Sn–W deposit of the Mueilha mine is one of many other Sn–W deposits in the Eastern desert of Egypt that associated with albite granite. Two forms of Sn–Wmineralizations are known at the Mueilha Sn-mine area, namely fissure filling quartz veins and greisen. Cassiterite and/or wolframite, sheelite, and beryl are the main ore minerals in the greisen and quartz veins. Subordinate chalcopyrite and supergene malachite and limonite are also observed in the mineralized veins. To constrain the P–T conditions of the Sn–W mineralizations, fluid inclusions trapped in quartz and cassiterite, have been investigated. The following primary fluid inclusion types are observed: CO2-rich, two-phase (L+V) aqueous, and immiscible three-phase (H2O–CO2) inclusions. Low temperature and low salinity secondary inclusions were also detected in the studied samples. Microthermometric results revealed that Sn–W deposition seem to have taken place due to immiscibility at temperature between 260°C and 340°C, and estimated pressure between 1.2 to 2.2 kb. Microthermometric results of fluid inclusions in fluorite from fluorite veins illustrated that fluorite seems to be deposited due to mixing of two fluids at minimum temperature 140°C and 180°C, and estimated minimum pressure at 800 bars.

The Neoproterozoic pluton of Gabal Gharib granite Eastern Desert of Egypt is intruded in subduction-related calcalkaline granitic rocks of granodiorite to adamellite composition. A zone of metasomatized granite was developed along the contacts at the expense of the calc-alkaline granite. The granite of Gabal Gharib is hypersolvus, composed mainly of orthoclase-microperthite, quartz, and interstitial arfvedsonite. Fluorite, zircon, ilmenite, allanite, and astrophyllite are the main accessories. Pegmatite pods as well as miarolitic cavities (mineral-lined cavities) are common and ranging in size from a few millimeters to 50 cm. Rare-metal minerals such as columbite, cassiterite, and fluorite have been identified from the miarolitic cavities. Geochemical studies revealed that Gabal Gharib granite is a highly fractionated granite, homogeneous in composition, with high contents of SiO2, and alkalis, high Ga/Al, and Fe/Mg ratios, and low concentrations of Al, Mg, and CaO relative to granodiorite– adamellite country rocks. Gabal Gharib granite is metaluminous to peralkaline with ASI (0.94–1.07). Trace element characteristics of Gabal Gharib granite include abundances of Rb, Nb, Ta, Sn, Th, U, Y, Ga, Zn, rare earth elements (REEs, except Eu), and F, and depletion in Sr, and Ba relative to granodiorite–adamellite country rocks. It has the geochemical characteristic of anorogenic A-type granite. The uniform trends of differentiation, normal REE distribution patterns, and low calculated tetrad effects of REE (0.2) indicate that the effect of post-magmatic subsolidus processes were minimal in the studied granite. Fluid inclusions were studied in quartz crystals from Gabal Gharib granite, quartz pods, and metasomatized granite. The study revealed the presence of high-temperature (480–550°C), high-salinity (19.45–39.13 wt. % NaCl eq.) primary inclusions in both metasomatized and rare-metal granites coexisting with melt inclusions and medium-temperature (350–450°C), medium-salinity (10– 16 wt.% NaCl esq.) aqueous inclusions coexisting hydrocarbon-bearing inclusions. Hydrocarbon is represented by magmatic CH4 in Gabal Gharib granite, while heavier aliphatic compounds may be present in quartz pods. Melt inclusions with temperatures of homogenization >600°C were also reported. Petrographic, geochemical, and fluid inclusion studies constrain that the peralkaline anorogenic granite of Gabal Gharib was derived from highly evolved magma probably originated by fractional crystallization of mantle source.

Rare-metal granites of Nuweibi and Abu Dabbab, central Eastern Desert of Egypt, have mineralogical and geochemical specialization. These granites are acidic, slightly peraluminous to metaaluminous, Li–F–Na-rich, and Sn–Nb– Ta-mineralized. Snowball textures, homogenous distribution of rock-forming accessory minerals, disseminated mineralization, and melt inclusions in quartz phenocrysts are typical features indicative of their petrographic specialization. Geochemical characterizations are consistent with low-P-rare metal granite derived from highly evolved I-type magma in the late stage of crystallization. Melt and fluid inclusions were studied in granites, mineralized veins, and greisen. The study revealed that at least two stages of liquid immiscibility played an important role in the evolution of magma–hydrothermal transition as well as mineral deposition. The early stage is melt/fluid case. This stage is represented by the coexistence of type-B melt and aqueous-CO2 inclusions in association with topaz, columbite–tantalite, as well as cassiterite mineral inclusions. This stage seems to have taken place at the late magmatic stage at temperatures between 450 °C and 550 °C. The late magmatic to early hydrothermal stage is represented by vapor-rich H2O and CO2 inclusions, sometimes with small crystallized silicic melt in greisen and the outer margins of the mineralized veins. These inclusions are associated with beryl, topaz, and cassiterite mineralization and probably trapped at 400 °C. The last stage of immiscibility is fluid–fluid and represented by the coexisting H2O-rich and CO2-rich inclusions. Cassiterite, wolframite ± chalcopyrite, and fluorite are the main mineral assemblage in this stage. The trapping temperature was estimated between 200 °C and 350 °C. The latest phase of fluid is low-saline, low-temperature (100–180 °C), and liquid-rich aqueous fluid.

The Qreiya Beds that record the ‘mid-Paleocene event’ at Gabal Nezzazat occur within the Igorina albeari (P3b) Zone and constitute part of a 14-m thick shale succession that ranges in age from Early to Late Paleocene. They are composed of four alternating dark grey and brown shale beds, which are thinly laminated, phosphatic, organic-rich and extremely sulphidic. They are characterized by distinct enrichment and high peak anomalies in chalcophiles (Zn, Co, Ni, Cu and Pb) and organic association elements (V and Cr), especially within the brown organic-rich beds. It is concluded that these elements are incorporated into the phosphatic debris, sulphides and organic matter. In contrast, the grey beds are enriched in clay minerals and quartz. Clay mineral assemblages indicate alternating periods of warm/humid climate (high kaolinite) and dry climate (low kaolinite) during the formation of the grey and brown beds, respectively. The sediments of the Qreiya Beds yield lithological, biotic, geochemical and mineralogical data indicative of suboxic/anoxic marine environments as a result of high productivity and/or upwelling. The top metre of the succession below the Qreiya Beds is characterized by a progressive change from faunas dominated by praemurcurids to faunas dominated by Morozovilids, and by a progressive upward decrease in δ13Ccarb and δ18Ocarb values. The foraminiferal faunal change may reflect shallowing and warming preceding deposition of the Qreiya Beds. The change in isotopic values is inferred to be the result of surface weathering, fluvial input and diagenesis with no evidence of any primary change that could support presence of a hyperthermal event.

The Qreiya Beds that record the ‘mid-Paleocene event’ at Gabal Nezzazat occur within the Igorina albeari (P3b) Zone and constitute part of a 14-m thick shale succession that ranges in age from Early to Late Paleocene. They are composed of four alternating dark grey and brown shale beds, which are thinly laminated, phosphatic, organic-rich and extremely sulphidic. They are characterized by distinct enrichment and high peak anomalies in chalcophiles (Zn, Co, Ni, Cu and Pb) and organic association elements (V and Cr), especially within the brown organic-rich beds. It is concluded that these elements are incorporated into the phosphatic debris, sulphides and organic matter. In contrast, the grey beds are enriched in clay minerals and quartz. Clay mineral assemblages indicate alternating periods of warm/humid climate (high kaolinite) and dry climate (low kaolinite) during the formation of the grey and brown beds, respectively. The sediments of the Qreiya Beds yield lithological, biotic, geochemical and mineralogical data indicative of suboxic/anoxic marine environments as a result of high productivity and/or upwelling. The top metre of the succession below the Qreiya Beds is characterized by a progressive change from faunas dominated by praemurcurids to faunas dominated by Morozovilids, and by a progressive upward decrease in δ13Ccarb and δ18Ocarb values. The foraminiferal faunal change may reflect shallowing and warming preceding deposition of the Qreiya Beds. The change in isotopic values is inferred to be the result of surface weathering, fluvial input and diagenesis with no evidence of any primary change that could support presence of a hyperthermal event.

The Qreiya Beds that record the ‘mid-Paleocene event’ at Gabal Nezzazat occur within the Igorina albeari (P3b) Zone and constitute part of a 14-m thick shale succession that ranges in age from Early to Late Paleocene. They are composed of four alternating dark grey and brown shale beds, which are thinly laminated, phosphatic, organic-rich and extremely sulphidic. They are characterized by distinct enrichment and high peak anomalies in chalcophiles (Zn, Co, Ni, Cu and Pb) and organic association elements (V and Cr), especially within the brown organic-rich beds. It is concluded that these elements are incorporated into the phosphatic debris, sulphides and organic matter. In contrast, the grey beds are enriched in clay minerals and quartz. Clay mineral assemblages indicate alternating periods of warm/humid climate (high kaolinite) and dry climate (low kaolinite) during the formation of the grey and brown beds, respectively. The sediments of the Qreiya Beds yield lithological, biotic, geochemical and mineralogical data indicative of suboxic/anoxic marine environments as a result of high productivity and/or upwelling. The top metre of the succession below the Qreiya Beds is characterized by a progressive change from faunas dominated by praemurcurids to faunas dominated by Morozovilids, and by a progressive upward decrease in δ13Ccarb and δ18Ocarb values. The foraminiferal faunal change may reflect shallowing and warming preceding deposition of the Qreiya Beds. The change in isotopic values is inferred to be the result of surface weathering, fluvial input and diagenesis with no evidence of any primary change that could support presence of a hyperthermal event.

The Qreiya Beds that record the ‘mid-Paleocene event’ at Gabal Nezzazat occur within the Igorina albeari (P3b) Zone and constitute part of a 14-m thick shale succession that ranges in age from Early to Late Paleocene. They are composed of four alternating dark grey and brown shale beds, which are thinly laminated, phosphatic, organic-rich and extremely sulphidic. They are characterized by distinct enrichment and high peak anomalies in chalcophiles (Zn, Co, Ni, Cu and Pb) and organic association elements (V and Cr), especially within the brown organic-rich beds. It is concluded that these elements are incorporated into the phosphatic debris, sulphides and organic matter. In contrast, the grey beds are enriched in clay minerals and quartz. Clay mineral assemblages indicate alternating periods of warm/humid climate (high kaolinite) and dry climate (low kaolinite) during the formation of the grey and brown beds, respectively. The sediments of the Qreiya Beds yield lithological, biotic, geochemical and mineralogical data indicative of suboxic/anoxic marine environments as a result of high productivity and/or upwelling. The top metre of the succession below the Qreiya Beds is characterized by a progressive change from faunas dominated by praemurcurids to faunas dominated by Morozovilids, and by a progressive upward decrease in δ13Ccarb and δ18Ocarb values. The foraminiferal faunal change may reflect shallowing and warming preceding deposition of the Qreiya Beds. The change in isotopic values is inferred to be the result of surface weathering, fluvial input and diagenesis with no evidence of any primary change that could support presence of a hyperthermal event.

The growth and some metablic activites of Anabaena circinalis, which were grown under different salinity stress levels were followed and it has been found that these species can tolerate NaCl salinity to the level of 80 mM and survived to the level of 0.5 M of NaCl. Higher doses of salinity caused reduction in growth criteria (Absorbance, chlorophyll content) with the time elapsed, reduction of protein content, and caused increasing in carbohydrate content, significance increasing in proline content was also recorded. Addition of Ca+2 to the salinized culture caused improvement in growth and improved K+/Na+ ratio which increase the osmoprotectant, as well as protect this organism from the toxic effect of NaCl.

The effect of glyphosate herbicide concentrations on the growth and some metabolic activities of the green alga Scenedesmus quadricauda and the blue-green alga (cyanobacteria) Merismopedia glauca isolated from soil (Assiut, Egypt) were assessed. The growth of Scenedesmus quadricauda and Merismopedia glauca was negatively affected by glyphosate herbicide. In addition, decreasing of the cell number as well as chlorophyll a, b and the dry weight of Scenedesmus were occurred with increasing the herbicide concentrations, while the dry weight and chlorophyll a of Merismopedia was increased by low concentration of glyphosate herbicide. The photosynthesis and respiration were increased in the two algae with increasing glyphosate herbicide. Increasing of soluble and insoluble carbohydrates with increasing of the herbicide in Scenedesmus. But in case of Merismopedia glauca the soluble sugars only were enhanced by all concentrations used of the herbicide. Decreasing soluble and insoluble proteins was occurred in Scenedesmus with increasing glyphosate. Also, glutelins, globulins and prolamines were decreased with increasing of glyphosate herbicide. The insoluble proteins, glutelins, globulins were increased and soluble proteins as well as prolamines were decreased with increasing of glyphosate herbicide to Merismopedia. Free amino acids were increased by increasing glyphosate herbicide in Scenedesmus and Merismopedia. Glyphosate herbicide inhibited the growth and some metabolic activities in the tested algae, this effect depend on the algal species, the type and concentration of the herbicide.

The effect of glyphosate herbicide concentrations on the growth and some metabolic activities of the green alga Scenedesmus quadricauda and the blue-green alga (cyanobacteria) Merismopedia glauca isolated from soil (Assiut, Egypt) were assessed. The growth of Scenedesmus quadricauda and Merismopedia glauca was negatively affected by glyphosate herbicide. In addition, decreasing of the cell number as well as chlorophyll a, b and the dry weight of Scenedesmus were occurred with increasing the herbicide concentrations, while the dry weight and chlorophyll a of Merismopedia was increased by low concentration of glyphosate herbicide. The photosynthesis and respiration were increased in the two algae with increasing glyphosate herbicide. Increasing of soluble and insoluble carbohydrates with increasing of the herbicide in Scenedesmus. But in case of Merismopedia glauca the soluble sugars only were enhanced by all concentrations used of the herbicide. Decreasing soluble and insoluble proteins was occurred in Scenedesmus with increasing glyphosate. Also, glutelins, globulins and prolamines were decreased with increasing of glyphosate herbicide. The insoluble proteins, glutelins, globulins were increased and soluble proteins as well as prolamines were decreased with increasing of glyphosate herbicide to Merismopedia. Free amino acids were increased by increasing glyphosate herbicide in Scenedesmus and Merismopedia. Glyphosate herbicide inhibited the growth and some metabolic activities in the tested algae, this effect depend on the algal species, the type and concentration of the herbicide.