Geological Interpretation and Identification of Albian-Aged Petroleum Prospects in Block A, San Pedro Margin (Côte d’Ivoire)

The study aims to identify Albian-age oil prospects in Block A of the San Pedro margin, Côte d’Ivoire, by conducting a detailed geological interpretation. The objective is to confirm the presence of oil reservoirs trapped by favorable geological structures, identifiable through geophysical and seismic methods. The methodological approach is based on a combined analysis of studies and seismic data. Drilling data from well PA, including well logs and end-of-well reports, were used to characterize the lithological formations encountered, particularly those of the Albian. 3D seismic profiles were interpreted to identify structures conducive to hydrocarbon accumulation. Isochrone, isovelocity, and isobath maps were developed to refine the interpretation. Sedimentological analyses revealed five sandy/gritty levels between 2610 m and 3100 m, interspersed with clay, limestone, and siltstone beds. The seismic profiles highlighted two main prospects. These prospects exhibit favorable geological structures, including normal faults and structural traps that provide oil traps.

Main geological and mining factors affecting ground cracks induced by underground coal mining in Shanxi Province, China

As one of the largest coal-rich provinces in China,Shanxi has extensive underground coal-mining operations.These operations have caused numerous ground cracks and substantial environmental damage.To study the main geological and mining factors influencing mining-related ground cracks in Shanxi,a detailed investigation was conducted on 13 mining-induced surface cracks in Shanxi.Based on the results,the degrees of damage at the study sites were empirically classified into serious,moderate,and minor,and the influential geological and mining factors(e.g.,proportions of loess and sandstone in the mining depth,ratio of rock thickness to mining thickness,and ground slope)were discussed.According to the analysis results,three factors(proportion of loess,ratio of rock thickness to mining thickness,and ground slope)play a decisive role in ground cracks and can be respectively considered as the critical material,mechanical,and geometric conditions for the occurrence of mining surface disasters.Together,these three factors have a strong influence on the occurrence of serious discontinuous ground deformation.The results can be applied to help prevent and control ground damage caused by coal mining.The findings also provide a direct reference for predicting and eliminating hidden ground hazards in mining areas.

Chemical and Geological Control on Surface Water within the Shade River Watershed in Southeastern Ohio

The under-sampled middle and western branches of Shade River Watershed (SRW) in SE Ohio were investigated as part of the Ohio University—U.S. Environmental Protection Agency (EPA) STAR grant. This project was for monitoring the quality of watersheds in Ohio and classifying them according to their physical, chemical, and biological conditions. Water samples, as well as field parameters, were taken at twenty-two sites for chemical analyses. The ions analyzed included Ca, Mg, Na, Fe, Mn, Al, NO3, SO4, HCO3, and total PO4, while the field parameters measured included pH, dissolved oxygen (DO), total dissolved solids (TDS), electrical conductivity (EC), and alkalinity. To assess the water quality within the SRW, the analyzed ions and field parameters were compared to the USEPA criteria for the survival of aquatic life. Analytical results showed that the watershed is dominated by Ca-HCO3waters with DO, Fe, Mn, and PO4being the main causes of impairment within the streams. The relatively elevated concentrations of manganese and less extent iron may be associated with the local geology and the acidic nature of the soils. The high alkalinity and calcium concentrations are due to the limestone geology. The elevated phosphate concentration may be due to anthropogenic sources, fertilizers, or contributions from phosphorus-rich bedrock that differs geochemically from other areas.

Hydrogeological and Hydrochemical Assessment of Basin Granitoids in Assin and Breman Districts of Ghana

Hydrogeological and hydrochemical assessments were carried out in Assin and Breman districts of Ghana. A multi-criteria approach was used in the assessment of the basin granitoids including;electrical resistivity survey, pumping test and water quality analysis. A total of twenty-five (25) representative boreholes were drilled, developed and pumped;obtaining data for aquifer hydraulic parameters estimation. Correlation analysis was used to determine relationships that exist between aquifer hydraulic parameters. Schoeller, Piper, Stiff plot and Gibbs diagrams were used to determine the hydrogeochemical facies, water types and the mechanism that control groundwater quality. The statistical analysis determined that aquifer hydraulic parameters discharge rate (Q), hydraulic conductivity (K) and Transmissivity (T) showed a strong positive correlation with specific capacity (Q/Sw) with R value 0.8462, 0.8738 and 0.8332 respectively. The K and T were respectively between 0.02 - 0.90 m/day and 0.36 - 13.47 m2/day with mean of 0.24 m/day and 3.03 m2/day respectively. The K values indicate a hydrogeological condition of aquiclude with relatively low permeability and medium water bearing capacity. The aquifer T magnitude is very low to low, groundwater potential is adequate for local water supply with limited and private consumption. All physicochemical parameters were within the permissible limits of Ghana Standards Authority (GSA) and World Health Organisation (WHO) except for apparent colour, pH, Fe and Mn. Distribution of major ions in groundwater samples was calculated and the general trend among cations and anions was found to be Ca2+ > Na+ > Mg2+ and Cl? > HCO3? > SO42? respectively. The study area shows five main water types namely;Ca-HCO3, Na-Mg-HCO3-SO4, Ca-SO4, Na-Cl and Mg-Na-Cl. Weathering of rock-forming minerals as the mechanism controlling the groundwater chemistry. Microbiological parameters were above the permissible limits. Groundwater is suitable for drinking after treatment with chlorination, aeration and slow sand filtration methods.

Integrating artificial neural networks and geostatistics for optimum 3D geological block modeling in mineral reserve estimation:A case study

In this research, a method called ANNMG is presented to integrate Artificial Neural Networks and Geostatistics for optimum mineral reserve evaluation. The word ANNMG simply means Artificial Neural Network Model integrated with Geostatiscs, In this procedure, the Artificial Neural Network was trained, tested and validated using assay values obtained from exploratory drillholes. Next, the validated model was used to generalize mineral grades at known and unknown sampled locations inside the drilling region respectively. Finally, the reproduced and generalized assay values were combined and fed to geostatistics in order to develop a geological 3D block model. The regression analysis revealed that the predicted sample grades were in close proximity to the actual sample grades, The generalized grades from the ANNMG show that this process could be used to complement exploration activities thereby reducing drilling requirement. It could also be an effective mineral reserve evaluation method that could oroduce optimum block model for mine design.

Aerogeophysical,Geological and Geochemical Investigation of the Late Archaean Granitoids in the Musoma-Mara Greenstone Belt,NE Tanzania

Based on the analysis and interpretations made on high resolution airborne radiometric data and previous geological maps,a geophysical interpretation map of Musoma-Mara Greenstone Belt(MMGB) was obtained, and the map categorized the MMGB granitoids into two types:high K,U and Th granites and high K relative to U and Th granites.The geophysical interpretation map used as base map during ground follow-up whereby granite types were sampled accordingly.Geochemical

Geological Hazards in Malawi

Geohazards are events caused by geological features and processes that present severe threats to humans,property and the natural built environment. Earthquakes,landslides,volcanoes,and tsunamis are typical examples of such events.Globally,earthquakes, tsunamis and floods are often considered as the most devastating geohazards,comparing to landslides and large mass flows triggered by them.

Geochemical characteristics and geological significance of picritic rocks in Permian Tiaohu Formation from Santanghu Basin, Xinjiang, NW China

1 Introduction Santanghu Basin is located between the Armantai and Karamaili suture zone,at the junction of the Siberia,Kazakhstan and Tarim plates(Chen and Jahn,2004;Xiao et al.,2008).As an important part of the Central Asian

Evaluation of Geological Hazards for Landuse Planning in Nabq Protectorate, Southeastern Sinai Using GIS Techniques

Nabq protectorate is one of wonderful natural places in Egypt. It is characterized by diversity of bio-lives such as mangrove forests, coral colonies, wild life plants and migratory birds. Ongoing growth of tourism industries at Sharm El Sheikh northward into the Nabq protectorate causes severe hazards on its natural resources. The aim of the present study is to assess the present geo-environmental hazards in the Nabq protectorate. Assessment includes the analysis of satellite images, topographical, geological and other ancillary geological data using GIS technology. GIS data analyses indicate that the area is under threat from some of geo-hazards. Rough topography and mass wasting with high probability of flash flooding threaten different constructions in this area. The mobilization of coastal sand dunes, wave action and tidal currents are natural impacts on Nabq ecosystems, where moved dunes leave clay soils that are removed in some places by tropical storms increasing sea water turbidity that threaten the corals and other living organisms in the tidal flat region. The seismic activity hazard in the study area is usually active on lineaments extending parallel to the trend of the Gulf of Aqaba-Dead Sea transform fault where the Nabq protectorate occupies its southern segment. Unwise planning activities destroy the natural environmental resources in Nabq area by construction of new resorts on mangrove forests, coral colonies and raised beaches. Hazard assessment identifies land suitability and land use maps that are clearly exhibit models of traditional dams and buffer strips on coastal zone and highways as well as around the Bedouin communities which are worked on tourism and fishing. These maps are urgent in need of an assessment and rehabilitation program to mitigate geo-hazard.

Landforms Evolution of Wadi Qudaid Area, West Central Arabian Shield, Saudi Arabia: An Example of the Role of the Geological Factors in the Urban Extensions

Wadi Qudaid is located in the west central part of Saudi Arabia. It about 135 km to the northeast of Jeddah city along Al Haramein highway and it represents the upstream of the very large alluvial plain along the Red Sea coast. It runs in NE direction parallel to many wadis of the west central part of Saudi Arabia i.e. Wadi Fatima, wadi Sitarah. The wadi floor is filled by Quaternary deposits which represent good groundwater aquifer. Geologically, the present-day residual landforms of Wadi Qudaid are composed mainly of Precambrian Arabia shield rocks overlained by Tertiary sedimentary rocks and finally harrat (Tertiary volcanic). The Precambrian rocks are represented by 1) a lower layered basic and intermediate volcanic and the intercalated volcaniclastics. This unit is correlatable with Samran Group, 2) an upper layered acidic volcanic and the intercalated acidic volcaniclastics. The Arabian shield rocks are intensively folded and dragged along the major NE faults. They are directly overlain by Tertiary basic volcanic (harrat) and the related volcanoclastic red beds). The main geomorphologic elements of the study area include plateau, scarps, and the wadi floor. The plateau is represented by the black basaltic sheet that contains some semi-rounded depressions filled with Quaternary eolian sands. The scarps of the main wadi and its tributaries are nearly steep and contain many asphaltic roads with some isolated cone hills detached from the scarps. Geomorphological, Wadi Qudaid represents the incomplete erosion cycle that begins with the formation of deep galleries and very steep and narrow wadies formed along the major NE faults and related fractures and folds. The progress of the erosion processes led to the formation of narrow interfluves as a result of pedimentation and sculpturing of the wadies sides by scarp retreat. The peniplanation stages of the erosion cycles are reached in the southwestern and the central part of the wadi where fast peniplained areas were formed. The results of this study revealed the role of the different geological processes (lithology, structural elements and climatic conditions) in the distribution of present-day human populations in urban extensions. Qudaid, Dhubaya-Jumah, Dabyah, Al Khamrah, Almansa and Al Massamah are the main villages of Wadi Qudaid area.

The Pendawa Hill, Jering, Sleman Is on of Geosite to Added Yogyakarta Geoheritage Very Interesting to Be Developed in to Geological Tourism Object

Pendawa Hill is located in Jering,Sleman,Yogyakarta.It is one of the hills that formed by diorite intrusion(Miocene)and intruded claystone of Nanggulan Formation Ages of Eocene.In this area will be built a simple housing and open some of the western side of the Pendawa Hill.So that exposes some of the lithology on the Pendawa Hill.The beauty of the rare outcrop in the Pendawa Hill,Jering,Sleman,than the authors proposes that some of the area has preserved to become the geoheritage.Then it will be planned that the construction of simple housing is integrated with geological touriem objectsin this area.There are Yogyakarta Geoheritage areas,among others:pillow lava in Berbah-Sleman,tuff breccia in Candi Ijo-Sleman,Eocene Limestone in Sleman,Nglanggran Old Volcanic in Nglanggran-Gunungkidul,Batur old Volcanic in Gunungkidul,Burrow Fossils in Kali Ngalang-Gunungkidul,Barchan sand-done in Bantul,Kiskendo Cave in Kulon Progo and Mangan mine in Kulon Progo.

Contribution of the 3D Geological Model to the Study of the High Basin Ziz Jurassic Aquifers Structure (Central High Atlas, Morocco)

The high Ziz’s basin, which is part of the Central High Atlas, contains Jurassic superficial and deep aquifers. The information sheets are still fragmentary and insufficient because of the basin’s large size and its complex geological structure. In order to improve the knowledge of these aquifers and the determination of the structure of aquifers, a 3D geological model was developed in this study. It was constructed from information provided by 200 mechanical soundings and 81 electrical surveys and geological maps. Compiled holes were analyzed, coded and integrated in the software Groundwater Modeling System 6.0 (GMS 6.0). For doing this, five lithostratigraphic units were considered: the Domerian, the Toarcian, the Aalenian, the Bajo-Bathonian and the Quaternary. The operation of the 3D stratigraphic model allowed making it closer to the geometry of Jurassic aquifers.

DEM-Based GIS Algorithms and 3D Geospatial Mapping for Creation of Hydrogeological Models Data in Foussana Basin (Central Tunisia)

There are many factors which affect the hydrological, geomorphologic and hydrogeological condition of the area. In order to better comprehend all processes, a Digital Elevation Model (DEM) was developed based on Geographical Information System. This latter appears as an essential tool to facilitate the decision support and can provide very important geological information. In fact, the use of the DEM is growing dramatically with the use of the GIS and the improvement of information extracted from elevation data such as mapping of floods, forest areas, erosion, and lineaments. The spatial distribution of topographic attributes can often be used as an indirect measure of the spatial variability of these processes and allows them to be mapped using relatively simple techniques. The main purpose of this study is to model the natural surface of the earth as the most accurate and the most precise. For this end we have tried in this work to develop various types of Digital Elevation Models DEM of the Foussana rift in Central Tunisia and to demonstrate the role of these models in geological, hydrogeological and hydrological study. The 3D model is also coupled in this study with piezometric and hydrochemistry study, so a new information’s plan was mapped by multiple GIS techniques like Spatial analysis and interpolation;in order 1) to comprehend the hydrodynamic of the aquifer, 2) to quantify surface and subsurface water resources and 3) to generate water management scenarios in the study area. To this end, several groundwater samples were collected and analyzed from wells and piezometers. Examining the corresponding physical and chemical parameters showed an increase in the concentrations of hydraulic conductivity in the center of the study area and it coincided with zones with high nutrient concentration. Recommendations are proposed in this zone.

The Importance of Integrating Geological Mapping Information with Validated Assay Data for Generating Accurate Geological Wireframes in Orebody Modelling of Mineral Deposit in Mineral Resource Estimation: A Case Study in AngloGold Ashanti, Obuasi Mine

The basis of accurate mineral resource estimates is to have a geological model which replicates the nature and style of the orebody. Key inputs into the generation of a good geological model are the sample data and mapping information. The Obuasi Mine sample data with a lot of legacy issues were subjected to a robust validation process and integrated with mapping information to generate an accurate geological orebody model for mineral resource estimation in Block 8 Lower. Validation of the sample data focused on replacing missing collar coordinates, missing assays, and correcting magnetic declination that was used to convert the downhole surveys from true to magnetic, fix missing lithology and finally assign confidence numbers to all the sample data. The missing coordinates which were replaced ensured that the sample data plotted at their correct location in space as intended from the planning stage. Magnetic declination data, which was maintained constant throughout all the years even though it changes every year, was also corrected in the validation project. The corrected magnetic declination ensured that the drillholes were plotted on their accurate trajectory as per the planned azimuth and also reflected the true position of the intercepted mineralized fissure(s) which was previously not the case and marked a major blot in the modelling of the Obuasi orebody. The incorporation of mapped data with the validated sample data in the wireframes resulted in a better interpretation of the orebody. The updated mineral resource generated by domaining quartz from the sulphides and compared with the old resource showed that the sulphide tonnes in the old resource estimates were overestimated by 1% and the grade overestimated by 8.5%.

Purang Ultramafic Complex and Their Geological Origin, Southwest Tibet

Neoproterozoic ophiolitic Serpentinites are common in the Arabian-Nubian Shield （ANS） of the Eastern Desert （ED） of Egypt, which were formed in arc stage in different tectonic setting. Thus they might subject to exchange with the crustal material derived from recycling subducting oceanic lithosphere. This caused metasomatism enriching the rocks in incompatible elements and forming non- residual minerals. Herein,

Reservoir quality evaluation of the Narimba Formation in Bass Basin,Australia:Implications from petrophysical analysis,sedimentological features,capillary pressure and wetting fluid saturation

The evaluation of reservoir quality was accomplished on the Late Paleocene to Early Eocene Narimba Formation in Bass Basin,Australia.This study involved combination methods such as petrophysical analysis,petrography and sedimentological studies,reservoir quality and fluid flow units from derivative parameters,and capillary pressure and wetting fluid saturation relationship.Textural and diagenetic features are affecting the reservoir quality.Cementation,compaction,and presence of clay minerals such as kaolinite are found to reduce the quality while dissolution and secondary porosity are noticed to improve it.It is believed that the Narimba Formation is a potential reservoir with a wide range of porosity and permeability.Porosity ranges from 3.1%to 25.4%with a mean of 15.84%,while permeability ranges between 0.01 mD and 510 mD,with a mean of 31.05 mD.Based on the heterogenous lithology,the formation has been categorized into five groups based on permeability variations.Group I showed an excellent to good quality reservoir with coarse grains.The impacts of both textural and diagenetic features improve the reservoir and producing higher reservoir quality index(RQI)and flow zone indicators(FZI)as well as mostly mega pores.The non-wetting fluid migration has the higher possibility to flow in the formation while displacement pressure recorded as zero.Group II showed a fair quality reservoir with lower petrophysical properties in macro pores.The irreducible water saturation is increasing while the textural and digenetic properties are still enhancing the reservoir quality.Group III reflects lower quality reservoir with mostly macro pores and higher displacement pressure.It may indicate smaller grain size and increasing amount of cement and clay minerals.Group IV,and V are interpreted as a poor-quality reservoir that has lower RQI and FZI.The textural and digenetic features are negatively affecting the reservoir and are leading to smaller pore size and pore throat radii(r35)values to be within the range of macro,meso-,micro-,and nano pores.The capillary displacement pressure curves of the three groups show increases reaching the maximum value of 400 psia in group V.Agreement with the classification of permeability,r35 values,and pore type can be used in identifying the quality of reservoir.

Origin and geochemical characteristics of beryllium mineralization in the Zabara-Wadi El Gemal region,South Eastern Desert,Egypt

Beryl is the commercial source of beryllium and several varieties of it are valued as a gemstone.To contribute to understanding the mechanism of beryl formation,we carried out detailed geological,petrographical,and geochemical investigations on beryl mineralization occurrences in the Zabara-Wadi El Gemal(Z-WG)region.This region is an NW-SE trending tract that includes six berylhosting areas.The green gem variety of beryl(emerald)is restricted to phlogopite schist,pegmatite,and quartz veins.Prismatic hexagonal emerald crystals are well-developed in phlogopite schist and pegmatite.The gem variety emerald examined is sodic and Cr-dominant.It contains high concentrations of chromophore transition elements ordering Cr(up to 1511 ppm)>V(up to 242 ppm)>Sc(up to 245 ppm),giving rise to its vivid green color,refl ecting mafic-ultramafic source contribution.Among the investigated emeralds,the Sikait area contains the highest BeO(av.10.76wt.%)concentration.The compositional variability of emeralds is most likely attributed to the contribution from the host rocks.This is revealed by the examined emerald mineralization,for instance;the Abu Rusheid area(one of the best areas exposing rare metal-bearing granitoids)possesses the highest average of trace and REEs concentrations.In contrast,Um Kabu emerald has the highest contents of Co(av.20 ppm),Ni(av.299 ppm),MgO(av.8.2wt.%),Fe_(2)O_(3)(av.3.12wt.%),and CaO(avg.3.4wt.%)relative to other areas,which may be linked to contribution of ultramafic rocks exposed there.The proposed mechanism we suggest for emerald genesis is metasomatic interaction between felsic intrusions,that are enriched with K,Na,Be,Li,and B,with mafic-ultramafic rocks that are enriched in Cr,V,Mg,Fe,and Ca.This interaction is marked by the formation of phlogopite schist,the growth of emerald crystals,and desilicated pegmatite.

Mineralogical and geochemical characterization of the Wadi Natash volcanic field(WNVF),Egypt:Alkaline magmatism in a Late Cretaceous continental rift system

The Wadi Natash volcanic field(WNVF)in the south of the Eastern Desert of Egypt is a typical example of well-preserved intraplate alkaline magmatism during the Late Cretaceous,i.e.,prior to the Oligo-Miocene Red Sea rift.We compiled stratigraphic sections at two sectors;namely East Gabal Nuqra and West Khashm Natash(WKN)where the volcanic flows are intercalated with the Turonian Abu Agag sandstone with occasional paleosols when volcanic activity is intermittent.Peridotite mantle xenoliths are encountered in the first sector whereas flows in the second sector are interrupted by trachyte plugs and ring dykes.On a geochemical basis,the maifc melt originating from the lithospheric mantle beneath the WNVF practiced~5%partial melting of phlogopite-bearing garnet peridotite.Basalts dominate in the two sectors and highly evolved(silicic)rocks are confined to the WKN sector.Rejuvenation of ancient Precambrian fractures following the NW-SE and ENE-WSW trends facilitated the ascend of Late Cretaceous mantle-derived alkaline magma.Structurally,the WNVF developed at the eastern shoulder of the so-called"Kom Ombo-Nuqra-Kharit rift system"that represents a well-defined NW-trending intracontinental rift basin in the southern Eastern Desert.In such a structural setup,the Natash volcanic are confined to half-grabens at the East Gabal Nuqra sector whereas the West Khashm Natash sector is subjected to extensional stresses that propagated eastwards.The WNVF is a typical example of fluvial clastics(Turonian)intercalation with rift-related alkaline volcanic rocks in northeast Africa.

Long-term hydrochemical monitoring and geothermometry:understanding groundwater salinization and thermal fluid contamination in Mila’s basin,Northeastern Algeria

The regular hydrochemical monitoring of groundwater in the Mila basin over an extended period has provided valuable insights into the origin of dissolved salts and the hydrogeochemical processes controlling water salinization.The data reveals that the shallow Karst aquifer shows an increase in TDS of 162 mg L^(-1) while the ther-mal carbonate aquifer that is also used for drinking water supply exhibits an increase of 178 mg L^(-1).Additionally,significant temperature variations are recorded at the sur-face in the shallow aquifers and the waters are carbo-gaseous.Analysis of dissolved major and minor elements has identified several processes influencing the chemical composition namely:dissolution of evaporitic minerals,reduction of sulphates,congruent and incongruent car-bonates’dissolution,dedolomitization and silicates’weathering.The hydrogeochemical and geothermometric results show a mixing of saline thermal water with recharge water of meteoric origin.Two main geothermalfields have been identified,a partially evolved water reservoir and a water reservoir whosefluid interacts with sulphuric acid(H_(2)S)of magmatic origin.These hot waters that are char-acterized by a strong hydrothermal alteration do ascend through faults and fractures and contribute to the contamination of shallower aquifers.Understanding the geothermometry and the hydrogeochemistry of waters is crucial for managing and protecting the quality of groundwater resources in the Mila basin,in order to ensure sustainable water supply for the region.A conceptual model for groundwater circulation and mineralization acquisition has been established to further enhance under-standing in this regard.

Geochemistry of island arc assemblage in the Eastern Desert of Egypt and the role of Pan-African magmatism in crustal growth of the Arabian–Nubian Shield:A review

Neoproterozoic island arc assemblage of the Arabian–Nubian Shield(ANS)in the Eastern Desert(ED)of Egypt comprises juvenile suites of metavolcanics(MV),large amounts of meta-sedimentary rocks(MS),and voluminous metagabbros-diorites(MGD)and syn-tectonic intrusions of older granitoids(OG).We report here the updates of these four rock units in terms of classification,distribution,chemical characteristics,geodynamic evolution,metamorphism,and ages.In addition,we discuss these integrated data to elucidate a reasonable and reliable model for crustal evolution in the ANS.The main features of these rock units indicate their relation to each other and the geodynamic environment dominated by early immature oceanic island arcs to primitive continental arcs.Integrated information of the island arc metavolcanic and plutonic rocks(gabbros,diorites,tonalites,and granodiorites)furnish evidence of the genetic relationships.These include proximity and a coeval nature in the field;all protolith magmas are subalkaline in nature following calc-alkaline series with minor tholeiitic affinities;common geochemical signature of the arc rocks and subduction-related magmatism;their similar enrichment in LREEs;and similar major element compositions with mafic melts derived from metasomatized mantle wedge.The volcano-sedimentary and the OG rocks underwent multiphase deformation events whereas the MGD complexes deformed slightly.Based on the magmatic,sedimentological,and metamorphic evolutions constrained by geochronological data as well as the progressive evolutionary trend from extensional to compressional regimes,a possible gradual decrease in the subducted slab dip angle is the most infl uential in any geodynamic model for arc assemblage in the ED of Egypt.