Abstract
The Paleocene section measured to the east of Budkhulu village (20 Km north of Mut city) consists from base to top of 71 m thick of the Kharga shale Member (the upper part of the Dakhla Formation), and 25 m thick of the Tarawan Formation.
The Kharga shale member is composed of grey and dark grey papery shale in its lower part and ferruginous and varicolored shale at the upper part. Generally, it is intercalated with 6 thin bands of glauconite, and many parts of the shale are also glauconitic in habit. The Tarawan Formation consists of whitish chalky limestone. It is glauconitic at the lower most 2 meters and contains detrital quartz as well as some other detrital silicates and ilmenite grains up to the lower 8 meters. However, the upper 17 meters are barren of these detritals.
The sediments of the Paleocene east Budkhulu contain variable abundances of detrital minerals, Co, Ni-rich manganese oxide crusts glauconite, goethite pseudomorphs, pyrite and chalcopyrite and elemental carbon particles.
The detrital minerals, are represented mostly by Fe-Ti oxides (mainly ilmenite and rutile with very rare magnetite) and different types of silicates (quarts, feldspars, amphibole and pyroxene). The ilmenite grains show moderate oxidation and alteration and enclose numerous inclusions of different grain sizes (few microns up to 40 µm). These inclusions are either irregular or drop-like spheres in shape. Their chemical compositions reflect the original basic melt from which they are trapped within the ilmenite grains. The altered ilmenite is relatively enriched in TiO2 near the top of the succession, and there is a gradual decrease in the TiO2 content with depth.
The survival and fresh nature of the unstable Feldspar, pyroxene and amphibole minerals within the sediments as well as the presence of some euhedral grains of these minerals may reflect a short distance of transportation from the source rocks. On the other hand, the climate has a large effect by which the mechanical weathering predominated the chemical weathering on the rocks. However, the subrounded and rounded forms of the larger grains of these detritals and the alteration of ilmenite may indicate multicycled and derivation from pre-existing rocks.
Characteristic physical, geochemical enrichment (Co, Ni, and Zn) and geochemical association signatures, in conjunction with several diagnostic plots as well as the low Fe/Mn ratio (0.14) would suggest that the manganese-oxide particles are of marine sedimentary origin (diagenetic). The chalcopyrite in the black shale is associated with grains containing bacterial pyrite spheres and octahedron crystals of -goethite. The co-existence of chalcopyrite with framboidal pyrite indicates that both minerals are of bacterial origin. Carbon inclusions are found disseminated in the grains of shale of the upper most ferruginated bed of the Kharga shale Member. The morphology, the grain size and the chemical composition of these carbon particles are similar to those found by the first author at the K/T boundary at G. Duwi and G. Oweina and which could be interpreted as soot formed by wildfire.