bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrocarbon plays and prospectivity of the Levantine Basin, offshore Lebanon and Syria from modern seismic data
Authors: Roberts Glyn , Peace David 
Published: October 2021

ABSTRACT
The Levantine Basin is located in the easternmost region of the Mediterranean Sea between Cyprus and the Nile Delta marine cone in Egypt. Based on an analysis of more than 20,000 line-km of 2-D seismic data, the basin appears to contain up to 10,000 metres of Mesozoic and Cenozoic rocks above a rifted Triassic-Lower Jurassic terrain. Although many hydrocarbon discoveries have been made in the Nile Delta and the near-offshore areas in the southeastern Mediterranean Sea, no exploration wells have been drilled in its deep offshore or anywhere offshore Lebanon, Syria and Cyprus. Widespread occurrence of oil seeps (over 200) that closely correlate to hydrocarbon indication on seismic (e.g. bright spots and gas chimneys associated with possible migration pathways) suggest that the undrilled parts of the Levantine Basin can be prospective. Thirteen potential exploration plays are identified in this study and illustrated with seismic examples. The plays range in age from the Triassic to the Neogene-Pliocene.
Microfacies and sequence stratigraphy of the Late Campanian Bekhme Formation in the Dohuk area, north Iraq
Authors: Al-Mutwali Majid M. , Al-Banna Nabil Y. , Al-Ghrear Jamal S. 
Published: October 2021

ABSTRACT
The Bekhme Formation represents the lower part of a regional Upper Cretaceous (Campanian - Maastrichtian) succession that was deposited over most of Iraq and adjacent regions. The formation unconformably overlies the Qamchuqa Limestone Formation (Hauterivian-Albian) and is overlain by the Shiranish Formation (Upper Campanian - Maastrichtian). Northeast of the city of Dohuk, an incomplete, but well-exposed, section of the Bekhme Formation crops out in a 75-m-thick section that formed the basis for our study. Twenty-five samples were collected from the section and used for biostratigraphic and microfacies analysis. The study of planktonic foraminifera resulted in the recognition of two Campanian biozones: the Globotruncanita calcarata Zone and the Globotruncanita stuartiformis–Globotruncanita stuarti Zone, both considered to be of Late Campanian age. Three main microfacies were distinguished throughout the formation, which represent middle-shelf, outer-shelf and upper-bathyal environments. Sequence stratigraphic analysis, as calibrated by microfacies, delineated five depositional sequences of probable fourth-order, thus suggesting the studies section was deposited in about 2.0 million years and represents an overall third-order sequence.
A new upper Oligocene marine record from northern Sinai (Egypt) and its paleogeographic context
Authors: Kuss Jochen , Boukhary Mohamed A. 
Published: October 2021

ABSTRACT
The upper Oligocene Wadi Arish Formation is composed of a carbonate-dominated succession at Gebel Risan Aneiza (Sinai). The 77-m-thick unit disconformably overlies Jurassic to lower Cretaceous carbonates and is subdivided into three members, comprising six lithofacies units. The lower Wadi Arish member contains three units, a gypsiferous sandstone unit (Oa), overlain by two limestone units (Ob and Oc). The middle Wadi Arish member is represented by a conspicuous marl unit (Od) that is overlain by two upper limestone units (Oe and Of) of the upper Wadi Arish member. We discuss the euphotic subtidal depositional environments in conjunction with macro- and microfacies characteristics. Six microfacies types are defined, dominated by grain associations of rhodoliths, larger benthic foraminifera (rotaliids), corallinaceans, bivalves, peloids, few corals, and bryozoans. They characterize rhodalgal associations, common in non-tropical warm-temperate settings. Biostratigraphy is based on larger foraminifera. The middle Wadi Arish member corresponds with SB 23 (Chattian) and may correlate with Pg50, a regional maximum flooding surface. Our sequence stratigraphic interpretations define a late lowstand to early transgressive systems tract (lower Wadi Arish member), a late transgressive systems tract (middle Wadi Arish member), while the upper Wadi Arish member reflects highstand conditions. The paleogeographic setting and sequence stratigraphic interpretation of this unique upper Oligocene outcrop is placed in context of the northeast African-Arabian region.
Evolution of fractures in a highly dynamic thermal, hydraulic, and mechanical system – (I) Field observations in Mesozoic Carbonates, Jabal Shams, Oman Mountains
Authors: Holland Marc , Urai Janos L. , Muchez Philippe , Willemse Emanuel J.M. 
Published: October 2021

ABSTRACT
We studied an exhumed high-pressure cell in outcrops of Cretaceous carbonates on the southern flank of Jabal Shams in the Oman Mountains. This more than 2 km thick sedimentary pile contains reservoir and source rocks in northern Oman and the United Arab Emirates. It develops a complex and rapidly changing anisotropy, due to mechanical stratigraphy and several generations of pervasive regional fault and fracture sets. Calcite cement healed faults and fractures before the next sets were formed.
Burial extension within a high fluid-pressure environment led to the formation of four fracture generations by an anticlockwise rotating stress field. This was followed by bedding-parallel shear under lithostatic fluid-pressure conditions at a minimum temperature of 134–221°C deduced from primary and pseudosecondary fluid inclusions in quartz. The high pressure cell was drained along dilatant normal faults that were also repeatedly cemented and reactivated.
The rapidly changing mechanical anisotropy, in combination with a chemically reactive system formed a complex feedback system in which the mechanical strength, strain and the permeability underwent major changes in this coupled thermal, hydraulic, and mechanical (THM) system.
Diagenetic and epigenetic alteration of Cretaceous to Paleogene organic-rich sedimentary successions in northwestern Jordan, typical of the western margin of the Arabian Plate
Authors: Dill Harald G. , Kus Jolanta , Abed Abdulkader M. , Sachsenhofer Reinhard F. , Khair Hani Abul 
Published: October 2021

ABSTRACTFour reference sections through the calcareous-siliciclastic rocks of the Lower Cretaceous Kurnub Group and the Amman and Muwaqqar formations of the Upper Cretaceous to Paleogene Belqa Group in Jordan document the various processes of accumulation and alteration of organic matter (OM). Sections at Jerash, Sultani, Wadi Isal, and in the Kharazeh area were investigated by means of sedimentary petrography/mineralogy, organic petrography, and organic chemistry, and correlated with equivalent deposits in Syria and Egypt. The impacts of oxidation potential (Eh), acidity/basicity (pH) and temperature variations during the post-depositional alteration of these organic concentrations were assessed using x-y plots. Syngenetic Aptian-Albian coaly and organic-rich amber beds near Jerash developed in a tide-dominated delta under marginally alkaline conditions and were altered under slightly acidic conditions at temperatures of less than 100°C. Environmental analysis focused on Maastrichtian-Paleocene (?), oil shales in the Sultani area that were deposited in a small restricted basin on the continental shelf of the Neo-Tethys Ocean. Abnormally high contents of vanadium (V), phosphorus (P), zinc (Zn), and uranium (U) gave rise to yellow uranium ore minerals, phosphates and zinc sulfides and so bridge the gap between OM concentrations and those of uranium. The western part of the Arabian Peninsula is known for its uraniferous phosphorites and U-bearing calcretes. Reducing conditions during deposition of syngenetic OM in the oil shales may have shifted, in places, toward more oxidizing conditions in the course of post-depositional alteration at temperatures well below 200°C. Epigenetic fault-related concentration of OM was responsible for the Wadi Isal Aptian-Albian tar sand deposit and the oil seepage system in calcareous wall rocks of the Kharazeh Fault. The alteration of the tar sands (fluvial sandstones) is designated a high-sulfidation type (introduced aluminum sulfate minerals), whereas the oil seepage in Campanian shallow-marine carbonates is a low-sulfidation type (removal of aluminum sulfate minerals). Both alteration patterns may have implications for structure-bound base- and precious-metal deposits whose emplacement involves hydrocarbons as a carrier of metals in the mineralizing fluids. The Jordanian oil shales, tar sands, and uranium mineralization are possible sources of energy. Recent economic deals on the recovery and use of oil shales and uranium in Jordan are reviewed.
Subsidence history, gravity anomalies and flexure of the United Arab Emirates (UAE) foreland basin
Authors: Ali Mohammed Y. , Watts A. B. 
Published: October 2021

ABSTRACT
Seismic reflection profile, gravity anomaly, and exploratory well data have been used to determine the structure and evolution of the United Arab Emirates (UAE) foreland basin. The basin is of tectonic significance because it formed by ophiolite obduction in the northern Oman Mountains and flexural loading of an underlying Tethyan rifted margin. Existing stratigraphic data shows that this margin is characterised by an early syn-rift sequence of mainly Triassic age that is overlain by a post-rift sequence of Lower Jurassic to Upper Cretaceous age. Backstripping of the well data provides new constraints on the age of rifting, the amount of crustal and mantle extension, and the flexural effects of ophiolite load emplacement. The tectonic subsidence and uplift history at the wells can be generally explained by either a uniform extension model with an initial age of rifting of 210 Ma and a stretching factor, β, of 2.5 or a depth-dependant extension model with crustal extension factor of, γ, 1.3 and a mantle extension factor, β, of 2.5. While both models account for the general exponential decrease that is observed in the tectonic subsidence and uplift between 210 Ma and 95 Ma, we prefer the depth-dependant model because the depth-to-Moho that is implied better accounts for the increase that is observed in the regional Bouguer gravity anomaly between the UAE foreland and the Oman coastline. However, there are discrepancies, which we attribute to uncertainties in palaeobathymetry, sea level, and stratigraphic ages. Irrespective, the backstrip curves suggest that there was a significant thinning of the continental crust prior to ophiolite emplacement. The timing of emplacement cannot be constrained precisely, but the backstrip curves suggest that ophiolite loading and foreland basin flexure was initiated during the Late Cretaceous. The basin shape can be explained by a simple model in which both surface (i.e. topographic) and subsurface (i.e. ophiolitic) loads were emplaced on a lithosphere with an effective elastic thickness, Te´ of c. 20–25 km. This Te is similar to what we would expect for loading of extended continental lithosphere 80 My after a rifting event. It predicts a c. 4 km flexural depression and a few hundred metres flanking bulge that is presently located beneath the Abu Dhabi region. The bulge is obscured, however, by at least 2 km of sediment, possibly because of an increase in accommodation space due to dynamic effects associated with the subduction of the Arabian Plate beneath the Eurasian Plate.
Ichnology as a tool in carbonate reservoir characterization: A case study from the Permian – Triassic Khuff Formation in the Middle East
Authors: Knaust Dirk 
Published: October 2021

ABSTRACTIn the Upper Permian to Lower Triassic Khuff Formation in the Arabian Gulf, a vast shallow-marine carbonate platform developed broad facies belts with little significant changes in the lithofacies. However, trace fossil assemblages and ichnofabrics, in combination with sedimentological observations, serve in subdividing this platform and in distinguishing sub-environments. From proximal to distal, these are sabkha and salina, tidal flat, restricted lagoon, open lagoon, platform margin, shoreface/inner ramp, slope/outer ramp and basin/deeper intra-shelf. In this way, changes in relative sea level can be better reconstructed and guide the sequence stratigraphic interpretation. Meter-scale shallowing-upward cycles dominate the succession and, in addition to conventional methods, bioturbation, trace fossil assemblages and tiering patterns aid in interpreting subtidal, lower and upper intertidal and supratidal portions of these peritidal cycles. Bioturbation (and cryptobioturbation) have an impact on the primary reservoir quality before diagenetic processes overprint the deposits. For instance, deposit-feeders (such as vermiform organisms) introduce a certain amount of mud and decrease porosity and permeability considerably, whereas others like the Zoophycos-producers fill their dwellings with ooid grains and turn a mudstone from a barrier to a flow unit. This novel study demonstrates the value of ichnological information in carbonate reservoir characterization and the significance of trace fossil analysis in facies interpretation, reservoir zonation and the impact of bioturbation on the reservoir quality.
Biogenic silica microfossils in sediments of the Permian – Carboniferous Unayzah Formation, Saudi Arabia
Authors: Garming Johanna F.L. , Franks Stephen G. , Cremer Holger , Abbink Oscar A. 
Published: October 2021

ABSTRACT
Biogenic silica particles (BSPs) have been discovered in sediments of the Permian – Carboniferous Unayzah Formation of Saudi Arabia. The BSPs are extracted from sediments that are generally barren of macro- or microfossils. BSPs have been found in the Basal Khuff Clastics (BKC), and the Unayzah A, B, and C members, that were sampled in six different wells over a large geographic area. More than 3,500 BSPs have been identified in 83 samples examined and have been classified into 14 different BSP morphotypes. Furthermore, three outcrop samples of the Permian – Carboniferous Al Khlata and Gharif formations of Oman were analysed. Herein seven BSP morphotypes were identified. For comparison of the Paleozoic BSPs with modern analogues, recent plant material from the Rub’ Al Khali Desert was studied. The presence of BSPs in Paleozoic deposits and their morphological difference is encouraging. Variations in morphotype abundance and occurrence may ultimately provide a means of subdividing and correlating the Unayzah Formation. Research presently underway is testing the distribution of morphotypes in terms of stratigraphic position, depositional facies, and paleoclimatic setting.
Orbital-forcing glacio-eustasy: A sequence-stratigraphic time scale
Authors: Matthews Robley K. , Al-Husseini Moujahed I. 
Published: October 2021

ABSTRACTThis essay provides further explanation of the mathematical details of orbital forcing and glacio-eustatic modeling (Parametric Forward Modeling, PFM) aspects and applications. A slight tune-up of the Earth’s eccentricity calculations (LA04 of Lasker et al., 2004) produces a near-perfect repeat of 14.58 million-year period and allows PFM to predict the glacio-eustatic component of sea-level fluctuation throughout the Phanerozoic. Generalities of an exploratory grid search of the parameter space of the model are reviewed and repetitive peak sea levels and low sea levels are noted in context of the Arabian Orbital Stratigraphy (AROS) terminology and time scale. Emphasis on the straton (405,000 year “tuning fork” of stratigraphic time) will lead to improvements in sequence-stratigraphic methods and results.
Late Albian, Cenomanian and Turonian Natih Supersequence of Oman: Type section for Orbiton 7 (103.6–89.0 Ma)
Authors: Al-Husseini Moujahed I. 
Published: October 2021

ABSTRACT
The Upper Albian, Cenomanian and Turonian Natih Formation in Oman was interpreted by previous authors in terms of the regional Natih I to V depositional sequences comprising 34 higher-order subsequences (referred to as the Adopted Interpretation in this paper). It mainly consists of limestones, and is separated from the underlying Albian shales of the Nahr Umr Formation by the Natih Sequence Boundary. The interpreted position of the Cenomanian Stage within the formation differs substantially depending on carbon-isotope and/or biostratigraphic data (ammonite, microfaunal and nannofossil). The top of the Natih Formation is a regional subaerial exposure surface (incised by channels with depths reaching 150–200 m) that was transgressed by Lower Coniacian marine shales (Muti Formation at outcrop, and Shargi Member of the Fiqa Formation in subsurface; Fiqa Transgression above the Fiqa Sequence Boundary). Over paleohighs the lower part of the Fiqa, Natih and older formations are eroded by the Campanian angular Intra-Fiqa Unconformity that is attributed to far-field compressional tectonism along the margins of the Arabian Plate.
The paper tunes the 34 Natih subsequences (each named a Straton) at 405 Ky/cycle: the period of the long-eccentricity signal of the Earth’s orbit. They are dated using a time scale that is based on an orbital-forcing model of glacioeustasy, which consists of ca. 14.58 My (36 stratons) repeating, orbital cycles named orbitons. Orbitons are predicted to be separated by major glacio-eustatic lowstands (regional sequence boundary), with Orbiton 1 spanning ca. 16.1 to 1.5 Ma. The Natih Formation completely falls within Orbiton 7 (ca. 103.6–89.0 Ma) in the Late Albian – Turonian time interval of the Geological Time Scale of the International Commission on Stratigraphy (GTS). The Formation consists of only 34 subsequences (compared to the 36 predicted for a complete orbiton). This implies two stratons are represented by a hiatus (ca. 810 Ky) between ca. 89.8–89.0 Ma near the end of Orbiton 7 and the Turonian/Coniacian boundary (88.6 Ma in GTS). The hiatus corresponds to a Late Turonian – ?earliest Coniacian biostratigraphic break at the Sub-Fiqa Unconformity and is correlated to a model-predicted major polar glaciation and sea-level lowstand. The hiatus is unrelated to the structural deformation in Interior Oman (First Alpine Event), which started some 10 My later in Campanian time. Orbiton 7 (ca. 103.6–89.0 Ma) correlates by architecture (sequence boundaries and maximum flooding surfaces) and age to the global Late Albian – Turonian UZA 2 Supersequence inclusive of the shortlived 100+ m sea-level drop in latest Turonian (ca. 102.5–88.6 Ma in empirical time scale). The Formation is proposed as the Natih Supersequence and the type section of Orbiton 7.
Seal turns into reservoir: Sudair equivalents in outcrops, Al Jabal al-Akhdar, Sultanate of Oman
Authors: Pöppelreiter Michael C. , Schneider Christoph J. , Obermaier Michael , Forke Holger C. , Koehrer Bastian , Aigner Thomas 
Published: October 2021

ABSTRACT
The Lower Triassic Sudair Formation represents the deposits of an epeiric carbonate-evaporite-siliciclastic platform. It is widely known as top seal for the underlying Khuff reservoir in some of the largest hydrocarbon accumulations in the world (e.g. the North Dome and the Ghawar field). Towards the seaward edge of the platform however, in northeast Oman for example, the sealing anhydrites and shales pinch out. Dolomite layers turn increasingly grainy, forming up to 8 m-thick individual grainstone bodies. Thus, on a regional scale, a top seal turns laterally into a potential reservoir. This paper outlines facies, depositional environment and stratigraphic architecture of the Middle Mahil Member, the outcrop equivalent of the Sudair Formation in northeast Oman.
The Middle Mahil, some 260 m thick, is made up of just a few facies types: argillaceous, muddy, microbially-laminated, graded, and cross-bedded dolomites. These represent tidal flat, backshoal and shoal environments. Facies are arranged in regular sequences; the smallest units being 2–5 m thick cycles. A clear hierarchical organization of sequences is apparent with bundling of 4–8 cycles into cycle sets, and 2–3 cycle sets forming depositional sequences. The lower third of the Middle Mahil is dominated by rather muddy textures, the middle part is grain-dominated and the upper part again is muddier with a higher percentage of microbial laminites. The maximum grainstone thickness is observed in the middle of the Middle Mahil, at the interpreted zone of maximum flooding.
Overall the Middle Mahil shows “layer-cake” type architecture over distances of 4–8 km. Grainstone layers are laterally continuous at this scale. Pinching and swelling geometries of grainstones are widespread. Grainstones gradually increase in thickness towards the northeast, the direction of the seaward platform edge. Mapping of Middle Mahil grainstones suggest excellent reservoir potential in such platform margin settings. The observations from Oman provide a calibration point to explorationists targeting the Lower Triassic carbonate sequence in the Middle East.
Heavy mineral stratigraphy of Palaeozoic and Mesozoic sandstones of southwestern Sinai, Egypt: A reassessment
Authors: Knox Robert W.O’B. , Soliman Mamdouh F. , Essa Mahmoud A. 
Published: October 2021

ABSTRACT
Improved methods of analysis and quantification of heavy mineral assemblages in Cambrian to Early Cretaceous sandstones of southwest Sinai have revealed successive changes in provenance that reflect both rejuvenation of the Arabian Shield and changes in the topographic configuration of the source area. Three mineral units have been identified in the Cambrian succession, at least three in the Carboniferous and three in the Cretaceous. It is predicted that the genetic units defined by these successive changes in mineralogy will be of regional extent and thus assist in elucidating the history of uplift of the Arabian-Nubian Shield and provide a better means of correlating sandstone units into adjacent areas. Variation in the abundance of apatite in the Cambrian succession is independent of provenance signature and is interpreted as reflecting alternating dry and humid climatic conditions.
Stratigraphic Note: Update on the palynology of the Akbarah and Kuhlan formations, northwest Yemen
Authors: Stephenson Mike H. , Kader Al-Mashaikie Sa’ad Zeki A. 
Published: October 2021

SUMMARY
Following a preliminary palynological report of two samples from the lower part of the Kuhlan Formation (Unit A) near Kuhlan village, northwest Yemen (Stephenson and Al-Mashaikie, 2010), a further seven samples from Unit A, and an additional 22 samples from the underlying Akbarah Formation in the same locality are reported. The seven new samples from the Kuhlan Formation support the 2165A to 2141A Biozone age originally suggested by Stephenson and Al-Mashaikie (2010), and the new Akbarah Formation samples suggest an age not markedly different since Anapiculatisporites concinnus and Spelaeotriletes triangulus are also present in the Akbarah Formation (e.g. samples AK-11 and AK-12). This correlation confirms that the lower Kuhlan Formation and the Akbarah Formation, are likely to be late Carboniferous in age and equivalent to the lower parts of the Al Khlata Formation of Oman.