bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accommodation zones and tectono-stratigraphy of the Gulf of Suez, Egypt: A contribution from aeromagnetic analysis
Authors: Farhoud Khamis 
Published: October 2021

ABSTRACT
This paper starts with an up-to-date literature review of the pre-rift, syn-rift and post-rift stratigraphy of the Gulf of Suez. The geometry and depth of the Proterozoic basement is not generally known due to poor seismic images below the Upper Miocene evaporites (including massive rock salt) and clastics. The pre-rift Paleozoic to Early Oligocene succession shows that several local basins (c. 10s of km in extent) occur in the Gulf, with thick sedimentary sections (e.g. c. 3,000 m for Paleozoic and 1,000 m for Jurassic and Lower Cretaceous). The origin and distribution of these basins is not well understood and the presence of similar pre-rift basins in the southern Gulf is not known to occur. The syn-rift Late Oligocene to Middle Miocene and post-rift Late Miocene – Pliocene successions are widely distributed within the rift basin and reach a thickness in excess of 5,000 m.
In order to visualize the grain and relative relief of the Proterozoic basement, a series of aeromagnetic images are shown in this paper. The images include Total Magnetic Intensity (TMI), Reduced-to-Pole (RTP), filtered regional and structural RTP, and Second Vertical Derivative (SVD). The paper also shows a three-dimensional visualization image of the magnetic basement that highlights the distribution of the basins in the Gulf. The magnetic lows do not generally trend along the Suez (NNW-trending Clysmic) Fault, but instead show highly variable orientations attributed to a complex pattern of criss-crossing faults. In particular, two areas were selected to interpret the geometry and depth of the basement. The first area covered the northern Zaafarana Accommodation Zone and involved modeling five aeromagnetic profiles. The Zone was interpreted as an EW-trending basement plateau bounded by basins that are c. 8,000 m deep. The second modeled area (four profiles) covered the southern Morgan Accommodation Zone. This zone was interpreted as an ENE-trending plateau of similar relief to the Zaafarana Zone. The Morgan Zone is terminated in the eastern Gulf by the 8,000-m-deep Morgan Basin. The very deep basins surrounding the two plateaus may contain both pre-rift and syn-rift source rocks, from which the numerous surrounding petroleum fields were sourced.
Overview of the Triassic System in Syria: Lithostratigraphic and biostratigraphic correlations with neighboring areas
Authors: Mouty Mikhail , Gout Claude 
Published: October 2021

ABSTRACT
Biostratigraphic data provide evidence of the presence of Triassic sedimentary successions in the main mountain belts in Syria. The study of the sedimentary successions in these chains and in the main deep wells lead to a new subdivision of the Triassic in Syria into four lithological units/formations: (1) The lower Habari Formation is clastic and Scythian to Early Anisian in age. (2) The overlying Abu Fayad Formation is generally carbonaceous, Late Anisian to Ladinian in age, and subdivided into three members. (3) The Hayan Formation is mainly evaporitic and Carnian – Norian in age. (4) The upper Safa Formation is generally carbonaceous, with some marl intercalations and thin evaporite beds. and Norian to ?Rhaetian in age. These lithological formations extend over the entire northern Arabian platform with very characteristic and distinguishable facies, rendering their correlation within Syria and to their equivalents in neighboring countries straightforward. Moreover, lateral facies changes in these formations enabled establishing a geological and paleogeographical evolution of Syria and the surrounding areas during the Triassic Period. This evolution revealed the presence of two NE-elongated Triassic paleostructures: Hamad Uplift in the south and Aleppo-Mardine High in the north, which separate the Palmyride Basin from the Rutbah Basin in the south, and the Palmyride Basin from the Ifrine Basin in the north, respectively.
New age for the lower part of the Kuhlan Formation, northwest Yemen
Authors: Stephenson Mike H. , Al-Mashaikie Sa’ad Zeki A. Kader 
Published: October 2021

abstract
The siliciclastic beds outcropping around the village of Kuhlan, northwest Yemen were originally designated the Kohlan Series. Later the sandstone part of the sequence was renamed the Kuhlan Formation by the Yemeni Stratigraphic Commission. The lower part of the Kuhlan Formation (Unit A) yielded diverse and well-preserved palynological assemblages. Their quantitative character and the presence of Anapiculatisporites concinnus, Brevitriletes cornutus, B. parmatus, Deusilities tentus, Dibolisporites disfacies, Microbaculispora tentula, Spelaeotriletes triangulus and Verrucosisporites andersonii, suggests a confident correlation to the 2165A to 2141A biozones of southern Oman, and to Arabian OSPZ2, indicating a Late Carboniferous age for the unit rather than the Late Triassic to Early Jurassic age given on the geological map of western Yemen. The date for the lower Kuhlan Formation indicates that the underlying Akbra Formation, which was previously dated as possibly Early Permian, and Late Carboniferous to Early Permian in age respectively, is probably not younger than the 2165A Biozone and therefore likely to be equivalent to the lower parts of the Al Khlata Formation of Oman.
GeoArabia’s Infracambrian Debate: Cryogenian versus Ediacaran Models
Authors: Al-Husseini Moujahed I. 
Published: October 2021

ABSTRACT
The Middle Eastern Infracambrian Debate offers specific choices between profoundly different tectono-stratigraphic models that have important scientific and petroleum exploration implications worldwide. A crucial first step in the Debate is choosing between the interpretations of zircon geochronology (Cryogenian Model) or regional chrono-stratigraphy based on much younger age-dating by alternative radiometric techniques (e.g. K-Ar, Rb-Sr, Ar/Ar; Ediacaran Model). The interpretation of zircon geochronology implies Oman’s oldest diamictites of the Abu Mahara Group represent the Sturtian (ca. 720–700 Ma) and Miranoan (ca. 663–636 Ma) glaciations of the Cryogenian Period (850–630 Ma) separated by the ca. 50 My Fiq-Ghubrah Hiatus. The Cryogenian Model implies three phases of rifting in the same regions between ca. 723–530 Ma, and another younger but disputed ca. 30–40 My Shuram-Khufai Hiatus occurring in a tectonically quiescent platform setting (post-glacial Nafun Group’s fine clastics and carbonates).
This combined essay and book review of Global Neoproterozoic Petroleum Systems disputes the interpretation of zircon geochronology to establish absolute time for Oman’s oldest rocks. It argues for the single-rift-without-hiatus Ediacaran Model based on ages of basement and volcanic rocks using alternative radiometric techniques in Jordan, Oman and Saudi Arabia. Oman’s Hadash Formation and coeval Mirbat Cap Carbonate are believed to provide an important correlative marker that recorded the start of the great sea-level rise of the Nafun Transgression at ca. 572 Ma, not 636 Ma. The Transgression was due to the melt-out of the late Ediacaran Varanginian Glaciation (represented in Oman by the diamictites of the Ayn, combined Fiq-Ghubrah and subsurface Ghadir Manqil formations, all of the Abu Mahara Group, deposited between ca. 585–572 Ma), not the Sturtian and Miranoan glaciations. The deep-marine organic-rich shales and siliciclastics of Oman’s Masirah Bay Formation (coeval Arkahawl Formation of Mirbat Group) are syn-rift and reflect the Nafun Transgression spilling beyond the rift basins and their surrounding lowlands. As proposed in the Middle East Geologic Time Scale 2010 and GeoArabia’s Infracambrian Debate, the time interval ca. 585–530 Ma can best be cast in terms of transgressive-regressive chrono-sequences in a regional tectono-stratigraphic extensional framework.
Structural evolution of the Hawasina Window, Oman Mountains
Authors: Csontos László , Pocsai Tamás , Sasvári Ágoston , Palotai Márton , Árgyelán-Bagoly Gizella , Fodor László I. , Magyari Árpád , Al-Wardi Mohammed 
Published: October 2021

ABSTRACT
This paper presents field observations and measurements from the Hawasina Window, Oman Mountains. An updated geological map is based partly on previous publications and four NEtrending cross-sections. Along each cross-section key structural features are described, illustrated and interpreted. Based on these (and other) observations several differences between our interpretation and the former published geological maps and cross sections were noted as follows.(1) Late Cretaceous original (Hamrat Duru; Haybi) nappes that formed during intra-oceanic obduction underwent out-of-sequence thrusting beneath the Semail thrust. The repetitions of the nappe complexes are out-of-sequence because: (a) repetition of original nappe packages; (b) the presence of Haybi-derived lenses along boundaries between two Hamrat Duru nappes; (c) the presence of sheared serpentinite in the same nappe boundaries. The Hamrat Duru and Haybi nappes are repeated three times.(2) The tectonic boundaries of the Hawasina Window are steep, normal- or strike-slip faults, unconformable to, and cutting the original nappe boundaries. A main strike-slip corridor at the southern edge of the Hawasina structure was mapped. The northern edge is a top-north thrust.(3) Ductile-brittle extension created mega-boudins of preserved nappe units and areas where complete nappe units are missing. Extension is present in Sumeini and Hamrat Duru units; therefore it is post-out-of-sequence thrusting.(4) Two main antiforms were recognised inside the Hawasina Window (Jabal Rais and its northward and southward continuations in Hamrat Duru units, and Jabals Mawq - Matid). Several folding phases were recognised and the two antiforms are the result of interference. A main, sub-horizontal axial plane, syn-regional cleavage folding is present in the whole Window. This folding gives top NE or N regional shear.(5) Structural dips of regional cleavage suggest a major NW-striking dome beneath the Hawasina Window. This dome would correspond to the upwarp of the Autochthon, similar to Al Jabal al-Akhdar. In the southern zone of this dome we observed several occurrences of small gypsum diapirs. The best outcrops of these features are in the Wadi ad Dil-Wadi Hawasina area, where the evaporite bodies rise from beneath the Hawasina nappes. We suggest that they originate from the underlying Arabian Platform, or they form the basal detachment of the Sumeini units.
Our observations are fit into a proposed deformation scenario resulting from plate-tectonic events occurring at the Arabian Plate margin during Cretaceous – Tertiary time.
Oligocene stratigraphy in the Sinjar Basin, northwestern Iraq
Authors: Al-Banna Nabil Y. , Al-Mutwali Majid M. , Ismail Nawzat R. 
Published: October 2021

ABSTRACTThe distribution of the Oligocene succession (basinal and reef–back-reef deposits) in Iraq closely follows the pattern set in Middle to Late Eocene times. Reef–back-reef limestone has a linear outcrop across northern Iraq from northwest (the eastern part of the studied area) to southeast. In the Sinjar Basin, the Oligocene succession is unconformable on the Middle Eocene Jaddala Formation and unconformably to relative conformably underlies the Lower Miocene Anah or Ibrahim formations. Two surface sections on the Sinjar Anticline and one cored borehole in the Butmah Anticline formed the basis for our study.Biostratigraphic analysis indicated four planktonic and three benthonic foraminiferal biozones. The planktonic biozones are Pseudohastigerina micra and Globigerina ampliapertura Partial-Range zones, Globorotalia opima opima Total-Range Zone and Globigerina ciperonesis ciperoensis Partial-Range Zone; the three benthonic biozones are Nummulites fichteli-Nummulites intermedius Assemblage Zone, Borelis pygmaeus Total-Range Zone, and Praerhapydionina delicata-Austrotrillina howchini-Peneroplis evolutus Assemblage Zone. Three depositional sequences are present in the sections and borehole and comprise two third-order sedimentary cycles. The first consists of the Palani, Sheikh Alas and Shurau formations and the lower part of the Tarjil Formation deposited in upper-bathyal to intertidal environments; the second is the upper Tarjil Formation and Bajwan Formation. The Baba Formation (a barrier deposit) was not seen in the studied sections, but probably reflects lateral stacking development of the barrier to the west. The upper Tarjil Formation was deposited in upper-bathyal to middle-shelf environments whereas the Bajwan Formation consists of subtidal to tidal-flat deposits.Sequence-stratigraphic analysis, as calibrated by sedimentary facies and biostratigraphy, delineated the two third-order depositional cycles as the Oligocene First Cycle of Rupelian age and the Chattian Oligocene Second Cycle. This suggests that the studied Oligocene succession was deposited over a period of about 9 million years and shows good correlation of the northeastern Arabian Platform with other parts of the Platform and with European Oligocene sequences.
Early – Middle Miocene Suez Syn-rift-Basin, Egypt: A sequence stratigraphy framework
Authors: Youssef Abdulkader 
Published: October 2021

ABSTRACT
The analyses of thirteen planktonic and benthonic biozones, paleobathymetry and electric log data were used to interpret the sequence stratigraphy of the Early to early Middle Miocene syn-rift section in the Gulf of Suez. The study area is located in the central province of the Gulf and includes six boreholes located in two half grabens and the October Field. The new framework proposes the Suez Supersequence and Suez Depositional Sequence DS 50 instead of the five paleontological sequences commonly cited in the literature (S10 to S50). The Supersequence starts above the regional unconformity that separates the pre-and syn-rift rocks, commonly referred to as Terrace T00. The shallow-marine deposits of the Aquitanian Nukhul Formation form the lowstand systems tract. The Burdigalian Mheiherrat Formation starts with the Uvigerina costata flooding event and forms the transgressive systems tract deposited in outer-neritic to upper-bathyal settings. The overlying Langhian Hawara Formation was deposited in upper to middle bathyal settings and represents the maximum flooding interval. The Langhian Asl Formation (early falling stage systems tract, upper bathyal to outer neritic) and overlying Langhian Lagia Member of the Ayun Musa Formation (late falling stage systems tract) closed the Supersequence. Suez Depositional Sequence DS 50 lies unconformably on the Supersequence, and represents a major transgression starting with the Praeorbulina glomerosa s.l. flooding event. DS 50 corresponds to the Ras Budran Member of the Ayun Musa Formation (paleontological sequence S50). Its setting is outer neritic and its upper sequence boundary is an unconformable with the Belayim Formation. The Suez Supersequence is interpreted in terms of 35 genetic parasequences and DS 50 by 10 more. The parasequences are interpreted by the coincidence of quantitative paleontological faunal and paleobathymetric breaks with the electric log shifts. The sequences and parasequences are correlated between the six wells to show the evolution of the half-grabens and October Field at different times.
Structural evolution of the northwestern Zagros, Kurdistan Region, Iraq: Implications on oil migration
Authors: László Csontos , Ágoston Sasvári , Tamás Pocsai , László Kósa , Salae Azad T. , Athar Ali 
Published: October 2021

ABSTRACT
The studied area in Kurdistan Region of Iraq lies across an important topographic/structural boundary between the southern lowlands and the northern, folded and imbricated Zagros Mountains. It also encompasses a prominent change in structural orientation of the northern Zagros, from a general NW-SE “Zagros” to an E-W “Taurus” trend. Geological mapping and structural observations, both in the mountains (Mesozoic–Palaeogene) and in the lowlands (Neogene), led to the following conclusions. (1) The oldest recorded deformation is a layer-parallel shortening, coupled with southwest-vergent shear that was followed by major folding of ca. 10 km wavelength and ca. 1,000 m amplitude. Even the Upper Miocene–Pliocene Bakhtiari Formation has steep to overturned beds in some parts, and synclines preserve syn-tectonic strata of Neogene–Pliocene age. Box folding is associated with crestal collapse, internal thrusting in the core and with formation of systematic joint sets. (2) On the southern limb of the major folds, thrusting of variable offset can be observed. The thrusts on the southern and northern limbs are considered responsible for the major uplift during main folding. (3) En-échelon fold-relay patterns suggest left-lateral shear along the EW-oriented segment and right-lateral shear along the NW-oriented segment. (4) A quick-look qualitative analysis of striated fault planes suggests a variable shortening trend from NE-SW to N-S, and some rare NW-SE shortening all associated with thrust faults. (5) The general structural setting of the area is linked to the north-eastwards to northwards propagation of the Arabian Margin beneath Eurasia. The ca. 30° bend in the mountain chain may be explained by the original shape of the Arabian Margin, or by pre-existing tectonic zones of E-W orientation in the northern part. Several observations suggest that there was no oroclinal bending (i.e. major rotation) of different parts of the chain, but the structures simply molded on their local buttress (almost) according to present orientations. However, a limited amount of rigid-body rotation in the different segments cannot be ruled out. The changing shortening directions generated several structural combinations on both the NW-SE Zagros and the E-W Taurus segments of the arc, many of which are still preserved. (6) Spectacular bitumen seepage in Upper Cretaceous and Palaeocene limestone originates from fractures or geodes of these formations. Many of these bitumen-filled voids are linked to the above-described Late Neogene–Recent shortening-folding process; therefore hydrocarbon migration into these voids is interpreted to be very young. This contradicts earlier ideas about massive Late Cretaceous breaching and bleeding off of hydrocarbons in this region.
Upper Jurassic source rocks in the Sab’atayn Basin, Yemen: Depositional environment, source potential and hydrocarbon generation
Authors: Sachsenhofer Reinhard F. , Bechtel Achim , Dellmour Rudolf W. , Mobarakabad Afshin Fathi , Gratzer Reinhard , Salman Adel 
Published: October 2021

ABSTRACT
The Sab’atayn Basin is a major hydrocarbon province in Yemen. Important source rocks occur in Upper Jurassic units (Lam Member of the Madbi Formation, Sab’atayn Formation). Depositional environment, source potential and maturity of the source rocks were investigated using 60 cuttings samples from the Tagina South-1 Well. All samples were analysed for bulk parameters (total organic carbon (TOC), carbonate, sulphur, RockEval). A subset of samples was selected for biomarker analysis, pyrolysis-gas chromatography and isotope investigations.
A carbonate-rich, euhaline, dysoxic to anoxic environment prevailed during deposition of the Lam Member. Bituminous shales within the overlying Sab’atayn Formation formed in a hypersaline, strictly anoxic depositional setting. Changes in the phytoplankton communities coincide with the outlined changes in the water body. Upward decreasing δ13C values suggest changes in carbon cycling due to changing redox conditions.
The Lam Member, at least 500 m thick, is a good to very good source rock with an average TOC of 2.2%. The hydrogen index is controlled by maturity, but reaches 300 mg HC/g TOC in samples with low maturity (type II-III kerogen). The Lam Member produces sulphur-poor, paraffinic-naphthenic-aromatic low-wax oil. Bituminous shales in the Sab’atayn Formation contain up to 11% TOC and a type II (to III) kerogen (HI: up to 427 mg HC/g TOC). These shales are excellent sources for oil (and gas), but their source potential is limited by their relatively low thickness. Both, bituminous shales in the Sab’atayn Formation and the Lam Member are mature. The maturity of the deepest drilled part of the Lam Member is close to the zone of main oil generation. Numeric models show that Cenozoic heat flow is about 50 mW/m2. An increase in heat flow during Jurassic rifting is likely, but cannot be quantified. Major hydrocarbon generation occurred during Eocene–Oligocene times (assuming a Late Cretaceous heat flow of 50 mW/m2) or during both, Late Cretaceous and Eocene–Oligocene times (assuming a Late Cretaceous heat flow of 68 mW/m2).
Ichnofabrics of Eocene oil shales from central Jordan and their use for paleoenvironmental reconstructions
Authors: Hussein Mohammad Ali , Alqudah Mohammad , Podlaha Olaf G. 
Published: October 2021

ABSTRACT
The study of trace fossils is widely used in facies interpretation. It provides a crucial tool for reconstructing depositional paleoenvironments when used in combination with other sedimentological and paleontological proxies. Here we present the first detailed study of Eocene trace fossils from Jordan. Two sections of Early to Middle Eocene age, with a total thickness of 478.7 m, from central Jordan were cored and investigated. The results of individually occurring (isolated) or co-occurring (combined) ichnofabrics and bioturbation levels, in combination with results from biostratigraphic and geochemical studies, were used for stratigraphic and paleoenvironmental reconstructions. The bioturbation index (BI) was used to classify the burrowing density versus the preservation of the original sedimentary structures. The two cores show highly variable grades of bioturbation with BI ranging from 0 to 6. Four ichnogenera were identified: Thalassinoides, Chondrites, Teichichnus and Zoophycos. Both the ichnofabrics and the variations of the BI suggest a shallow, highly dynamic depositional system with rapid changes of water depth and degree of bottom-water oxygenation.
Carbonate reservoir characteristics and porosity distribution in Souedih Oilfield, northeast Syria
Authors: Ghabra Amer , Tatum Dominic , Gardiner Andy , Stow Dorrik 
Published: October 2021

ABSTRACT
The Souedih (also spelled Suwaidiyah) Oilfield is located in the extreme northeast of Syria in part of the Mesopotamian Basin. The principal reservoir of most fields in this region is the Upper Cretaceous, carbonate-rich Massive Formation. Using data from 25 wells and 36 samples/thin sections, this study focuses on the nature and distribution of porosity in the main Souedih reservoir. The Massive A reservoir is 100Ð120 m thick and represented by uniform, bioturbated bioclastic packstone and bioclastic packstone-grainstone, deposited in a well-oxygenated, moderate to high-energy, shallow-marine environment. It is generally well cemented by microsparite and micrite, and more rarely by sparite. Porosity is highly variable, ranging from &lt; 1% to 20%. Mouldic porosity is the most common type, with rare channel and fracture porosity. Average porosity values tend to decrease eastward across the reservoir, which can also be divided vertically into five zones. The uppermost of these shows the highest average porosity &gt; 15%. The dominance of mouldic porosity throughout the study area indicates that secondary dissolution was the primary cause and that pre-existing bioclasts were the principal targets for this dissolution. The source of these diagenetic fluids is still unclear, although our data do lend some support to the karstification theory. These characteristics are important for understanding and managing reservoir production, not only for Souedih but for the region in general.