الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 191 |  |  |
| | | from | 191 | | |
Abstract
The primary objective of the present study was to conduct palynological and palynofacies analyses of the Albian-Cenomanian interval in the Safir-N-2 well, located in the Matruh field in the north Western Desert. This aims to establish a palynostratigraphic framework, interpret paleoenvironmental, paleoecological, and paleoclimatical conditions, reconstruct floristic composition, and assess the source rock potential in this interval. To achieve this goal, a total of 37 cutting samples were collected from the lower upper Cretaceous Kharita and Bahariya formations encountered in the Safir-N-2 well. These samples underwent palynological processing using standard acid techniques. The analyses yielded several important findings, summarized as follows:
1. The total assemblage of identified palynomorphs obtained from the present study comprises a total of 131 species. Among these, 43 spores account for 32.8% of the total which include 5 bryophytes and 38 pteridophytes, while 28 gymnosperm pollen represent 21.4%, and 22 angiosperm pollen constitute 16.7%. Additionally, there are five fungal palynomorphs, making up 3.8%, and four freshwater algae, contributing 3.1%. Dinoflagellate cysts are represented by 24 species, comprising 19.8% of the total, along with three acritarchs, accounting for 2.3%. The assemblage also includes various morphological forms of insect parts and microforaminiferal inner test linings.
2. Utilizing zonally diagnostic species, four Interval palynozones are proposed and correlated with their local and international counterparts. These zones, listed in descending stratigraphic order, are as follows:
Palynozone 1: Concavissimisporites punctatus Interval zone (early/middle Albian).
Palynozone 2: Oligosphaeridium complex Interval zone (late Albian).
Palynozone 3: Elaterosporites klaszii Interval zone (early Cenomanian).
Palynozone 4: Afropollis jardinus Interval zone (middle Cenomanian).
3. Based on qualitative and semi-quantitative analysis of palynofacies, two distinct palynofacies associations are defined within the studied intervals.
3.1.1 Palynofacies association-1 (PFA-1) (phytoclast and opaque major domination)
PFA-1 was characterized by a high abundance of phytoclasts, with a moderately abundant AOM ranging from 20% to 35%. These phytoclasts are primarily opaque and non-opaque fragments from terrestrial plants. Opaque phytoclasts include lath and equant-shaped fragments displaying various sizes and colors (ranging from dark brown to black). Translucent phytoclasts (non-opaque) consist of biostructure and non-biostructure elements. The AOM can originate from natural products or biodegradation of land plant tissues and phytoplankton. The recommended kerogen type for this facies is Type III, prone to gas formation.
3.1.2 Palynofacies association-2 (PFA-2) (AOM major domination)
PFA-2, located between 1972-1762 m in the Bahariya Formation, shows a significant increase in AOM (averaging 49%), with a small portion of this comprising resin. Conversely, phytoclast amounts decline, and palynomorphs are scarce. AOM is composed of preserved particles with various colors. Phytoclasts in PFA-2 are mainly opaque and translucent, indicating Kerogen Type II, an oil-prone material.
4. The analysis of palynomorphs recovered from the studied well indicates warm humid paleotropical conditions. This interval is marked by a high relative abundance and diversity of hygrophilous and hygro-mesophilous pteridophytic spores, including species from Gleicheniaceae, Osmundaceae, Marsileaceae, Schizeaceae, Cibotiaceae, Salviniaceae, Dicksoniaceae/Cyatheaceae, Matoniaceae, and Polypodiaceae. The presence of Afropollis jardinus further suggests a moist habitat. This coincides with the very low abundance of Classopollis and Ephedripites pollen which were described as high temperature and aridity markers. As a result, the Safir-N-2 well is attributed to the paleoequatorial Albian-Cenomanian Elaterates Province described by Herngreen et al. (1996). This province is characterized by warm and highly humid conditions, likely due to the highest rainfall rates occurring at or near the equator. This humidity contrasts with the predominantly arid to semi-arid paleoclimate observed in most of the Albian–Cenomanian Elaterates Province. The shift in the paleogeographic position of Egypt during this period may account for these climatic differences.
Combining data from micro- and macrofossil remains revealed consistent representation of parent plant families across both assemblages, with recorded classes exhibiting substantial similarity. Palynological evidence facilitated the identification of two distinct paleofloral types in the Safir-N-2 well, situated in the Matruh Basin during the Cretaceous period: a lowland marsh fern community and an upland pollen grain producer community.