Walid A. Makled

Palynomorph biostratigraphy of the Cretaceous (Hauterivian–lower Cenomanian) of the South Sallum Well, North Western Desert, Egypt

A palynological analysis has been carried out on the lower–middle Cretaceous rock units encountered in the subsurface section of the South Sallum well, north Western Desert of Egypt. Eighty-three ditch cutting samples have been analyzed palynologically and produced 71 species belonging to 49 genera, which allow recognizing ten informal sporomorph zones restricted to northern Western Desert ranging from early Cenomanian to Hauterivian. The erected palynozones are not only applicable to the western part of the Western Desert, but valid to the north Western Desert as well. They are correlated with well-documented zonations established for the same interval from other localities in the north Western Desert of Egypt and outside in north Africa.

Implications of calcareous nannoplankton biostratigraphy and biochronology of the Middle–Late Miocene of the Nile Delta, Egypt

The Middle–Late Miocene subsurface successions from the Southeastern Mediterranean coast were studied based on the calcareous nannoplankton. The study was established on three boreholes selected from the offshore Nile Delta region, which are Port Fouad M-5, Baltim-1, and NDOB-1. The boreholes were chosen from different petroleum concessions within the North Delta basin. The standard nannoplankton biozonation of Mediterranean areas was used in this study. The studied rock successions cover the Sidi Salim and Qawasim formations, which are widely recognized targets for gas exploration. The study of the calcareous nannoplankton in the studied successions revealed eight biozones, and they are from base to top: Sphenolithus heteromorphus (NN5), Discoaster exilis (NN6), Discoaster kugleri (NN7), Catinaster coalitus (NN8), Discoaster hamatus (NN9), Discoaster calcaris (NN10), Discoaster quinqueramus (NN11), and Amaurolitus tricorniculatus (NN12). The Langhian/Serravalian, the Serravalian/Tortonian, and the Tortonian/Messinian boundaries were defined and discussed. The biochronological dates of the identified nannoplankton biozones were used to calculate the sedimentation rates of the studied rock successions. The calculations revealed two cycles of successive changes of sedimentation rates, which are attributed to regressions phases in Sidi Salim and Qawasim formations.

The biostratigraphic and paleoecological importance of the subsurface Carboniferous microfossil assemblages from Faghur-1x well, Western Desert of Egypt

The microfossil assemblages of subsurface Carboniferous rocks from Faghur-1x were examined and identified. Their biostratigraphical and paleoenvironmental importance were investigated. The assemblage included well-preserved foraminifera like Omphalotis omphalota, Omphalotis sp. 2, Omphalotis sp. 3, Paraarchaediscus stilus, Paraarchaediscus koktjubensis, Archaediscus krestovnikovi, Archaediscus complanatus, Archaediscus inflatus, Archaediscus karreri, Diplosphearina inequalis, Eotubertina sp., Tetrataxis conica, Cribrostomum lecomptei, Palaeotextularia angulata, and Palaeotextularia longiseptata. This foraminiferal association indicates the late Viséan-early Serpukhovian. The other microfossils are gastropods, brachiopods, ostracods, crinoidal ossicles, frond-like fenestrate bryozoan types and stick-like colonies, echinoderms, microproblematica like Draffania biloba and algal Calcisphaera and the dasyclad Koninckopora. This microfossils assemblage points to the deposition in a restricted to open platform in a lagoonal framework environment. The Tehenu Basin is the eastern segment of northern African Sahara basins that provided refuge for the foraminiferal genera through the mass extinction events during the glacial Viséan-Serpukhovian times. However, its foraminiferal associations have lower diversities than the western basins, which indicate that it was more readily affected by the mass extinction event.

Discovery of Devonian scolecodonts from the subsurface Western Desert, Egypt

ABSTRACT The scolecodonts (polychaete jaws) are a significant group of dispersed palynomorphs in Palaeozoic rocks. The growing literature considering the taxonomy of fossil jaw-bearing polychaetes presents some debates on their systematics and has generally limited their role in biostratigraphy. This contribution is the first record that focuses on the scolecodonts from the Devonian (Eifelian) subsurface succession in the Western Desert of Egypt and their biostratigraphic significance. The jaw apparatuses of four different polychaete families are examined and documented from the Devonian of Faghour-1X borehole. The identified families are Paulinitidae, Kielanoprionidae, Polychaetaspidae and Mochtyellidae. Four genera are identified: Kettnerites, Oblongiprion, Oenonites and Mochtyella. The scolecodont associations are compared with coeval associations of the same age from other Gondwanan, Baltic and Laurentian areas to assess their palaeogeographic distribution and biostratigraphic importance.