Abstract Aptian and Albian palynofloras were extracted from a Lower Cretaceous succession penetrated by the Kabrit-1 borehole, northern Gulf of Suez. Representatives of Murospora and pollen such as Afropollis operculatus and A. zonatus are diagnostic of the Aptian palynoflora. Afropollis jardinus, Crybelosporites pannuceus spores and elaterate pollens such as Elaterosporites klaszii and E. verrucatus date the overlying succession as Albian and Upper Albian–lower Cenomanian? Reyrea polymorphus and Cicatricosisporites sinuosus co-occur only in the Albian. The palynofloras are suggestive of shallow marine environment and warm humid palaeoclimate, as directly inferred from the nature and composition of the palynomorph content, which is dominated by pteridophytic spores, along with marine dinoflagellates. The occurrence of rich terrestrial influx of palynomorphs and palynodebris suggests proximity of the depositional sites to source vegetation. The vertical distribution of terrestrial versus marine palynomorphs cannot reflect contemporaneous regressive/transgressive cycles during deposition of the different rock units. The Kabrit-1 palynoflora share general features of the Northern Gondwana province.

Abstract The basal mudstones from the El-Nom borehole in the Gebel Abraq area in southern Egypt have yielded a diverse and relatively well preserved terrestrial palynoflora that includes Balmeisporites holodictyus, Crybelosporites pannuceus, Foveotricolpites gigantoreticulatus, Nyssapollenites albertensis, Retimonocolpites variplicatus and Rousea delicipollis. These suggest an Albian–Cenomanian age and deposition in a fluvio-deltaic environment; no marine phytoplankton is reported. The fern-dominated palynoflora and the overwhelming presence of kaolinitic clays suggest a warm, humid palaeoclimate. According to available knowledge, the mudstones in the Gebel Abraq area, equivalents of the so-called ‘‘Timsah Formation’’, might be correlated with an older rock unit, the Maghrabi Formation, based on the new palynological age assessment. This new definition of local stratigraphy implies that the Bernice sheet of geological map of Egypt [Klitzsch, E., List, F., Po¨hlmann, G., 1987. Geological map of Egypt, sheet NF 36 NE Bernice, 1: 500000. Conoco and the Egyptian General Petroleum Corporation, Cairo] ought to be reconsidered.

Abstract The basal mudstones from the El-Nom borehole in the Gebel Abraq area in southern Egypt have yielded a diverse and relatively well preserved terrestrial palynoflora that includes Balmeisporites holodictyus, Crybelosporites pannuceus, Foveotricolpites gigantoreticulatus, Nyssapollenites albertensis, Retimonocolpites variplicatus and Rousea delicipollis. These suggest an Albian–Cenomanian age and deposition in a fluvio-deltaic environment; no marine phytoplankton is reported. The fern-dominated palynoflora and the overwhelming presence of kaolinitic clays suggest a warm, humid palaeoclimate. According to available knowledge, the mudstones in the Gebel Abraq area, equivalents of the so-called ‘‘Timsah Formation’’, might be correlated with an older rock unit, the Maghrabi Formation, based on the new palynological age assessment. This new definition of local stratigraphy implies that the Bernice sheet of geological map of Egypt [Klitzsch, E., List, F., Po¨hlmann, G., 1987. Geological map of Egypt, sheet NF 36 NE Bernice, 1: 500000. Conoco and the Egyptian General Petroleum Corporation, Cairo] ought to be reconsidered.

Abstract A well diversified Campanian/Maastrichtian palynoflora has been recovered from two wells situated in the Atmur Nuqra area of southeast Egypt. Pteridophytic spores, pollen of gymnosperms and angiosperms as well as dinoflagellates have been identified in addition to some fungal spores and freshwater algae. Angiosperm pollen include typical members of the Late Cretaceous Palmae Province such as Monocolpopollenites spp., Longapertites spp., Echitriporites trianguliformis, Scabratriporites simpliformis, Proteacidites sigalii and Spinizonocolpites baculatus. The Nuqra assemblages are similar to other West and East African assemblages and are outside (south) of a zone of intermixing with the northern hemispheric Normapolles Province. They are slightly different from the assemblages mentioned because of the absence of Mauritiidites, Ctenolophonidites, Tubistephanocolpites and others. Racemonocolpites is a pollen present at Nuqra and in coeval palynofloras in neighbouring Sudan, but it seems to be rare or absent elsewhere in the Late Cretaceous of northeast Africa. Among the identified palynomorph taxa are forms (Gabonisporis cristata, Echidiporites cf. barbeitoensis, Monocolpites marginatus, Racemonocolpites, Spinizonocolpites? kostinensis, Andalusiella mauthei) that are identified for the first time from Egypt. Based on the occurrence of biostratigraphically significant dinoflagellates such as Andalusiella, Cerodinium granulostriatum, Trichodinium castanea subsp. bifurcatum and Odontochitina operculata the studied sections are correlated with the Campanian Duwi (Phosphate) Formation although equivalents of the underlying Quseir and overlying Dakhla Formation may also be present. The upward increase in relative abundance of marine vs. terrestrial palynomorphs reflects a major marine transgression. Abundance of palm pollen and of pteridophytic spores related to water ferns (Ariadnaesporites) suggest a prevalence of humid tropical conditions during the deposition of the sediments examined.

Abstract Palynological and palynofacies analyses were carried out on some Lower Cretaceous samples from the Matruh2-1X well, Northern Western Desert., Egypt. A refinement of the original chronostratigraphy has been suggested and the stages Barremian-Aptian, Aptian, Early and Late Albian are recognized. The palaeoenvironment was interpreted on the basis of the palynomorphs, in the light of their ecological preferences. It was fluctuating between marginal to open (inner-middle shelf) marine. A single horizon (at depth 2170 m) might reflect a continental condition and is thought to have occurred during the Early Albian. A warm–humid climate is thought to have mostly prevailed during deposition of the section. This is reflected in the palynofloras by abundance of ferns, and other hygrophilous spores, and rare xerophytes. Palms, as an important element in tropical humid lowlands of the coastal plains, dominate the terrestrial vegetation and associate petridophytes and other lowland inhabitants. Based on the recovered palynological organic matter two palynofacies are recognized. Data gathered from the theoretically estimated vitrinite reflectances, that are based on spore/pollen colouration, and visual petrographic kerogen analysis are used to define the source rock potentialities of the studied sediments.

Abstract The current work investigates the hydrocarbon potentiality of the upper Jurassic–lower Cretaceous rocks in the Marib-Shabwah Basin, Central Yemen, through the Sabatayn-1 well. Therefore, palynological and organic geochemical analyses were carried out on 37 ditch cutting and 12 core samples from the well. Palynofacies analysis of the Madbi (late Oxfordian–early Tithonian) and Nayfa (Berriasian–Valanginian) Formations sediments indicates deposition of their organic-rich shale, calcareous shale and marl in middle to outer shelf environments under dysoxic– anoxic conditions, containing mainly kerogen of types II to III. However, the shales of the lower Sabatayn (Tithonian) Formation were deposited in an inner shelf environment of prevailing dysoxic–suboxic conditions, and show kerogen types III to II. Regional warmand relatively dry palaeoclimate but with local humid conditions developed near the site of the well is thought to have prevailed during deposition of the studied well sediments. The geochemical analyses of the Madbi Formation show higher total organic carbon content (TOC) than the overlying Sabatayn and Nayfa formations: it is varies between 1.2 and 7, and with average 4 wt% TOC, and the obtained S2 values (∼3–10, average 7 mg HC/g rock) indicates that the Madbi Formation is mainly good source rock. It shows a good petroleum potential of 4–11 mg HC/g dry rock, and the Rock-Eval pyrolysis indicates mainly kerogen types II to III (oil to gas prone) of hydrogen index values (132–258, and only one sample from Lam Member is of 360 and average 215 mg HC/g TOC). The thermal maturation parameters as Tmax (425–440 °C), production index (average 0.13 mg HC/g rock) and thermal alteration index (2 to 2+) reflected that this formation is present at margin of maturation to early mature stage oil window. So, the Lam Member (upper part) of the Madbi Formation is considered the main hydrocarbon (oil and gas) source rock in the Marib-Shabwah Basin. Accordingly, we predict that the Meem Member is an active source for gas and oil accumulations in the overlying sandstone reservoir of the Sabatayn Formation in the Sabatayn-1 well.

Abstract The current work investigates the hydrocarbon potentiality of the upper Jurassic–lower Cretaceous rocks in the Marib-Shabwah Basin, Central Yemen, through the Sabatayn-1 well. Therefore, palynological and organic geochemical analyses were carried out on 37 ditch cutting and 12 core samples from the well. Palynofacies analysis of the Madbi (late Oxfordian–early Tithonian) and Nayfa (Berriasian–Valanginian) Formations sediments indicates deposition of their organic-rich shale, calcareous shale and marl in middle to outer shelf environments under dysoxic– anoxic conditions, containing mainly kerogen of types II to III. However, the shales of the lower Sabatayn (Tithonian) Formation were deposited in an inner shelf environment of prevailing dysoxic–suboxic conditions, and show kerogen types III to II. Regional warmand relatively dry palaeoclimate but with local humid conditions developed near the site of the well is thought to have prevailed during deposition of the studied well sediments. The geochemical analyses of the Madbi Formation show higher total organic carbon content (TOC) than the overlying Sabatayn and Nayfa formations: it is varies between 1.2 and 7, and with average 4 wt% TOC, and the obtained S2 values (∼3–10, average 7 mg HC/g rock) indicates that the Madbi Formation is mainly good source rock. It shows a good petroleum potential of 4–11 mg HC/g dry rock, and the Rock-Eval pyrolysis indicates mainly kerogen types II to III (oil to gas prone) of hydrogen index values (132–258, and only one sample from Lam Member is of 360 and average 215 mg HC/g TOC). The thermal maturation parameters as Tmax (425–440 °C), production index (average 0.13 mg HC/g rock) and thermal alteration index (2 to 2+) reflected that this formation is present at margin of maturation to early mature stage oil window. So, the Lam Member (upper part) of the Madbi Formation is considered the main hydrocarbon (oil and gas) source rock in the Marib-Shabwah Basin. Accordingly, we predict that the Meem Member is an active source for gas and oil accumulations in the overlying sandstone reservoir of the Sabatayn Formation in the Sabatayn-1 well.

A detailed palynofacies analysis was carried out on 56 ditch-cutting samples obtained from the lower Cretaceous of Siqeifa 1x borehole, north Western Desert, Egypt. The main aim of this study is to identify depositional palaeoenvironments in details, reconstruct vegetation cover and to infer palaeoclimate conditions. Three palynofacies types were recognised; palynofacies type (PF-1) corresponds to the lower-middle Alam El Buieb Formation (Berriasian-Barremian). This is deposited in a deltaic (prodelta) subenvironment during a Berriasian-early Barremian regression episode, and the lower upper Alam El Buieb deposited in an inner shallow marine environment during a partial regain of a late Barremian-Aptian transgression, under prevailing dysoxic-anoxic to suboxic-anoxic conditions. The second palynofacies (PF-2) represents the uppermost Alam El Buieb, Alamein, and Dahab formations (late Barremian-Aptian), where the uppermost Alam El-Buieb Formation was deposited in a distal bar of a prograding delta, accumulated during a minor local regression. However, the carbonate of the Alamein Formation and the shale of the Dahab Formation was deposited in a saline lagoon environment developed during a partial regain of the local early Aptian marine transgression. Suboxic-anoxic to dysoxic-anoxic conditions are interpreted to prevail during deposition of the PF-2. Third palynofacies (PF-3) represents the Kharita Formation (Albian), where the lower Kharita was deposited in a lagoon setting, while the upper Kharita was deposited in a deltaic environment due to a major marine regression, under dysoxic-suboxic conditions. Local pteridophyte vegetation on low lands near the borehole and conifers on relatively dry hinterlands is interpreted to thrive under a regional warm and relatively dry palaeoclimate. Possible seasonal dry periods may be developed during deposition of the uppermost Alam El Buieb, Dahab and Alamein formations.