Sherif Farouk

Integrated biostratigraphy of two Upper Maastrichtian – Palaeocene successions in north-central Sinai, Egypt

Integration of the calcareous nannofossil and planktonic foraminiferal biostratigraphies has been performed for theUpper Maastrichtian – Palaeocene successions at Gebel Umm Khushayb and west El-Hassana sections (north-centralSinai, Egypt). The studied successions include the uppermost part of the Sudr, Dakhla, and their lateral coeval Beida Formation. Biostratigraphic analysis has allowed recognition from Zone CF2 to Zone P4in terms of planktonic foraminifera and from Zone CC26c to Zone NP7/8 in terms of calcareous nannofossils. Maastrichtian/Palaeogene (K/Pg) boundary is characterized by an erosional surface that marks a hiatus between theSudr/Dakhla or Sudr/Beida formation boundaries, as confi rmed by the absence of the planktonic foraminiferal CF1to P1a zones and their equivalent nannofossil zones (top part of CC26c to lowest part of Zone NP3). Selandian (Da/Se) boundary lies in the upper part of the Dakhla Formation within the top of nannofossil Zone NP4,and within planktonic foraminiferal Zone P3b, similar to that of the Global Standard Stratotype-section and Point(GSSP) of the D/S boundary which has recently been chosen at the Zumaia section, northern Spain. was observed across the Selandian/Thanetian boundary as indicated by a lithological change and a very condensedZone NP6, corresponding to the Dakhla and Tarawan formation boundary in the west El-Hassana section.

Benthic foraminiferal response to relative sea-level changes in the Maastrichtian–Danian succession at the Dakhla Oasis, Western Desert, Egypt

The Maastrichtian–Danian benthic foraminiferal diversity and assemblages through sequence stratigraphy were studied at Dakhla Oasis, Egypt. Benthic foraminifera numbers (BFN), high-flux species and characteristic benthic foraminiferal species and genera distribution are also incorporated to assess palaeobathymetry, palaeoenvironment and palaeoproductivity. All these proxies are then taken together to construct a sea-level curve and interpreted in terms of regional tectonics, climate and eustasy. Data suggest a remarkably highly equitable benthic environment deposited in a brackish littoral and/or marsh setting with moderate (?) to low oxygen conditions and reduced salinity (oligotrophic), possibly due to increased precipitation and terrestrial runoff. The interrupted dominance of calcareous forms and high-organic-flux species suggests occasional marine incursions and high palaeoproductivity, due to local upwelling. The inferred sea-level curve replicates the global eustatic curve and suggests that the curve is more influenced by the prevailing climate and global eustasy rather than by regional tectonics. The post-Cretaceous–Palaeogene boundary displays improvement in the environment in terms of diversity and number of species and specimens, with a marked reduction in the abundance of high-organic-flux species during early Paleocene (Danian) time, indicating a shift from a more mesotrophic open marine environment to much reduced oligotrophic conditions.

Integrated microfossil biostratigraphy, facies distribution, and depositional sequences of the upper Turonian to Campanian succession in northeast Egypt and Jordan

Six upper Turonian to Campanian sections in Egypt (Sinai) and Jordan were studied for their microfossil biostratigraphy (calcareous nannofossils and planktonic foraminifera), facies distribution and sequence stratigraphic frameworks. Carbonate (mostly chalk) and chert lithofacies dominate the basinward northern sections passing laterally and vertically to mixed carbonate/siliciclastic lithofacies towards the shoreline in the southeast. Twenty-six lithofacies types have been identified and grouped into six lithofacies associations: littoral siliciclastic facies belt; peritidal carbonate; intertidal carbonate platform/ramp; high-energy ooidal shoals and shelly biostromes; shallow subtidal; and pelagic facies association. The following calcareous nannofossil biozones were recognized: Luianorhabdus malefomis (CC12) (late Turonian), Micula staurophora (CC14) (early Coniacian), Reinhardtites anthophorus (CC15) (late Coniacian), Lucianorhabdus cayeuxii (CC16) (early Santonian) and Broinsonia parcaparca (CC18) (Campanian). Equivalent planktonic foraminifera zones recognized are: Dicarinella concavata (Coniacian), the lower most part of Dicarinella asymetrica (earliest Santonian) and Globotruncanita elevata (early Campanian). The integrated zonation presented here is considered to provide higher resolution than the use of either group alone. The absence of calcareous nannofossil biozones CC13 and CC17 in most of the studied sections, associated with regional vertical lithofacies changes, indicates that recognition of the Turonian/Coniacian and Santonian/Campanian stage boundary intervals in the region have been hampered by depositional hiatuses at major sequence boundaries resulting in incomplete sections. These disconformities are attributed to eustatic sea-level fluctuations and regional tectonics resulting from flexuring of the Syrian Arc fold belt. The Coniacian to Santonian succession can be divided into three third-order depositional sequences, which are bounded by four widely recognized sequence boundaries.

Macrofauna and paleobiogeography of the Callovian Tuwaiq Mountain Formation in central Saudi Arabia

Forty-six Callovian macrofaunal species including 13 brachiopods, 19 bivalves, and 14 gastropods were collected from three surface sections—Shaib Al Hisyan, Khashm Al Giddiyah, and Dirab—in the Tuwaiq Mountain Formation around Riyadh City in central Saudi Arabia. The fauna is discussed systematically and with respect to biostratigraphic implications and its paleobiogeographic distribution. Four macrobiozones with two barren intervals are identified. These zones are from base upward: Pholadomya (Bucardiomya) lirata, Barren interval (1), Sphringanaria capax, Pholadomya inornata, and Coral Zone of Middle Callovian age and Barren interval (2) of Middle to Late Callovian age. The paleobiogeographic distribution of the fauna confirmed the endemism along the southern Tethyan margin of the Ethiopian Province.

Integrated planktonic stratigraphy and paleoenvironments of the Lower-Middle Miocene successions in the central and southern parts of the Gulf of Suez, Egypt

Lower to Middle Miocene successions in three offshore wells named GS 160-2, QQ-89, and Ras Elush-2 located in the central and southern parts of the Gulf of Suez were examined for their planktonic foraminifera, calcareous nannofossil assemblages, and paleoenvironments. These successions are subdivided from older to younger into Aquitanian Nukhul, Burdigalian-Langhian Rudeis, Langhian Kareem, and Serravallian Belayim formations. The identified foraminifera includes 54 benthic species belonging to 25 genera and 47 planktonic species belonging to 11 genera, in addition to 64 calcareous nannofossil species belonging to 21 genera. The stratigraphic distribution of these assemblages suggests classifying the studied successions into seven planktonic foraminiferal and six calcareous nannoplankton biozones. The planktonic foraminiferal and calcareous nannoplankton biozones are integrated. Different environments ranging from shallow inner to outer shelf are recognized. This is based on quantitative analyses of foraminifera including benthic biofacies, planktonic/benthonic ratio, and diversity. Syn-rift tectonics played an important role in configuration of the Miocene depositional history in the Gulf of Suez region.

Facies associations of the Bathonian Hamam Formation from Northwestern Jordan

Two stratigraphic sections of the Hamam Formation (Bathonian Stage, Middle Jurassic) exposed in the western part of Wadi Zarqa region, northwestern Jordan, are described and interpreted on the basis of palynoflora and facies analysis in order to reconstruct their depositional environments and sequence stratigraphic framework, which not discussed before. Five facies associations have been identified in the Hamam Formation characterized by a mixed carbonate–siliciclastic ramp setting, ranging from incised fluvial valley fill facies, beach foreshore restricted inner ramp to high-energy shoals and mid-ramp settings. The palynoflora includes well-preserved miospore assemblages which are recorded only from the incised fluvial valley fill facies for the first time and yielded 64 miospore species belonging to 40 genera. Most of these taxa are long-ranging and have been reported from Jurassic and Cretaceous rocks worldwide, except Callialasporites dampieri, Murospora florida, Granulatisporites jurassicus, Piceites expositus, Pityosporites parvisaccatus, Leptolepidites verrucatus, and Protopinus scanicus which have short ranges in the Middle Jurassic. Furthermore, these rocks are rich in shallow-marine Neo-Tethys macro-invertebrates supporting a Bathonian age. Two third-order depositional sequences bounded by three regional unconformities at the Bajocian–Bathonian and Bathonian–Callovian stage boundaries as well as within the Bathonian are defined based upon facies characteristics and stratal geometries. A regional correlation of sequence boundaries of similar age indicates that they are eustatic in origin.

Microfacies and depositional environments of Jurassic (Callovian) Tuwaiq Mountain Formation in central Saudi Arabia

Three stratigraphic sections of the Callovian Tuwaiq Mountain Formation at Shaib El-Hisyan, Khashm Al-Giddayah and Dirab, near Riyadh City, central Saudi Arabia have been studied to distinguish their microfacies features and the equivalent probable depositional environments. Lithostratigraphically, the Tuwaiq Mountain Formation is subdivided into two lower and upper Tuwaiq members. The part that informally is known as upper Tuwaiq Member is subdivided from base to top into T1, T2, and T3 members, respectively. The microfacies analysis of the Tuwaiq Mountain Formation led to the recognition of 12 microfacies types (FT1–FT12) that are grouped into three associations: (1) open platform facies association (FT1–FT5); (2) high-energy shoals of ooids and patch reefs facies association (FT6–FT9); and (3) restricted carbonate platform facies association (FT10, FT12). The lower part of the Tuwaiq Mountain Formation is characterized by relative abundance of wackestone and wacke/packstone facies that are capped by thin peloidal molluscan floatstone facies. The former indicates a quiet open platform environment with periodic agitation, while the later indicates deposition in a sand shoal environment. The facies of basal unit of the upper Tuwaiq Mountain Formation, T1, are enriched with dense micrite matrix and shell fragments of epifaunal and deep infaunal organisms (e.g., Pholadomya spp.). The microfacies pattern of Baladiyah Member (T1) indicates a quiet open platform with low and sometimes high water circulation. The Maysiah Member (T2) is composed of hard limestone with abundance of coralline microfacies in framestone, grainstone, and packstone textures suggesting a high-energy shallow reefal environment with periods of quiet open platform conditions. This shallow reefal environment becomes more restricted southward, where shales and algal dolomitic grainstones were formed. The Daddiyah Member (T3) that made up of chalky limestone with chert intercalations is predominated by matrix-support lime mudstone, wackestone, and packstone facies. These microfacies reflect open platform with slightly low circulation below fair-weather wave base with period of restricted marine conditions forming rudstone microfacies. Southward, these environments became shallower and subjected to considerable quartz influx in an agitated sand shoal.

New lithofacies and stable isotope records from the Middle Jurassic succession of northwestern Jordan: stratigraphic implications

The Hamam and Mughanniyya formations of northwestern Jordan form part of the major carbonate shelf that existed over Arabia and the associated southern Tethyan margin during the Jurassic, but their precise age context and depositional setting have not yet been firmly established. To address this issue, the Hamam and Mughanniyya formations are compared with better biostratigraphically constrained successions in adjacent countries using a sequence stratigraphic framework. Two stratigraphic sections of the Hamam and Mughanniyya formations are shown by analysis of vertical trends from new lithofacies descriptions to comprise two primary depositional sequences that equate to the Bathonian and Middle-Late Callovian J30 and J40 Arabian Plate sequences sensu Sharland et al. (2001). New carbon (δ13C) and oxygen (δ18O) isotope records (amongst the first published for the Jurassic of Arabia) are helpful in locating sequence boundaries by means of diagenetically induced abrupt shifts in values and provide general support to the age interpretations of the formations/sequences.

A Callovian (Middle Jurassic) poriferan fauna from northwestern Jordan: taxonomy, palaeoecology and palaeobiogeography

Abstract The present work describes the first fossil sponge assemblage from Jordan, belonging to Demospongiae and Calcarea; hexactinellid sponges are absent from the collections. Mughanniyyum hanium gen nov., sp. nov. is described, and a new subfamily, Jordaniinae, is proposed, belonging to Scleritodermatidae (Demospongiae). Another new demosponge species, Geoditesia jordaniensis sp. nov., is described on the basis of well-preserved specimens. The genus Geoditesia is previously known only from loose Geodia-type spicules. It is the first description of an articulated sponge bearing this kind of spicule. The assemblage is compared with similar occurrences in the Negev Desert (Israel) and Kachchh Basin (India). While the sponge fauna and the facies represented by the Negev Desert assemblage are very different, in the Kachchh Basin there are sponges present with similar external morphology belonging to related taxonomic groups. The palaeobathymetry of the studied sections from Jordan indicates slightly shallower water than in the Kachchh Basin. There is also slight stratigraphic difference between Jordan and the Indian Basin, in that the Jordanian assemblage is of Callovian age, while in Kachchh it is Bathonian.urn:lsid:zoobank.org:pub:6ED83BB8-E199-47B5-9A11-7B03E2C449F4

A New Stratigraphic Correlation for the Upper Campanian Phosphorites and Associated Rocks in Egypt and Jordan

The Campanian Duwi and Amman phosphate-rich formations, deposited within shallow marine environments in Egypt and Jordan, have been intensely studied due to their economic interest. These deposits belonged to the giant Tethyan phosphorite belt extending from the Caribbean in the west, through North Africa to the Middle East in the east (Notholt in J Geol Soc London 137:805–893, 1980). This province accounts for the greatest known accumulation of marine phosphorites, possibly in excess of 70 billion metric tons of phosphate rocks (Glenn and Arthur in Egypt Sediment 37:123–148, 1990).