Palaeomagnetism of early miocene basaltic eruptions in the areas east and west of Cairo

Lotfy, Hamza; Voo, Rob Van der; Hall, Chris M.; Kamel, Omar A.; Aal, A.Y. Abdel

doi:10.1016/0899-5362(95)00097-d

Cited by 19 publications

(9 citation statements)

References 24 publications

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“…Three 40 Ar/ 39 Ar analyses there gave ages between 23.6 and 22.4 Ma ( Fig. 4; Kappelman et al, 1992;Lotfy et al, 1995). Further north in Jordan, early volcanic activity in the Harrat ash Shama similarly cluster between 26 and 22 Ma (K-Ar; Ilani et al, 2001).…”

Section: Rift Initiationmentioning

confidence: 89%

“…Compilation of published 40 Ar/ 39 Ar dates for the Red Sea basin, and location of major Tertiary magmatism in Arabia and Sinai. Relative positions of Cairo (Kappelman et al, 1992;Lotfy et al, 1995) and Derudeb basalts (Kenea et al, 2001) and Ethiopia traps are also indicated, but minor dikes along the African margin are not. K-Ar analyses are not included, as in many areas they are shown to be unreliable.…”

Section: Oligocene Plume Volcanismmentioning

confidence: 98%

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The Red Sea and Gulf of Aden Basins

Bosworth

Huchon

McClay

2005

Journal of African Earth Sciences

808

346

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Section: Rift Initiationmentioning

confidence: 89%

Section: Oligocene Plume Volcanismmentioning

confidence: 98%

The Red Sea and Gulf of Aden Basins

Bosworth

Huchon

McClay

2005

Journal of African Earth Sciences

808

346

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“…Kappelman et al (1992) ran three splits from the same whole-rock sample and determined very consistent 40 Ar/ 39 Ar plateau ages of 23.67 ± 0.15, 23.68 ± 0.14, and 23.62 ± 0.16 Ma. Lotfy et al (1995) next obtained whole-rock plateau ages of 22.4 and 22.6 Ma for basalt flows of the Cairo area (locations and other details of the dated samples were not given). Bosworth et al (2015) resampled the ϳ22 m thick basalt from the Gebel Qatrani section and from base to top determined whole-rock isochron ages of 22.0 ± 0.5, 21.9 ± 0.6, and 22.6 ± 0.8 Ma.…”

Section: Cairo Basaltsmentioning

confidence: 99%

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

Bosworth¹,

Stöckli

2016

Can. J. Earth Sci.

104

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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 ϳ46 Ma but was not accompanied by any significant extensional faulting. Continental rifting began in the eastern and central Gulf of Aden at ϳ31-30 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 ϳ26.5 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 ϳ21 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.Résumé : Dans l'ensemble du grand système du rift de la mer Rouge, les strates initiales syn-rifting et l'extension par failles d'âge cénozoïque tardif sont étroitement associées à un volcanisme basaltique alcalin. Les unités stratigraphiques plus anciennes précèdent la formation du rift ou ont été déposées durant l'affaiblissement mécanique de la lithosphère qui a précédé la rupture. Le superpanache est-africain est apparu dans le nord-est de l'Afrique à ϳ46 Ma, mais n'était pas accompagné d'une importante déformation par failles. Le rifting continental a commencé dans l'est et le centre du golfe d'Aden à ϳ31-30 Ma, en même temps que le début du volcanisme continental de plateau dans le nord de l'Éthiopie, en Érythrée et dans l'ouest du Yémen. Le volcanisme est apparu peu après à Derudeb, dans le sud du Soudan, et aux Harrats Hadan et As Sirat, en Arabie saoudite. À partir de ϳ26,5-25 Ma, une nouvelle phase de volcanisme a débuté avec l'intrusion d'un essaim de dykes allant du sud-est d'Afar jusque dans l'Ogaden. À 24-23 Ma, des dykes ont été mis en place presque simultanément au nord d'Afar et s'étalant sur plus de 2000 km jusque dans le nord de l'Égypte. L'intrusion de dykes a relié Afar au mini-panache plus petit du Caire et correspond au début de la distension et de la rupture lithosphériques dans le centre et le nord de la mer Rouge et le golfe de Suez. À ϳ21 Ma, l'intrusion de dykes sur toute la longueur de ...

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“…Samples from the Bahariya Oasis are H4 and BAH1. Based on differences in age, paleomagnetism, and petrology, two distinct basalt flow sequences occur in the Cairo area (Lotfy et al, 1995). The Haddadin basalt sequence is exposed largely to the west of Cairo and is represented by samples from Abu Roash (ARF1), El Haddadin (HD1, HD2, HAD2, K32/2), the 6th October City (6OCT1, 6OCT2, and 6OCT3), and Gebel Qatrani (GQ) localities (see Figure 1).…”

Section: Figurementioning

confidence: 99%

The origin and use of basalt in Old Kingdom funerary temples

2000

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Conventional petrographic analysis suggests that basalts in Old Kingdom funerary temples are mineralogically and texturally similar to the Haddadin basalt flow of northern Egypt. To affirm that the Haddadin flow is the stone source, a total of 88 augite and 74 plagioclase electron microprobe analyses were obtained from two Abu Sir (Sahure, Fifth Dynasty) and three Giza (Khufu, Fourth Dynasty) temple paving stone samples and compared to all known, possible (unaltered), basalt units in Egypt (total of 379 augite and 265 plagioclase analyses). Cluster analysis using the averaged temple paving stone and flow unit mineral chemistry data shows that indeed the paving stones are most similar to the Haddadin flow. Discriminant analysis applied to individual augite and plagioclase analyses substantiates this conclusion. Quarrying of the Haddadin flow, probably at Gebel Qatrani, may have lasted more than 900 years, but production peaked during a 320-year period in the Old Kingdom when funerary temples were being constructed. It is not clear why the Haddadin basalt was so popular, but ease of quarrying (because of columnar jointing), transportability, homogeneity, lack of tectonic joints, religious and symbolic traditions related to color, and resistance to wear may have all been important factors. The methods presented here are applicable to a wide variety of provenance questions involving igneous rocks. More specifically, the discriminant diagrams used to source the temple floor rocks should help in determining the origin of basalts used in other Egyptian artefacts. ᭧

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Palaeomagnetism of early miocene basaltic eruptions in the areas east and west of Cairo

Cited by 19 publications

References 24 publications

The Red Sea and Gulf of Aden Basins

The Red Sea and Gulf of Aden Basins

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

The origin and use of basalt in Old Kingdom funerary temples

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