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Climatic variability and silicate weathering are remarkable features throughout the Late Cretaceous period. Late Campanian black shale is considered the most significant silicate source rock in the southern Tethys. Here, we used mineralogical and geochemical data to evaluate the continental weathering intensity and climatic changes as well as their impact on the deposition of the Late Campanian black shale in the Western Desert of Egypt. The studied black shale has a relatively high concentration of Al, Fe, Mg, Ca, Sr, Ga, Co, Cr, and V when compared to the average Post-Archean Australian Shales (PAAS). The studied samples have elevated values of Ga/Rb, and low values of Rb/Sr, Sr/Cu, and K2O/Al2O3, supporting the deposition of Late Campanian shale under warm/humid conditions. Furthermore, the average chemical index of alteration (CIA, 78.6%), chemical index of weathering (CIW; 83.8%), C-value (1.26), Fe/Mn (408), and Mg/Ca (1.54) reveal the predominance of warm/humid climate. The chemical weathering proxies (CIA, CIW, PIA, LnAl2O3/Na2O) and ACNK diagram imply that the Late Campanian samples were exposed to a moderate grade of chemical alteration. The deposition of black shale occurred under high seawater salinity conditions based on Sr/Ba (Avg = 3.6). Additionally, the weathering indices are well correlated with paleoclimatic proxies, suggesting that weathering intensity is strongly affected by paleoclimate. However, chemical weathering during the Late Campanian has a weak influence on oceanic nutrient fluxes. No substantial impact of the paleoclimate during the deposition of Late Campanian black shale on water salinity was reported.

The utilization of phosphorite deposits as an industrial resource is of paramount importance, and its sustainability largely depends on ensuring safe and responsible practices. This study aims to evaluate the suitability of phosphorite deposits for industrial applications such as the production of phosphoric acid and phosphatic fertilizers. To achieve this goal, the study meticulously examines the geochemical characteristics of the deposits, investigates the distribution of natural Radioactivity within them, and assesses the potential radiological risk associated with their use. The phosphorites are massive and collected from different beds within the Duwi Formation at the Hamadat mining area. They are grain-supported and composed of phosphatic pellets, bioclasts (bones), non-phosphatic minerals, and cement. Geochemically, phosphorites contain high concentrations of P 2 O 5 (23.59–28.36 wt.%) and CaO (40.85–44.35 wt.%), with low amounts of Al 2 O 3 (0.23–0.51 wt.%), TiO 2 (0.01–0.03 wt.%), Fe 2 O 3 (1.14–2.28 wt.%), Na 2 O (0.37–1.19 wt.%), K 2 O (0.03–0.12 wt.%), and MnO (0.08–0.18 wt.%), suggesting the low contribution of the detrital material during their deposition. Moreover, they belong to contain enhanced U concentration (55–128 ppm). They are also enriched with Sr, Ba, Cr, V, and Zn and depleted in Th, Zr, and Rb, which strongly supports the low detrital input during the formation of the Hamadat phosphorites. The high Radioactivity of the studied phosphorites is probably due to the widespread occurrence of phosphatic components (e.g., apatite) that accommodate U in high concentrations. Gamma spectrometry based on NaI (Tl) crystal 3×3 has been used to measure occurring radionuclides in the phosphorite samples. The results indicate that the radioactive concentrations’ average values of 226 Ra, 232 Th, and 40 K are 184.18±9.19, 125.82±6.29, and 63.82±3.19 Bq Kg -1 , respectively. Additionally, evaluations have been made of the radiological hazards. The calculated risk indicators exceeded the recommended national and world averages. The data obtained will serve as a reference for follow-up studies to evaluate the effectiveness of the Radioactivity of phosphatic materials collected from the Hamdat mine area.

The Upper Miocene–Pliocene Kampungbaru Formation crops out in the easternmost part of the Lower Kutai Basin, Indonesia. The sedimentological analysis of seven outcrops was carried out, and a total of twenty-five samples from these outcrops was analyzed for bulk geochemistry, organic petrography, and bulk and clay mineralogy to assess the effect of the climate and depositional environment on organic matter enrichment. The Kampungbaru Formation consists of interbedded sandstone, siltstone, claystone, and thick coal beds, which were classified into eleven lithofacies. Subsequently, seven facies associations were identified, namely the fluvial-dominated distributary channel, sheet-like sandstone, tide-influenced distributary channel, mouth bar, crevasse splay, delta plain, and delta front. The coal facies generally have a high amount of total organic carbon (TOC, 5.1–16.9; avg. 10.11 wt.%), and non-coal layers range from 0.03 to 4.22 wt.% (avg. 1.54 wt.%). The dominant maceral is vitrinite, while liptinite occurs only rarely in the samples. Organic matter is inferred to have originated from terrestrial plants growing in mangrove swamps. Identified clay minerals include varying proportions of kaolinite, illite, chlorite, and mixed layer illite/smectite (I/S). Kaolinite, which commonly constitutes up to 30% of the clay volume, indicates intensive chemical weathering during a warm and humid climate. In accordance with the Köppen climate classification, the paleoclimate during the deposition of the Kampungbaru Formation is classified as type Af, which is a tropical rainforest. Tropical climate was favorable for the growth of higher plants and deposition of organic matter under anoxic conditions and led to higher amounts of TOC in the Kampungbaru Formation.

The Neoproterozoic granitic rocks of Mount Abu Kibash and Tulayah in the central Eastern Desert of Egypt are of geodynamic interest and provide us with important information about the evolution and growth of the northern part of the Arabian–Nubian Shield (ANS) continental crust. They are primarily composed of granodiorites and syenogranites based on new field, mineralogical, and geochemical analyses. The granodiorites are marked by an enrichment of LILEs such as Sr, K, Rb, Ba compared to HFSEs like Nb, Ta, Ti and show a higher concentration of LREEs relative to HREEs. This composition suggests a subduction-related setting and aligns with the characteristics of subducted I-type granites in the ANS. Chemistry of the analyzed primary amphiboles in the investigated granodiorites support a calc-alkaline nature, mixed source and subduction-related setting. The granodiorites represent an early magmatic phase in this setting, likely formed from a mix of mantle-derived mafic magmas and lower crust material, with subsequent fractional crystallization. On the other hand, syenogranites exhibit high SiO2 (72.02–74.02 wt%), total alkali (7.82–8.01 wt%), and Al2O3 (13.79–14.25 wt%) levels, suggesting their derivation from peraluminous (A/CNK > 1) parental magmas. Their REE-normalized patterns are flat with a pronounced negative Eu anomaly, typical of post-collisional A2-type granites worldwide. These rocks originated from the partial melting of a juvenile lower crustal source (tonalite) in a post-collisional setting, driven by lithospheric delamination that facilitated mantle upwelling and underplating to the lower crust. Interaction between the upwelled mantle and lower crust led to fertilization (enrichment with HFSE and alkalis) of the lithosphere before partial melting. Fractional crystallization coupled with less considerable crustal assimilation are the main magmatic processes during the evolution of these rocks. The transition from subduction to post-collisional setting was accompanied by crustal uplifting, thickening and extensional collapse of ANS continental crust that caused emplacement of large masses of A-type granites in the northern ANS.

This study investigates the distribution of natural radioactivity and geological, geochemical, and environmental risk assessments of phosphorite deposits to determine their suitability for international applications (such as phosphoric acid and phosphatic fertilizers). The examined Late Cretaceous phosphorite deposits belong to the Duwi Formation, which is well exposed on the southern scarp boundary at the central part of Abu Tartur Plateau, Gebel Qulu El Sabaya, East Dakhla Oasis. This formation is classified into lower phosphorite, middle shale, and upper phosphorite members. The lower phosphorite ranges in thickness from 2 to 3.5 m and mainly comprises apatite (possibly francolite), dolomite, calcite, quartz, hematite, anhydrite, and kaolinite. They contain an average concentration of CaO (38.35 wt.%), P2O5 (24.92 wt.%), SiO2 (7.19 wt.%), Fe2O3 (4.18 wt.%), MgO (3.99 wt.%), F (1.59 wt.%), Al2O3 (1.84 wt.%), Na2O (1.33 wt.%), and K2O (0.22 wt.%). Natural radioactivity and radiological parameters were investigated for fifteen samples of phosphorites using a NaI (Tl) scintillation detector. Absorbed dose rates, outdoor and indoor annual effective dose, radium equivalent activity, external and internal hazard, and excess cancer risk values are higher than the recommended levels, reflecting that exposure to these deposits for a long time may lead to health risks to human organs.

Celestine (SrSO4) is the principal ore of Sr and a sensitive tracer of diagenetic fluid–rock interaction in carbonate–evaporite successions. This study presents integrated petrographic mineral chemistry and Sr–S isotopic data for epigenetic celestine hosted by Asmari carbonates at Jabal Hafit, Al Ain (UAE), to constrain fluid source, and mechanisms of SrSO4 precipitation during basin diagenesis. Field and SEM observations show celestine as stratabound, vug- and fracture-filling euhedral to subhedral crystals within dolomitised limestone, suggesting precipitation after initial lithification during early-to-mid burial diagenesis. Electron microprobe analyses show nearly stoichiometric SrSO4 (55.15–57.30 wt.% SrO; 42.43–44.35 wt.% SO3) with very low Ba and Ca. The characteristically high Sr/Ba signature of the celestine reflects a complex diagenetic history driven by efficient Sr remobilisation during carbonate recrystallisation within an inherently Ba-poor marine sequence. Measured 87Sr/86Sr ratios are tightly clustered (0.707841–0.707854) with a high degree of isotopic homogeneity, which indicates a stable, well-buffered fluid reservoir, while the absolute values align with an Oligocene marine signature. Sulphur isotope values (δ34S = +27.3 to +29.1‰) are enriched relative to coeval marine sulphate, which could be attributed to closed-system Rayleigh fractionation driven by bacterial sulphate reduction. We propose that celestine precipitated from stable, marine-buffered burial brines, where supersaturation was achieved through coupled Sr enrichment from carbonate diagenesis and microbial modification of the sulphate reservoir.

The widely distributed granitic intrusions in the Nubian Shield can provide comprehensive data for understanding its crustal evolution. We present new bulk-rock geochemistry and isotopic (zircon U-Pb and Lu-Hf) data from the Haweit granodiorites in the Gabgaba Terrane (NE Sudan). The dated zircons presented a 206Pb/238U Concordia age of 718.5 ± 2.2 Ma, indicating that they crystallized during the Cryogenian. The granodiorites contain both biotite and amphibole as the main mafic constituents. The samples exhibit metaluminous (A/CNK = 0.84–0.94) and calc-alkaline signatures. Their mineralogical composition and remarkable low P2O5, Zr, Ce, and Nb concentrations confirm that they belong to I-type granites. They exhibit subduction-related magma geochemical characters such as enrichment in LILEs and LREEs and depletion in HFSEs and HREEs, with a low (La/Yb)N ratio (3.0–5.9) and apparent negative Nb anomaly. The positive Hf(t) values (+7.34 to +11.21) and young crustal model age (TDMC = 734–985 Ma) indicates a juvenile composition of the granodiorites. The data suggest that the Haweit granodiorites may have formed from partially melting a juvenile low-K mafic source. During subduction, the ascending asthenosphere melts might heat and partially melt the pre-existing lower crust mafic materials to generate the Haweit granodiorites in the middle segment of the Nubian Shield.

The depositional period of the early Miaolingian Maozhuang Formation in the North China Platform (NCP) is characterized by sediments of a restricted tidal-flat facies zone, i.e., transgressive red bed (sabkha facies) and highstand dolostone, and by sediments of an open tidal-flat facies zone, i.e., transgressive red bed and highstand limestone. The Maozhuang Formation at the Jinzhouwan section is composed of sediments of an open tidal-flat facies in which highstand limestone is marked by a set of bioherms that represent rare examples of microbial carbonates in the NCP. They consist of stromatolites and leiolites with intercalations of oolitic grainstones that can be categorized into four units: Unit [1] encompasses large-scale columnar stromatolites, small quartz grains and trilobite fragments; Unit [2] consists of structureless leiolites that contain trilobite fragments, quartz grains, and few dark and dense clumps of micrite dominated by calcified sheaths of filamentous cyanobacteria which probably grew in relatively thick cyanobacterial mats; Unit [3] comprises radial ooids that contain abundant fossils of calcified sheaths of filamentous cyanobacteria that might be genetically involved in the formation of ooids; Unit [4] contains small columnar stromatolites and small-scale micritic clumps dominated by filamentous cyanobacteria. The filamentous fossils in units [3] and [4] provide useful information regarding the origin of radial ooids and stromatolites in normal marine environment. Further, the large and small columnar stromatolites of early Miaolingian age in units [1] and [4] represent a unique example because they belong to the first episode of cyanbacterial calcification at the base of Phanerozoic.

The Pan-African domain of Batouri shows many generations of post-collisional granitoids emplaced between 640 and 500 Ma. They are affected by secondary Riedel faults systems R⁓N084E, R′⁓N016E P⁓N140E and T⁓N060E arranged into en-echelon systems oblique to the prominent Y shear bands directed N091E or to the related C′ or Y⁓N091E. The description and analysis of these brittle-ductile faults are based on classic structural geological methods, including structural surveys, analysis and stereographic projection of mesostructures (planar and linear fabrics) and microscopic observation. The results show two Riedel fault systems with two major bands, C′ and Y, oriented E-W with dextral and sinistral polarities. There are two shortening directions (Z) oriented: NW–SE, which accounts for dextral shear bands, and NE-SW, which develops the sinistral shear bands. The high values of dihedral angles (⁓78°–80°) between the R and R′ faults indicate a compressive tectonic regime of the basement, confirmed by the presence of the B n and B n +1 boudins stretching NE-SW and NW–SE. These faults likely interact with the neighbouring and regional scale CCSZ, which control gold mineralization in the Batouri granitoids. The mineralization is hosted by Qz-Fk veins in the R, R′, P and C′ Riedel faults. These mark the late-D 3 phase of deformation, which correlates with the nappes stacking event on the WAC at 600 Ma. The relative chronology of deformation at the regional scale suggests that gold mineralization is controlled by Qz-Fk veins in the R, R′, P and C′ Riedel faults, which correlate with the post-collisional phase of the CAFB around 585–580 Ma.

Identifying the hydrocarbon potential zones in the structurally complex Potwar Basin, Pakistan is a challenging. The basin comprises of repeated thrust sheets and duplex structures indicating intense complication in structural interpretation, however such interpretations proved to be significant regarding hydrocarbon prospective. In current investigation, assimilation is made via seismic lines and conventional well logs of the Rajian oilfield of the Potwar Basin to delineate the comprehensive subsurface structures along with the assessment of petrophysical characteristics of the potential facies of the Paleogene carbonates. The time contour maps, and 3D faults interpreted on seismic sections were used as input for structural framework modeling showing the occurrence of repeated thrusts sheets, duplex structures in the region. In combination, the time and depth structural contour maps were assessed for stratigraphic trend of Paleogene strata i.e., Lockhart, Nammal, Sakessar and Chorgali Formation that showed deepening in south-west direction in comparison to shallow south-east. Hydrocarbon possessing perspective zones and reservoir properties of the Lockhart, Nammal, Sakesar and Chorgali formations of Rajian 01 well in the studied Potwar Basin were evaluated based on different conventional logs behavior including gamma ray, resistivity logs, density, sonic and neutron logs. The lithofacies were confirmed on petro-elastic cross plot that clearly discriminate the dolomite and limestone by quantitatively analyzing the values of cross plot. This investigation has resulted in an enhanced understanding of the structural complexities and stratigraphic heterogeneities that can influence the hydrocarbon exploration in the study area.