Paleozoic Era 2003

Tectonic Framework : 

Tectonic Framework Based on the structural and lithological characteristics. Egypt could be subdivided into two main units

Arabo Nubian Massif : 

Arabo Nubian Massif - Active site of erosion - It has a platform and basin of deposition nature - Lithologic characters: its mountain were peneplained and its sediments were highly deformed and metamorphose - Distribution: this massif are developed in South Sinai, Red sea mountain ranges and SW of Western desert.

1- Stable Shelf : 

1- Stable Shelf Nature: this unit characterized by thin continental and epicontinental sediments(Nubia sandstone). Distribution: surrounding the Arabo Nubian Massif. Lithology: composed mainly of clastic rocks (Cambrian – L. Cretaceous) as Nubia Sandstone and shallow marine deposits (Up Cratacous- L Tertiary). Thickness: the sedimentary column reach about 350-400 ms. Near nucleus, and increase away from the nucleus, it reach about 1100 ms near El Kharga and 2500 at Bahariya oasis.

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Structures: A characteristic structural feature is the faulting and Folding 1) Faulting, A major fault of regional dimension was crossed as in Nile valley (major fault zone). Also a number of well represented faults are recorded in Kharga and Qena. 2) Folding, in the Stable Shelf are gently folded. Three sets of folds are observed A) North-south folds: Two anticlines separated by syncline B) Tethyan fold: Represented by the two Galalas plateaus anticline and Wadi Araba syncline C) Domal structures: The first example of such anticline is recorded at the Eocene plateau between the two Galalas and the Nile

2- Gulf of Suez Rift Valley : 

2- Gulf of Suez Rift Valley Distribution: Situated within the stable belt of Egypt it considered as area of subsidence Thickness: it has great thickness of sediments Structures: The forces caused this gulf were tensional type that were continuously rising and sinking (vertical faults and Normal faults )

3- Unstable Shelf : 

3- Unstable Shelf Distribution: it cover most of the northern Egypt which lie between foreland and geosyncline. Lithology: Calcareous and organic sediments are predominated. The terrigenous sediments are rare except near the contact with stable belt.

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Stratigraphically :The sedimentary section composed of the following lithological division:

Structures : 

Structures Surface tectonics show the effect of lateral stress, over thrusts are recorded in some of the northern structures. In subsurface Seismic studies suggest the presence of regional structure systems running in a NE direction Compressive movements began as early as Paleozoic And continued until Pliocene. The compressive forces caused a numerous folds in a NE direction, these folds are known as the Syrian arc system

Syrian arc system : 

Syrian arc system Are characterized by: 1. All the anticlines are in NE trend. 2. All the anticlines are assymetrical, the steeper limbs are mostly in the south. 3. All the anticlines are faulted or fractured in Erythrean trend

The following are the most important ridges : 

The following are the most important ridges Matruh line. Dabaa line. Qattara line. Moghra – Qaret Agnes. Khatatba line. Gobel Maghara – Abu Roash line. Maghara- Um Mufrouth – Rizan Aneiza – Shabraweet. Hara line – Bahyelleg – Giddi – Um makhassa – Libni – Hamra – Minsherah, … Wadi Araba line – Aref El Naqa – Somar – W. Araba – Forofro.

PALEOZOIC : 

PALEOZOIC

PALEOZOIC : 

PALEOZOIC

Early Paleozoic : 

Early Paleozoic Surface exposures of Paleozoic strata are only known as a small area on the geological map of Egypt.

1- Cambrian : 

1- Cambrian The early Cambrian is represented by yellowish brown to multicolored, fine to medium S.S. with thin streak of shale, solidified patches about 100 ms thick.

Cambrian of Sinai : 

Cambrian of Sinai Distribution : Cambrian strata are exposed in the Wadi Feiran and in the area around Um Bogma . Facies: Clastic sediments which represent several cycles of fluvial to near – shore marine over laying the basment. Lithology : The Geologists divided S.S overlying Granitic massive outcropped in the form of chains of hillocke into

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2. Naqus Formation (Late – Cambrian): light gray colored S.S., with rare organic spots and iron oxides, coarse pebble and iron oxides, coarse pebble and gravels repeatedly intercalate (25 ms). 1. Araba Formation (Early –Cambrian): yellowish brown to multicolored, fine to medium grained S.S. with thin streak of shale, silicified patches, organic spots and vertical borrows (100 ms).

Cambrian of Eastern Desert : 

Cambrian of Eastern Desert Distribution : Exposed in the area of wadi Qena and in the surroundings of Somr El Qaa and South Wadi El Dakhal. Lithology : The recorded sequence here is similar to Cambrian of Sinai.

Cambrian of Western Desert : 

Cambrian of Western Desert Distribution : Cambrian strata are recorded in the subsurface of NW of W Desert, four wells in the Bahariya oasis and Qattara depression and between them. Lithology : mainly clastic rocks.

2- ORDOVECIAN : 

2- ORDOVECIAN Distribution : Exposed in Karkur El Talh area in the NE part of Gebel Oweinat at the Egyptian-Sudanese border. Lithology: Represented mainly by clastic Formation. Karkur El Talh Formation: (Klitzsch and Lejal Nicol 1984) It consists of several ten meters of fluvial and shallow marine sandstone with trilobite tracks. The Ordovician strata is the part of the extensive sheet which cover large area in south Libya and Chad.

3- Silurian : 

3- Silurian Distribution: exposed in SW Egypt in the area between Gebel Oweinant and Abu Ras plateau west of Gilf Kebir, around Um Ras passage south of Abu Ras plateau. Lithology: mainly clastic. Um Ras Formation: (Klitzch and Lejal Nicol 1984) Fine to medium and partially coarse grained white sandstone of fluvial and deltaic interbedded by near-shore marine sandstone (beach sand), solty shale to clayey siltstone with borrowed fossils as Scoliths sp……400 m.

Late Paleozoic : 

Late Paleozoic

Devonian : 

Devonian Distribution: Devonian sediments are recorded in at least 12 wells in NW Egypt as subsurface. They exposed on surface along the Western and SW edge of Abu Ras plateau near the Lybia border and at the NE of Gebel Oweinat. Lithology: the sequence consists of tabular cross bedded, fine to coarse S.S., partially conglomeratic with 50-70 ms.

CARBONIFEROUS : 

CARBONIFEROUS Carboniferous strata range from fully marine carbonate, shallow and deep marine clastics, lacustrine and continental fluviatile S.S. to lacustrine and fluvio-glacial deposits, Marine Carboniferous Continental Carboniferous

Continental Carboniferous : 

Continental Carboniferous Unfossiliferous sandstone recorded at Gebel Oweinat and Wadi Abd El Malik

Marine Carboniferous : 

Marine Carboniferous Eastern Desert -Wadi Araba SW Sinai - Umm Bogma

Permian : 

Permian E Desert At W Malha and N Galal Sinai At UMM Bogma Thick sequance of red shalle and browen sand stone. W Desert N of W Malak ,G Oweinet (350-400 ms) clay sand stone and mud stone

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Subsurface At N Siwa and N Qattara

Remarks on Permian : 

Remarks on Permian The continental fauna indicate gradually elevation of land begin at the end of Carboniferous and the territory remained dry land. It reach it maximum uplift by Hercenian tectonic movement