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Metamorphic an magmatic events in the Uweinat — Bir Safsaf Uplift (Western Desert/Egypt)

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Zusammenfassung

Die Grundgebirgsschwelle zwischen Gebel Uweinat und Bir Safsaf (Western Desert/ Ägypten) war während des Präkambriums durch vier Episoden von Deformation, Metamorphose und Anatexis gekennzeichnet. Die endgültige Kratonisierung erfolgte im Jungproterozoikum im Verlauf eines Pan-Afrikanischen Thermalereignisses. Die während des Jungproterozoikums als Folge großräumiger Intraplattentektonik entstandenen Bruchsysteme wurden während des Phanerozoikums periodisch reaktiviert. Die Platznahme anorogener Magmen erfolgte in mindestens sechs verschiedenen Zeiträumen hauptsächlich entlang dieser Bruchstrukturen.

Abstract

The Uweinat — Bir Safsaf Uplift, Western Desert/Egypt, four episodes of deformation and related metamorphism and anatexis occurred until the final cratonisation during the Late Pan-African event was completed. From that time on, probably six independent (Table 4) magmatic episodes can be recognized up to the Quaternary. This anorogenic type of magmatism is mainly related to a fracture system which originated in the Late Precambrian as a result of intraplate block faulting. Periodical reactivation of these older fracture zones throughout the Phanerozoic gave way to the different types of plutonic and volcanic rock assemblages.

Résumé

Le massif soulevé compris entre le Gebel Uweinat et Bir Safsaf, dans le Désert occidental de l'Egypte, a été le siège de 4 épisodes de déformations avec métamorphisme et anatexie jusqu'à sa cratonisation finale au cours de la Phase Pan-africaine tardive. A partir de ce moment, probablement six épisodes magmatiques indépendants peuvent être reconnus jusqu'au Quaternaire. Ce type anorogénique de magmatisme est principalement en relation avec un système de fractures qui a pris naissance au Précambrien supérieur comme le résultat d'une régime de fracturation intraplaque. La réactivation périodique des ces zones de fractures anciennes durant le Phanérozoïque a conduit à la formation de ces différents types d'associations de roches volcaniques et plutoniques.

Краткое

содержание Порог основных гор ме жду Gebei Uweinat и Bir Safsaf (западная пус тыня. Египет) претерпел во время до кембрия 4 деформации, сопровождающиеся ме таморфизмом и анатексисом. Окончат ельная кратонизация произошла только в позднем прот ерозое в течение некого панаф риканского термичес кого события. Возникшая во время по зднего протерозоя система р азломов, как следстви е крупномасштабной ме жплитовой тектоники, претерпела реактиви рование во время фане розоя. В образовавшихся в эти х структурах разломах скопились м агмы. Причем такое зам ещение происходило, по-крайн ей мере, шесть раз.

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Schandelmeier, H., Darbyshire, F. Metamorphic an magmatic events in the Uweinat — Bir Safsaf Uplift (Western Desert/Egypt). Geol Rundsch 73, 819–831 (1984). https://doi.org/10.1007/BF01824984

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Keywords

  • Volcanic Rock
  • Fracture Zone
  • Fracture System
  • Periodical Reactivation
  • Block Fault