Neorotalia omanensis and Operculina musawaensis from the Sultanate of Oman

Two new species of larger benthic foraminifera, Neorotalia omanensis n. sp. and Operculina musawaensis n. sp. are described and illustrated from the eastern Oman Mountains. N. omanensis n. sp. occurs in the Musawa Formation in association with the planktonic foraminifera Morozovella edgari and Truncarotaloides topilensis indicating an early to middle Eocene age (P10-P13). Operculina musawaensis n. sp. occurs in the Abat Formation in association with the planktonic foraminifera Acarinina esnaensis and A. soldadensis indicating an early Eocene age (P6).  This is the first known record showing the presence of genus Neorotalia in the Middle East. Representatives of the larger foraminiferal genus Linderina sp. are also described and illustrated from the Musawa Formation and compared with the published Linderina species in the surrounding countries

The first described Arsinoitherium from the upper Eocene Aydim Formation of Oman: Biogeographic implications

A new fossiliferous locality is discovered from the upper Eocene Aydim Formation, in Dhofar, Southern Sultanate of Oman. A left ulna of Arsinoitherium is described, and cranial and postcranial specimens found in close proximity are referred to the same taxon. The locality is promising for the recovery of additional fossil specimens. Moreover, the presence of Arsinoitherium in Oman is of biogeographic significance; as the Red Sea did not exist during the late Eocene, these large-bodied animals were able to freely travel between what is now the Arabian Peninsula and continental Africa

Microfacies, Biostratigraphy, Depositional Environment, Seismic Refraction and Correlation of Coralline Limestones of the Barzaman Formation (Oligocene-Pliocene? Al-Khod, Muscat Area, Sultanate of Oman): GEOLOGY OF THE BARZAMAN FORMATION

The “Carbonates” unit of the Oligocene-Pliocene Barzaman Formation, north of the Oman Mountains at Sultan Qaboos Campus, is at least 10 m thick. It consists of three coralline limestone beds in (1) bedded facies (base; eastern outcrop), (2) very thick-bedded debris facies (middle; western and eastern outcrops) and (3) bedded facies (top; western and eastern outcrops). These three beds can be correlated between two outcrops over a distance of 160 m based on facies, stratigraphic positions and thickness as well as on a seismic refraction survey. The most common bioclasts are poritid corals, red algae and benthic foraminifers. Dasycladacean algae are common, and, sporadically, small gastropods, bryozoans, echinoderms, echinoid spines, bivalves, worm tubes and ostracods occur. Based on facies analysis we suggest that the studied limestones formed in a lagoon with backreef coral facies and that the barrier that separated the lagoon from the open sea (and which is not exposed) was made of coral reefs. Because of the abundance of coral colonies we assume for the studied coral limestones a water depth within the light saturation zone, not deeper than 10 to 20 m for the lagoon. Based on the occurrence of the following foraminifer genera Praerhapydionina, Archaias, Dendritina, Operculina, Spiroclypeus, Lepidocyclina, Miogypsina, Amphistegina and Subterraniphyllum, the “Carbonates” unit can be dated as upper Upper Oligocene to Lower Miocene. This is the first indication of the Upper Oligocene of the Barzaman Formation for the study area

عناقيد الحديد في تكوين الدمام من العصر الثلاثي السفلي في منطقة دخان : معادن ، جيوكيمياء وظروف ترسيبها

Ferricretes of the Middle Eocene Dammam Formation, Western Qatar, were investigated using petrographic and ore microscopy, IR TGA, XRD, and geochemical analyses. The ferricretes mainly consist of goethite, which is very varigated in habit and texture. Geochemical analyses show that the ferricretes consist of impure chemical sediments, iron hydroxides plus variable amounts of carbonate and siliciclastic materials. The ferricretes resemble with respect to texture, mineralogy and chemistry modem ferrous sediments described as verdine facies. The ferricretes found within the Midra Shale are indicative of a reducing environment of deposition to have occurred during the early Tertiary in the Dukhan Area. These duricrusts may also be used to put some constrains on the climatic conditions as these marine calcareous host rocks gradually emerged during the Late Tertiary and Quaternary.تم دراسة عناقيد الحديد المتواجدة ضمن تكوين الدمام من العصر الايوسيني الأوسط بواسطة المجهر المستقطب والعاكس ، الاشعة تحتا الحمراء، التفاضل الحراري والتحليل الكيميائي . تتكون العناقيد بشكل رئيسي من الجوثيت الذي يوجد على هيئات متعدده وبنيات مختلفة . تدل التحاليل الجيوكيميائية على احتواء الحاقيد على رسوبيات كيميائية، هيدروكسيدات الحديد وكميات مختلفة من الكربونات والمواد السليكاتية . تتشابة العناقيد من الناحية المعدنية والنسيجية والكييمائية مع الرسوبيات الحديدية كما وصفت تحت اسم سحنة النردين . تدل العناقيد الموجودة في طين المدرا على بيئة ترسيب مختزلة خلال العصر الثلاثي في منطقة دخان . كما تدل هذه العناقيد على الظروف المناخية حيث أن الصخور الكلسية الحاوية عليها قد صعدت للأعلى بانتظام خاجل العصر الثلاثي العلوي والعصر الرباعي

Lithostratigraphy and limestone microfacies of the Oligocene lagoonal, coral patch reef‐bearing Maʼahm Beds (South Mawaleh, Oman)

The Oligocene of the eastern area of the Arabian Plate is worthwhile studying due to it being both poorly exposed and understood. This first bed-by-bed lithostratigraphic/microfacies study of the Oligocene coral-bearing Ma’ahm Beds elucidates their depositional environments by analyzing their standard microfacies (SMF). The Ma’ahm Beds are >112 m thick. The basal Unit 1 is ≧22 m thick, dominated by thick-bedded foraminferal wackestones, packstones, and grainstones. Unit 1 evolves from restricted lagoonal conditions (SMF 16) to a transition toward open marine lagoonal conditions. Coarsening-up and thickening-up trends in Unit 1 last into Unit 2, which is 65 m thick, mainly characterized by very thick-bedded floatstones and float- to rudstones. This unit is more coarsely grained and thicker bedded than Unit 1, with prevailing corals and red algae. Unit 2 represents open marine lagoonal conditions (SMF 8). Unit 3 is 25 m thick and defined by alternating of boundstones (SMF 7) and floatstones (SMF 8), the dominant bioclasts being corals. Unit 3 represents an open marine lagoon, and its top contains a coral patch reef complex. The limestones are typically pure as the influx of siliciclastic material was negligible. The corals indicate clean water, lacking high amounts of suspended fines, which is compatible with (1) the slow regional doming of the southerly located Jabal Akhdar and Saih Hatat domes after 30 Ma (low/moderate relief), (2) the absence of the South Asian Monsoon (limited fluvial discharge of fines) and (3) the long-term rise of the eustatic sea level during much of the Oligocene shifting the depocenter landward. The lagoon was likely protected by coral barrier reefs, separated by reef gaps, allowing for an efficient water exchange with the open ocean. The coral patch reefs formed within the lagoon. Based on the scattered outcrop pattern of the Ma’ahm Beds, we suggest that future facies maps of the easternmost part of the Arabian Plate should consider marly deposits as the most widespread Oligocene sediment, while pure limestones (patch reefs and their debris) should represent only small speckles on such maps

Lagoonal Microfacies, Lithostratigraphy, Correlation and Shale Migration of the Basal Middle Eocene Seeb Formation (Rusayl Embayment, Sultanate of Oman)

The study improves the understanding of the basal part of the Eocene Seeb Formation of Oman, informally known as “Unit 1”, in terms of microfacies, lithostratigraphy and shale migration within the context of regional tectonics. We logged four sections bed-by-bed over a distance of 8.3 km, collected samples and analyzed thin-sections as well as XRD samples. For the first time, the microfacies and stratigraphic correlation of the lowermost part of the limestone-dominated Seeb Formation were studied in detail. In the analyzed area, Unit 1 is ~20 to 40 m thick, with the thickness increasing to the SE. In the upper part of Unit 1 is a laterally continuous shale horizon. The limestones of Unit 1 contain mostly packstones and grainstones. The dominant standard microfacies types are SMF 18-FOR and SMF 16. The former is dominated by benthic foraminifera, and the latter by peloids. Both SMFs indicate restricted lagoonal conditions. Foraminifera are common in Unit 1 and indicate a middle Eocene age. Considering the abundance of encountered foraminiferal bioclasts, it appears probable that the lagoon barrier was mainly composed of foraminiferal tests. Gutter casts, slumps and debrites indicate an active, partly unstable syndepositional slope, which was likely initially created by uplift of the Saih Hatat Dome and Jabal Nakhl Subdome. Differential regional uplift due to a more pronounced overall doming in the NW (Jabal Nakhl Subdome) than in the SE (Saih Hatat Dome) explains more accommodation space and greater thickness towards the SE. For the first time, we report visco-plastic shale migration/intrusion within the Seeb Formation, related to a shale horizon of Unit 1. This shale locally migrated as indicated by (1) local thickness variations, (2) detached limestone boulders floating in the shale, (3) limestone beds that have been cut-off by the shale and (4) dragged by the shale (5) an upward shale intrusion/injection which then spread parallelly to bedding similar to a salt tongue and (6) tilting overlying limestones. We suggest that shale migration is related to post-“mid”-Eocene E-W convergence between Arabia and India and to faulting or to the second, late Paleogene/early Neogene, faulting interval of the Frontal Range Fault. The shale horizon in the upper part of Unit 1 is a marker bed, which can be correlated across the study area

Ornithopod and Sauropod Dinosaur Remains from the Maastrichtian Al-Khod Conglomerate, Sultanate of Oman

Fieldwork in the Upper Cretaceous (Maastrichtian) Al-Khod Conglomerates in the Sultanate of Oman led to the discovery of a large bone fragment tentatively identified as a partial distal left humerus of a sauropod and an ornithopod dorsal vertebra. The very fragmentary state of preservation of the dorsal vertebra makes specific attribution difficult, but it shows remarkable similarities to the rhabdodontid dinosaurs Rhabdodon and Zalmoxes