Aley El-Shazly

• Professor (Full) at Marshall University

The Abu Ghalaga pluton in the southern eastern desert of Egypt (SED) consists of undeformed norite and hornblende gabbro intruding island arc metavolcanics, ophiolitic rocks, and syn-tectonic older granitic rocks. The Fe-Ti ore (mainly ilmenite) occurs in the form of lenses at the base of the norite. Based on microtextures, mineralogy, and chemical...

The Sir Bakis area in the central Eastern Desert of Egypt hosts orogenic type gold deposits in shear-related, structurally controlled, quartz veins. These NNW–SSE-trending veins cross-cut Precambrian metavolcanics and granitoids of the Arabian Nubian shield that formed during the Pan-African Orogeny (780–610 Ma). The primary ore mineral assemblage...

Banded iron formations (BIF) occur intercalated with Neoproterozoic volcanosedimentary units in 13 localities in the Egyptian Central Eastern Desert (CED). These units are characterized by magnetite and hematite-rich layers alternating with quartz-rich layers containing andradite–rich garnet, epidote, ± calcite in the southern parts of CED, and chl...

The Central Eastern Desert (CED) of Egypt which is part of the Arabian–Nubian Shield, is characterized by the unique occurrence of small bodies of banded iron formation (BIF) intercalated with volcanic and volcaniclastic rocks of an “ophiolitic – island arc succession”. All BIFs and their host rocks were regionally metamorphosed under greenschist t...

Banded iron formations (BIF) in Um Nar, central eastern desert of Egypt, occur intercalated with schists of volcaniclastic and epiclastic origin within “ophiolitic – island arc rocks” of the Arabo-Nubian Shield. The BIF and its host rocks were affected by folding, thrusting, and regional metamorphism during the Pan-African Orogeny resulting in the...

The banded iron formations in the eastern desert of Egypt are small, deformed, bodies intercalated with metamorphosed Neoproterozoic volcaniclastic rocks. Although the 13 banded iron deposits have their own mineralogical, chemical, and textural characteristics, they have many similarities, the most notable of which are the lack of sulphide and pauc...

Banded iron formations (BIFs) occur in thirteen localities in an area approximately 30,000 km2 within the eastern desert of Egypt. With the exception of the Um Nar deposit which is suspected to be pre-Panafrican, all BIFs are considered Neoproterozoic in age. The iron ore occurs as rhythmically layered bands, or separate lenses < 100 m thick, inter...

The Melrose Stock in the Dolly Varden Mountains of east-central Nevada is one of the many Mesozoic intrusion s in the Basin and Range Province. It consists of monzonites, quartz monzonites, granodiorites, and granites sharply intruding Mississippian to Triassic units. Phenocrysts of plagioclase (An38–An24) with oscillatory zoning and albitic rims,...

The Winding Stair Gap in the Central Blue Ridge province exposes granulite facies schists, gneisses, granofelses and migmatites characterized by the mineral assemblages: garnet–biotite–sillimanite–plagioclase–quartz, garnet–hornblende–biotite–plagioclase–quartz ± orthopyroxene ± clinopyroxene and orthopyroxene–biotite–quartz. Multiple textural popu...

Shear zone-related, mesothermal gold deposits of Um Egat and Dungash in the Egyptian Eastern Desert are hosted by greenschist facies metavolcanic and/or metasedimentary rocks of Pan-African age. Both deposits comprise boudinaged quartz veins that show evidence of incipient recrystallization, and are similar in alteration style, structural control,...

The Winding Stair Gap, NW of Franklin, North Carolina, exposes schists, gneisses, granofelses, stromatic metatexites, and minor diatexites representing mostly pelitic and semipelitic rocks affected by granulite facies conditions. Characteristic mineral assemblages in mesosomes and melanosomes include: garnet (Gt) + biotite (Bt) + sillimanite (Sill)...

The assemblages chlorite‐pumpellyite‐lawsonite‐albite‐quartz, chlorite‐lawsonite‐quartz‐epidote and chlorite‐epidote‐albite‐quartz occur in metabasaltic blocks and veins in a metamorphosed tectonic mélange in the structurally highest unit of the autochthonous and parautochthonous section underlying the Semail ophiolite in Saih Hatat, north‐east Oma...

Several types of Ca-rich, metasomatically altered rocks occur as blocks or reaction zones in a serpentinite-matrix mélange in the Bawshir-Al-Khuwair area, west of Ruwi in northeastern Oman. Type A rodingites contain mainly hydrogarnet, with smaller amounts of diopside, tremolite ± pumpellyite ± prehnite. Type B rocks contain more diopside ± tremoli...

Thrust sheets of the upper plate of the Saih Hatat window, NE Oman contain metasediments formed under lawsonite albite facies conditions. Quartz and Fe-Mg carpholite in these metasediments contain several types of fluid inclusions; most are two-phase at room T with an aqueous NaCl-HO or NaCl-MgCl2-H2O solution. Texturally early fluid inclusions dis...

Small geoscience departments with 5 faculty members or less in undergraduate institutions are facing serious challenges that will have a profound impact on their future, as well as the future of geoscience education. In addition to past and future budget cuts that affect all departments, small departments are more vulnerable to such problems as (i)...

Basement and continental shelf units structurally underlying the Semail ophiolite in Saih Hatat, NE Oman were metamorphosed under high pressure, low temperature (high P/T) conditions, and occur in two plates. The lower plate consists of eclogite facies rocks that grade westward into garnet blueschists and crossite epidote schists. The upper plate c...

Seven eclogite facies samples from lithologically different units which structurally underlie the Semail ophiolite were dated by the 40 Ar/ 39 Ar and Rb--Sr methods. Despite extensive efforts, phengite dated by the 40 Ar/ 39 Ar method yielded saddle, hump or irregularly shaped spectra with uninterpretable isochrons. The total gas ages for the pheng...

Seven eclogite facies samples from lithologically different units which structurally underlie the Semail ophiolite were dated by the 40Ar/39Ar and Rb–Sr methods. Despite extensive efforts, phengite dated by the 40Ar/39Ar method yielded saddle, hump or irregularly shaped spectra with uninterpretable isochrons. The total gas ages for the phengite ran...

The high pressure, low temperature metamorphic rocks of the structurally deepest regions of Saih Hatat, NE Oman exhibit an eastward increase in metamorphic grade from epidote blueschist facies conditions in central Saih Hatat to eclogitic conditions along the eastern coast. Mineral assemblages in these rocks allow the application of one or two reli...

Eclogite facies rocks from eastern Saih Hatat (Oman), metamorphosed under peak conditions of P>12 kbar, and T of 550–580°C, have several types of fluid inclusions in quartz, clinopyroxene, and garnet. Most of these inclusions are two-phase at room T, and contain an aqueous fluid belonging to the system NaCl–MgCl2–H2O. Final melting temperatures for...

Eclogites, blueschists, clinopyroxene-rich rocks and epidote amphibolites occur interlayered on a millimetre to decimetre scale in a mafic unit interbedded with calcareous and quartz mica schists in NE Oman. These rocks constitute part of the continental margin of Oman subducted during the Cretaceous. Petrological data indicate that they evolved th...

Phase equilibria in the system NASH calculated using Berman's (1988) data base are inconsistent with field and petrological data on the stability of paragonite and the assem- blage albite + kaolinite. This inconsistency appears to result from erroneous values for entropy and enthalpy for kaolinite. Although the entropy value of 203.7 J/(mol. K) in...

Abstract Fe-Mg carpholite occurs in metasediments of tectonically disrupted basement, shelf and foreland basin units that structurally underlie the Semail ophiolite in NE Oman. In the lower grade, structurally higher units, Fe-rich carpholite coexists with paragonite, quartz, illite, kaolinite and chlorite, whereas in deeper units, Fe-Mg carpholite...

Field and petrological data, combined with major, trace and rare earth element analysis of mafic rocks that structurally underlie the Semail ophiolite in Saih Hatat, have led to their subdivision into five groups: (a) crossite-bearing mafic schists that represent metamorphosed within-plate alkali basalts, erupted in a Proterozoic continental rift o...

The assemblages chlorite-pumpellyite-lawsonite-albite-quartz, chlorite-lawsonite-quartz-epidote and chlorite-epidote-albite-quartz occur in metabasaltic blocks and veins in a metamorphosed tectonic melange in the structurally highest unit of the autochthonous and parautochthonous section underlying the Semail ophiolite in Saih Hatat, north-east Oma...

The Saih Hatat tectonic window in NE Oman exposes basement and shelf units that structurally underlie the Semail ophiolite. These units were metamorphosed under high-pressure conditions, as evidenced by the occurrence of lawsonite schists, carpholite-bearing metasediments, blueschists, and eclogites. Conventional K-Ar and $^{40}Ar/^{39}Ar$ dating o...

The Saih Hatat tectonic window in NE Oman exposes basement and shelf units that structurally underlie the Semail ophiolite. These units were metamorposed under high-pressure conditions. K-Ar and 40Ar/39Ar data, combined with structural and petrological criteria, suggest that many units exposed in Saih Hatat experienced two high-pressure, low temper...

Pelitic layers and lenses interbedded with blueschists and eclogites in Saih Hatat, NE Oman contain chloritoid- and sodic amphibole-bearing mineral assemblages that are useful for reconstructing the P-T history of the area. Textural and mineral chemical relations suggest that coexisting glaucophane (Gln) and chloritoid (Ctd) formed at the expense o...

The metamorphic rocks associated with the Semail ophiolite in the Oman Mountains represent two different facies series. Amphibolites and greenshists at the base of the Semail ophiolite constitute a metamorphic sole formed in a high-temperature, lowpressure environment. Eclogites, blueschists, lawsonite schists and other metasediments occurring at d...

Eclogites and blueschists occur in the basement and continental shelf deposits in the Saih Hatat tectonic window of northeastern Oman, where they structurally underlie the Semail ophiolite. These eclogites and blueschists constitute part of a coherent high- P / T metamorphic terrain comprised of interlayered metabasites, metapelites, and quartzofel...