A proposed classiflcation for the exposed rock units : at al uwaynate are

Abstract EN

This paper presents the results of a photogeological interpretation supplemented with 21 days reconnaissance field trip to Al Uwaynate area.

The area is hound by latitudes 22

and Longitudes 24 00 and 25 30 E.

and includes Jabal Arkenu (NF 35-5) and Jabal Asbah (NF 35-1) sheets.

A new photogcological map scale l:250,(XX) was constructed on the basis of aerial photographs (scale l:60.(XX) and l:50.(XH)) and photomosaics (scale 1:100.000).

A new legend was constructed for this map.

and twenty one rock units are identified.

These are shown as formations and members according to the American Code of Stratigraphic Nomenclature.

The rock units rccognized pertain to Precambrian.

Cambrian.

Ordovi- cian.

Silurian.

Devonian.

Carboniferous, Cretaceous and Quaternary.

The Precambrian rocks consist mainly of gneisses, amphibolites.

and marbles, ex¬posed in the east and south of the area and extend into Egypt.

The Cambrian and Ordovician formations are well preserved at Jabal Arkenu.

Jabal Al Uwaynate and east of Jabal Rukn.

Devonian and Silurian rock units crop out in the north and southeast o the area while the Carboniferous and Creataceous rocks are dominant to the west and south.

These sediments are partly continental and partly marine and comprise interbeds of sandstone, siltstone and shale with occasional congiomcr.itic beds.

The Precaranbrian basement anil the later sediments are intruded by acid and alka¬line igneous rocks believed to the Ordovician to Devonian in age.

Ring complexes are common in the eastern side of the area while plugs exposed in the woMcni side and are considered to be of Tertiary age.

The study shows that regional photolinears pattern is characterized by a strong pre¬ferred orientation in NE.

NW and E-W directions.

Quartz veins hosting, pyrite.

arsenopyrite and malachite are recorded at the north¬eastern part of Jabal Arkenu and the central part of Jabal Baboir.

The area is currently under detailed field mapping and geological investigation