining bounding surfaces within and between eoli...
Journal Article
Journal: Geosphere
Published: 01 February 2016
Geosphere (2016) 12 (1): 221–236.
... continental conglomerates and breccias of the Tortonian Draa Sidi Saada Formation. Shallow-marine sedimentation followed with the deposition of the Ras el Ksar Formation, which is composed of rippled sandstones, biolithites, and alternating siltstones and mudstones. These strata recorded the assimilation...
FIGURES
First thumbnail for: Sedimentary provenance of the Taza-Guercif Basin, ...
Second thumbnail for: Sedimentary provenance of the Taza-Guercif Basin, ...
Third thumbnail for: Sedimentary provenance of the Taza-Guercif Basin, ...
Journal Article
Published: 04 August 2022
Journal of the Geological Society (2022) 179 (5): jgs2021-114.
... upper crustal granitoid batholiths ( Bryan et al. 2002 , 2010 ; Bryan 2007 ). In the Anti-Atlas Mountains, rocks belonging to the West African Craton crop out at the deepest levels of the Bas Draâ, Sidi Ifni, Tagragra d'Akka, Kerdous, Tagragra de Tata, Iguerda and Zenaga inliers ( Fig. 1b...
FIGURES
First thumbnail for: The Ouarzazate Supergroup and its plutonic keel: t...
Second thumbnail for: The Ouarzazate Supergroup and its plutonic keel: t...
Third thumbnail for: The Ouarzazate Supergroup and its plutonic keel: t...
Journal Article
Published: 14 February 2006
Canadian Journal of Earth Sciences (2005) 42 (12): 2195–2216.
... flow tuffs from the uppermost Ouarzazate Group have remarkably similar ages across the Anti-Atlas, suggesting near synchronous termination of rift volcanism at ∼560 Ma: 560.0±2.1 Ma for the Houssi El Gah rhyolite at Bas Drâa ( Maloof 2004 ), 564.6 ± 3.2 Ma for the Igherm tuff ( Maloof 2004 ), 562.89...
FIGURES
First thumbnail for: An expanded record of Early Cambrian carbon cyclin...
Second thumbnail for: An expanded record of Early Cambrian carbon cyclin...
Third thumbnail for: An expanded record of Early Cambrian carbon cyclin...
Journal Article
Published: 01 May 2012
Journal of Sedimentary Research (2012) 82 (5): 345–363.
... in the background are approximately 3 to 6 m tall. We interpret Facies A as the product of eolian processes, based on the sedimentary structures and surface hierarchy exhibited by the beds. The large-scale cross beds are interpreted to represent the deposits of large eolian bedforms (dunes and draas...
FIGURES
First thumbnail for: Sedimentology of An Erg To An Erg-Margin Depositio...
Second thumbnail for: Sedimentology of An Erg To An Erg-Margin Depositio...
Third thumbnail for: Sedimentology of An Erg To An Erg-Margin Depositio...
Journal Article
Journal: Economic Geology
Published: 01 December 2008
Economic Geology (2008) 103 (8): 1731–1733.
... of complex noble metal mineralization in the Karelian Proterozoic —V.I. Ivashchenko, K. Sundblad, A.N. Toritsin, A.I. Golubev, and O.B. Lavrov 1187 Peculiarities of composition and possible source of PGE minerals from the placer gold deposit of the Taymen’ river (Western Priokhotsk Region, Russia) —V.V...
Journal Article
Published: 01 June 1996
Journal of the Geological Society (1996) 153 (3): 451–466.
... of water from rivers. The thin dune sets contrast with those of the draa in the frequent presence of IWL bottom set bedding both within and at the bases of cosets, which suggests that the interdunes remained close to the water table. The three environments envisaged are illustrated in Fig. 11, which...
Journal Article
Journal: Economic Geology
Published: 01 May 2021
Economic Geology (2021) 116 (3): 719–746.
... margin of the Siberian craton, extending for almost 700 km along the Yenisei River in a northwest-southeast direction ( Fig. 4 ). It is subdivided into five lithotectonic terranes: Angara-Kan, East Angara, Central Angara, Isakovka, and Predivinsk ( Vernikovsky et al., 2003 ). The oldest domains...
FIGURES
First thumbnail for: Geology and Genesis of the Giant Gorevskoe Pb-Zn-A...
Second thumbnail for: Geology and Genesis of the Giant Gorevskoe Pb-Zn-A...
Third thumbnail for: Geology and Genesis of the Giant Gorevskoe Pb-Zn-A...
Journal Article
Journal: Geology
Published: 22 November 2021
Geology (2022) 50 (3): 289–294.
... in Proterozoic successions can be interpreted in these terms ( Fig.2B ). The radiation of grasses at 66 Ma likely further limited the mobility of Cenozoic river systems ( Davies-Colley, 1997 ; Fig. 3 ). Moreover, grasses play a crucial role in dune construction and stabilization by disrupting primary...
FIGURES
First thumbnail for: Eolian stratigraphic record of environmental chang...
Second thumbnail for: Eolian stratigraphic record of environmental chang...
Third thumbnail for: Eolian stratigraphic record of environmental chang...
Journal Article
Journal: Geology
Published: 11 September 2018
Geology (2018) 46 (10): 919–922.
... deposition; 270–318 m: Wuqia Group Unit C, interpreted as shallow lacustrine and playa; 318–525 m: Wuqia Group Pakabulake Formation, interpreted as meandering river and floodplain; 1698–3285 m: Atushi Formation (also called the Artux Formation), interpreted as channelized fluvial and floodplain; 3285–3800 m...
FIGURES
First thumbnail for: Erg deposition and development of the ancestral Ta...
Second thumbnail for: Erg deposition and development of the ancestral Ta...
Third thumbnail for: Erg deposition and development of the ancestral Ta...
Journal Article
Journal: AAPG Bulletin
Published: 01 July 1955
AAPG Bulletin (1955) 39 (7): 1320–1361.
... concession comprises the area (89 blocks of about 400 sq. kms. each) between the 30th Meridian and the Nile River extending northward to the Mediterranean and southward to the 28th Parallel. Subsequently, an exploration company for the whole Western Desert, the Egyptian American Oil Company, was formed...
FIGURES
First thumbnail for: Petroleum Developments in Africa in 1954
Second thumbnail for: Petroleum Developments in Africa in 1954
Third thumbnail for: Petroleum Developments in Africa in 1954
Series: Geological Society, London, Special Publications
Published: 01 January 2008
DOI: 10.1144/SP297.20
EISBN: 9781862395459
... of the areas studied: 1, western Atlantic Bas Drâa; 2, eastern Bas Drâa and western Bani; 3, Lakhssas Plateau; 4, Irherm–Tata; 5, Bou Azzer–El Graara; 6, Saghro–Ougnate. Inliers: BD, Bas Drâa; If, Ifni; Kr, Kerdous; Ir, Igherm; TA, Tagragra d’Akka; TT, Tagragra Tata; AM, Agadir Melloul; Ze, Zenaga; Sr, Sirwa...
Journal Article
Journal: AAPG Bulletin
Published: 01 July 1956
AAPG Bulletin (1956) 40 (7): 1582–1632.
... and exploration permit over all of the sedimentary border south of River Zaire. 5 As already mentioned, oil was discovered in the Benfica field. In addition, one gas occurrence has been discovered in a shallow well near Luanda. Development drilling is being pushed in the Benfica field. Some other known...
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First thumbnail for: Petroleum Developments in Africa in 1955
Second thumbnail for: Petroleum Developments in Africa in 1955
Third thumbnail for: Petroleum Developments in Africa in 1955
Journal Article
Published: 01 September 2005
The Journal of Geology (2005) 113 (5): 503–516.
... regularly. Using Mulder and Syvitski’s ( 1995 ) criteria and expanding the database to ∼600 rivers (J. D. Milliman and K. L. Farnsworth, unpub. data) add another six rivers to the dirty river list: the Agroun (Algeria), Draa and Massa (Morocco), Hualien (China), Semani (Albania), and Santa Maria (southern...
FIGURES
First thumbnail for: Hyperpycnal Discharge of Fluvial Sediment to the O...
Second thumbnail for: Hyperpycnal Discharge of Fluvial Sediment to the O...
Third thumbnail for: Hyperpycnal Discharge of Fluvial Sediment to the O...