Fayez Ahmad

Jurassic Rhynchonellide Brachiopods from the Jordan Valley

Jurassic rhynchonellide brachiopods from the Jordan Valley are herein revised and new taxa are added to the faunal list. In this study of Jurassic rhynchonellides from Wadi Zarqa, northwestern Jordan, we recognize the following taxa: Eurysites rotundus, Cymatorhynchia quadriplicata, Daghanirhynchia triangulata, D. angulocostata, Pycnoria magna, Schizoria elongata, and Schizoria cf. intermedia. The following new taxa are described: Daghanirhynchia susanae sp. nov. and Amydroptychus markowitzi sp. nov. The Middle Jurassic Mughanniyya Formation of northwest Jordan is dominated by limestone beds. The sedimentary environment is interpreted as neritic, light, and nutrient-rich resulting in high faunal diversity. The high rhynchonellide endemism of this fauna is yet another confirmation of pronounced Middle Jurassic endemism along the southern Tethyan margin of the Ethiopian Province. Brachiopods of the Jordanian Mughanniyya Formation can be correlated with the fauna of the Aroussiah Formation in Sinai and the Zohar and Matmor formations in Southern Israel.

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.

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.

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.

Karst development related to extensional fracture network at Bany-Kanana area, northern Jordan

The study area lies east of the northern segment of the Dead Sea Transform (DST), within the Jordan valley active strike-slip fault system. The exposed rocks in the study area consist of Upper Cretaceous to Cenozoic carbonates and cherts. This study concentrated on detailed field measurements of the various structural elements such as extensional fractures, normal faults, and strike-slip faults, with a total of 1,976 measurements. The predominant trends of all fractures (faults and joints) in the study area are N-S, NNW-SSE, and NW-SE with steep dips and characterized by sinistral and extensional modes of deformation. The NNW to NW trend has the same general trend of the water flow path in the study area. Normal and strike-slip conjugate and hybrid fracture sets with different acute dihedral angles and steep dips were observed in the study area. These fractures connect with the vertical extensional fractures in the same stratigraphic level. In addition, the interconnected orthogonal fracture systems with bedding parallel fractures play a major role conducting fluid movement and therefore, in initiation of karst development in the study area. These fractures network were enlarged by water dissolution forming small caverns.

A Jurassic (Bathonian-Callovian) Daghanirhynchia brachiopod fauna from Jordan

A Jurassic (Bathonian-Callovian) brachiopod fauna from Jordan consists of seven rhynchonellid species all belonging to the genus Daghanirhynchia of which two are new: Daghanirhynchia rawyaensis and D. jordanica. Emended diagnoses are given for Daghanirhynchia daghaniensis and D. macfadyeni. Additional taxa described include Daghanirhynchia angulocostata, D. susanae and D. triangulata. Threedimensional reconstructions illustrate the internal morphology of the articulated shells for the first time in this genus. The material studied herein was collected from Wadi Zarqa in northwestern Jordan, almost due north of the Dead Sea, and to the east of the Rift Valley. Most species seem to be geographically restricted within the Jurassic Ethiopian Province, however specimens from Somalia and Ethiopia are larger in size than in other parts of the Province and shell size increases in stratigraphically younger specimens. The occurrence of Daghanirhynchia in India is the only appearance of the genus outside the Ethiopian Province.

Talexirhynchia , a new rhynchonellid genus from the Jurassic Ethiopian Province of Jordan

A new genus and species of a rhynchonellide brachiopod from the Jurassic of Jordan, Talexirhynchia kadishi gen. et sp. nov., is described. The specimens were collected from the Mughanniyya Formation (Callovian) of Wadi Zarqa from alternating claystones, siltstones, and marly limestones with minor dolomite, dolomitic limestone, and coquinas that represent the upper part of the Jurassic sequence in Jordan. The environment of deposition was neritic; food supply and light were unlikely to have been limiting factors. The specimens are related to Ethiopian-Somali taxa and are consistent with the endemism that characterizes the rhynchonellide brachiopod faunas of the Jurassic Ethiopian Province. Specimens of Talexirhynchia lived with the umbo in an upright position directed toward the seafloor or with the dorsal valve slightly above the ventral valve. Juveniles were attached to the seafloor by the pedicle; carbonate shell material as well as other debris scattered on a limy substrate, such as shells and rocks, could have served as an attachment site for juveniles. With increasing growth, the loss of the pedicle and a semi-infaunal position resulted in an increasingly incurved ventral umbo that concealed the foramen.KurzfassungEine neue rhynchonellide Brachiopoden-Gattung und––Art, Talexirhynchia kadishi gen. et sp. nov., aus dem Jura von Jordan wird beschrieben. Die Exemplare wurden in der Mughanniyya Formation (Callovium) von Wadi Zarqa gesammelt und kommen in abwechselnden Lagen von Tonsteinen, Siltsteinen und mergeligen Kalken mit geringen Anteilen an Dolomiten, dolomitischen Kalken und Coquinas vor, die die jüngsten jurassischen Ablagerungen Jordaniens repräsentieren. Die Schichten wurden in neritischer Fazies abgelagert, die wahrschein reich an Nahrungsangebot und Licht durchflutet war. Die gesammelten Exemplare sind mit äthiopischen-somalischen Taxa verwandt und spiegeln den Endemismus wieder, der die rhynchonellide Brachiopodenfauna der jurassischen Äthiopischen Provininz charakterisiert. Vertreter von Talexirhynchia leben in senkrechter Position mit der Dorsalklappe gering höher als die Ventralklappe und dem Wirbel zum Meeresboden hin gerichtet. Juvenile Exemplare waren mit dem Stiel an Schalenmaterial und anderem Schuttdebris, z.B. Schalen oder Steine, der auf dem Meeresboden verteilt vorlag, festgehaftet. Mit zunehmender Größe änderte sich die Lebensweise in eine semi-infaunale Position, die zu einem Verlust des Stieles und eines ständig weiter gebogenen ventralen Wirbels bis hin zu vollständigen Bedeckung des Stiellochs, führte.

Correlation of the Middle Jurassic (Callovian) Formations Across the Dead Sea Rift

We have correlated the highest of the Middle Jurassic units exposed on both sides of the Dead Sea Rift (DSR) in Jordan, Israel, and adjacent Egypt. Because the scarcity of cosmopolitan ammonites renders correlation of these units within the standard biostratigraphic time scale difficult, we compared the brachiopod and molluscan faunas in order to constrain the ages of Jurassic formations in the Levant. The Callovian Mughanniyya Formation in the Zarqa–Arda area of northwest Jordan, east of the DSR, is compared with the Zohar and Matmor formations of the Negev (Israel) and Gebel Minshera (Sinai, Egypt), west of the DSR, as well as with the Arroussiah Formation of Gebel El-Maghara (northern Sinai, Egypt). The Mughanniyya Formation is correlative with the lowermost part of the Zohar Formation in the Negev, which is coeval with the lowermost part of the Arroussiah Formation in Sinai (Egypt).

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).