The history of palynology in Egypt

This contribution marks the achievements made in the past decades by a group of mainly Egyptian palynologists. The data generated covers a long-time span from the Precambrian to the Holocene of Egypt. Previously published results are devoted primarily to the study of many exploration wells and outcrop sections. Comprehensive studies were carried out on a range of palynomorph groups including spores and pollen, algae and prasinophytes, dinoflagellate cysts, acritarchs, scolecodonts, chitinozo-ans, and other miscellaneous forms as well as palynofacies. Particular attention is given to the history of palaeopalynology. This study has identified three main phases. The results of the first phase were limited, as the knowledge of palynology in Egypt was poorly known from 1959 until 1979. Between 1980 and 2000, which represents the second or shaping phase, an intensive study of surface and sub-surface material was carried out. The third phase (2000 until now) provides the academic and commercial expansion of palynological research in Egypt, where palynology can have immediate application in petroleum exploration studies. In the first phase, the application of palynology was seriously hampered by the limited extent of the published data. Only 27 works emerged by the end of 1979. A considerable acceleration was noted in the second phase when palynological research was established in many national institutions and started to play a considerable role in petroleum exploration. Beyond academia, some of the operating oil companies started to set up palynological laboratories and staff as part of biostratigraphy teams. These included, for example, GPC, Khalda Petroleum Company with a focus on the north Western Desert, and GUPCO with a focus on the Gulf of Suez, and most of the results obtained were incorporated with the internal data on the well files. During the period 2000–2009, especially when palynofacies studies were incorporated, the progress and the direction of palynological research changed. This allowed for a more accurate reconstruction of the depositional process and eventually a palaeobiogeographical history mainly for the Cretaceous, which is an important target for hydrocarbon exploration in Egypt. From 2010 onwards, the number of publications has clearly grown and reached 23 publications in 2020. Such a high pace of development seems to have been at the expense of basic research comprising taxonomy and biostratigraphy, some-thing that might negatively impact the quality of research and also researchers, especially early career researchers. The change brought about through this phase by integrating organic geochemistry, sedi-mentology, and other disciplines may, however, have left a positive impact, principally in terms of international collaborations and expansion of palynological applications beyond the standard academic cluster. Important highlights and outputs, and prospective forthcoming developments and recommendations pertaining to Egyptian palynology generally (and in each phase) are discussed.


Introduction
Applications of palynology have comprised many potential achievements, particularly in terms of age constraints for sedimentary strata, metamorphic rocks, and stratigraphically challenging continental sediments that are barren of marine microfossils (Traverse 2007).Not only palynostratigraphy, palynofacies, palaeoecological and palaeoenvironmental applications but also pollen analysis applications in archaeology and Quaternary studies, and other commercially valuable applications related to petroleum exploration.
Until the second half of the last century, studies on (palaeo)palynology of Egyptian strata were virtually unknown.However, the first investigation in 1959 on palynomorphs from Egypt undertaken on Carboniferous strata in west Central Sinai (Synelnikor and Kollerov 1959) is an acknowledged milestone in the development of palynology.During the 1970s, the eminent palynologist, Shokry I. Saad, played a vital role in launching and shaping palynological research in Egypt.Over the last 70 years, palynological studies on Egyptian rocks have made significant progress in traditional and new applications in conjunction with other geological disciplines.These studies have greatly enhanced our understanding of ancient vegetation throughout geological history.As shown in our dataset graphs, researchers have examined palynomorph assemblages from Precambrian to Quaternary surface and subsurface deposits from different areas of Egypt (Figure 1).In this work, we aim to provide an overview of the history of palynology in Egypt and shed light on the pioneering palynologists and benchmark palynological studies.

Historical matters
The history of palynology in Egypt can be subdivided into three phases: i) the earliest studies and the initiation of early pioneer research ; ii) the period of shaping and developing experienced palynologists ; and iii) the expansion and petroleum palynology trend (2000-to date).

Initiation phase (earliest studies)
The Geological Survey and Mineral Research Department (now the Egyptian General Authority of Survey Geological and Mining Projects; EGSMA) sponsored the early palynological research in Egypt based on their expedition work in Sinai.Synelnikor and Kollerov (1959) initiated the research and introduced the first report on spores from the Carboniferous of west central Sinai.Their modest report includes only line drawings as well as identification of some spore taxa with no discussion (Figures 2 and 3).A year later, Helal (1960) retrieved coal samples from the Jurassic Ayun Musa Well no. 4 in Sinai (Figure 1).Dr Ahmed Helmy Helal (Figure 4), together with Professor Ulrich Jux, University of Cologne, Germany (Figure 4) employed palynomorphs as stratigraphical tools and assigned the studied part of the Nubia Sandstone in Ayun Musa to the Upper Jurassic which was very important for mapping the area; see Helal and Jux (1962).Helal (1965Helal ( , 1966) ) later targeted the Jurassic coaly or carbonaceous shales in the Nubia Sandstone in the El-Sherka no. 3 well in the Kharga Oasis, Western Desert (Figure 1).A few years later, Professor Shokry Ibrahim Saad (Figure 5) from Alexandria University, who is considered the father of palynological research in Egypt, published two articles (Saad 1963(Saad , 1965)).He described and illustrated the palynomorph content of coal samples retrieved from Ayun Moussa and Um Bogma areas in Sinai (Figure 1).Similarly, Omara and Schultz (1965) described the palynomorph assemblages from the Lower Carboniferous (Vis� ean) of the Um Bogma area.These works encouraged Professor Mahmoud Ahmed Kora (Figure 6) from Mansoura University to cooperate with Dr. George Schultz, University of Cologne to continue the palynological investigation of the Carboniferous in Sinai (Kora and Schultz, 1987).During the same period, Ismail Z. Sultan (Figure 6) from Alexandria University studied the Carboniferous palynology of the East Gharib no 1 well in the Gulf of Suez (Sultan 1977), which was later also studied by Eames (1984).Saad (1974Saad ( , 1978) ) turned his attention to the study of Cretaceous palynology from the Umbarka IX borehole, north Western Desert.Professor Saad together with Professor Gamal El-Ghazaly (Figure 6), Alexandria University, and Stockholm University, continued to publish on the Cretaceous of southern Egypt from the Kharga Oasis (Figure 1).Particularly, the development of hydrocarbon exploration in Egypt led to rapid development and started a new phase of palynological research with intensive work on subsurface Cretaceous strata.The impetus was provided by a number of   Egyptian scientists who performed the bulk activity during this phase: arranged in chronological order, Hassan A. Soliman, Nabil M. Aboul Ela, Abdel Ghani A. El Shamma, Ahmed M. Omran, and Sayed Abdel Mohsen (Figure 6).This phase represents the shaping of palynology research in Egypt with all of the abovementioned pioneer researchers who established palynostratigraphical frameworks on different time scales and geography.They also undoubtedly contributed and helped in implementing palynology as a discipline in Egyptian universities and research institutes.Among those who are still active are Nabil M. Aboul Ela and Abdel Ghani A. El Shamma (Figure 6).Despite their early interest in foraminifera, they both helped in installing and building palynological teams and laboratories at Cairo University and the Egyptian Petroleum Research Institute (EPRI), respectively.

Shaping phase
The study of Cenozoic palynology of Egypt was also introduced in the late 1960s by Saad and Sami (1967) followed by a series of contributions on the same era from Mikl� os Kedves (Figure 6) from Szeged, Hungary.Kedves's work was illustrated, mostly in a botanical sense, and many taxa and new species were erected starting with Kedves (1981) and continued until 2004 with studies of wood from Aswan, together with Professor Wagih El-Saadawi (Figure 7) from Ain Shams University.El-Saadawi contributed with his team more than anyone else to the macroflora of Egypt; see El-Saadawi et al. ( 2020).In a similar context, Mohamed Naguib El-Sabrouty (Figure 7) produced some valuable reports on Neogene pollen and spores (e.g.Guinet et al. 1987).During this phase, archaeopalynology (e.g.Mehringer et al. 1979) and pollen morphology (e.g.Ayyad et al. 1992) were studied only by isolated researchers, e.g.Professor Sekina M. Ayyad (Figure 7) from Mansoura University.Recently, Professor Suzan E. Kholeif (Figure 7) from the National Institute of Oceanography and Fisheries, despite her works on the pre-Quaternary, also published on the Quaternary (e.g.Kholeif 2004).
A significant advance in palynology research in Egypt was achieved when the late German scientist Dr. Eckart Schrank (Figure 8) from the Technical University of Berlin turned his attention to the Cretaceous palynology of Egypt (Schrank 1982).This was part of a German project (DFG Sonderforschungsbereichs 69: SFB 69) and between 1981 to 1995 targeted the arid areas in Africa including Egypt.A few years later, in 1985, Professor Salah Y. El Beialy (Figure 8) returned to Egypt after receiving his PhD from the University of Sheffield, United Kingdom.He started his career with a focus on Neogene palynology, especially on the Nile Delta (Saad et al. 1987), which was followed by a series of publications mostly in international peer-reviewed journals (Supplementary data; Appendix 1).As a former MSc student of Shokry Saad, El Beialy has continued to publish on the palynology of Egypt and has established a research school, with alumni that include, among others, the two authors of this paper.
As the subject grew, Professor Magdy S. Mahmoud (Figure 8) from Assuit University started to contribute to the palynology of Egypt in 1989 (Omran et al. 1989) and continued with a significant effort on Cretaceous palynology especially in southern Egypt (e.g.Schrank and Mahmoud 2002).He also contributed to developing palynological capacity in Egyptian universities (Supplementary data; Appendix 3) and published several papers, e.g.Mahmoud et al. (2017).This phase, which we prefer to call the shaping phase, is completed with the work of Professor Mohamed I. Ibrahim (Figure 8) from Alexandria University.He was a former MSc student of Sh.Saad and a PhD student of E. Schrank.To our knowledge, he contributed more than anyone else to Cretaceous palynology of Egypt, particularly the north Western Desert, and this merits special attention, e.g.Ibrahim et al. (1995).His contributions to the Cretaceous are numerous (Supplementary data; Appendix 1), particularly his unique monograph (Ibrahim et al. 2009).

Expansion phase
At the beginning of the third millennium, a new phase of research (expansion phase) has been started, targeting the Miocene (e.g.Wescott et al. 2000) and a continuation of Mesozoic research.This focus is via a series of oil industrydriven contributions which comprised the integration of palynofacies analysis, spore colour index, and organic geochemistry, as well as other petroleum-related proxies.This phase started with the work of Ibrahim (1996a) on the Nile Delta and was followed by El Beialy et al. (2010a) on the north Western Desert.The latter was the first study to incorporate organic geochemistry and vitrinite reflectance data as supplementary interpretations, which is followed by a long list of publications (Supplementary data; Appendices 1 and 2).
To the best of our knowledge, we have cited all previous works in Supplementary data; Appendix 1 and classified them in such a manner (Supplementary data; Appendix 2) to make it easy for those interested in a specific spatial or temporal window.We also tried to support our readers with a directory service that hosts all active Egyptian palynologists with their current affiliations (Supplementary data; Appendix 3).

Highlights and review of palynology in Egypt
After collecting and reviewing all published data on the palynology of Egypt, statistical analyses were performed (Figures 9 and 10).We wish to highlight the following:

Precambrian-Palaeozoic palynology
Precambrian rocks in Egypt are mostly igneous and metamorphic and are distributed mainly in the Eastern Desert and Sinai.However, some of the metasediments have been gently metamorphosed and yielded organic-walled microfossils as first highlighted from Sinai (Shimron and Horowitz 1972) followed by a few additional studies, summarized in Supplementary data; Appendix 2.
Published works on the Palaeozoic palynology of Egyptian strata have been few and started in the 1960s, e.g.Sch€ urmann et al. (1963) and were followed by a series of publications, mainly on Sinai; however, A.A. El Shamma and his colleagues in EPRI focused their attention on the north Western Desert (e.g.El-Shamma and Baioumi 1993).There is still a need for additional research, especially to produce a palynostratigraphical framework that serves as a basis for the ongoing exploration of the north Western Desert where other microfossil groups are almost exclusively absent as is the case in the Nubia Sandstone.Unfortunately, most of the available contributions were published in local journals/conference proceedings that cannot be accessed by the international community (e.g.Eames, 1984).

Mesozoic palynology
Palynological research on Mesozoic strata lacks any record of the Triassic.It started with Helal (1965) on the Jurassic of the Kharga Oasis and was followed by a series of contributions on Sinai (e.g.Aboul Ela and Aly 1988;El Beialy and Ibrahim 1997) and the north Western Desert (e.g.El Beialy et al. 2002aBeialy et al. , 2002b) that continued until the current year (see Supplementary data; Appendix 2).This research interest was due to the exploration and drilling activities, with a key focus on the north Western Desert, and a lesser focus on the Eastern Desert (e.g.El-Shamma et al. 1997).In this context, it is important to highlight the work of Ibrahim et al. (1997) which was the first to introduce palynofacies in combination with palynostratigraphy on Jurassic strata.

Cenozoic (Pre-Quaternary) palynology
Palynological investigation of Cenozoic deposits was inaugurated by the pioneering work of Saad and Sami (1967) who employed pollen analysis to interpret the human impact on the Nile Delta and its vegetation.Thereafter, a series of scholarly publications focused on the Neogene palynology of Wadi El Natrun and Wadi El Farigh, located in the northwestern expanse of the Western Desert, were embarked upon (e.g.Kedves 1981Kedves , 1983)).Recently, the vegetational history of the Oligocene and Miocene of the north Western Desert was tackled by a series of publications (e.g.El Atfy et al. 2021Atfy et al. , 2022)).In the 1980s, S.Y.El Beialy published several papers that established a comprehensive Cenozoic palynostratigraphy (mainly dinoflagellate cyst-based) for the Nile Delta (e.g.El-Beialy 1988) and a few on the north Western Desert (e.g.El-Bassiouni et al. 1988) and Sinai (e.g.El- Beialy and Gheith 1989).An important publication targeted the Upper Eocene to Lower Oligocene miospores of the fluviomarine Qasr El Sagha Formation, exposed in the Fayum Oasis (Takahashi and Jux 1989).
The Gulf of Suez, a major Neogene petroleum system, was extensively studied, and Miocene palynostratigraphical schemes and palynofacies studies were published (e.g.Soliman et al. 2012;El Atfy et al. 2014, 2017b;El-Soughier and Mahmoud 2019;Makled et al. 2020).Also, the Pliocene climate and depositional environment delineation in the Gulf of Suez were studied by Pocknall et al. (1999).Furthermore, Mahmoud (1996) and Mahmoud et al. (2015) used organicwalled microfossils to interpret the palaeoenvironment and palaeoclimate of the Late Neogene in southern Egypt to discuss the history of the proto-Nile sediments.A full list of publications dealing with Cenozoic palynology and related applications is presented in Supplementary data; Appendices 1 and 2.

Conclusions
During the course of this work, we have identified shortcomings in the palynological record of Egypt and we can make the following recommendations: 1. Focus should turn to investigating surface sections, despite the problem that outcrop samples in Egypt are mostly barren.
2. More effort needs to be made to better understand the palynology of the Paleogene and to complete the stratigraphical framework of this Period.3. Work on stage boundaries in Egypt requires more focus, especially the K-Pg boundary.4. Integration with foraminifera and nannofossils has been made over many decades but more could be done to build the chronostratigraphy of Egypt based on palynology.In this context, multi-proxy biostratigraphy is rare and more collaboration between biostratigraphers is recommended.5. We recommend the continuance of large-scale projects, along with large-scale international collaboration, focusing on vegetation change and palynostratigraphy.This will foster cooperation with international groups and undoubtedly contribute to the future development of palynologists.6. Collaboration with the oil and gas industry and water exploration companies is sometimes challenging, but the benefits for both the industry and researchers are important and the cooperation between both parties should continue and hopefully increase in future years.
In this context, a continuing effort must be made to facilitate sample acquisition.This will undoubtedly enhance palynological studies in Egypt.

Figure 1 .Figure 2 .
Figure 1.The location map of Egypt shows the discussed locations and spatial distribution of previous palynological studies.The red sign outlines the location of the first work.Source: d-maps.com

Figure 5 .
Figure 5.The father of palynological research in Egypt; Shokry Ibrahim Saad died in 1994; from Mohamed I. Ibrahim.

Figure 9 .
Figure 9. Bar graph showing the annual number of palynological publications in the three established phases.

Figure 10 .
Figure 10.Pie charts displaying palynological contributions in different aspects.

HAYTHAM
EL ATFY is an associate professor at Mansoura University (Egypt) from where he received a BSc degree in geology and an MSc in palynology.He received a PhD in geosciences (palynology and organic geochemistry) from Goethe University, Frankfurt (Germany) in 2014, and a PD (Habilitation) from the University of T€ ubingen (Germany) in 2022.Since 2023, Haytham joined the Palaeobotany Group, Institute of Geology and Palaeontology, University of M€ unster, Germany.He acquired experience in industrial palynology through work with GUPCO (BP), Egypt.Haytham has been a Research Fellow of the Alexander von Humboldt Foundation at the University of T€ ubingen (Germany) since 2019.He was recently a visiting scientist at the Senckenberg Research Institute in Germany.His research interests span all aspects of palynology and its applications in dating, palaeoenvironmental and palaeoclimatic reconstructions, and hydrocarbon exploration, particularly of the Mesozoic and Cenozoic and, to a lesser extent, the Palaeozoic.He has more recently become involved in organic geochemistry.He is a member of the AASP-The Palynological Society, the Micropalaeontological Society (TMS), Arbeitskreis f€ ur Pal€ aobotanik und Palynologie (APP), and the Palaeontological Society of Egypt (PSE).He received many awards, including the Bernd Rendel Prize from the German Science Foundation (DFG), the Egyptian State Incentive Award, and the First-Class Excellence Concession that the Egyptian president provides.